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Animal Phys Ex. 4
University of Michigan Animal Phys Exam 4 study
145
Physiology
Undergraduate 2
04/18/2013

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Cards

Term
Purpose of Circulatory System
Definition

1) Nutrients and Oxygen to cells

2) Waste, carbon dioxide to excretion organs

3) Transport signaling molecules

4) Transport immune cells

5) Regulate body temperature

 

Diffusion is very slow over long distances

Term
Who elvolved circulatory systems? Why?
Definition

Metazoans

Diffusion is slow - solution is bulk flow 

Primarily evolved to transport gasses in relation to respiration

Oxygen for ATP and waste CO2 secretion

Term
How to calculate time for a molecule to diffuse
Definition

Time necessary for molecule to diffuse between two points is proportional to the square of the distance between them

 

Exponentially increases ad distance gets greater

Term
Bulk flow / Law of Bulk Flow
Definition

Circulatory system - functionally connects organs of exchange with cells

Convective transport

Tubes, pumps, one-way valves

 

Fluids move down pressure gradients (ΔP)  and are opposed by resistance (R)

Q(flow) = ΔP/ R

 

Ohm's Law: Movement result of a force. Movement impeded by resistance.

Term
Types of pumps in circulatory system
Definition

Contractile chambers - heart chambers or vessels

External pumps - peripheral skeletal muscle 

Peristaltic contractions - heart or vessels

[image]

 

Term
Two types of circulatory systems
Definition

Open - Elongated dorsal tube with multiple chanmbers that have calves that move hymolymph (no blood / extracellular fluid difference) that moves out of heart and into open area in body called sinus. Sinus flow is unidirectional.


 

Closed - high pressure connected tube unidirectional, circular system. The blood is always distinct from the interstitial fluid

 

Term
Basic circulatory system of all vertebrates
Definition

Heart 

Arteries 

Arterioles

Cappilaries (start flow back to heart)

Venules 

Veins

Term
Do arteries always have oxygenated blood?
Definition

No, Arteries do not always have oxygenated blood and viens do not always have deoxygenated blood

Arteries defined - away from heart

Viens - toward heart

Term
How are arteries and veins defined?
Definition

By their direction of flow

Arteries away from heart

Veins into heart

Term
Types of closed circuits
Definition

Single circuit - Fishes - Only two chamers (1 atrium and ventricle) that make a single loop to first the gill then the systemic capillaries, back to heart.

Double circuit - Mammals and Bird - 4 chambered heart, pulmonary (lung) and systemic systems

Amphibians - 3 chambered heart- not complete separation of lung (pulmocutenous) and systemic circuit.

Reptiles - connection of the two circuits  

Term
Advantages to mammalian and avian heart
Definition

Higher gradient created for gas exchange because of oxygenated and deoxygenated blood is separated

 

Oxygenated blood to systemic circuit high necessary for movement and energy

Term
Resistance and radius
Definition

Resistance is inversly proportional to the function of the radius to the fourth power

Tube gets smaller, resistance gets larger

NS modulates by contricting or dilating blood vessels

Term
Resistors in parallel versus resistors in series
Definition

Resistors in series increases total resistance in series

- decrease flow

 

Resistors in parallel decrease the total resistance in series

- increase flow because increased total radius.

- Individual capillaries will have slower flow but the total circuit will have greater flow b/c of multiple in parallel.

Term
Flow
Definition

Voume ⁄ unit time

 

Low in capillaries; High in heart

 

 

Term
Velocity of Flow
Definition

Distance traveled/ unit time

 

Determined by pressure and cross-sectional area of blood vessel

 

Velocity is inversly related to radial size

- Capillaries have low velocity of flow

- The capillary bed however has velocity similar to larger vessels b/c total cross-sectional area is large

Term
Anastomoses
Definition
[image]
Term
Cardiac cycle: Diastole / systole
Definition
[image]
Term
Blood flow in the mammalian heart
Definition
[image]
Term
Blood flow in mammalian heart
Definition

Right Atrium

Right Ventricle

Pulmonary Artery

Lungs

Pulmonary Vein

Left Atrium 

Left Ventricle

Aorta

Organ System

Systemic Veins

Anterior Vena Cava

Right Atrium

* Atrioventricular valves are between Atrium and Vetricles

** Semilunar valves are between Ventricles and Arteries (Pulmonary or Aorta)

Term
AV valve
Definition

Atrioventricular valve between Atrium and Ventricles

Also called tricuspid (right) and bicuspid (left) 

Open during ventricular relaxation(diastole) and artial dilation (systole)

Term
Semilunar valves
Definition

Between the Right venticle and the pulmonary artery & the left ventricle and aorta

Open during ventricular contraction (systole) / atrial relaxation (diastole)

Term

The pulmonary semilunar valve prevents back flow to what area

During what stage in cardiac cycle? 

