bi205- circulatory system

most outer layer of blood vessels, have fibers that anchor the blood vessel

adventitia

middle layer of blood vessels, made of muscle, involved in vasoconstriction and vasodilation

media

innermost layer of blood vessels, made of simple squamos epithelia

intima

the walls of the thickest vessels contain their own blood vessels, these blood vessels are called…

vasa vasorum

structural differences between arteries and veins

arteries have thicker walls, arteries have circular lumen, veins lumen collapses when cut

contain elastic membranes in the media and intima, very resilient, recoil during diastole helps propel blood forward, ex: aorta, brachiocephalic trunk, pulmonary trunk

elastic arteries

media sized arteries, thicker media than elastic arteries, vessel diameter under control of autonomic nervous system, ex: radial and ulnar, external carotid, brachial, femoral, mesenteric

muscular arteries

smallest arteries, very thin adventitia, media may have incomplete smooth muscle layers, control blood flow between arteries and capillaries

arterioles

smallest of all vessels, most delicate of all vessels, lack adventitia and media, only vessels where nutrient/waste exchange occurs between blood and tissues

capillaries

type of capillary, endothelial lining is complete, most common

continuous

type of capillary, endothelial lining is not complete, these capillaries have pores in their lining

fenestrated

type of capillary, also called discontinuous capillaries, endothelial lining is not complete, contains pores and large gaps in their lining

sinusoids

the 4 mechanisms regarding the passage of material across the walls of capillaries

• material can diffuse across the endothelial cells

• material can diffuse through gaps between adjacent endothelial cells

• material can diffuse through pores or gaps in fenestrated capillaries

• material can move via vesicular transport

connection between artery and vein

arteriovenous anastomoses

sphincters within the capillary bed

metarterioles

a direct capillary pathway that allows blood to bypass the true capillaries

thoroughfare channels

when more than one artery supplies a specific area collateral arteries fuse to form…

arterial anastomosis

in joints or visceral organs, blood flow may be hindered due to body movement, to accommodate this, there must be a direct connection between arterioles and venules that is known as…

arteriovenous anastomosis

smallest of the veins, collect blood from the capillaries, lack or have thin tunica media

venules

adventitia is the largest of the layers, contains elastic fibers, one-way valves are present, found alongside muscular arteries, ex: radial vein, tibial vein, popliteal vein

medium-sized veins

blood in the veins returning from the lower extremities has to go against gravity, to assist in this process many medium veins have valves known as…

venous valves

adventitia is thickest layer and contains some smooth muscle, no valves, ex: superior vena cava, inferior vena cava

large veins

what percentage of blood volume do the arteries contain

30-35%

what percentage of blood volume do the veins contain

65-70%

what are veins known as since they act as blood reservoirs

capacitance vessels

this function of veins shifts blood toward arterial side of the circulation

venoconstriction

blood pressure in the pulmonary circuit is ____ than in the systemic circuit

lower

walls of the pulmonary arteries are ____ than the walls of systemic arteries

thinner

branches off the brachiocephalic trunk and supplies blood to the right side of the head and brain

right common carotid artery

branches off the brachiocephalic trunk and supplies blood to the right arm and right side of the head, brain, and spinal cord

right subclavian artery

branches off the aortic arch and supplies blood to the left side of the head and brain

left common carotid artery

branches off the aortic arch and supplies blood to the left arm, brain, and spinal cord

left subclavian artery

the subclavian artery continues to the _____ which goes into the arm

axillary artery

branches off the subclavian artery and supplies tissues of the neck, shoulder, and upper back

thyrocervical trunk

branches off the subclavian and supplies the pericardium and anterior wall of the chest

internal thoracic artery

branches off the subclavian and supplies the brain and spinal cord

vertebral artery

arteries anastomose at the wrist forming…

superficial palmar arch and deep palmar arch

this is at the base of internal carotid artery and contain baroreceptors and chemoreceptors

carotid sinus

branches off the common carotid artery and supply the neck and outside of the skull

external carotid

branches off the internal carotid and supplies the eyes

ophthalmic artery

branches off the internal carotid and supplies frontal and parietal lobes of the brain

anterior cerebral artery

branches off the internal carotid and supplies the midbrain and lateral surfaces of the cerebrum

middle cerebral artery

how does blood reach the brain?

