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Microscopic anatomy test 2
written exam
119
Medical
Professional
02/25/2008

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Cards

Term
How is the high pressure from the pumping of blood into the aorta absorbed?
Definition
by expansion of the wall of the aorta
Term
What keeps flow constant through the cardiovascular system?
Definition
the tonicity of the muscular layers of the muscular arteries and arterioles
Term
What maintains pressure and blood flow through the arterioles into the capillary bed during diastole?
Definition
recoil of the arteries
Term
What are the three layers of blood vessels?
Definition
tunica intima, tunica media, tunica adventitia
Term
What type of endothelium lines the lumen of all blood vessels and how is it arranged?
Definition

simple squamous

 

longitudinally oriented with respect to long axis of vessel 

Term
What comprises the tunica media and how is it organized?
Definition

smooth muscle, connective tissue, fenestrated elastic sheets and/or elastic fibers

 

circularly organized 

Term
What does the tunica adventitia additionally contain in larger blood vessels?
Definition
nerves and nutrient vessels (vaso vasorum and nervi vasorum)
Term
What is the tunica adventitia?
Definition
outermost layer, connective tissue which blends with surrounding tissue
Term
Which layers does the capillary not have which all other vessels do?
Definition

tunica media* and tunica adventitia

 

*lymphatic also may not have tunica media 

Term
Which type of vessel has the most extensive tunica media?
Definition
artery
Term
Which is thicker, artery or vein?
Definition
artery due to much thicker tunica media
Term
What is the internal elastic membrane?
Definition
a thick sheet of elastic tissue on which sits the tunica intima of large, elastic arteries
Term
What is the extermal elastic membrane?
Definition
a discontinuous band of elastic tissue at the junction of the media and the adventitia
Term
What happens at the transition of elastic arteries to muscular arteries? (2 things)
Definition

1 diameter of artery becomes smaller

 

2 elastic fibers of media gradually replaced by smooth muscle 

Term
3 functional properties of arterial walls
Definition

1 thick wall permits high pressure system

 

2 muscles in arterioles permit shunting of blood past some areas into others. this allows temp control and rich irrigation of muscle beds in stress

 

3 rectification of pulsatile flow 

Term
What are a group of disorders with thickening and loss of elasticity of arterial wall?
Definition
atherosclerosis and arteriosclerosis
Term
What is the basic lesion in atherosclerosis?
Definition
formation of a fibrous fatty plaque within the intima
Term
What happens in arteriosclerosis?
Definition
extracellular substance is deposited in the intima and media resulting in hardening and thinning of the vessel lumen
Term
What are venous valves?
Definition
a sheet like out-folding of the endothelium and underlying connective tissue to form a pair of flaps that permit unidirectional blood flow
Term
What is the immediate postcapillary venule characterized by?
Definition
the presence of pericytes
Term
How are venules important in inflammation?
Definition
endothelial cells are sensitive to histamine, contract and sparate from one another exposing naked basement membrane. neutrophils stick to the exposed collagen and move out into the connective tissue (extravasate).
Term
What are the three types of capillaries?
Definition
continuous, fenestrated, and discontinuous
Term
What are characteristics of continous capillaries?
Definition
endothelial cells rolled upon themselves and joined together by junctions, have a continuous basal lamina
Term
What are characteristics of fenestrated capillaries and where can you find them?
Definition

cell cytoplasm thins to form pores, have a continous basal lamina

 

kidney, endocrine glands 

Term
What are the characteristics of discontinous capillaries and where can you find them?
Definition

sinusoids, cells not joined continuously by junctions at their margins resulting in irregular gaps between them, have a discontinous basal lamina

 

liver, spleen 

Term
What is the function of lymphatic vessels?
Definition
collect fluid and proteins and other material from the connective tissue and return them to the blood after passing hrough the lymph nodes
Term
What happens at the lymph nodes?
Definition
foreign materials are removed by macrophages and antigens are presented to the antibody producing cells
Term
What does insufficient draining by lymph vessels cause?
Definition
edema
Term

What is the corresponding heart structure for the following:

 

1 tunica intima

 

2 tunica media

 

3 tunica adventitia 

Definition

1 endocardium

 

2 myocardium

 

3 epicardium 

Term

What is the layer of loose connective tissue beween the endocardium and myocardium?

 

What does it contain? 