Definition

Prevents backflow into right ventricle

During ventricular diastole, artial systole

 

The valve is open during ventricular systole (contraction)

Term
Cardiac muscle
Definition

Uninucleated

Intercalcated disks - desmosomes and gap junctions allow for conduction of electricle signals. High tensile ability.

Vertebrate hearts are myogenic - cnotraction initiated by cardiomyocyte

Term
What makes the high tensile ability in cardaic muscle?
Definition

Intercalcated disks 

desmosomes and gap junctions allow for electrical conduction

Term
Pacemaker cells
Definition

In the sinoatrial (SA) node (pacemaker)

Cells with fastest rhythm

Sodium permeability is higher → spontaneous depolarization

Resting potential higher ~-65 mV

 

Na+ funny channels open, at depolarization close and T-Ca2+ channels open, AP, T channels close K+ open

Term
How can cardiac rhythm be altered?
Definition

Autonomic - parasympathetic and sympathetics

or

Hormones

Thyroid hormones control beta-adrenergic receptors sensitive to norepinephrine

Epinephrine from adrenal medulla

Term
How are cardiac contractions/ action potentials synchronized?
Definition
communication via gap junctions
Term
Sinoatrial node
Definition

SA node / Pacemaker

Sets rate and timing of cardiomyocyte (muscle) contraction

Electrical impulses originate here

Alone depolarize at 100 bmp

Parasympathetics turn down to 70 bpm

Term
Atrioventricular node
Definition

AV node

Delays the electrical impulse from the SA node through the internodal pathways by 0.1 sec allowing the atria to empty completely

 

Sends impulse through bundle of His to Purkinje fibers

 

Alone 40-60 bmp (w/out SA node)

Term
Bundle of His
Definition

Specialized cardiac muscle fibers that carry electrical impulses from the AV node to the purkinje fibers

 

Term
Purkinje fibers
Definition

Apex of heart 

Speciallized cardiomyocytes w/ rudamentary contractile elements that also receive electrical impulses from bundle of His

Causes contraction of Ventricles up through artia 

Term
Impulse conduction through heart
Definition
[image]
Term
What causes the spontanous depolarization of pacemaker cells?
Definition

Higher resting potential -65mV v -85 of other cells

Funny non-seletive cation channels - influx Na+

Higher Na+ permeability

Term
Action potential in spontanous pacemaker cell
Definition
[image]
Term
Look at pic of cardiac cycle Lecture 1 slide 33
Definition
[image]
Term
Stroke Volume
Definition

Amount of blood (mL) pumped by the R and L ventricle in each contraction

Avg. in human is 0.07 liter 

Term
Cardiac output
Definition

CO = SV x HR

 

Stroke volume (blood pumped by ventricles per contractions) x HR (bpm)

 

avg. for human is 5 liter/ min (all blood in your body)

Term
Cardiovasular control in medulla oblongata
Definition
[image]
Term
Parasympathetic action on HR
Definition
[image]
Term
Sympathetic control of HR
Definition
[image]
Term
EKG P wave
Definition

depolarization of atria

Signal is at pacemaker and AV node

initial bump on graph

Term
EKG QRS complex
Definition

measures the depolarization of the large ventricle muscles

Spike in middle of graph

Term
EKG T wave
Definition

measure of repolarization of ventricle

last bump on the graph

Term
What is the driving force for pressure throughout circulatory system?
Definition
ventricular ejection
Term
How does blood pressure vary throughout circulatory system
Definition

Pressure is very high and very low in verticle

Remains only high in arteries (does not drop)

Pressure drops as it goes through arterioles, capillaries, venules, and lowest at veins.

