chapter 18: blood vessels

pulmonary circuit

carries blood to the lungs for gas exchange and then returns oxygenated blood back to the heart

systemic circuit

supplies oxygenated blood to the entire body returns to the heart after dropping of the oxygen to the tissues of the body

anastomoses

allow blood to enter a capillary bed by more than one route

BP + effects: blood flow

C.O. amt or vol of blood that flows PER minute, how much blood removed per min

BP + effects: blood pressure

high concentration → low concentration, outward force that blood exerts on wall of blood vessels

BP + effects: resistance

as resistance increase, blood flow increase (inversely proportional)

edema

a condition by an excessive amt of water in interstitial fluid (swell)

hydrostatic pressure

force that fluid exerts on wall of its container = BP (HC→LC)

osmotic pressure

WATER FOLLOWS SOLUTE + solute particles exert a force or pull-on water molecules

fenestration

capillary with small pores within their endothelial cells

skeletal muscle pumps

when muscle contracts blood is squeezed and pushes the valve open

venous valves

when muscles relax, blood flows backwards and the valves close

function of blood vessels: arteries

transport blood FROM heart TO tissue

function of blood vessels: capillaries

embedded in tissue, transport gases, nutrients, and waste FROM blood TO tissue

function of blood vessels: veins

DRAIN tissue of blood back to heart

layers of blood vessels: tunica externa

superficial CT + anchor blood vessels/organs in place + prevent overstretch

layers of blood vessels: tunica media

smooth muscle layer, involuntary + vasodilation & vasoconstriction

layers of blood vessels: tunica intima

deepest epithelial tissue, regenerate + reduce friction erosion

Vaso Basora

tiny blood vessels supplying tunica media & tunica externa

elastic / conducting arteries

Highest pressure and largest, closest to the heart

muscular / distributing arteries

supply organs with blood

arterioles

smallest arteries, lead to capillary beds inside organ/tissue

baroreceptors

in common carotid artery & aorta detect and monitor BP

chemoreceptors

no pressure + detect chemicals in periodic table

capillaries

site of gas exchange nutrient exhange and waste exchange

continuous capillaries

brain does not allow in/out of bloodstream

fenestrated capillaries

pores, allow quick diffusion and gas exchange between blood tissue

sinusoid

gaps, allow cells to go in/out commonly bone marrow

capillary beds

organized web network of capillaries

diffusion

high concentration to low concentration

structure and function of veins: veins

medium & large, DRAIN blood from the organ

structure and function of veins: venules

smallest vein, DRAIN blood from the capillary beds

structure and function of veins: venous sinuses

non constricting veins located in the heart & brain

circulatory pathway:

all blood that leaves the heart has to return.

simple pathway

1 capillary bed (heart)

portal system pathway/route

blood flows through 2 capillary beds before returning to the heart

• ex: veins in intestines travel to the liver before returning to the heart.

arteriovenous shunt

capillary bed is damaged, and blood is rerouted to bypass a capillary

BP + effects: hemodynamics

physiology of blood flow in cardiovascular system (mvmt of blood)

BP + effects: velocity

give time for nutrients to get absorbed

increase resistance decrease velocity

peripheral resistance

directly Directly proportional, as resistance increases BP also increases, as resistance decreases BP also decreases. 4 factors

peripheral resistance: 4 factors: Blood vessel radius

diameter on test vasoconstriction increases BP and vasodilation decrease BP

peripheral resistance: 4 factors: Blood viscosity

(thickness of blood) increase in viscosity = increase in resistance thus increase BP

peripheral resistance: 4 factors: Blood vessel length

the LONGER the blood vessel the GREATER the resistance + more BP + shorter blood vessels less BP

peripheral resistance: 4 factors: Physical obstruction:

obstruction increase resistance and thus increase BP

Atherosclerosis

deposit of fatty plaque in the blood vessels

Cardiac output (CO):

amt of blood pumped by the heart per minute CO= HR*SV

• When cardiac output increases, BP increases vice versa.

blood volume

the volume of blood in the body

• Directly linked to amt of water in blood

• When blood contains more water, blood volume increases, as BV increase BP increase 

systole

contraction d

diastole

relaxation

pulmonary circuit

lower pressure, deoxygenated blood to lungs

systemic circuit

higher pressure, blood to body

pressure of blood vessels: arteries

highest pressure

pressure of blood vessels: capillaries

mid range pressure

pressure of blood vessels: veins

lowest blood pressure

Pressure at work in a capillary: hydrostatic pressure

force that fluid exerts on wall of its container = BP  (HC-> LC)

Pressure at work in a capillary: osmotic pressure

WATER FOLLOWS SOLUTES + Solute particles exert a force or pull-on water molecules (HC→LC)

Difference between Hydrostatic pressure and osmotic pressure

the net filtration pressure (NFP)

pressure at work in capillary: arteriole side

pressure is HIGH

pressure at work in capillary: venule side

pressure is LOW

function: artery

away from heart SUPPLY tissue with blood

function: vein

DRAINS tissue of used blood & bring back to heart