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Avian A&P Test 1
Avian A&P Test 1
374
Anatomy
Undergraduate 4
01/11/2019

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Cards

Term
reptilian characteristics of archaeopterix
Definition
-teeth
-gastrilla (belly ribs)
-flat/small sternum (no keel)
-long, bony tail
-3 claws on each wing
-no horny bill
-skull
Term
bird characteristics of archaeopterix
Definition
-light skeleton (pneumatic, hollow)
-feathers
-reduced phalanges (fusion)
-wishbone (furcula)
-flight
Term
What is cladistics?
Definition
classifying organisms based on shared derived characteristics that can be traced to most recent common ancestor
Term
Based upon cladistics, from which dinosaur group did birds evolve?
Definition
Theropods
Term
Why do you think birds survived, while most non-avian dinosaurs went extinct.
Definition
musta been due to more manageable metabolism due to smaller size
Term
atavisdm
Definition
trait that has disappeared phenotypically, but is still present in the genotype
Term
vestige
Definition
part of an organism that has become reduced or functionless over the course of evolution
Term
examples of vestiges
Definition
-wings of ostriches, emus, and other flightless birds
-goose bumps
Term
examples of atavisms
Definition
-some babies being born with vestigial tail
-vitamin C pathway in humans
Term
What is significant about the Talpid-2 mutation
Definition
if it's expressed, it can cayuse a chicken to develop teeth that resemble those of a crocodile
Term
What would be the best route to create a dinosaur?
Definition
reengineering the genome such that atavisms are reversed and the traits are expressed
Term
Explain what could be targeted in avian embryonic development to create a dinosaur.
Definition
-preventing fusion of the hand
-preventing resorption of the tail
Term
the potential purpose of early feathers in dinosaurs
Definition
-brooding
-anti-predation
-social signaling
-insulation
-camo
BASIC
Term
Provide a possible scenario for the development of feathers leading to the evolution of pennaceous feathers and flight.
Definition
1 and 2: simple feathers likely used for thermoregulation or display
3: body feathers likely provided ancestors of birds more aerodynamic shape useful for leaping between branches in arboreal lifestyle
4 and 5: simple pennaceous feathers on forelimbs possibly provided parachuting ability
6: larger pennaceous feathers that were symmetrical may have permitted gliding
7: asymmetrical pennaceous feathers may have made the gliding more efficient
8: powered flight
[image]
Term
Why would it make evolutionary sense to lose the ability to fly in certain situations? (evolution of flightless birds in New Zealand).
Definition
no predators, negating the need to fly
Term
What avian order do Chickens belong to?
Definition
Galliformes
Term
What is the largest avian order?
Definition
Passeriformes
Term
the relationship between metabolic rate (heart rate) and size in birds
Definition
-the heart in a bird is about 40% bigger by body weight than in mammals
-chicken heart is 200-400 bpm
Term
What characteristics of bones in birds allows them to be both strong and light weight for flight?
Definition
-light because they are hollow and pneumatic
-strong because of lots of fusion in the hands, hips, and feet
Term
What muscle powers down stroke of wing?
Definition
pectoralis major
Term
What muscle powers up stroke of wing?
Definition
pectoralis minor aka supracoracoideus
Term
adaptive characteristics for flight in the digestive system
Definition
-quick and efficient
-centrally located gizzard instead of teeth
-very small large intestine, so they poop ASAP
Term
adaptive characteristics for flight in the renal system
Definition
-large kidneys (twice the size of mammals)
-no urinary bladder
-uric acid (conserves water)
Term
adaptive characteristics for flight in the cardiovascular system
Definition
-heart about 40% bigger than in mammals
-large hearts that beat fast
Term
adaptive characteristics for flight in the respiratory system
Definition
-9 air sacs (2 cervical, 2 anterior thoracic, 2 posterior thoracic, 2 caudal, and 1 interclavicular)
-these air sacs enable unidirectional air flow through lungs, making birds more efficient at absorbing oxygen
-air sacs, no diaphragm, rigid lungs
+w/o diaphragm, birds use obliques to move air around
Term
What advantage does uric acid provide the bird?
Definition
-greatly reduces water loss
-insoluble in water; necessary because that way, it can't harm the embryo
Term
Overall function of skin
Definition
-barrier to pathogens
-retains vital fluids and gases
-sensory organ
Term
how avian skin differs from mammalian skin
Definition
-thin
-semi-transparent
-thinner and less keratinized than in mammals, but this less stringent barrier can facilitate evaporate cooling (birds don't have sweat glands)
Term
statum corneum
Definition
stratified, keratinized, squamous epithelium, several layers of dead, scaly, keratinized skin
Term
why feathering has become an issue with broiler breeders
Definition
-absence of feathers leads to skin wounds, which is a serious welfare issue
-if they lose their feathers, they won't wanna dfo their job, which is to mate and lay eggs
Term
Uropygial Gland (Preen Gland)
Definition
-bilobed sebaceous gland at the dorsal base of the tail
-this is a holocrine gland
Term
holocrine
Definition
holocrine secretions are produced in the cytoplasm and released by rupture of the plasma membrane, destroying the cell and releasing the product into the lumen.
Term
Holocrine vs Apocrine
Definition
[image]
-holocrine secretions are produced when the mature cell dies and releases content
-apocrine secretions are when the pinched off part of the cell is the secretion
Term
uses of Uropygial Gland (Preen Gland)
Definition
-secretion inhibits fungal growth and bacterial infection
-secretion helps maintain feather health
-secretion can help waterproof feathers
-secretion provides 7-dehydrocholesterol for vitamin D synthesis
-some birds use the secretion to deter predators (fowl smell) or cosmetic (flamingo)
Term
the pathway to produce active vitamin D3 (DRAW THIS!!!!)
Definition
[image]
Term
What is the rate limiting step in the vitamin D3 pathway?
Definition
PTH regulates 1-alpha-hydroxylase
Term
What is the trigger to activate the rate limiting step in the vitamin D3 pathway?
Definition
PTH causes 1-alpha-hydroxylase to be expressed in the kidney and convert 25-OH-cholicalciferol into 1,25-dihydrocholicalciferol
Term
What is the relationship between calbindin and 1,25 (OH)2D3?
Definition
-1,25 (OH)2D3 promotes synthesis of calbindin (calcium-binding protein, CaBP) and other proteins -1,25 (OH)2D3 also stimulates Ca and P absorption
Term
depiction of how 1,25 (OH)2D3 promotes synthesis of calbindin (calcium-binding protein, CaBP) and other proteins
Definition
[image]
Term
How does 1,25 (OH)2D3 increase both renal and intestinal absorption of Ca?
