Exam I | Systems Overview: Cardiovascular and Lymphatic Flashcards
arteries
carry oxygenated blood away form the heart
veins
return deoxygenated blood to the heart (except pulmonary and umbilical veins)
pulmonary arteries
carry deoxygenated blood to the lungs
3 ways arteries are classified
1) composition of walls
2) size
3) thickness of wall relative to lumen
3 general morphological classes of artery
1) conducting arteries (large elastic arteries)
2) distributing arteries (medium muscular arteries)
3) small arteries and arterioles
large elastic arteries
- aka conducting arteries
- multiple elastic layers in walls
- e.g. aorta
medium muscular arteries
- aka distributing arteries
- walls predominately of radial smooth muscle
- capable of significant vasoconstriction for blood flow regulation
- e.g. femoral artery
small arteries and arterioles
- narrow lumina with thick muscular walls
- capable of constriction for maintenance of peripheral pressure
end (terminal) arteries
- do not communicate with adjacent arteries
- blockage may result in significant ischemia and tissue damage
functional terminal arteries
- very limited communication with adjacent arteries
- present in the brain, kidney, spleen, and intestines
anastaomses
- interconnect arteries and veins at various points (branching interconnected system)
- often present in the joints
- may be relatively sparse or dense reticulating
- provide potential of re-routing blood in the event of blockage/compression, trauma, or dz. This generally requires time
arteriosclerosis
- hardening of arteries
- wall thickens and becomes less elastic
- can contribute to elevated BP
Atherosclerosis
- type of arteriosclerosis
- fat (cholesterol) accumulates on arterial wall, Ca deposition precipitates formation of atheromatous plaque
- flow is reduced as lumen narrows
What are the consequences of atherosclerosis?
- can potentially lead to thrombosis and ischemia or infarction (tissue damage)
- risk elevated as plaque is ruptured or becomes inflamed
What are venae comitantes?
- interconnected paired veins
- when veins accompany medium-sized deep arteries as an enveloping anastomosis
venous valves
- aka “check valves”
- present in medium veins of limbs, where gravity may oppose normal venous blood flow
- only allow blood flow to the heart
- contraction of surrounding skeletal muscle pumps blood unidirectionally (musculovenous pump)
composition of large veins
-extensive lengthwise smooth muscle and tunica adventitia (connective tissue encapsulement)
What is the blood pressure in the vena cava?
close to 0
what are the 4 classifications of veins?
- superficial veins
- deep veins
- pulmonary veins
- systemic veins
superficial veins
- near surface of body
- lack accompanying arteries
- important for thermoregulation
deep veins
- usually accompany artery of similar name
- generally carry more blood than superficial veins
- occlusion (blockage) of certain deep veins can be life threatening
- contraction of muscle tends to divert blood to superficial veins
systemic veins
carry deoxygenated blood from body tissues to right atrium
pulmonary veins
4 vessels (2 from each lung) carry oxygenated blood to left atrium of heart
What is anatomically more variable, arteries or veins?
veins
What is a perforating vein?
connects superficial veins to deep veins
Where do phlebitis and thrombophlebitis occur?
phlebitis occurs in superficial veins; thrombophlebitis occurs in deep veins
varicose veins
- vessel becomes distended due to prolonged high hydrostatic blood pressure
- have impaired of dysfunctional valves (often following inflammation)
- common in the legs where distal pressure is greatest
what are the three functions of the lymphatic system?
- returns excess ECF to venous circulation as lymph
- returns ECF protein and fats to circulation
- facilitates clearing of cellular debris from ECF
lymphatic system includes what 3 main things?
- lymphatic vessels
- lymphatic capillaries
- lymphatic plexuses (networks)
what is lymph?
clear fluid, similar to plasma
What are the characteristics of lymphatic vessels?
- present in all tissues, except bone
- thin walls
- have check valves
- pass through lymph nodes into large lymphatic trunks that join to form right lymphatic duct or thoracic duct
right lymphatic duct
drains lymph from right head, neck, thorax, and right upper limb
thoracic duct
drains the remainder of the body that right lymphatic duct does not
what are lymphatic nodes?
dispersed clusters of lymphatic tissue that filter lymph
what are lymph nodules?
-aggregations of lymphoid tissue (e.g lymphocytes) present along GI, respiratory, and urinary tract
often small, unencapsulated regions largely independent of lymphatic vessels (& therefore do not act as lymph filters)
what is an example of a lymphatic nodule?
GI Peyer’s patches of ileum
What are lymphocytes?
specialized small WBCs that participate in immunological defense
Where do you find lymphatic tissue?
- concentrated in lymphatic nodules and nodules of spleen and thymus
- in red bone marrow
- along GI tract