[image]

 

Term
Why do arteries low fluctuation in pressures?
Definition
Though arteries pressure is maintained high the fluctuation in pressure is dampened by their elastictiy
Term
How does blood get back to heart if veins have low pressure?
Definition

Respiratory pumps - as we inhale  blood flows into blood vessels, but as we exhale compresses vessels pushing blood to heart

Skeletal muscle contractions

Backflow of blood is prevented by one-way valves

Term
Compliance
Definition

A measure of how eaily a structure can be stretched

Veins are highly compliant reservoirs for blood

Complaince = ΔVolume / ΔPressure

 

Can be adjusted by adjusting venomotor tone - increasing increases venous return to heart

Term
How is blood pressure monitored?
Definition

Through baroreceptors 

Increased mean arterial pressure (MAP) increases barorecptor firing

goes to Medulla

decreases sympathetic output 

less NE release 

Baroreceptors in kidneys regulate blood volume thus pressure

Chemoreceptors

 

Negative feedback and opposite can occur

[image]

Term
Chemoreceptor regulation of blood pressure
Definition

Located in Carotid and Aortic arteries

↓ Partal pressure of PO2 and ↑ PCO2 or ↓ pH cause decrease in parasympathetic activity leading to an incease in HR [image]

Term
How do Cardiac Output and Total Peripheral Resistance regulate BP
Definition

CO is adjusted in concern with TPR

TPR is regulated by the dilation and constriction of arterioles

Result: Blood flow = physiological demand

 

PRINT SLIDE 20 LECTURE 2

Term
Regulating blood flow to specific tissues : Capillaries
Definition

Depends on the metabolic need of the tissues under hormonal or NS control

 

1) Contraction of smooth muscle (tunica media) of the arterioles supplying capillaries

2) Pre-capillary sphincters

- rings of smooth muscle control flow between arterioles and venules (throughfare channels bypass the capillary bed) - contraction decreases flow to capillaries and increases to throughfare channels.

Term
How does tissue metabolism affect local blood flow?
Definition
↑ Metabolism → ↑ CO2,  ↑Waste,  ↓O2 → Arteriolar smooth muscle dilation→ ↑ blood flow → increase oxygen and waste removal → negative feedback
Term
Types of Capillaries
Definition

Continuous, Fenestrated, and Sinusoidal

[image]

Term
Types of movement across capillary walls
Definition

Slow rate of blood flow through capillaries allows for movement

1) Simple diffusion

2) Endocytosis/Exocytosis - transcytosis

3) Paracellular pathway - hydrostatic pressure

Term
Lymphatic system
Definition

Lymphatic capillaries = network of closed end tubules in intercellular space

Lymph capillaries→ lymph ducts → lymph nodes 

Lymph nodes filter before returning to veins

 

Functions

1) Transports interstitial fluid back to blood

2) Transports absorbed fat from small intestine to blood

3) Provides immunologic defences 

Term
Role and limits to diffusion. What influences diffusion?
Definition

The larger the gradient the faster the diffusion

1) Solubility

2) Partial pressure gradient

3) Temperature 

4) Distance 

5) Surface area - large banching into alveoli in lungs

 

Laws you need to know: Fick's, Ideal gas, Henry's, Grahams, and combination law of F's H, and G's.

Term
Fick's Law
Definition

dQ/dT = D x A x (dc/dx)

 

Rate of Diffusion (mol/sec) = Diffusion coefficient (D) x Surface area x Concentration (pressure) gradient (dc/dx)

 

D=Diffusion coefficient (cm2/sec) - index of ease of diffusion of particular substance in given medium (depends on temp and solubility

A = Surface area membrane (cm2

Diffusion is greatest if x is smaller (distance)


Combines importance of temperature, solubility, surface area, distance concentration of gasses (all factors of diffusion) 

Term
Gas pressure & Dalton's Law
Definition

Measure of the thermodynamic activity of molecule

 

Dalton's Law of Partial Pressures: 

Each gas exerts its own partial pressure that adds to the total pressure of system

 

Sum of the partial pressures (total pressure) is proportional to the total # gas molecules

Term
Ideal Gas Law
Definition

Relates presure to the # gas molecules and volume of chamber

 

PV = nRT

 

Pressure x Volume = # moles x Gas constant x Temp (Kelvin) 

 

Total pressure is proportional to # gas molecules at a constant temperature

 

Term
Partial pressure of gasses depend on what?
Definition

Gases dissolve, diffuse, and react according to their partial pressures, and not necessarily according to their concentrations in a gas mixture.


Partial pressure depends on the temperature of the gas.