Definition
by increasing synthesis of Ca binding proteins, mainly calbindin-D28k
Term
[image]
Definition
fowl pox
Term
synonyms for fowl pox
Definition
-chicken pox (the human form doesn't affect chickens and vice versa)
-sore head
-avian diphtheria
-bird pox
Term
species affected by fowl pox
Definition
-most poultry, such as chickens, turkeys, quail, ducks, pheasants, psittacine, and rattites
-poultry of all ages are susceptible
Term
the 2 forms of fowl pox
Definition
-dry
-wet
Term
clinical signs of the dry form of fowl pox
Definition
-wart-like lesions on unfeathered areas
-unthriftiness
-retarded growth
-transient egg decline in laying hens
Term
clinical signs of the wet form of fowl pox
Definition
canker-like lesions in the mouth, pharynx, larynx, and trachea
-possible respiratory distress by blocking upper passages
Term
how fowl pox is transmitted
Definition
-direct contact between birds
-mosquitoes
-virus-containing scabs
-tend to be more rampant during winter and early spring because of mosquitoes overwintering in poultry houses
Term
treatment for fowl pox
Definition
none, but vaccination can stop outbreak, since it's slow-spreading
Term
prevention for fowl pox
Definition
-spraying to kill mosquitoes
-if endemic to area, vaccination is recommended
Term
[image]
Definition
Marek’s disease
Term
synonyms for Marek’s disease
Definition
-acute leukosis
-neural leukosis
-range paralysis
-gray eye (when eye affected)
Term
species affected by Marek's disease
Definition
-most commonly chickens 12-25 weeks old
-occasionally pheasants, quail, game fowl, and turkeys
Term
clinical signs of Marek's disease
Definition
-cancerous tumors
-in nerves, they cause lameness and paralysis
-in eyes, they cause irregularly shaped pupils and blindness
-in other tissues, they cause incoordination, unthriftiness, paleness, weak labored breathing, and enlarged feather follicles
-in terminal stages, emaciation with pale, scaly combs and greenish diarrhea
Term
transmission of Maerek's disease
Definition
-by air
-feather dander
-chicken house dust
-feces and saliva
-birds infected for life
Term
treatment for Merek's disease
Definition
none
Term
prevention of Maerek's disease
Definition
vaccination at hatchery
-this prevents tumor formation, but not virus infection
Term
what type of virus is Maerek's disease?
Definition
oncovirus
-this was one of the first oncoviruses to be discovered
-oncogenes were first discovered in chicken oncoviruses
Term
where were oncogenes first discovered?
Definition
oncoviruses
Term
[image]
Definition
bumblefoot aka Staphylococcus
Term
synonyms for bumblefoot aka Staphylococcus
Definition
-staph infection
-staph septicemia
-staph arthritis
-bumblefoot
Term
species affected by bumblefoot aka Staphylococcus
Definition
all fowl, especially turkeys, chickens, game birds, and water fowl
Term
the 3 forms of staphylococcal infection
Definition
-septicemia (acute)
-arthritic (chronic)
-bumblefoot
Term
clinical signs of the septicemia (acute) form of Staphylococcus infection
Definition
-listless
-no appetite
-feverish
-show pain during movement
-possible black rot in eggs, since it's passed down through eggs
-fetid diarrhea
-many have swollen joints (arthritis)
Term
clinical signs of the arthritic (chronic) form of Staphylococcus infection
Definition
-follows the acute form
-lameness
-breast blisters
-painful movement
-reluctant to walk, preferring to sit instead of stand
Term
clinical signs of the bumblefoot form of Staphylococcus infection
Definition
-localized chronic staph infection of foot, thought to be caused by puncture
-bird becomes lame
Term
transmission of bumblefoot aka Staphylococcus
Definition
-Staphylococcus aureus, which is a soil-borne pathogen -outbreaks occur when birds drink from stagnant ponds
Term
treatment for bumblefoot aka Staphylococcus
Definition
-Novobiocin (350 g/ton) given in the feed for 5-7 days
-erythromycin and penicillin in water for 3-5 days or in feed (200 g/ton) for 5 days
-other antibiotics and drugs only occasionally effective
Term
prevention of bumblefoot aka Staphylococcus
Definition
-remove objects that cause injury
-isolate affected birds
-balanced nutrition
Term
[image]
Definition
omphalitis (mush chick)
Term
clinical signs of omphalitis (mush chick)
Definition
-external navel infection
-large unabsorbed yolk sacs
-peritonitis with fetid odor
-exudates adhering to the navel
-edema of the skin of the ventral body area
-septicemia and dehydration
Term
transmission of omphalitis (mush chick)
Definition
-infection at hatching or shortly thereafter, before navels are healed
-chicks from dirty eggs or eggs with poor quality shells are susceptible
-chicks placed in dirty boxes are also susceptible
-chicks removed before the navel heals due to improper temp and/or humidity are also susceptible
-eggs that explode contaminate other eggs
-
Term
treatment for omphalitis (mush chick)
Definition
none
Term
prevention for omphalitis (mush chick)
Definition
-effective hatchery sanitation
-effective hatchery procedures
-breeder flock surveillance
-proper preincubation handling of eggs
Term
Why has prevention of food pad dermatitis become a major issue in the poultry industry?
Definition
-podotheca (paws) have become the 3rd most valuable part of the chicken ($280-300 million/yr)
-feet used for welfare assessments
Term
What are some potential litter management factors that can lead to an increase in foot pad dermatitis?
Definition
-humidity >70% --> caking
-the resulting friction causes hypoerplasia and hyperkeratosis, causing thicker foot skin
Term
What are some potential diet factors that can lead to an increase in foot pad dermatitis?
Definition
more watery stool caused by high levels of non-starch polysaccharides (NST) in all-veggie diet, since NST is not as readily digestible
Term
What are some potential drinker system factors that can lead to an increase in foot pad dermatitis?
Definition
leakiness causes more watery floor
Term
hyperkeratosis
Definition
thickening of the outer layer of the skin
Term
hyperplasia
Definition
enlargement of organ or tissue caused by increased reproduction rate of its cells
Term
What modifications have occurred in the avian neck and head that allows for the rhamphotheca to be an effective organ for prehension?
