BIOL 2823 Cardiovascular system

Arteries

carry blood away from the heart; thicker connective walls than veins

Arterioles

smallest branches of arteries

Capillaries

blood vessels where diffusion between blood and interstitial fluid occurs; tunica intima only

Veins

carry blood towards the heart; contain majority of the bodies blood

Venules

smallest branches of veins

Diameter of blood vessels

larger close to the heart; smaller far from the heart

Three layers of vein/artery walls

tunica intima, tunica media, tunica externa

Tunica intima

endothelium, connective tissue, elastic fibers

Tunica media

Sheets of smooth muscle; contraction and relaxation of blood vessel

Tunica externa

Connective tissue mixed with adjacent tissues; stability of blood vessel

Elastic arteries

largest; more elastic to accommodate for blood leaving the heart

Muscular arteries

blood distribution to extremities; main layer is tunica media

Large veins

similar to elastic arteries

Medium-sized veins

similar to muscular arteries, except main layer is tunica externa

Types of capillaries

Continuous, Fenestrated, Sinusoid

Pulmonary circulation

Between heart and lungs

Systemic circulation

Heart and rest of the body

Vessel cross-sectional area

lower diameter = higher cross-sectional area

Velocity

Arteries(highest) → veins → capillaries

Blood pressure

Arteries(highest) → capillaries → veins

Autoregulation

changes in the blood flow patterns of capillary beds to maintain homeostasis

Vasodilators

promote dilation of precapillary sphincters

Baroreceptors

adjust cardiac output to maintain adequate blood flow to vital tissues and organs

Chemoreceptors

monitor pH levels and dissolved gases (CO2)

Endocrine regulation

responses of the sympathetic nervous system when homeostasis is disturbed

Anti diuretic hormone (ADH)

hormone for water retention in the kidneys

Pulmonary circuit

right ventricle → pulmonary trunk → pulmonary capillaries → lung alveoli (gas exchange) → left atrium

Vena cava

two largest veins; enter into the right atrium

Carotid arteries

blood supply to brain

Subclavian arteries

blood supply to arms

Aortic arch

artery that curves over the top of the heart

Ascending aorta

part of aortic arch that flows upwards

Descending aorta

extension of aortic arch that flows downward

Three arteries attached to aortic arch

Brachiocephalic trunk, left common carotid artery and left subclavian artery

Renal artery

artery for kidneys

Gonadal artery

artery for pelvic region

Mesenteric artery

pancreas, small intestine, most of large intestine

Iliac arteries

blood supply to pelvis(internal) and legs(external)

Femoral artery

extension of iliac arteries into upper leg(femur)

Jugular veins

blood supply from head

Iliac veins

blood supply from pelvis(internal) and legs(external)