Exam 1 - Blood Vessels

layers of vessel walls

tunica intima

tunica media

tunica externa

tunica intima

innermost layer made up of an endothelium (simple squamous epithelium) and a thin layer of areolar tissue

tunica media

middle layer made up of smooth muscle cells with some elastic fibers

responsible for changing diameter of vessel —> vasoconstriction and vasodilation

vasoconstriction

vessel contraction

vasodilation

vessel relaxation

tunica externa

outer layer made up of areolar CT with elastic and collagen fibers

arteries

thicker tunica media

narrower lumen

more elastic and collagen fibers

veins

thicker tunica externa

larger lumen

less elastic and collagen fibers —> collapse if no blood is in it

types of arteries

elastic

muscular

arterioles

elastic arteries

conduct blood from heart to muscular arteries

muscular arteries

distribute blood to specific regions/organs of the body

thicker tunica media —> greater ability to constrict and dilate

arterioles

smallest arteries that lead to capillaries

capillaries

the smallest blood vessels where exchange of substances (gases, nutrients, wastes) occur between the blood and body tissues

capillaries

made of only a single endothelial cell sitting on a very thin basement membrane (there are no other layers)

type of capillaries

continuous

fenestrated

sinusoids (discontinuous)

sphincters (smooth muscle)

control the movement of blood into the capillary beds

can bypass bed and go directly into venule

veins

carry blood back toward the heart

serve as blood reservoirs

valves

many veins contain these to prevent blood from pooling in the limbs; blood pressure in veins usually too low to overcome gravity

pulmonary circulation

carries deoxygenated blood from the right side of the heart to the lungs and returns oxygenated blood to the left side of the heart

blood pressure is lower throughout this type of circulation

pulmonary arteries

have less elastic tissue

have wider lumens

shorter than systemic arteries

arteries exiting the heart

contains….

right and left coronary arteries

aortic arch:

• brachiocephalic

  • right common carotid and right subclavian

• left common carotid

• left subclavian

aortic arch

contains….

• brachiocephalic

  • right common carotid and right subclavian

• left common carotid

• left subclavian

brachiocephalic

contains…

• right common carotid

• right subclavian

internal and external carotids

the common carotid arteries branch into the ________ and _________

internal carotids

artery that supply the brain and orbits with blood

subclavian artery

artery that supplies the upper limb with blood

radial artery

artery that supplies the lateral aspect of forearm, wrist, and hand

ulnar artery

artery that supplies the medial forearm, wrist and hand

arteries of the abdominal region

celiac trunk

• left gastric artery

• splenic artery

• common hepatic artery

adrenal (suprarenal) arteries

superior mesenteric artery

renal arteries

inferior mesenteric artery

celiac trunk

first branch off the abdominal aorta

immediately branches into:

• left gastric artery

• splenic artery

• common hepatic artery

left gastric artery

supplies part of stomach and esophagus

splenic artery

supplies spleen, pancreas, part of stomach

common hepatic artery

supplies liver and gallbladder

adrenal (suprarenal) arteries

artery that supplies the adrenal glands

superior mesenteric artery

artery that supplies the small intestines

renal arteries

artery that supplies the kidneys

inferior mesenteric artery

artery that supplies the large intestines

arteries of the pelvic region

abdominal aorta —> left and right common iliac arteries —> internal iliac artery and external iliac artery

internal iliac artery

artery that supplies the pelvis and perineum

external iliac artery

artery that primarily supplies the lower extremity

lower extremity arteries

external iliac —> femoral artery —> popliteal artery —> anterior and posterior tibial arteries

upper extremity arteries

subclavian artery —> axillary artery —> brachial artery —> radial and ulnar artery —> palmar and digital arteries

popliteal artery

artery at the knee that supplies the knee joint region

veins entering the heart

left and right brachiocephalic veins

superior vena cava

inferior vena cava

coronary sinus

superior vena cava

left and right brachiocephalic veins merge to form the __________

inferior vena cava

veins inferior to the diaphragm merge to form the __________

coronary sinus

vein that drains the heart wall

internal jugular

vein that drains the cranial cavity

joins subclavian to form the brachiocephalic vein

median cubital vein

connects the cephalic and basilic veins in antecubital space (front of elbow) —> where blood draws are usually taken from

vein of upper extremity

azygous vein

vein that drains the abdominal and thoracic walls

vein of the thoracic region

lower extremity veins

planter and digital veins —> fibular and tibial veins —> popliteal vein —> femoral vein —> external iliac vein —> external and internal iliac veins —> common iliac vein

great saphenous vein

vein often used for coronary bypass grafting

vein of the lower extremity

hepatic portal system

all 4 venous branches (gastric, splenic, inferior mesenteric, and superior mesenteric vein) drain into the hepatic portal vein —> then liver —> then blood filtered and leaves the liver through the hepatic vein

hepatic portal system function

liver must filter, process, detoxify substances that have been absorbed by the organs of the gastrointestinal tract