Definition
-more cervical vertebrae, ranging from low teens to mid twenties, based on length of neck
-bird skull has single occipital condyle, allowing nearly 360 degree rotation of head
Term
ossifications that occurred in the Synsacrum as an adaptation to flight
Definition
-fusion of pelvis and vertebrae
-fused ilium and ischium
-fusion of 3 lumbar, 7 sacral, and 6 caudal vertebrae
Term
ossifications that occurred in the Pygostyle as an adaptation to flight
Definition
fusion of last few caudal vertebrae
Term
ossifications that occurred in the Thorax as an adaptation to flight
Definition
fusion of thoracic vertebrae to increase strength and prevent crushing of lungs during downbeat of the wing
Term
ossifications that occurred in the Uncinate processes as an adaptation to flight
Definition
strengthen rib cage by overlapping witht he rib behind it
Term
ossifications that occurred in the ribs as an adaptation to flight
Definition
vertebral ribs... sternal ribs
Term
cortical bone
Definition
thin layer of compact bone that covers the spongy bone of each epiphysis
-functional unit is the osteon
-contains osteocytes, which are former bone cells that have become trapped by the bone matrix
Term
spongy bone
Definition
-made of lattice of delicate slivers of bone called spicules and trabeculae
-has spongy appearance
-covered with endosteum
-permeated by spaces filled with bone marrow
-typically found at the ends of long bones
-covered by compact bone
Term
medullary cavity
Definition
central cavity of bone shaft where red or yellow bone marrow is stored
-has walls made of spongy bone and lined with endosteum
Term
periosteum
Definition
dense irregular connective tissue that covers the outer surface of all bones
-provides blood supply to the body of the marrow
-attachment site for muscles
+becomes continuous with tendon muscles
+contains chondroblasts, osteoblasts, and mesenchymal stem cells
Term
endosteum
Definition
thin layer of reticular connective tissue that lines the internal marrow cavity
-covers spongy bone
-lines the canal system in compact bone
+reticular connective tissue
+contains osteoclasts
Term
epiphyseal plate
Definition
hyaline cartilage that separates the marrow spaces f the epiphysis and diaphysis, where the bone can grow in length
-interstitial growth occurs at epiphyseal plate
Term
articular cartilage (AC)
Definition
the layer of hyaline cartilage that covers the joint surface where one bone meets another
Term
diaphysis
Definition
extended tubular shaft
-cortical bone with medullary cavity
-red bone marrow
+hematopoiesis
Term
epiphysis
Definition
expanded areas at each end
Term
metaphysis
Definition
narrow zone between diaphysis and epiphysis
-growth plate for bone elongation; this is the growth plate
Term
osteoid
Definition
organic part of bone matrix that forms before maturation of bone tissue
-osteoblasts begin the process of forming bone tissue by secreting the osteoid
Term
lacunae
Definition
tiny cavities inside the bone that contain osteocytes and are interconnected by channels called canaliculi
Term
osteon or Haversian system
Definition
functional unit of compact bone
-contains central canal and its lamellae
+its central canal contains arteries and veins
+matrix in concentric rings, called lamellae, around canal
Term
canaliculi
Definition
channels that connect the tiny cavities called lacunae and contain cytoplasmic extensions of osteocytes
Term
osteocytes
Definition
former osteoblasts that have become trapped in the matrix they deposited
Term
osteoblasts
Definition
produce new bone in process called ossification
-they make and release proteins and other organic compounds into the matrix
Term
osteoclasts
Definition
cells that remove and recycle bone matrix
-they have 50+ nuclei
-they dissolve bone matrix by releasing acids and proteoglycan enzymes
-the minerals go into interstitial fluid
Term
osteogenic/osteoprogenitor cells
Definition
cells of the osteogenic layer
Term
osteogenic layer
Definition
the inner layer of the periosteum
-contains osteoblasts
-important for bone growth and healing of fractures
Term
avian skin
Definition
[image]
Term
what's number 1?
[image]
Definition
dander or scruf
Term
what's number 2?
[image]
Definition
flattened horney cell layer- Stratum corneum
Term
what's number 3?
[image]
Definition
transitional cells or prickle cells- Stratum spinosum
Term
what's number 4?
[image]
Definition
epidermis
Term
what's number 5?
[image]
Definition
columnar cells- Stratum germinativum
Term
what's number 6?
[image]
Definition
basement membrane
Term
what's number 7?
[image]
Definition
dermis
Term
what's number 8?
[image]
Definition
collagen and elastin fibres
Term
what's number 9?
[image]
Definition
hypodermis
Term
How thick is avian skin?
Definition
usually about 3-5 layers thicvk, but thicker in exposed areas such as the rampotheca (beak) and podotheca (feet)
Term
layers of the epidermis
Definition
-Stratum corneum -Stratum spinosum -Stratum germinativum
Term
Stratum corneum (surface layer)
Definition
-several layers of dead, scaly, keratinized cells
+mammals have the alpha-helix form of keratin while birds and reptiles have the harder to digest beta form
-resists abrasion, penetration, and water loss
-constant shedding of this layer prevents microbes and such from getting a foothold
Term
Stratum Spinosum
Definition
keratinochytes joined together by desmosomes and tight junctions
-make more keratin filaments as they migrate superficially, causing them to flatten
Term
function of desmosomes
Definition
hold adjacent cells together
Term
Stratum basale/germinativum (deepest epidermal layer)
Definition
single layer of stem cells and keratinocytes resting on the basement membrane
-these cells give rise to keratinocytes and migrate superficially
-may contain melanocytes that give off pseudopodia that distribute melanin to migrating keratinocytes
Term
Function of Melanin?
Definition
prevent UV damage to underlying cells
Term
pterylae
Definition
area of skin where feathers grow
Term
apteria
Definition
area of skin without sprouting feathers
Term
pennaceous feathers
Definition
consists of
-calamus or quill
-vane
-rachis
-barb
-ramus
-barbule
-barbicels/hooklets
Term
plumulaceous feathers
Definition
seem to consist of just barbs and barbules; this is what down feathers are
Term
what's number 1?
[image]
Definition
barbules
Term
what's number 2?
[image]
Definition
barb
Term
the different microstructural components of feathers
Definition
-calamus or quill
-rachis
-barbs
-barbules
-barbicels/hooklets
Term
what's number 1?
[image]
Definition
hollow shaft, calamus
Term
what's number 2?
[image]
Definition
downy barbs
Term
what's number 3?
[image]
Definition
afterfeather
Term
what's number 4?
[image]
Definition
vane
Term
what's number 5?
[image]
Definition
rachis
Term
what's number 6?
[image]
Definition
barb
Term
what's number 7?
[image]
Definition
barbule
Term
what's number 8?
[image]
Definition
barb
Term
what's number 9?
[image]
Definition
barbule
Term
what's number 10?
[image]
Definition
barbicels/hooklets
Term
Calamus or Quill
Definition
hollow shaft connected to skin or bone
-oldest part is the tip
-this part used to have blood running through it
Term
components of the vane
Definition
-rachis
-barbs
Term
rachis
Definition
continuation of calamus but center of vane (barbs projecting out from either side)
Term
barbs
Definition
extensions of rachis that form vane in pennaceous feathers
Term
ramus
Definition
part of the barb from which the barbule extends
Term
barbules
Definition
projections off the ramus of the barb
Term
barbicels/hooklets
Definition
tiny microscopic projections that interlock with proximal barbs
Term
[image]
Definition
bristles
Term
[image]
Definition
filoplumes
Term
[image]
Definition
contour feathers
Term
[image]
Definition
down
Term
[image]
Definition
semiplume
Term
Remiges (wing) vs rectrices (tail)
Definition
tail seems more symmetrical and remiges seems more asymmetrical
[image]
Term
PTH vs Calcitonin
Definition
PTH
-increases blood Ca, 1-alpha-hydroxylase activity, osteoclastic maturation and activity, and Ca absorption in gut
-decreases osteoblast

Calcitonin
-decreases blood Ca, osteoclastic activity, and Ca absorption
Term
PTH
Definition
-increases blood Ca, 1-alpha-hydroxylase activity, osteoclastic maturation and activity, and Ca absorption in gut
Term
calcitonin
Definition
-decreases blood Ca, osteoclastic activity, and Ca absorption
Term
How does the body respond to hypocalcemia (low blood Ca2+) and how is homeostasis reestablished?