vertebral arteries

left and right vertebral arteries fuse to from the…

basilar artery

these connect the basilar artery and internal carotid arteries

posterior cerebral and posterior communicating arteries

the ring like anastomosis between the basilar and carotid arteries is called the…

cerebral arterial circle

the diaphragm separates which 2 arteries

thoracic aorta and abdominal aorta

branches off the thoracic aorta and supplies the organs of the chest

visceral branches

branches off the thoracic aorta and supplies the chest wall

parietal branches

a visceral branch that supplies the lungs

bronchial arteries

a visceral branch that supplies the exterior of the heart

pericardial arteries

a visceral branch that supplies in between the lungs

mediastinal arteries

a visceral branch that supplies that esophagus

esophageal arteries

a parietal branch that supplies the ribs

intercostal arteries

a parietal branch that supplies the diaphragm

superior phrenic arteries

branches off the abdominal aorta and supplies the liver, stomach, esophagus, gallbladder, duodenum, pancreas, spleen

celiac trunk

branches off the celiac trunk and supplies the stomach

left gastric artery

branches off the celiac trunk and supplies the spleen

splenic artery

branches off the splenic artery and supplies the stomach

left gastro-epiploic artery

branches off the splenic artery and supplies the pancreas

pancreatic arteries

branches off the common hepatic artery and supplies the liver

hepatic artery proper

branches off the common hepatic artery and supplies the stomach

right gastric artery

branches off the common hepatic artery and supplies the gallbladder

cystic artery

branches off the common hepatic artery and supplies the duodenum

gastroduodenal artery

branches off the superior mesenteric artery and supplies the pancreas and duodenum

inferior pancreaticoduodenal artery

branches off the superior mesenteric artery and supplies the small intestine

intestinal arteries

branch off the superior mesenteric artery and supply the large intestine

right colic artery, middle colic artery, ileocolic artery

branch off the inferior mesenteric artery and supplies the terminal portion of the large intestine

left colic artery, sigmoid arteries

branches off the inferior mesenteric artery and supplies the rectum

rectal arteries

paired artery that branches off the abdominal aorta and supplies the inferior portion of the esophagus and diaphragm

inferior phrenic arteries

paired arteries that branch off the abdominal aorta and supply the adrenal glands

adrenal arteries

paired arteries that branch off the abdominal aorta and supplies the right and left kidneys

renal arteries

paired arteries that branch off the abdominal aorta and supply the testes, scrotum, ovaries, uterine tubes, uterus

gonadal arteries

paired arteries that branch off the abdominal aorta and supply the vertebrae, spinal cord, and abdominal wall

lumbar arteries

where do the left and right common iliac arteries split

terminal segment of the aorta

branches off the common iliac arteries and supplies the urinary bladder, walls of the pelvis, external genitalia, and the medial side of the thigh

internal iliac artery

branches off the common iliac artery and supplies blood to the legs

external iliac artery

how does blood return to the heart from the lower extremities

inferior vena cava

how does blood return to the heart from the upper extremities

superior vena cava

how does blood return to the heart from the lungs

pulmonary veins

the only veins that do not drain into the superior or inferior vena cava

cardiac veins

drain into dural sinuses

superficial cerebral veins

drains the internal cerebral veins and great cerebral vein

straight sinus

drains the petrosal sinuses

cavernous sinuses

confluence of sinuses drains to _____ which drains to the….

sigmoid sinus, internal jugular veins

drain into the brachiocephalic veins

vertebral veins

drain into the external jugular vein and then into the subclavian vein

temporal vein, maxillary veins

drains into the internal jugular vein then into the subclavian veins

facial vein

the superficial palmar veins drain into these 2 veins and they then merge immediately distal to the elbow

basilic vein, median antebrachial vein

drains the esophageal and right intercostal veins

azygos veins

in fetal circulation, blood in the right atrium can enter the left atrium via…

foramen ovale

in fetal circulation, blood in the pulmonary trunk can enter into the aortic arch via the…

ductus arteriosus

upon birth smooth muscles of the ductus arteriosus contract, eventually forming the _____ found in the adult heart

ligamentum arteriosum

upon birth, pressure in the left atrium increases, thus closing the valvular flap of the foramen ovale, which eventually form the _____ found in the adult heart

fossa ovalis

age related changes in blood

• decreased hematocrit

• thrombi and emboli form more easily

• pooling of blood in veins of the leg

age-related changes in the heart

• reduced efficiency and elasticity

• atherosclerosis of coronary vessels

• scar tissue forms

age-related changes in blood vessels

• loss of elasticity and aneurysms

• calcium deposits damage vessel walls