Definition

subendocardial layer

 

blood vessels, nerves and branches of impulse-conducting system 

Term
What is the structure and function of the endocardium?
Definition

simple squamous epithelium, subendothelial connective tissue

 

semi-permeable barrier, support, elastic tension 

Term
What is the structure and function of myocardium?
Definition

bundles of cardiac muscle embedded in connective tissue

 

contraction 

Term
What is the structure and function of the epicardium?
Definition

loose connective tissue with coronary vessels, lymphatics and nerves, mesothelium of visceral pericardium

 

support, vasculature, innervation 

Term
What cells establish the pace for the rest of the heart?
Definition
cells of the sinoatrial node
Term
Why is it important that the ventricular muscle is excited after the atrial muscle?
Definition
so that the ventricles are filled as much as possible before ventricular contraction occurs
Term
What does the AV bundle (of His) do?
Definition
sens branches to both ventricles
Term
What do Purkinje fibers do?
Definition
carry the impulse to the cardiac myocytes
Term
Which cells are larger than the normal cardiac myocite, contain abundant glycogen, and travel to the subendocardial space to become intramyocardiac and continuous with normal cardiac myocytes?
Definition
Purkinje
Term
What are the three components of the cardiac skeleton?
Definition
septum membranaceum, trigona fibrosa, annuli fibrosi
Term
What is the location of the cardiac skeleton?
Definition
myocardial layer surrounding major openings; in intraventricular septum
Term
What is the function of the cardiac skeleton?
Definition
anchorage for the attachment of atrial and ventricular muscle; valves
Term
Where do the base of cardiac valves attach to?
Definition
annuli fibosi of cardiac skeleton
Term
What is the function of the chordae tendinae and what are they composed of?
Definition

prevent the av valves from prolapsing into the atrial chamber during ventricular contraction

 

composed of cords of collagen that extend from the free edge of the av valves to muscular projections from the wall of the ventricles called papillary muscle 

Term
What are the primary lymphoid organs and what is their function?
Definition
bone marrow and thymus, they function in the production and maturation of B and T lymphocytes
Term
Which secondary lymphoid organs are unencapsulated?
Definition
tonsils, peyer's patch, appendix, and lymphoid nodules
Term
Which secondary lymphoid organs are encapsulated?
Definition
lymph noeds and spleen
Term
What is produced by the bone marrow?
Definition
B lymphocytes, T lymphocyte precursors, natural killer cells
Term
What is produced in the thymus?
Definition
mature T lymphocytes
Term
What are macrophages involved in?
Definition
cytokine production, innate immunity and antigen presentation
Term
Name four antigen presenting cells.
Definition

macrophages

b-lymphocytes

interdigitating dendritic cells

langerhans cells 

Term
What happens to the thymus after puberty?
Definition
involutes and becomes infiltrated with adipose connective tissue
Term
What is the structure and function of the epithelial reticular cells?
Definition

stellate shaped cells that form a supporting framework for the maturing T lymphocytes

 

joined via desmosomes

 

component of blood thymus barrier 

Term
What is the function of macrophages in the thymus?
Definition
antigen presentation of self antigens during the maturation process, phagocytosis of apoptotic T lymphocytes selected against durring differention, blood-thymic barrier
Term
What happens in the medulla of the thymus and what is its distinctive structure?
Definition

mature lymphocytes leavew

 

Hassels' corpuscles- composed of concentrically arranged, flattened epithelial reticular cells that can be calcified 

Term
What is the function of the blood thymus barrier?
Definition
critical for the process of learning to distinguish self from non-self, do not see blood before they are ready to
Term
How do mature T lymphocytes leave the thymus?
Definition
via postcapillary venules located at the cortex/medulla jxn
Term
Which organ does not contain postcapillary venules?
Definition
spleen
Term
What is the difference between a primary nodule and a secondary nodule?
Definition
primary is a cluster of unstimulated lymphocytes, secondary develops from a primary nodule after antigenic stimulation
Term
What is a germinal center?
Definition
a lighter staining portion of a secondary nodule
Term
What is mucosa associated lymphoid tissue, what is its function and give an example?
Definition

unencapsulated lymphoid tissue found in the mucosa and submucosa of the gi, respiratory and genitourinary tracts

 

protect common sites of microbial invasion wher elumens are open to external environment

 

gut associated lymphoid tissue (GALT) 