Definition
1: hypocalcemia triggers release of PTH 2: PTH increases renal expression of 1-alpha-hydroxylase at kidney 3: 1,25-(OH)2 vitamin D3 binds to nuclear VDR (vitamin D receptor) to increase calbindin expression (type 2 steroid receptor) -sit in particular promoter region -binding of vitamin D to VDR allows RNA polymerases to bind and transcribe calbindin gene 4: calcibindin temporarily sequesters recently absorbed Ca2+ to allow for optimal absorption from intestinal lumen 5: Ca2+-ATPase pumps on basal lateral side "push" Ca2+ into blood, which increases blood pH
Term
How does the body respond to hypercalcemia (high blood Ca2+) and how is homeostasis reestablished?
Definition
1: increased calbindin expression (ultimobranchial glands)
2: increased 24-hydroxylase (decreased 1-alpha-hydroxylase)
3: decreased osteoclast, increased osteoblast
[image]
Term
How does the relationship between calbindin and 1,25 (OH)2D3 increase both renal and intestinal absorption of Ca?
Definition
by increasing synthesis of Ca-binding proteins, mainly calbindin-D28k
Term
central canal contains...
Definition
-arteriole
-lymphatic
-nerves
-venule
Term
osteon or Haversian system contains...
Definition
concentric layers, or lamellae, of compact bone tissue that surround a central canal, the Haversian canal
Term
depiction of the organization of osteons and lamellae in compact bone
Definition
[image]
Term
Osteoid (organic part of bone matrix)
Definition
organic component of bone matrix made of collagen III and X, glycosminoglycans, proteoglycans, and glycoproteins
-provides framework upon which hydroxyapatite crystals can form
1/3 of bone is collagen, which provides tensile strength (ability to withstand bending and twisting) but poor compressive strength (ability to withstand pressure)
-secreted by osteoblasts
Term
Hydroxyapatite crystals (inorganic part of bone matrix)
Definition
-hydroxyapatite (Ca10(PO4)6(OH)2) makes up 2/3 of the bone matrix -provides compressive strength (ability to withstand pressure) -rigid strength and density
Term
the result of the combination of organic and inorganic components of bone matrix
Definition
a protein-crystal combination that has the flexibiity of collagen and the compressive strength of hydroxyapatite crystals
-this allows bone to be strong, somewhat flexible, and highly resistant to shattering
Term
How would a bone behave in the absence of adequate hydroxyapatite?
Definition
it would have tensile strength (flexible), but it would lack compressive strength (wouldn't be able to handle pressure)
Term
function of osteoprogenitor (mesenchymal stem) cells
Definition
precursor to osteoblasts
Term
where osteoprogenitor (mesenchymal stem) cells are found
Definition
in the periosteum outer covering
Term
Explain the difference between compact and spongy bone
Definition
compact bone:
-80% of the osseous tissue
-has osteon as its functional unit
-forms outer shell of most bones
-denser than spongy bone

spongy bone:
-made of lattice of delicate structures called spicules and trabeculae
-spongy appearance
-covered with endosteum
-permeatefd by spaces filled with bone marrow
-typically found at ends of long bones
-covered by compact bone
Term
depiction of the spatial relationship between compact ad spongy bone
Definition
[image]
Term
what's number 1?
[image]
Definition
spongy bone
Term
what's number 2?
[image]
Definition
compact bone
Term
what's number 3?
[image]
Definition
medullary cavity
Term
what's number 4?
[image]
Definition
epiphysis
Term
what's number 5?
[image]
Definition
metaphysis
Term
what's number 6?
[image]
Definition
diaphysis (shaft)
Term
what's number 7?
[image]
Definition
metaphysis
Term
what's number 8?
[image]
Definition
epiphysis
Term
functions of the skeletal system other than supporting the body and protecting some of the internal organs
Definition
-producing red blood cells (bone marrow) -regulating blood pH -regulating blood Ca2+ and PO23- -medullary bone used for egg shell formation
Term
How does an osteoblast become an osteocyte?
Definition
by becoming completely surrounded by the bone matrix it forms
Term
[image]
Definition
osteon
Term
what's number 1?
[image]
Definition
Osteon
Term
what's number 2?
[image]
Definition
Central canal
Term
what's number 3?
[image]
Definition
Lamellae
Term
what's number 4?
[image]
Definition
Lacunae
Term
What is the difference between the organic and inorganic forms of bone matrix?
Definition
-organic made of collagen, which provides tensile strength
-inorganic made of hydroxyapatite, which provides compressive strength
Term
principle component of the osteoid
Definition
collagen
Term
principle component of the inorganic matrix
Definition
hydroxyapatite crystals
Term
what strength does the organic portion of the bone matrix provide bone?
Definition
tensile strength (withstands twisting)
Term
what strength does the inorganic portion of the bone matrix provide bone?
Definition
compressive strength (withstands pressure)
Term
What is the role of alkaline phosphatase when secreted by osteoblast?
Definition
formation of hydroxyapatite
Term
How do osteoblasts contribute to bone matrix formation?
Definition
-making and releasing organic compounds into the matrix
-increasing Ca phosphate levels such that Ca salts are deposited onto the organic matrix to form bone
Term
How are osteoclast regulated? (Role of RANKL and OPG)
Definition
RANKL
-1: pre-osteoblasts/osteoblasts release soluble RANKL (RANK ligand)
-2: RANKL binds to RANK receptor on pre-osteoblast
-3: binding of RANKL activates osteoclast

Osteopotegrin (OPG)
-protects the bone
-secreted by osteoblast and competitively blocks RANKL
+impedes osteoclast activity

[image]
Term
role of RANKL in regulating osteoclast
Definition
1: pre-osteoblasts/osteoblasts release soluble RANKL (RANK ligand)
2: RANKL binds to RANK receptor on pre-osteoblast
3: binding of RANKL activates osteoclast
Term
role of Osteoprotegrin (OPG) in regulating osteoclast
Definition
-protects the bone
-secreted by osteoblast and competitively blocks RANKL
+impedes osteoclast activity
Term
depiction of how RANKL and Osteoprotegrin (OPG) regulate osteoclast
Definition
[image]
Term
Impact of estrogen on bone metabolism
Definition
-calcitonin estrogen leads to formation of osteoblasts
-affects OPG in humans
-faster bone growth
-faster cartilage growth and bone formation in epiphyseal plate
-bone formation faster than cartilage growth (eventually all cartilage gets replaced with bone)
-leads to formation of medullary bone in laying hens
Term
Impact of PTH on bone metabolism
Definition
1: increased osteoclasts 2: more Ca resorption in kidneys 3: promotes final step in vitamin D3 activation 4: inhibits collagen synthesis by osteoblast
Term
Impact of Calcitonin on bone metabolism
Definition
-calcitonin estrogen leads to formation of osteoblasts
-affects OPG
-lower blood Ca
-lower osteoclastic activity
-lower Ca absorption
-affects bone composition and growth pattern
Term
Impact of corticosteroids on bone metabolism
Definition
corticosterone:
-stress --> poor bone integrity

glucocorticoids:
-high amounts increase bone loss, impairing growth at epiphyseal plate in children
-induce apoptosis of osteoblasts and increase osteoclasts survival and activity
Term
Impact of blood calcium on bone metabolism
Definition
hypocalcemia -higher PTH production +higher 1-alpha-hydroxylase production in kidneys +lower 24-hydroxylase (inactive vitamin D3 hypercalcemia: -increased calbindin expression (ultimobranchial glands) -increased 24-hydroxylase (decreased 1-alpha-hydroxylase) -decreased osteoclasts and increased osteoblasts
Term
how osteoclasts use CAH to degrade bone
Definition
1: osteoclasts use this to release H atoms at its ruffled border to acidify and dissolve the bone matrix 2: allows for formation of H+ that can be pumped into the "bay" by H+-ATPase pump (lower pH)
Term
how osteoclasts use TRAP to degrade bone
Definition
-TRAP (tartrate-resistant acid phosphatase) is activated and is thought to assist with dissolution of hydroxyapatite crystals
-this is a marker for osteoclast activity
-this is thought to help break down hydroxyapatite
Term
how osteoclasts use Cathepsin K to degrade bone
Definition
this protease breaks down the osteoid (collagen)
Term
depiction of how PTH affects bone metabolism
Definition
[image]
[image]
Term
the zones of the bones
Definition
[image]
Term
what's number 1?
