Blood Vessels & Blood Pressure (Cardiovascular Info) Flashcards
Blood vessels
-functions (3)
FUNCTIONS: -transport blood through body
- exchange of substances btwn blood & body tissue cells
- diffuse of oxygen and nutrients from blood to tissue cells and waste products from cell to blood
percent of blood carried by vessels (5)
- systemic veins and venules (64%) (deoxygenated-> get quickly oxygenized)
- systemic arteries and arterioles (13%)
- pulmonary vessels (9%)
- heart (7%)
- systemic capillaries (7%)
type of vessels
arteries-> arterioles-> capillaries-> venules-> veins-> back to heart
arteries
def? description? controlled by? cause (2)?
carry oxygen rich blood away from heart thick walls, 3 tunic (layers) surround a lumen (hollow tube) controlled by ANS & local chemicals smooth muscle in walls cause: -vasoconstriction -vasodilation
vasoconstriction in arteries
contraction (lumen diam. narrows)
sympathetic
vasodilation in arteries
relaxation (luman diam. enlarges)
parasympathetic
arterioles
description? location? function?
almost microscopic
branches from small arteries into tissues
REGULATE BLOOD PRESSURE & BLOOD FLOW TO CAPILLARIES
Capillaries
description? what occurs? how many? contain?
(blood flow-slower in cap., single layer, farther from heart-slow down, flows back quicker-faster back to heart bc want oxygen)
- thin walls, microscopic
- blood cells move in singe file
- 20 billion from extensive network
- contain SPHINCTERS
Sphincters in capillaries
def? function?
SPHINCTERS (smooth muscle rings)-control direction of blood flow (act like valves, like butt hole)
-function: exchange of nutrients & wastes btwn blood and tissue fluid
venules
description? (4)
microscopic, thinner walls
low-pressure (blood back to heart)
carry blood away from capillaries
larger diameter than arterioles
veins
def? description? what helps?
carry oxygen poor blood from tissues to heart
thinner walls & larger lumen than arteries
can expand
largest blood reservoir in body
skeletal & respiratory muscles help blood movement (squeeze to push blood back up)
contain VALVES (prevent back flow)
vein structure (3)
tunica interna
tunia media
tunica externa
tunica interna
(inner layer)
simple squamous & basement membrane
tunia media
smooth muscle
tunica externa
(outer layer)
- elastic, tough, & stretchy
- thickest part of vein
Vascular Resistance
def? depends on (3)?
opposition to blood flow
Depends on: 1) Lumen Diameter
2) Blood viscosity
3) Total blood vessel length
(Vascular Resistance)
1) Lumen Diameter
(Vascular Resistance)
small lumen-> greater resistance
(Vascular Resistance)
2) Blood viscosity
(Vascular Resistance)
ratio of RBC’s to plasma volume
-high viscosity (more RBC’s)-> greater resistance
(Vascular Resistance)
3) Total blood vessel length
(Vascular Resistance)
longer blood vessel-> greater resistance
-obesity- additional blood vessels in adipose tissue
-400 miles added for each 2.2 lbs of fat
Blood pressure
how is it generated?
contraction of ventricles generates blood pressure (BP)
-pressure exerted on walls of arteries
what is BP determined by? (3)
- cardiac output (CO)
- blood volume
- vascular resistance
systolic BP
highest pressure in arteries during left ventricle systole
systole=contraction
diastolic BP
-highest pressure in arteries during ventricular diastole
-normal BP is 120/80 mm Hg for adults
(diastole=relaxation)
measuring BP
where? device? sounds called?
measured in BRACHIAL ARTERY of left arm
- device used: sphygmomanometer
- sounds heard called: Korotkoff Sounds
measuring systolic BP
what is it? how do you know?
-first sound heard through stethoscope
-force of BP on arterial walls just after ventricular contraction
(top of equation ex: 120)
measure diastolic BP
-when no sound is heard through stethoscope
-force exerted by blood remaining in arteries during ventricular relaxation
(bottom of equation ex: 80)
pulse
def? equal to?
alternate expanding & recoil of arterial walls
-equal to ventricle contractions
pulse
can be detected in which 5 places?
radial artery - wrist carotid artery - lower neck brachial artery - elbow femoral artery - groin popliteal artery - behind knee (use 2 fingers, never thumb)
names of the major veins and what they supply blood to?
6) (2
Right jugular - head & neck Right subclavian - arms (Superior vena cava) Right hepatic - liver Coronary sinus- heart Left renal - kidney (Inferior vena cava) Left iliac - legs
names of the major arteries and what they supply blood to?
carotid - brain left subclavian - arms (bc clavicle) mesenteric - intestine left iliac - legs right renal - kidney common hepatic - liver & spleen coronary - heart
lumen
definition??
the hollow space through which blood flows
vein structure vs artery structure
vein- thinner walls and larger lumen than arteries
