Cirrculation Flashcards
Inner most layer of arteries/ veins
Túnica íntima
Middle layer of vein/ artery
Túnica media
Smooth muscle vasoconstricción
Outer layer of veins/ artery
Tunica externa
Anchors blood vessels
Small arteries found in túnica externa
Vaso vasorum
3 types of arteries
Elastic
Muscular
Arterioles
Elastic arteries
Largest
Elastic fibers in all 3 tunics
Branch into muscular arteries
Muscular arteries
Medium size
2 concentric rings of elastic fibers
Internal elastic lamina
External elastic lamina
Arterioles
Smallest
Contain smooth muscle in tunica media
Contraction leads to increase bp
What does the inner ring of muscular artery do
Internal elastic lamina
Separates tunica íntima from media
What does the outer ring of muscular artery do
External elastic lamina
Separates túnica media from externa
Which layer do capillaries have
Túnica íntima only
What is each capillary bed fed by
Metarteriole
Supplies true capillaries
Contains a ring of smooth muscle
Branches off the metarteriole and becomes
Thoroughfare channel
Connects to postcapillary venule
Becomes the venous system
Three types of capillaries
Continuous
Fenestrated
Sinusoid
Continuous capillary
Most common, complete lining
Fenestrated
Contains pores that allow fluid exchange
Sinusoid capillary
Contain large gaps in membrane
Transport large molecules + cells
Veins categorized into two groups
Venules
Small medium and large
Venules
Smallest veins
The smallest are postcapillary venules
Diapedesis occurs
Small medium and large veins
S+M travel with muscular arteries
L travels to elastic arteries
Most contain valves
Skeletal muscle pump
Squeeze veins when muscle contracts
Forces blood towards heart
Respiratory pump
Abdominal pelvic cavity
Veins are compressed when diaphragm contracts
Compensate for low bp in veins
Systemic circulation
Starts at ascending aorta
Systemic circulation
Starts at ascending aorta
Two branches of ascending aorta
Left coronary artery
Right coronary artery
3 branches of the aortic arch
Brachiocephalic trunk
Bifurcates to R common carotid +right subclavian
Middle: left common carotid
Final: left subclavian
What does the aortic arch become
Descending thoracic aorta
Crosses through diaphragm becomes descending abdominal aorta
Bronchial arteries
3 or 4 small arteries that branch off to supple respiratory system
Descending abdominal aorta bifurcates into
R+L common iliac arteries
What is the IVC formed from
R+L common iliac veins