[image]
Definition
resting zone
Term
what's number 2?
[image]
Definition
proliferation zone
Term
what's number 3?
[image]
Definition
hypertrophic zone
Term
what's number 4?
[image]
Definition
calcification zone
Term
what's number 5?
[image]
Definition
ossification zone
Term
what's number 6?
[image]
Definition
calcified cartilage spicule
Term
what's number 7?
[image]
Definition
osseous tissue
Term
what happens in the resting zone?
Definition
this zone, furthest from the marrow cavity, is made of typical hyaline cartilage with resting chondrocytes and chondroblasts, showing no signs of bone formation
Term
what happens in the proliferative zone?
Definition
the chondroblasts/chondrocytes quickly divide and push the epiphysis away from the diaphysis, lengthening the bone -chondroblasts/chondrocytes form in lamellae -the growth hormone used here is T4/T3 -estrogen/testosterone increase proliferation of chondroblasts/chondrocytes
Term
what happens in the hypertrophic zone?
Definition
chondrocytes stop dividing and start to enlarge and signal the surrounding matrix to calcify
-the walls between the lacunae become very thin
Term
what happens in the calcification zone?
Definition
-matrix calcifies
-chondrocytes die, leaving behind trabeculae-shaped calcified cartilage; THIS IS NOT YET BONE!
-chondrocytes secrete collagen and alkaline phosphatase, forming hydroxyapatite crystals at thin walls of lacunae
Term
what happens in the ossification zone?
Definition
-osteoclasts digest calcified cartilage
-osteoblasts replace it with bone in the same shape as the calcified cartilage, resulting in bone trabeculae at metaphysis and bone elongation
-the osteoblasts and osteoclasts come from the metaphyseal blood supply
Term
role of chondroblasts in epiphyseal ossification and its general location among other zones
Definition
-in proliferation zone
-quickly divide and push epiphysis away from diaphysis, lengthening the bone
Term
role of chondrocytes in epiphyseal ossification and its general location among other zones
Definition
-in the hypertrophic zone
+older chondrocytes enlarge and signal surrounding matrix to calcify
-in the calcification zone
+chondrocytes die, leaving behind trabeculae-shaped calcified cartilage; THIS IS NOT YET BONE!
Term
role of osteoclasts in epiphyseal ossification and its general location among other zones
Definition
-in the ossification zone
-digests calcified cartilage
Term
role of osteoblasts in epiphyseal ossification and its general location among other zones
Definition
-in the ossification zone
-replace calcified cartilage with bone tissue in shape of the calcified cartilage, resulting in bone trabeculae
Term
the role of osteopontin (OPN) in bone formation
Definition
this hormone has lots of negative charges that allow Ca to stick to it
Term
Relate Wolff’s law to osteoporosis in chickens
Definition
according to Wolff's law, greater stress on bone causes the bone to become stronger, so osteoporosis in chickens may be partly due to lack of exercise for their bones
Term
How is osteoporosis different in humans and chickens?
Definition
-in humans, it's caused by lower levels of estrogen such that bone resorption increases and structural bone formation is suppressed, since estrogen stimulates osteoblasts and inhibits osteoclasts
-in laying hens, higher estrogen levels make osteoporosis possible because higher estrogen makes the osteoblasts switch from forming structural bone to forming medullary bone, which is weaker. Osteoblasts switch back to forming structural bone after the lay cycle.
Term
How is osteoporosis similar in humans and chickens?
Definition
causes less production of structural bone
Term
What are some potential strategies that could be implemented to alleviate osteoporosis in chickens?
Definition
-blocking sclerostin
-exercise
Term
why blocking sclerostin can alleviate osteoporosis in laying hens
Definition
sclerostin, which is secreted by osteocytes, inhibits osteoblast activity
Term
why exercise can alleviate osteoporosis in laying hens
Definition
more exercise leads to less sclerostin, leading to more structural bone
Term
What is TD?
Definition
tibial dyschondroplasia
-characterized by calcification defect and an abnormal mass of unvascularized cartilage in the proximal mass of the tibiotarsus
-abnormal cartilage seems to be the result of proliferation of prehypertrophic cells in relation to lack of metaphyseal vascularization
-formation of cartilage (collagen) plug at the epiphysis of long bones
+leads to secretion of osteoid (failure of ossification) typically at the tibiotarsus (proximal end)
--failure to develop metaphyseal blood supply
--rapid endochondrial growth with lack of calcification
+the lesion is cartilage or collagen on the bone (poor compressive strength
Term
How could TD be controlled in broilers that are susceptible to the condition?
Definition
vitamin D supplementation
Term
On a molecular level, how could you distinguish between TD and rickets?
Definition
test for PTH receptor or mRNA
-TD = normal levels
-rickets = lower PTH receptor due to chronic high PTH
+rickets caused by low vitamin D, causing low blood Ca and high PTH
+increased hormone levels cause downregulation of receptors
Term
What is the cause of the molecular difference between TD and rickets?
Definition
rickets = lower PTH receptor due to chronic high PTH
Term
What is appositional growth?
Definition
bone growing in diameter
Term
How does appositional bone growth occur?
Definition
1: osteoblasts in periosteum secrete bone matrix and secrete circumfrential lamellae
2: osteoclasts at endosteum actively resorb bone
3: bone matrix deposited within layers parallel to the surface called circumferential lamellae
4: osteoclasts resorb bone matrix along medullary cavity
Term
Name the three-classic calcium-regulating hormones present in birds.