Term
For a gas to diffuse into a cell it must first do what?
Definition

Disolve in liquid

based on partial pressure in air and solubility in liquid

Term
The amount of gas that will disolve in liquid is dependent on what?
Definition

Partial pressure in air and solubility in liquid

 

Henry's Law:

[G] = Pgas x Sgas

 

concentration gas in liquid = partial pressure in air x solubility in liquid

 

Solubility is affectd by temperature

Term
Henry's Law
Definition

[G] = Pgas x Sgas

 

Concentration gas dissolves = Partial pressure of that gad x Solubility of that gas in medium

 

O2 has low solubility in water

Term
What does Henry's Law mean for aquatic animals?
Definition

For oxygen to get to cells it must first dissolve in liquid 

Oxygen has low solubility in water

Henry's Law states: [G]  =Pgas x Sgas

 

The partial pressure of O2 is low in fishes exteral environment and the Solubility of O2 is low

In order to get the same amount of O2 as an air breathing animal it must pass 30x the amount of medium over gils. 

Also since as Temp increase solubility decreases, but fishes are ectotherms they look for thermoclimes

Term
Temperature and solubility of gasses
Definition
As temperature increases, solubility decreases
Term
What problem does thermoclimes solve for fish?
Definition

Fish are ectotherms so their metabolic demands increase with temperature 

However solubility of gasses (O2) decrease with temperature 

Term
Factors effecting solubility of gasses
Definition

Temperature

Salinity

Partial pressure / concentration in air

Solubility in medium

Term
Salinity and solubility of gasses
Definition

Graham's Law :

Diffusion of gas into liquid is proportional to its solubility, but inversly proportional to the square of its molecular weight

Smaller the gas the faster the diffusion

 

Difusion rate = Sgas / √MW

 

takes into account molecular weight and solubility of molecule in medium

Term
Graham's Law
Definition

Salinity and Solubility

 

Diffusion of gas into liquid is proportional to its solubility, but inversly proportional to the square of its molecular weight

Smaller the gas the faster the diffusion

 

Difusion rate = Sgas / √MW

Term
Combining Laws: Diffusion rate= ?
Definition

Diffusion rate = D × A × ΔPgas × Sgas / X × √MW

 

D = diffusion coefficient

A = surface area

ΔPgas = partial pressure gradient

Sgas = solubility in medium

X = diffusion difference

MW = molecular weight

Combines Fick's, Henry's, and Graham's

Term
Why does O2 go into body and CO2 out?
Definition
There is a steep O2 pressure gradient into body due to respiration/metabolism and high air oxygen partial pressure
Term
Why must the gas exchange organs be moist?
Definition
Gasses must dissolve in liquids before being transported / diffusing into cells
Term
How is O2 transported around body?
Definition

O2 requires a transport system within the body since diffusion is slow

 Circulatory system

 O2 transport molecules (e.g., hemoglobin)

and

O2 binding molecules in tissues with high metabolic demand (e.g., myoglobin in muscle). 

Term
Pros and Cons of water breathing v. air breathing
Definition

Dessication is problem for air breathing since respiratory surfaces must be moist and H2O is lost by evaporation

 

Water breathing must expend more energy moving medium over respiratory organ since low O2 concentration in water.

Term
How is O2 delivered in internal cells or tissues directly?
Definition

Bulk flow or ventilation

then diffusion

Term
Ventilarory strategies
Definition

Non-directional ventilation - wave gills through external environment

Tidal ventilation - system of tubes to lungs

Unidirectional ventilation - in through mouth to internal gills

Term
The mammalian respiratory system
Definition

Tidal ventilation (bidirectional)- PO2 of blood increases as PO2 of medium decreases

Not most efficient system, but avoids desiccation  

 

Lungs terminate in aveoli (sites of gas exchange)

Ventilation controlled by contraction and dilation of diaphragm 

Tidal Volume

Vital capacity

Risidual volume

Surfactant

 

Term
Tidal Volume
Definition

The volume of air inhales/ exhaled with each breath

~500 mL for adult

Term
Vital capacity
Definition

The maximum tidal volume during forced breath

~ 3.4 -4.8 L for college age

Term
Residual Volume
Definition

Prevents aveoli in lungs from collapsing

Some air remains in the lungs during exhalation

Lungs hold more air than vital capacity

Term
Surfactant
Definition

Reduces surface tension in liquid coating alveolar surface

Increases complaince of alveoli

Detergent (a mix of phospholipids and proteins) secreted by alveolar epithelium

Corticosteroids induce production 

Term
Why do the alveoli not collapse?
Definition

Residual volume

Surfactant

Term
Unidirectional ventilation
Definition

Makes greater exchange efficiency possible

Blood always exposed to O2 rich medium

Countercurrent flow best

[image]

 

Term
Birds lungs
Definition

Birds have stiff, hexagonal lungs and air sacs.

