Circulatory System Overview Flashcards
Cardiovascular system
. Transports blood throughout body
Lymphatic system
. Transports lymph from the body’s tissues to venous system
Atherosclerosis
. Build up of cholesterol plaques in arteries
. Form of arteriosclerosis
. Lead to thrombus that can occlude artery or enter bloodstream to block smaller vessels (embolus)
Aneurysm
Bulging of arterial walls
Aortic dissection
Tearing of vessel wall w/ blood flowing between layers of vessel
Varicose veins
Bulging of venous walls
Thrombosis
Formation of blood clots
Layers of arteries and veins
. tunica intima: innermost endothelium
. Tunica media: intermediate smooth muscle layer w/ collagen and elastic fibers
. Tunica adventitia: outermost CT layer
Large arteries
. Directly receive cardiac output are have v high pressure
. High collagen and numbers of elastic filaments in tunica media allow it to stretch w/ cardiac output
Medium arteries
. Muscular/distributing aa.
. Smaller vessels that draw blood from elastic arteries
. Able to vasoconstriction regulating blood flow to different regions
Small arteries
. Narrow lumen w/ thicker walls
. Distribute blood to arterioles
Arterioles
. Regulate blood flow into capillary beds by constricting or dilating
. Not named
Anastomoses
. Connections between multiple arterial branches that provide potential detours for blood flow more distal in case normal pathways are interrupted (collateral circulation)
Terminal arteries
. Don’t anastomose w/ anything
. Only supply of oxygenated blood to a tissue
Arteriosclerosis
Thickening and loss of elasticity of arterial walls
Veins compared with arteries in blood volume
. Veins more numerous and variable than arteries
. 60-80% blood volume in veins
. Larger lumina and thinner walls
Venae comitantes (accompanying veins)
. 2+ veins with single artery that form branching network around artery
. Arrangement plus gravity and extrinsic muscular contractions propel venous blood forward (arteriovenous pump)
Venues
Smallest veins that drain capillary beds (unnamed)
Small and medium veins
. Drain venous plexuses and accompany medium arteries
. Medium located in limbs w/ venous valves
Large veins
. Receive blood from medium veins
. Valves variable
. 1 large vein per 1 large artery
Blood capillaries
. Arranged I capillary beds w/in tissue
. Site of gas and nutrient exchange btw blood vessels and body tissues
. Composed of single layer endothelium
. Blood capillaries connect arterioles and venules
Arteriovenous anastomoses (AVA)
. Direct connections btw arterioles and venules in some regions
. Blood bypasses capillaries to pass directly from arterial to venous circulation
. also called shunts, popular in skin o conserve body heat
Portal venous system
. Links 2 capillary beds so blood passes through 2 capillary beds before returning to heart
Pulmonary circulation
. Low O2 blood returns from system circulation to RA -> RV -> pulmonary arteries to lungs -> pulmonary vein -> LA
Systemic circulation
. High O2 blood in LA -> LV -> aorta -> body -> returned to heart via vena cavas
Head and brain aortic subdivision
Aortic arch
Head and brain large arteries
Brachiocephalic trunks -> common carotid aa. And vertebral artery
Upper limbs aortic subdivision
Aortic arch
Upper limbs large arteries
Brachiocephalic trunk (right side only)
Upper limbs medium arteries
Subclavian aa -> axillary aa.
L. Side
Heart aortic subdivision
. Ascending aorta
Pelvic organs aortic subdivision
Abdominal aorta
Pelvic organs large arteries
. Common iliac aa.
Lower limbs aortic subdivision
Abdominal aorta
Lower limb large arteries
Common iliac aa.
Head and brain tributaries of the ___
Internal jugular via.
Head and brain medium vein and canal subdivision
. Brachiocephalic via.
. Sup. Vena cava
Upper limbs tributaries of the ___
Subclavian vv.
Upper limb medium vein and canal subdivision
. Brachiocephalic vv
. Sup. Vena cava
Pelvis organs tributaries of the ____
Internal iliac v.
Pelvic organs medium vein and canal subdivision
. Common iliac vv.
. Inf. Vena cava
Lower limbs tributaries of the ____
External iliac vv.
Lower limbs medium vein and canal subdivisions
Common iliac vv
Inf. Vena cava
Function of lymphatic system
. Forms accessory pathway to return excess interstitial fluid (lymph) and proteins from body’s tissues to venous circulation
How many liters of lymph are returned to cardiovascular system per day?
3 liters
Lymph nodes
. House immune response cells
Lymphatic capillaries
. Blind-ended
. Drain lymph from extracellular spaces of tissues except CNS, meninges, marrow, and avascular tissues
Lacteals
. Lymphatic capillaries in small intestine
. Drains chyle (lymph w/ digested fats from GI)
Lymphatic collecting vessels
. Superficial vessels drain into deep lymph vessels that accompany arteries
. Deep vessels drain internal organs
. Have thin walls and large number of internal valves to keep lymph flow unidirectional
Lymph trunks
. Converging lymph vessels that drain major body areas
Right lymphatic duct and thoracic duct location
. Occurs when lymph trunks unite and join the venous system near heart
Thoracic duct
. Drains lymph into venous system at junction of L subclavian and L. Internal jugular veins
. Receives lymph from lower limbs, pelvic walls, abdominal and pelvic walls, abdominal and pelvic organs, and L. Thoracic wall
Cisterna chyli
. Dilated sac at inf. End of thoracic duct inf. To thoracoabdominal diaphragm
. Receives fatty chyle from intestines and liver to act as conduit for lipid products of digestion
Right lymphatic duct
. Drains lymph into venous system at junction of the R. Internal jugular and R. Subclavian vein
. Receives lymph from upper right quadrant of body ( R. Side of head/neck, R. Thorax, an R. Upper limb)
Major lymph node clusters
. Head and neck . Tracheal . Axillary . Deep nodes along aorta . Inguinal and femoral
Head and neck node characteristics
. Superficial and deep horizontal rings around base of head
. Superficial cervical (along external jugular veins) and deep cervical (along internal jugular veins) chains on either side of neck
. Drain directly or indirectly into deep cervical nodes
T/F Lymph is under high pressure
F, under low pressure
Intrinsic contractions
. When vessel between 2 successive valves fills w/ lymph, smooth muscle of vessel contracts and prox. Valve opens so lymph flows to next segment
. Results in each segment of lymph vessel acting like pump between successive valves
Extrinsic contractions
. Contraction of surrounding muscles, arterial pulsation, and compression of tissues by outside forces compress/pump lymph vessels
Lymphedema
. Accumulation of lymph in interstitial spaces that initiates inflammatory rxn causing fibrosis and degeneration of CT
. Can occur from abnormal vessel development, trauma, surgery, radiation