Download Circulatory system micro

1) Identify the two major components of the circulatory system and their functions.
a) Heart
b) Blood vassals
2) Identify the components of the cardiovascular and lymphatic systems and integrate
the structure with the function of each component.
a) Cardiovascular system
i) Heart
ii) Arteries
iii) Veins
b) Lymphatic system
i) Lymph duct
ii) Lymph node
3) Describe the three layers of blood vassals and integrate their structural components to
specific functions. (tunica intima, media and adventitia)
a) tunica intima lines lumen. Lined with endothelium which has basal lamina.
Beyond basal lamina, have subendothelial CT, little longitudinal smooth
muscle deeper, have internal elastic lamina = network of elastic fibers, more
prevalent in arteries. Provides integrity and elasticity. Holes in network =
finestra allow substances to transport of nutrients / gasses.
b) tunica media = primarily Smooth muscle. These cells are in circular rings
around vessel. Most prominent layer in arteries. Rather small in veins. Has elastic
fibers, type III collagen reticular fibers, and proteoglycans secreted by smooth
muscle cells. Have external elastic lamina in large muscular arteries which is
boundary between tunica media and tunica adventitia. Capillaries / small venules
have pericytes = undifferentiated cells which create rings around capillaries,
effectively replace tunica media.
c) tunica adventitia, has irregular CT and other smooth muscle. Has elastic fibers
and longitudinal muscle fibers. Have fibroblasts with Type I collage. Contains
blood vessels / nerves. Nerves control the contraction of smooth muscle cells to
modulate flow. The BVs in larger vessels supports them whereas passive
diffusion from blood content would not. These vessels within vessels = vasa
vasorum = more numerous in veins (carries deoxy blood). Tunica adventitia also
has lymphoid cells. In arteries = demarcated by an external elastic lamina. Tunica
adventitia is more prominent in veins.
4) Compare and contrast the structural and functional differences between the various
types of vassals, arterial and venous as well as microcirculation.
a) p.296-297
5) Integrate the structure of the three types of capillaries with their functional capacities
and locations.
a) continuous – most common in muscle, connective tissue proper, and gut. Has
thin cytoplasm, connected by tight junctions. Basal lamina continuous all around
endothelium. No pores / fenestrations. Seen in muscle / nerve / CT.
b) fenestrated – single endothelial cell. Has Holes (fenestrations) which are brided
by diaphragms. Located in endocrine sweat glands, intestinal villi, exocrine
pancrease tissue. Do not have diaphragms in the renal glomeruli.
c) discontinuous capillary AKA sinusoid = larger diameter, irregular shape due to
molding by surrounding tissue. Large gaps between endothelial cells. Have tight
junctions. Endothelial cells are much larger. Have a discontinuous basal lamina
which does not have cross gaps between cells. Located in the liver, spleen, bone
marrow, and lymph nodes. These are blood pools (cisternae-like), flattened sac
like structures.
6) Integrate the structural components of an arteriovenous anastomosis and the
microcirculatory bed to their functions.
a) arteriovenous anastomosis - p. 301
b) microcirculatory bed - p. 301
7) Relate the microscopic structure of the heart to its gross anatomy.
a) P. 288-295
8) Identify and describe the layers of the pericardial sac and heart wall. Be able to relate
them to the function of the heart.
a) P. 289-290
9) Describe the structural components and function of the cardiac skeleton
a) Annulus fibnrosis
i) Ring of CT around valves
b) Fibrosis trigones
i) Triangular shped CT between valves
c) Septum membranaceum
i) CT form trigone to tip of interventricular septum
10) Describe the structural components of the cardiac conduction system and relate them
to their function
a) Sinuatrial node (SA node) = pacemaker
i) located along upper end of sulcus terminalis, near the Superior VC
ii) initiates heartbeat
iii) supplied by both sympathetic and parasympathetic nerves
b) atrioventricular node = located in interatrial septum adjacent to osteium of
coronary sinus
c) Atrioventricular bundle (bundle of His) = extends from the AV node along the
IV septum, made up of purkinje fibers.
AV bundle: divides into right and left bundle branches in the septum (near the
junction of membranous and muscular part of septum)
d) Subendocardial plexus
11) Locate and describe the function of the cardiac sinus and aortic bodies
a) coronary sinus is a vein that collects blood from the myocardium of the heart
b) aortic body is one of several small cluster of chemoreceptors, baroreceptors, and
supporting cells located along the aortic arch.
12) Integrate the lymphatic system circulation into the cardiac system both structurally
and functionally.
a) Collects excess interstitial fluid
b) Thoracic duct joins with superior vena cava
13) Relate how the following diseases affect the cardiovascular system: varicose veins,
Marfan’s syndrome, Ehler-Danlos syndrome, atherosclerosis, and aneurysm.
a) Varicose veins due to insufficiency of the valves in the communicating veins.
b) Marfan syndrome is an autosomal dominant disorder that affects a protein called
fibrillin-1, which is essential for the formation of elastic fibers found in
connective tissue.
c) Ehlers-Danlos syndrome is a group of rare genetic disorders caused by a defect
in collagen synthesis.
d) Atherosclerosis is formation of multiple plaques within the arteries
e) Aneurysm is a bulge in a blood vessal.