Birds maximize gas exchange at the respiratory surface by a crosscurrent mechanism.

Lungs employ unidirectional and continuous flow - air sacs and lungs fill separately

Term
Hemoglobin
Definition

A metalloprotein that bind O2 increasing carrying capacity of blood

Oxygen binds to the heme (iron containing) on hemeglobin → oxyhemoglobin

Oxygenated state is "relaxed" (R), deoxygenated is "tense" (T)

tetramere protein - each molecule can hold 4 oxygen

pH effects the O2 equillibrium of hemoglobin (the bohr effect) 

Term
The bohr effect
Definition

pH effects O2 equillibrium of hemoglobin

[image]

Term
Ways to alter hemoglobin content in blood
Definition

Physiological acclimatization - climbing mountain

Developmental acclimatization - living in high elevation

Term
How to increase O2 availability to cells
Definition

Decrease the affinity of hemoglobin for O2

1) Increase Temp

2) Increase CO2

3) Decrease pH

4) Increase 2,3- diphosphoglycerate (2,3-DPG) - allosteric regulator of hemoglobin made by red blood cells

[image]

Term
pH, CO2, 2,3-diphosphoglycerate relationship
Definition

More CO2 → lower pH

Decreased PO2 → red blood cells produce more 2,3-diphosphoglycerate 

 

→ decreased hemoglobin affinity for O2

more oxygen to cells

Term
Myoglobin
Definition

Only 1 heme group

High affinity for O2 (greater O2 saturation at pO2 than hemoglobin)

Good molecule for O2 storing in cells

Found in muscles, very high tissue content in diving mammals

Term
Carbon dioxide transport
Definition

Transported in 3 forms:

Dissolved, carbaminohemoglobin, or bicarbonate ion (reacted with water)

 

At tissues, conditions favor coversion to bicarbonate ion. (chloride shift)

In lungs, conditions favor release of CO2 from HCO3- (reverse chloride shift)

 

Haldane effect: deoxygenated blood can carry more CO2 than ozygenated

Term
In the tissues, conditions favor bicarbonate ion or CO2? mechinism?
Definition

Bicarbonate - PCO2 in cells in higher than in blood.

Carbonic anhydrase in RBC catalyzes CO2 + H2O to HCO3- + H+.

 A Cl-/bricarbonate exchanger moves bicarbonate out of RBC.

"Chloride shift"

 

[image]

 

Term
In lungs, conditions favor bicarbonate ion or CO2? mechanism?
Definition

PCO2 is ↑ in environment-bicorbonate converted to CO2 and leaves RBC

[image]

Term
What contains the central pattern generators for ventilation rhythm?
Definition

The brainstem (medulla oblongata and pons) 

Baroreceptors in carotids and aorta relay changes in [Co2] and [O2] 

Stretch receptors in lungs prevent over expansion through negative feedback

Aquatic animals primarily sense O2 while we sense CO2

Term
How does respiration increase during heavy exercise?
Definition

Does NOT depend on increased blood [CO2]

Increased body temp

Adrenal gland secretes epinephrine

Reflexes from body movements (proprioceptors) to cerebral cortex

Cerebral cortex

 

 

Term
How do we regulate the amount of gas exchange?
Definition

Dilation / contriction of smooth muscle around bronchioles

Parasympathetics - constrict - less gas exchange - cranial nerve X

Sympathetics - dilate - more gas exchane - thoracic spinal cord

 

Vasoconstriction/dilation: Low O2 (hypoxia) signals vasoconstriction

Low O2 - vasoconstriction - less gas exchange 

High O2 - vasodilation - more gas exchange

Term
Human response to high altitude (hypoxia)
Definition

PRINT SLIDE 29 lecture 4

Erethropoletin is hormone makes more RBC- more oxygen - hemocrit

[image]