Definition
-parathyroid hormone (PTH) -calcitonin -1,25-dihydroxyvitamin D3 (calcitrol)
Term
What three forms does calcium exist in birds?
Definition
-extracellular -intracellular -hydroxyapatite (Ca10 (PO4)6(OH)2) of the bone
Term
Which form of Ca constitutes about 99% of the total body calcium?
Definition
hydroxyapatite (Ca10 (PO4)6(OH)2) of the bone
Term
the physiologically active form of Ca
Definition
ionized Ca
Term
the fraction of calcium that is regulated by interaction with hormonal action
Definition
ionized Ca
Term
Protein-bound calcium is considered physiologically inactive and serves as an extracellular storage pool. What two proteins predominantly bind this calcium?
Definition
-albumin
-vitallogenin
Term
how much of a hen's Ca stores are in the shell of an egg?
Definition
about 10%
Term
why might zebra finches use a higher percentage of their Ca in their eggs?
Definition
because smaller birds lay proportionally larger eggs with more shell
Term
What is the main source of the calcium required for eggshell calcification?
Definition
greater intestinal absorption and resorption of Ca from the medullary bone
Term
What parathyroid cell type is responsible for producing PTH?
Definition
chief cells; the parathyroid gland is made entirely of these cells
Term
three mechanisms used by PTH that lead to an increase in blood calcium levels
Definition
1: faster synthesis of 1,25-(OH)2-D3 by the kidney 2: greater tubular resorption of Ca, leading to less Ca excreted and more PO4 excreted 3: greater bone resorption
Term
do birds have a delayed response to PTH compared to mammals?
Definition
no
Term
Why might PTH be more effective in egg-laying hens than in males?
Definition
either because...
-there's more PTH receptors in medullary bone and oviduct OR
-more Ca-binding proteins in the plasma
Term
What calcium regulating hormone is produced by the ultimobranchial glands?
Definition
calcitonin
Term
does calcitonin circulate at much higher levels in birds than in mammals?
Definition
yes
Term
Why is it thought that calcitonin levels are high in egg laying chickens immediately before or after oviposition?
Definition
because Ca is still being rapidly mobilized from the bones and absorbed from the intestines without the shell gland removing the Ca from the blood
Term
the two most important forms of vitamin D
Definition
-D2 -D3
Term
how vitamins D2 and D3 differ
Definition
-D2 seems to be only 1/10th as efficient as D3, possibly due to D2 having a lower affinity for Ca-binding proteins, which also means the D2 will be excreted more readily -essentially, D3 is 10 times more efficient and has higher affinity for Ca-binding proteins
Term
do birds often ingest nutritionally significant amounts of cholicalciferol during the preening process?
Definition
no
Term
25-OH-D3
Definition
-the major circulating form of D3 -serves as a pool for further activation or catabolism
Term
1,25-(OH)2-D3
Definition
the most active form of D3
Term
where PTH increases hydroxylation when Ca is low
Definition
position 1
Term
where PTH does hydroxylation when Ca levels are normal
Definition
position 24
Term
main target organs for D3
Definition
-intestine
-kidney
-bone
Term
which protein, increased in response to calcitriol, facilitates the absorption of Ca in the duodenum and jejunum?
Definition
calbindin-D28k
Term
where may calbindin-D28k be found other than the duodenum and jejunum?
Definition
oviduct, which is the distal portion of the uterus
Term
Why would PTH levels fall as calcitriol levels increase?
Definition
because calcitriol (1,25(OH)2-D3) decreases PTH production in the parathyroid gland
Term
the amount of medullary bone is sufficient to supply Ca for how many egg shells?
Definition
about 1
Term
Rising estrogen concentrations at the onset of egg production stimulate the osteoblast from forming ______ bone to producing spicules of medullary bone at the ______ surface.
Definition
-lamellar cortical
-endosteal surface
Term
Radiographically, where is medullary bone most prominent?
Definition
pelvic limb long bones (femur and tibiotarsus)
Term
What is osteomyelosclerosis?
Definition
formation of medullary bone such that a labile source of Ca becomes available
Term
What is the source of Vitamin D3 in the embryo?
Definition
yolk
Term
how does calcitriol facilitate the absorption of calcium?
Definition
by increasing the serum concentration of Ca to reduce the production of PTH
Term
Why is it thought fledglings of altricial species have higher dietary calcium requirements when compared to precocial species?
Definition
because hatchlings have a less calcified skeleton and grow faster
Term
How much sunlight exposure is needed in chickens to ensure sufficient production of endogenous vitamin D?
Definition
at least 11-30 minutes of direct exposure to sun light
Term
Why is Vitamin D2 an ineffective nutritional supplement for birds?
Definition
because compared to D3, it has a lower affinity for vit D binding proteins and is excreted more quickly
Term
Why do you think the dietary calcium requirements for broiler breeders are higher than egg type breeders?
Definition
because egg-laying birds have much higher levels of albumin, which carries vitamin D3
Term
the role of albumin in regulating calcium levels
Definition
excess Ca binds to it such that Ca can be released where it's needed
Term
How and why would a drop in blood pH affect calcium blood calcium readings?
Definition
increase blood Ca levels because of less binding to albumin
Term
Could you use a human Vitamin D assay kit to measure Vitamin D in avian blood?
Definition
yes
Term
What is the range of blood levels of ionized calcium for the domestic chicken?
Definition
1.3-1.6 mmol/L
Term
What is the range of blood levels of ionized 25-OH-D3 for the domestic chicken?
Definition
27.2-68 mmol/L
Term
What is the range of blood levels of PTH for the domestic chicken?
Definition
0.05-0.5 mmol/L
Term
How might excessive dietary manganese lead to hypocalcemia in birds?
Definition
by preventing the normal absorption of Ca
Term
Why isn’t hypocalcemia from parathyroid hyperplasia not detected until bone reserves are severely depleted?
Definition
because blood Ca is maintained at normal levels and fibrous tissue replaces the resorbed bone
Term
What are some common signs of calcium deficiency in adult female birds (hens)?
Definition
-egg binding
-egg abnormalities (soft shell, misshapen, thin shell)
-higher embryo mortality
-"cage paralysis"
-osteomalacia
-pathological fractures
Term
What is often correlated with hypercalcemia in birds?
Definition
-more Ca-binding protein production
-greater secretion of estrogen
Term
What are some clinical signs of hypercalcemia?
Definition
-hydroxylation of 25-OH-D3, mainly to 24,25-(OH)2D3 -higher excretion of Ca -more bone formation than resorption -release of calcitonin, likely to reduce bone resorption -lower 1,25(OH)2-D3 synthesis -lower intestinal absorption of Ca -lower PTH synthesis
Term
What percentage of hens experience fractures either during the production period or depopulations?
Definition
about 30%
Term
The zone of proliferative chondrocytes is nourished by ______ blood capillaries, while the hypertrophic zone receives its blood supply from the ______ blood vessels.
Definition
-epiphyseal
-metaphyseal
Term
Once fully hypertrophied, chondrocytes secrete this enzyme that helps to initiate the formation of hyrodxyapatite crystals.