Term
What are the function of M cells in peyer's patches?
Definition
capture and transport antigens from lumen to underlying ct where apc's and macrophages are present
Term
What are characteristics of palatine tonsils?
Definition
strat squamous epitehlium, invaginations form crypts, heavily infiltrated with lymphocytes
Term
What are characteristics of pharyngeal tonsils?
Definition
ciliated pseudostratified columnar epithelium, folded forming pleats
Term
What are characteristics of the lingual tonsils?
Definition

strat squamous epithelium, each has a crypt

Term
What are functions of lymph nodes?
Definition

filter lymph

 non-specific filtration of microorganisms and particulate matter

 antigen recognition/trapping and immune cell interactions

activation and proliferation of B and T cells 

Term
What happens at the hilum of a lymph node?
Definition
blood vessles and nerves enter and leave and efferent lymphatic vessels exit
Term
Where do afferent lymphatic vessels enter the node?
Definition
through the capsule
Term
What is the region of loosely organized, diffuse lymphatic tissue that receives lymph from the afferent lymphatic vessels and contains a loose network of reticular fibers and cells?
Definition
subcapsular sinus
Term
What are branched extensions of dense lymphatic tissue that arise in inner cortex that contain primarily B lymphocytes, plasma cells and macrophages?
Definition
medullary cords
Term
What are dilated spaces continuous with intermediate sinus that separate cords which are often bridged by reticular fibers and cells which join at the hilum to deliver lymph to the efferent lymphatic vessels?
Definition
medullary sinuses
Term
What is the order of lymph flow?
Definition

afferent lymphatics

subcapsular sinus

intermediate sinuses

medullary sinuses

efferent sinuses 

Term
What are functions of the spleen?
Definition

filters blood

immune response

removal of damaged rbc's

sequesters monocytes

hamatopoiesis

storage of blood/platelets

recycling of iron 

Term
What arise from the splenic capsule and subdivide the splenic pulp into incomplete compartments?
Definition
trabeculae
Term
What is the splenic pulp divided into?
Definition
red pulp and white pulp
Term
What is the function of splenic white pulp and how is it organized?
Definition
maximizes interaction between blood antigens and cells of immune system, organized around arteries: periarterial lymphoid sheath
Term
What is the function of splenic red pulp and how is it organized?
Definition

maximizes interactions between blood and macrophages

 

organized around venous sinuses 

Term
What is the order of splenic blood flow?
Definition
splenic artery enters at hilum, branch and follow trabeculae as trabecular arteries, branches become ensheatherd by T lymphocytes (PALS) and become central arteries, leaves white pum and looses PALS and subdivides to form penicillar arteries, enter sheathed capillaries (PAMS) which enmpty into the splenic cords and cells migrate through tissue to reenter the ciculation via the splenic sinusoids (open ciulation)
Term
What are splenic cords?
Definition
loose connective tissue/reticular fibers which contain capillaries, rbc's, macrophages, platelets, plasma cells, reticular cells
Term
What is the venous drainage of the red pulp sinuses?
Definition
pulp veins -> trabecular veins -> splenic vein
Term
What is the central artery surrounded by in white pulp?
Definition
a T lymphocyte rich sheath, the periarterial lymphatic sheath (PALS)
Term
What do the central artery and associated PALS become associated with periodically along its course?
Definition
B lymphocyte rich nodular lymphatic tissue
Term
What is the marginal zone in the white pulp?
Definition
surrounds the lymphatic nodules of white pulp. this consists of blood sinuses, loose lymphoid tissue whith many active macrophages, and an abundance of blood antigens. has a key role in the immune function of the spleen
Term

What is the major cell type in the epidermis?

 

What are some minor cell types? 

Definition

major: keratinocyte

 

minor: melanocytes, Langerhans cells, Merkel cells 

Term
What is special about the dermis?
Definition
ct layer, highly vascular, contains numerous specialized sensory receptors
Term
What is in the hypodermis?
Definition
loose ct, contains adipose cells, superficial fascia
Term
What are the five layers of the epidermis and what are they classified according to?
Definition

1 stratum germinativum  (basale)

2 stratum spinosum

3 statum granulosum

4 stratum lucidum

5 stratum corneum 

 

 

classified accourding to the maturation and differentiation of the major cell type: keratinocyte 

Term
What are the characteristics of the stratum germinativum?
Definition
the basal most layer resting on a basement membrane containing a single layer of low columnar cells with a high number of mitotic figures. these cells move upwards and replenish the cells lost at the surface during epidermal turnover. desmosomes bind te cells at their upper and lateral surfaces and hemidesmosomes bind these cells to the basal lamina. cells contain keratin assembled into tonofilaments inside the cytoplasm
Term
What are the characteristics of the stratum spinosum?
Definition
2-4 layers of cells connected by desmosomes. contain keratin filaments organized into tonofibril bundles
Term
What are the characteristics of the stratum granulosum?
Definition