Term
Adaptations to high altitude
Definition

Amino acid changes in hemoglobin allowing for more Oxygene - geese

Increase myoglobin concentration - seals

Term
To maintain homeostasis animals need to regulate what?
Definition

Water

ionic 

pH

Nitrogen balance

affect blood volume, BP, and thus heart function

Term
Maintenance of Cell Voluume
Definition

Osmosis: Net movement of water down its concentration gradient

1 osmole = 1 mol solute 

1 osmolar = 1 mol solute / Liter

Most important solutes : Na+, K+, Cl- 

Term
Tonicity
Definition
Measure of the effect that a solution has on cell shape. It depends on the concentration of nonpenetrating solutes in the solution (e.g., Na+, K+ and Cl-)
Term
Four central properties to epithelial cells
Definition

1) Asymmetric distribution of transporters/ channels

2) Junctions that regulate paracellular function

3) Diversity of epithelial cell types

4) High mitochondrial density to provide ATP for ATPases (ion pumps) 

 

Solutes move across epithelial layers by transcellular or paracellular transport

Term
Types of Osmoregulatory strategies
Definition

Osmoregulators 

Osmoconformers

Term
Osmoconformers
Definition

Having osmolarity equal to that of environment


Do not control osmotic condition of body fluids


Do regulate ionic composition somewhat - so not exact same composition


Marine invertebrate

Term
Osmoregulators
Definition

Actively control osmotic condition

 

Some are regulators, but almost isosmotic to environment - (Chondrichthyes; Elasmobranchii (e.g. sharks) and Holocephali)


Some have similar osmolarity as us - (Actinopterygii; Chondrostei and Neopterygii (Teleostei - bony fishes; e.g., tuna)

 

Different mechanisms for freshwater and saltwater fishes

Term
Freshwater v. Saltwater fish osmoregulation
Definition

Freshwater - do not drink, pee a lot, actively pump salt into body

Maintain osmotic pressure of body fluid above that of environment.

 

Saltwater - drink lots, pee little, continuously exrete salt.

Maintain osmotic pressure of body fluids below that of environment.

Term
Stenohaline v. Euryhaline regulation
Definition

Osmotic regulation in fishes

Stenohaline - restricted to narrow range of salinities

Euryhaline - can adapt to wide range of salinities (tilapia). Preform smoltification.

Term
Smoltification
Definition
The ability for a euryhaline osmoregulator to adapt from one salinity to the next.
Term
Osmoregulatory organs in fish in order of importance
Definition

Gills - chloride cells (epithelia) move ions against concentration gradients

Intestine 

Kidney

Term
Freshwater fish gill
Definition

Must actively take up salt

2 types of cells:

PNA- (take up sodium, acid secreting)

PNA+ (takes up Ca2+, base Cl- secreting

Both cells use carbonic anhydrous catalyst

[image]

Term
Marine fish gill
Definition

Actively gets rid of salt

[image]

Term
Osmoregulation in terrestrial animals
Definition

Must prevent dessication (water loss):

1) Body coverings

2) Nocturnal behavior

3) Production of disaccharide trehalose (protects cells by replacing water associated w/ proteins and membranes) 

4) Reduce evaporation

5) Reduce urine production / make concentrated urine

Term
Animal skin layers
Definition

Stratum corneum - dead outer layer drived from corneocytes that are derived from keratinocytes - prevent water loss

[image]

Term
What biological adaptation is necessary for more concentrated urine?
Definition
Kidney - Longer loop of henle
Term
Metabolic water
Definition

Oxidation of fats, proteins, and sugar make water

Camel 

Term
How nitrogenous wasted produced?
Definition
Through the protein metabolism --> ammonia
Term
How do animals avoid ammonia toxicity?
Definition

Exrete in dilute urine (ammonia - ammonioteles , uric acid - Birds/ uricoteles, urea - mammals/ ureoteles)

Or 

Convert to less toxic form Glutimine to transport

[image]

Term
Urea Production
Definition

Urea is produced in the liver, released into blood, and is excreted in the kidney

Ornithine-urea cycle - The main exretory product mammals

 

Glutamine (less toxic ammonia), CPSI or CPSII → carbmoyl phosphate → Urea

 

Uses ATP 

In mito and cyoplasm

Term
Why did we evolve the kidney?
Definition

So we can make more concentrated urine

conserve water

Term
Mammalian Kidney
Definition
[image]
Term
Renal pyramid
Definition
Where the nephrons lay
Term
Major and minor calyx
Definition