Definition
alkaline phosphatase
Term
______ produce the osteoid and raised concentration of Ca2+ and PO43- ions, while the bone-reabsorbing cells, ______, are also active during the formation of spongy bone in the marrow.
Definition
-Osteoblasts
-osteoclasts
Term
By what process to long bones widen?
Definition
intramembranous ossification
Term
During intramembranous ossification, osteoblast are present in the ______ and lay down concentric layers of lamellar compact bone, while on the ______ surface, osteoclast resorb bone.
Definition
-perichondrium
-endosteal
Term
When do osteoblast change from forming lamellar cortical bone to medullary bone?
Definition
when the hen becomes sexually mature
Term
What is the purpose of medullary bone?
Definition
labile Ca source for the formation of egg shells
Term
why structural bone content of the hen declines during lay
Definition
because the osteoblasts cease to form structural bone, but the osteoclasts continue to resorb structural bone
Term
2 reasons why medullary bone is weaker than structural bone
Definition
1: it is woven and based on very irregularly arranged collagen fibrils
2: much of it exists in isolated spicules
Term
Can one use radiographic density or ash to measure bone quality in laying hens? Why or Why not?
Definition
no, because medullary and structural bone have the same radiodensity
Term
How are human postmenopausal osteoporosis and laying hen osteoporosis different?
Definition
-the one in humans is caused by lower estrogen
-the one in hens is caused by estrogen making the osteoblasts switch from forming structural bone to forming medullary bone, which is weaker
Term
the relationship between medullary bone content and shell quality
Definition
Scarcely any, since egg quality declines during the lay cycle, during which the medullary bone content increases. Therefore, shell quality seems to be a matter of ability to move Ca from the bone to the egg shell, not medullary bone content.
Term
How can exercise potentially increase bone strength?
Definition
may be by either...
-inhibiting egg production OR
-stimulating formation of structural bone
Term
2 possible reasons why tibia strength increased within 20 days of transfer of hens from cages to an aviary
Definition
-stimulation of structural bone formation
-inhibition of egg production
Term
What is Bone Index (BI)?
Definition
seems to be a measure of a bone's radiographic density and its breaking strength
Term
how the number for bone index (BI) is obtained
Definition
using this equation:
BI = 0.27 x keel radiographic density + 0.37 x humerus strength + 0.61 x tibia strength - 0.35 x body weight
Term
At what age was there a greater difference in tibial cortical bone width between the two lines of hens selected for resistance (H) or susceptibility (L) to osteoporosis?
Definition
70 weeks
Term
Which of the two lines (resistance (H) or susceptibility (L)) had a higher number of osteoclast per unit of medullary bone?
Definition
the line selected for susceptibility to osteoporosis (L)
Term
What is osteomalacia?
Definition
bone loss caused by nutritional deficiencies in P, Ca, and cholicalciferol
Term
Why isn't the statement “osteoporosis occurs in hens because they deplete their bones by laying so many eggs” not entirely correct?
Definition
because the amount of Ca hens consume is greater than the amount used to lay eggs
Term
the relationship between Bone Index (BI) and rate of lay and why this is
Definition
very weak relationship, likely due to rate of lay being a matter of the lay cycle regulated by hormones
Term
the relationship between Bone Index (BI) and shell quality and why this is
Definition
-hens with higher bone index lay eggs with lower shell quality; inversely related
-this is because resistance to osteoporosis is associated with less bone resorption, leading to less Ca deposited on the egg
Term
Why might dietary calcium from a particulate rather than a powdered form improve egg shell and bone quality?
Definition
because particulate Ca stays in the digestive system longer, providing Ca such that hens are less reliant on bones for egg shell formation
Term
the 9 air sacs in birds
Definition
-2 cervical
-1 interclavicular
-2 anterior thoracic
-2 posterior thoracic
-2 abdominal
Term
flow of air in the avian respiratory system
Definition
1 way with cross-current exchange
Term
respiratory volume in birds vs. that in mammals
Definition
15% for birds and 7% for mammals
Term
how birds breathe
Definition
-no diaphragm; breathing dependent on inspiratory and expiratory muscles that extend the sternum and open the ribs to increase area (or decrease pressure) of thoracic cavity
-this is why you want to be careful when holding a bird
Term
movement of skeleton during breathing
Definition
[image]
Term
how the sternum and ribs move during inspiration
Definition
-sternum rocks cranially and ventrally with the coracoids and clavicle rotating at the shoulder
-vertebral ribs move cranially to expand the sternal ribs and abdominal cavity laterally
Term
the motion that occurs during inspiration
Definition
the ribs are drawn forward and the sternum is lowered, allowing the caudal air sacs to receive fresh air
Term
the motion that occurs during inspiration
Definition
the sternum is drawn caudal and dorsal, the air sacs are compressed, and air from the caudal air sac passes through the lungs while the air in the cranial air sac leaves via the trachea
Term
instead of alveoli, birds use...
Definition
parabronchi
Term
depictions of parabronchi
Definition
[image]
Term
Paleopulmonic Parabronchi
Definition
these are the main parabronchi and are arranged in parallel formation (neat stacks)
Term
Neopulmonic Parabronchi
Definition
these irregularly arranged parabronchi are located in the caudal region and occupy no more than 25% of the parabronchi
Term
lungs in mammals vs. lungs in birds
Definition
lungs in mammals are expandable while lungs in birds are rigid
Term
cardipulmonary
Definition
relating to the heart and lungs
Term
for O2 poor blood, the ______ side of the heart pumps to the ______ circulation through ______
Definition
-right
-pulmonary
-pulmonary arteries
Term
for O2 rich blood, the ______ side of the heart pumps to the ______ circulation through ______
Definition
-left
-systemic
-the aorta

this is AFTER receiving blood from pulmonary circulation
Term
What function do the Concha (meatus passageways) serve for respiratory system?
Definition
-filtering air (cilliated passageway)
-humidify and warm air
-ensures air comes into contact with respiratory epithelium
Term
nares
Definition
essentially the nostrils
[image]
Term
choana
Definition
seems to be the internal nostrils above the epiglottis
[image]
Term
glottis
Definition
opening to the trachea
Term
trachea
Definition
tube between the glottis and syrinx; this tube is surrounded by cartilage rings
Term
syrinx
Definition
where the trachea and bronchial tubes meet; this is basically the bird's voice box
[image]
Term
primary bronchus
Definition
the first bronchial tube that branches out from the trachea
[image]
Term
1st Inspiration: Air to posterior air sacs. (DRAW THIS!!!!)
Definition
External nares → concha → choanal slit → glottis → trachea → syrinx → primary bronchi → intrapulmonary bronchus → caudal air sacs (abdominal and posterior thorasic)
Term
1st Expiration: Gas exchange as air enters parabronchi of lungs. (DRAW THIS!!!!)
Definition
Caudal air sacs → neopulmonic parabronchi or dorsobronchi (gaseous exchange) → paleopulmonic bronchi (gaseous exchange)
Term
2nd Inspiration: Air now enters anterior air sacs. (DRAW THIS!!!!)
