blood supply Flashcards
main arteries in upper limb tree
subclavian axillary brachial radial ulnar common interosseous palmar carpal arch dorsal carpal arch
where does subclavian start and begin?
bifurcation of brachiocephalic trunk into subclavian and common carotid on the left side, on the right straight from aorta into subclavian
at the end of the clavicle becomes axillary
axillary artery beginning and end
end of the clavicle, enters the axilla and supplies the deltoid, end of axilla becomes brachial
brachial beginning and end
end of axilla, supplies upper arm, bifurcates into radial and ulnar at the elbow
what do the radial and ulnar vessels supply?
ulnar supplies the medial and ulnar aspect of the forearm and hand
radial supplies the lateral and radial aspect of the forearm and hand
beginning and end of common interosseous
originates from ulnar vessel, passes through the interosseous membrane, divides into anterior and posterior branches
end of radial and ulnar explained
anastomose to form the palmar and dorsal carpal arches
how are the digits vascularised?
metacarpal and digital arteries come off the carpal arches
what is the venous drainage composed of?
two systems of veins; deep and superficial
explain superficial veins
lie in the subcutaneous tissue and have valves to prevent the back flow of blood
arise from the dorsal venous palmar arch at the back of the hand, forming the cephalic and basilica veins
explain deep veins
deep veins lie within the deep fascia and in general run alongside the arteries
deep veins have valves to prevent back flow of blood
usually two veins run alongside each artery
deep veins in upper limb
axillary vein if formed as the basilic vein passes through the fascia to join the venue commit antes of the brachial artery
axillary vein ends at the first rib to become the subclavian vein
axillary vein receives blood from cephalic vein and abdominal veins
4 different types of lymphatics in upper limb
superficial lymphatics, cubital lymph nodes, delta-pectoral lymph nodes, deep lymphatics and axillary lymph nodes
explain superficial lymphatics
lymph drains from hand via superficial lymphatics which run alongside cephalic and basilic veins
where does the lymph ultimately drain?
into the axillary lymph nodes
explain deep lymphatics
run alongside deep venous return, also terminate at axillary lymph nodes
where do the axillary lymph nodes drain?
into the subclavian lymphatic trunk which join the right lymphatic duct or the thoracic duct on the left
anastomosis definition
any connection between tube like structures
arterial anastomoses provide an alternative blood supply to target areas in cases where the primary arterial pathway is obstructed
where are the arterial anastomoses most abundant? + why?
in regions where the blood supply may be easily damaged or blocked
such as the joints and intestines
important nodes within the axilla
central nodes, composed of 3-4 large lymph nodes near the base of the axilla which receive lymph via efferent vessels from the pectoral, sub scapular and humeral axillary lymph node groups
where does the lymph from the central nodes drain?
into the apical axillary lymph nodes, which are located in the apex of the axilla
they receive lymph from efferent vessels of the central axillary nodes, therefore all axillary lymph node groups
where else do the apical axillary nodes receive lymph from?
from superficial lymphatics running alongside the cephalic vein
what is an important feature of lymphatic vessels + function?
valves
found in large lymph vessels and collecting vessels, absent in lymphatic capillaries
prevent the back flow of fluid
when the pressure of lymph increases in the vessel (due to more lymph or smooth muscle contraction) the valve opens, allowing fluid to move into the next chamber, called a lymphangion
as the pressure falls, the open valve closes, preventing the back flow of lymph
what is the dominant pathway of lymph drainage from breast?
axillary
arteries in leg
external iliac, femoral, popliteal, anterior and posterior tibial, perineal, dosarlis pedis and plantar arch
explain passage of femoral artery
external iliac passes under the inguinal ligament, forming the femoral artery
femoral artery passes through the femoral triangle
continues down anterior aspect of thigh though the adductor canal, ending at the adductor hiatus
artery passes through the adductor hiatus and moves through to posterior compartment of the thigh
what is the next artery + where does it form?
popliteal artery formed when femoral moves posterior
what does the femoral artery supply?
anterior aspect of thigh
passage of popliteal artery
moves through popliteal fossa, exciting between gastrocnemius and popliteus muscles
at lower border of the popliteus new artery forms
what forms after the popliteal artery?
bifurcation into the anterior tibial artery and the tibioperoneal trunk
tibioperoneal trunk then birfucates into the posterior tibial and perineal aftery
passage of posterior tibial artery
continues along the surface of the deep posterior leg muscles
enters the sole of the food via the tarsal tunnel along with the tibial nerve
passage of perineal artery
descends posteriorly to the fibula within the posterior compartment of the leg - gives off branches to supply muscles in the lateraling compartment
passage of anterior tibial artery
passes anterior between the tibia and fibula
runs into the foot
what does the anterior tibial artery form?
dorsalis pedis
explain passage of dorsals pedis
at the beginning of the foot
passes over the dorsal aspect of the tarsal bones then towards the sole of the foot
anastomoses with lateral plantar artery to form the deep plantar arch
supplies tarsal bones and dorsal aspect of metatarsals
explain formation of deep plantar arch
anastamoses of dorsalis pedis and posterior tibial
what do extra abdominal veins below the heart have?
valves
valveless veins
brachiocephalic, portal venous system, superior vena cava, vertebral venous plexuses, thespian veins, inferior vena cava
varicose veins definition and explained
superficial veins that have become enlarged and twisted
could be due to venous reflux, damaged valves
which direction does blood travel in the veins (from which vessels)?
from superficial veins to deep
what greatly impacts venous return from legs?
gravity
what is this phenomenon called?
orthostatic, postural hypotension
explain what happens upon standing
- gravity acts on vascular volume causing blood to accumulate in lower extremeties
- venous compliance is high so veins will readily expand with blood
- venous volume and pressure become very high in feet
- thoracic venous blood volume decreases and therefore central venous pressure decreases
- preload is decreased, leading to a reduction in stroke volume by frank starling
5, this leads to decline in cardiac output and mean arterial pressure
what aids venous return?
musculovenous pump
explain musculovenous pump
rhythmic contraction of limb muscles promotes venous return
importance of fascial compartments
ensure there is space of veins to move,
explain structure of fascial compartments
different muscles are separated into compartments separated by septa formed from fascia
lymphatic drainage of the breast
three quarters into the axillary nodes, via the pectoral group around the edge of the pectorals muscle
through/between the pectoral muscles may lead directly to apical axilla nodes
lymphatics follow blood vessels through pectorals major and enter the parasternal nodes
where can pulses be palpated?
in any place that allows an artery to be compressed near the surface of the body
arterial pulse points
neck- carotid artery
wrist- radial artery
groin- femoral artery
knee- popliteal artery
ankle joint- posterior tibial artery
foot- dorsalis pedis