In the kidney where the urine drains

eventually leads to the ureter

Term
Ureter
Definition
Urine tube to bladder
Term
Roles kidneys play in homeostasis?
Definition

1) Ion balance

2) Osmotic balance

3) Blood Pressure

4) pH balance

5) Excretion

6) Hormone Production (metabolism/ catabolism)

Term
Erythropoetin
Definition

Excreted by the kidney

increases the oxygen carrying capacity in blood

 

Term
Renin
Definition

Excreted by kidney

precursor to angiotensin II 

regulates salt/water balance

Term
1alpha -hydroxyalase
Definition

Excreted by kidney

Created vitamin B

Term
Nephron
Definition

Functional unit of kidney

[image]

Term
Filtration of blood occurs in where?
Definition

The glomerulus

[image]

Term
Podocytes
Definition

Epithelium of Bowman's capsule that is fenestrated allowing for fluids and solutes to pass into capsule (not proteins) 

Has foot process / slits for filtration

Term
Ultrafilrate
Definition
In the bowman's capsule of the glomerulus - pre-urine
Term
Overall fluid movement between glomerulu and bowman's capsule controlled by ..?
Definition

hydrostatic pressue (due to gravity) and oncotic pressure (due to proteins remaining in capillaries pulling water)

 

[image]

 

Term
Regulation of glomeruli filtration
Definition

constriction/ dilation of afferent arterioles

 

By neural pathways: sympathetic cause constriction

 

Local regulation: increased BP activates stretch-sensitive ion channels on the afferent arteriole smooth muscle - depolarization contraction

 

[image]

Term
Reabsorption of water mostly occurs where?
Definition
In the proximal tubule of the nephron in the cortex of the kidney
Term
Distribution of microvilli in the nephron
Definition

Proximal tubule - large microvilli (for solute reabsorption along w/ H2O)

Decending limb - no microvilli (only H2O reabsorption)

Ascending limb - Largest microvilli (NaCl reabsorption) 

Collecting duct - No microvilli (H2O and urea reabsorption )

 

Term
Proximal tubule of nephron
Definition

Secondary active transport of Na+/ glucose symport on the apical (kidney) side 

Primary active transport of Na+/K+ on basolateral (cappilary) side

Cl- goes from apical to basolateral by diffusion

Primary urine (isosmotic to blood)

[image]

Term
Decending loop of Henle
Definition

Reabsorption of water

thin

 

Loop of henle is a coutercurrent multiplier = makes concentrated urine

Term
Ascending loop of Henle
Definition

NO aquaporins (impermeable to H2O)

NaCl moves into blood by seriers of secondary active transport 

[image]

Term
Distal tubule and Collecting duct of nephron
Definition

K+ secreted, Na+ and water are reclaimed

Potential hormone regulation

Duct in cortex permeable to H2O only

Duct in inner medulla permeable to urea (→ hyperosmotic peritublar fluid)

→ greater H2O reabsorption and hyperosmotic urine

[image]

Term
Hormonal regulation of reabsoption in kidney
Definition

Affects the collecting duct

Vasopressing (ADH): G-protein → ↑ aquaporin insertion in membrane

Aldosterone: nuclear receptor → ↑ Na+ channels in distal tubule and collecting duct and thus also ↑ water reabsoption

Renin/Angiotensin: Renin makes angiotensin that leads to vasoconstriction (slows filtration increasing blood volume), increased aldosterone, dipsogenic (makes thirsty)

Atrial Natriuretic peptide (ANP): vasodilation and ↓ Renin → Na+ excretion (into urine) followed by water, ↓Blood volume, ↓ BP, ↑urine

Term
Vasopressin
Definition

 G-protein → ↑ aquaporin insertion in membrane

 

Leads to increasing the blood vollume and BP 

 

Term
Aldosterone
Definition

nuclear receptor → ↑ Na+ channels in distal tubule and collecting duct and thus also ↑ water reabsoption

 

Leads to increased blood volume and BP

Term
Renin
Definition

 Renin makes angiotensin that leads to vasoconstriction (slows filtration increasing blood volume), increased aldosterone, dipsogenic (makes thirsty)

 

Leads to increased blood volume and BP

Term
Atrial Natriuretic peptide (ANP)
Definition

Vasodilation and ↓ Renin → Na+ excretion (into urine) followed by water, ↓Blood volume, ↓ BP, ↑urine

 

Leads to decreased blood volume and BP

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