Definition
Paleopulmonic bronchi → ventrobronchi → cranial secondary (anterior) bronchi → (anterior) cranial air sacs (cervical, interclavicular, and anterior thorasic)
Term
2nd Expiration: Air exhaled out the trachea. (DRAW THIS!!!!)
Definition
Cranial air sacs → cranial secondary bronchi (anterior) → primary bronchi → syrinx (sound) → trachea → glottis → conchal slit → concha → external nares
Term
the exchange that occurs in cross-current exchange
Definition
O2 rich air passing from posterior parabronchi exchanges with O2 poor blood flowing in an anterior to posterior manner... "cross-current"
Term
depictions of cross-current exchange
Definition
[image]
[image]
Term
what cross-current exchange does for gas concentration
Definition
maintains concentration gradient that allows diffusion of O2 into blood and CO2 out of blood
Term
where cross-current exchange occurs
Definition
air capillaries and blood capillaries exchange gases
Term
Henry's law
Definition
at the air-water interface for a given temperature, the amount of gas that dissolves in the water is determined by its solubility in water and its partial pressure in air
Term
How would altitude impact Henry’s law
Definition
thinner air means lower partial pressure, thus less dissolved gas in blood
Term
Even though the partial pressure difference is greater for O2 than for CO2, explain why CO2 exchanges at near an equal rate (consider Henry’s law)
Definition
because CO2 is 20 times more soluble
Term
Hemoglobin (Hb)
Definition
protein made of 4 globin subunits, each containing a heme group that binds 1 O2 to the ferrous ion (Fe2+); one hemoglobin molecule can carry up to 4 O2
Term
oxyhemoglobin (HbO2)
Definition
O2 bound to hemoglobin
Term
deoxyhemoglobin (HHb)
Definition
hemoglobin with no O2
Term
heme
Definition
the group in hemoglobin that binds 1 O2 to the ferrous ion (Fe2+)
Term
the tree different forms of CO2 transport in the blood
Definition
-carbonic acid
-carbamino compounds
-dissolved in plasma
Term
the formula for formation of carbonic acid
Definition
CO2 + H2) --> CH2O3 --> H+ + HCO3-
Term
the enzyme responsible for the formation of carbonic acid
Definition
carbonic anhydrase
Term
where is carbonic anhydrase located?
Definition
-red blood cells
-osteoclasts
Term
How/Why is Carbon Monoxide (CO) toxic
Definition
because it binds to the hems group 210 times more tightly than O2, making red blood cells more likely to carry it and less likely to release it; this ties up hemoglobin for a long time
Term
treatment for CO toxicity
Definition
hyperbaric oxygen therapy, which is treatment with O2 at more than 1 atm of pressure
Term
Bohr effect
Definition
increased CO2 in active tissue lowers blood pH, promoting release of O2 by way of an H+ released by CAH in red blood cells
Term
depiction of Bohr effect
Definition
[image]
Term
3 factors that adjust oxygen unloading for metabolically active tissues
Definition
-ambient PO2; atmosphere with lower partial pressure of O2 causes release of O2 -temperature; active tissue with higher temperature causes more O2 unloading -Bohr effect; active tissue with higher CO2 levels causes lower blood pH, which promotes O2 unloading
Term
relationship between hypocapnia and alkalosis
Definition
hypocapnia (decreased blood CO2) --> increased pH --> hypoventilate (bag) -high pH leads to alkalosis
Term
relationship between hypercapnia and acidosis
Definition
hypercapnia (increased blood CO2) --> lower pH --> hyperventilation --> decreased pH -lower pH leads to acidosis
Term
some unique adaptations of birds who travel (live) at high altitudes
Definition
-lungs with larger surface area -cross-current gas exchange -point mutation in hemoglobin (higher affinity for O2) -mitochondria closer to capillaries -higher levels of creatine kinase
Term
chart of some adaptations of birds to high altitudes
Definition
[image]
Term
What is the significance of mitochondria placement and creatine kinase in birds being adapted to high altitude?
Definition
-mitochondria being closer to the capillaries makes it easier for the O2 to diffuse to the mitochondria -higher levels of creatine kinase enhance the transport of phosphate to where it's needed
Term
What is the mucociliary escalator and why is it significant?
Definition
-cilia lining the trachea covered by a layer of mucous
-this helps keep gunk out of the respiratory system
Term
In poultry rearing, what can significantly compromise the mucociliary escalator
Definition
-high ammonia levels
-damages cilia such that they're no longer functional
Term
What is the resting membrane potential of neurons?
Definition
-70mV
Term
depolarization
Definition
when the membrane potential inside the cell increases -occurs when positive ions enter the cell (usually Na+) -this is excitatory
Term
repolarization
Definition
when the membrane potential inside the cell returns to resting potential
-this actually overshoots resting potential and gets down to -85 mV
Term
hyperpolarization
Definition
when the membrane potential goes below resting membrane potential
Term
What is threshold for voltage-gated Na channels?
Definition
-55 mV
Term
At what voltage are voltage-gated Na channels deactivated?
Definition
+30 mV
Term
At what voltage do K channels open for repolarization?
Definition
arount +30 mV
Term
During repolarization, the resting membrane is overshot to this voltage known as hyperpolarization.
Definition
-85 mV
Term
How is the membrane potential restored after an action potential?
Definition
the Na-K pump restores resting membrane potential
Term
how neurons code for stimulus intensity
Definition
-increased frequency of action potentials
-recruitment, which is activating more neurons in a nerve; more neurons get activated (recruited) as the stimulation increases
Term
recruitment
Definition
intensity of stimulation increases, activating more neurons and axons in a nerve
Term
Movement of an action potential down an axon relying on cable properties is inefficient, what is present, anatomically, that helps propagate the action potential quickly?
Definition
-myelin provides insulation
-Na channels reside at the nodes of Ranvier. Action potential kinda pops between the nodes.
Term
depiction of a neuron and all its components
Definition
[image]
Term
What is saltatory conduction?
Definition
propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials
Term
sequence of events that leads to the exocytosis of neurotransmitters into the synapse (WRITE THIS!!!!)
Definition
1: ACh binds to nicotinic receptor on dendrite of motor neuron 2: nicotinic receptor opens and allows entry of Na+, generating an excitatory postsynaptic potential (EPSP) -These voltage-gated Na channels open at threshold. These channels are concentrated at the axon. 3: if there's sufficient Na entry, and EPSP opening of voltage-gated Na channels at axon hillock --> action potential 4: action potential generated at axon hillock can travel down the axon via saltatory conduction 5: arrival of action potential at terminal bouton opens voltage-gated Ca channels -bouton is the end of the axon 6: Ca2+ enters terminal bouton and binds with synaptotagmin to form Ca2+-synaptotagmin complex 7: Ca2+-synaptotagmin complex disrupts SNARE docking proteins and causes neurotransmitter containing vesicles to fuse with synaptic membrane and release neurotransmitter into synapse -this neurotransmitter is acetylcholine (ACh)
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