2-3 layers of flattened squamous epithelial cells, their cytoplasm filled with coarse basophilic granules

(keratinohyalin granules) 

Term
What are the characteristics of the stratum lucidum?
Definition
an extremely thin translucent layer more apparent in thick skin
Term
What are the characteristics of the stratum corneum?
Definition
the apical most layer, contains many layers of flat-cornified cells, filled with keratin filaments. number of cell layers varies with the thickness of the skin
Term
What are the two major zones of the dermis?
Definition

papillary dermis (looser areolar ct, blood vessel plexus)

reticular dermis (dense, irregular ct) 

Term
Which contents of keratohyaline granules promote tonofilament assembly and initiate the process of cornification?
Definition
filaggrin and trichohyalin
Term
What is a characteristic feature of keratinocytes?
Definition
melanosome complexes (produced by melanocytes and phagocytosed by keratinocytes)
Term
What are melanocytes derived from?
Definition
neural crest
Term
Which layers are melanocytes found in?
Definition
stratum basale and basal layers of stratum spinosum with long processes extending among keratinocytes
Term
What is the function of melanin?
Definition
protects dividing cells from UV radiation
Term
What are the steps in the synthesis of melanin?
Definition
tyrosine -> 3,4 dihydroxyphenylalanine -> dopaqunione -> melanin
Term
What are Langerhans cells?
Definition
dendritic cells with long processes found primarily in the upper layers of the stratum spinosum; involved in binding, processing and presenting antigen to T lymphocytes
Term
Where are Merkel cells found?
Definition
thick skin of plams and soles, occur in the basal part of the epidermis
Term
What is the function of Merkel cells?
Definition
considered to be involved as sensory mechanoreceptors, evidence sugges a further possible role in the diffuse neuroendocrine system
Term
What are Ruffini endings?
Definition
expanded nerve endings sensitive to stretch
Term
What are Meissner's corpuscles?
Definition
an encapsulated nerve ending found in dermal papillae, sensitive tactile sensation, very rich in finger tips and lips
Term
What are Pacinian corpuscles?
Definition
an encapsulated nerve ending found in dermis and hypodermis sensitive to pressure
Term
What are Peritichial nerve endings?
Definition
associated with hair and sensitive to hair movement
Term
What is the structure of eccrine sweat glands and their mode of secretion?
Definition

simple coiled tubular glands, merocrine secretion

 

basal coiled secretory portion and a duct that empties directly onto skin surface 

Term
Where can apocrine sweat glands be found, how do they empty and what is their classification?
Definition

axilla, anal and genital areas

 

open into hair follicles

 

simple coiled tubular glands 

Term
Where can sebaceous glands be found, how to they secrete, what does the secretion contain, what is the mode of secretion, and what is the classification?
Definition

in dermis all over body except palms and soles

 

via a hair follicle, except in lips and genitals

 

triglycerides, fatty acids, and cholesterol

 

holocrine

 

simple branched acinar 

Term
How do hair follicles develop?
Definition
down growth of the epidermis into dermis and subcutaneous tissues
Term
What is the hair bulb?
Definition
terminal dilation of the hair follicle
Term
What is the hair papillae?
Definition
an invagination of loose ct that is richly vascularized, sustains the follicle
Term
What is the hair matrix?
Definition
epidermal cells covering the hair papillae, based on position, they give rise to hair cortex, medulla, and cuticle, region contains melanocytes
Term
What are epithelial sheaths of the hair follicle?
Definition
internal root sheath: dervied from most peripheral cell of hair matrix, multilayered surrounds lower portion of hair; external root sheath: continuous with epidermis, at the surace contains all layers of basale
Term
What is the connective tissue sheath of the hair follicle?
Definition
outermost layer of the follicle, continous with dermis, insertion of the arrector pili muscle
Term
What is the lymphatic drainage of the skin?
Definition
begin as closed sacs in the papillae and converge to from 2 plexuses
Term
What are the arteriovenous anastomoses in the skin?
Definition
function in thermoregulation, bypass the superficial capillary networks from the subpapillary plexus
Term
What is the subpapillary plexus?
Definition
found at the junction of the papillary and the reticular dermis, supplies capillary loops within dermal papillae
Term
What is the cutaneous plexus?
Definition
found at the border between the dermis and hypodermis, supplied by the subcutaneous tissue
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