The blood cycle

arteries

arteries

convey blood from high pressure from the heart ventricles

features of arteries

thick wall
narrow lumen
high pressure
inner layer of muscle and elastic fiber

function of thick wall in arteries

prevents arteries from bursting due to the high pressure

function of narrow lumen in arteries

increase the peripheral resistance

function of narrow muscle and elastic fibers in arteries

mentaning blood flow

structure of arteries

tunica externa
tunica media
tunica intima

tunica externa

tough layer of connective tissue

tunica media

thick layer consisting of smooth muscle and elastic fibers

tunica intima

lining of the artery, smooth endothelium

capillaries function

allow for the exchange of materials from blood to cells

what allows for the exchange of materials in capillaries

permeability

branching of arteries

1. arteries

2. arteriols

3. capillaries

features of capillaries

small diameter
low blood pressure
single layer of cells
narrow lumen
pores

function of small diameter in capillaries

passage of only single blood cells at a time

function of single layer of cells in capillaries

small diffusion distance

function of basement membrane in capillaries

permeability

function of pores in capillaries

transport of materials

name of capillaries with pores

fenestrated

divison of capillaries

arterial end

mid capillary

venous end

role of arterial end in capillaries

filtration

role of mid capillary in capillaries

no- net movement

role of venous end in capillaries

reabsorption

whats the relationship between capillary hydrostatic and blood osmotic pressure in arterial end

capillary hydrostatic higher than blood osmotic pressure

whats the relationship between capillary hydrostatic and blood osmotic pressure in mid capillary

capillary hydrostatic equal to blood osmotic pressure

whats the relationship between capillary hydrostatic and blood osmotic pressure in venous end

capillary hydrostatic lower than blood osmotic pressure

veins

collect blood at low pressure from the tissues and return it to atria

pathway of blood from capillaries to heart

1. capillaries

2. veins

3. atria

4. heart

features of veins

wide lumen

thin wall

small amount of muscle and elastic fibers

posses valves

role of wide lumen in veins

maximizing of blood flow

role of thin walls in veins

low blood pressure

role of valves in veins

prevention of backflow

how many chambers does heart have

4

division of heart chambers

atria
ventricles

role of atria

collect blood from the body

role of ventricles

pump blood to the body

role of vena cava

return deoxydised blood to the heart

role of pulmonary arteries

return deoxydised blood to the lungs

role of pulmonary vein

return oxygenated blood from lungs

role of the aorta

send oxygenated blood to the body

types of circulation

pulmonary

systematic

pulmonary circulation

circulation lungs-heart

systematic circulation

circulation heart-organs

sinoatrial node

primary peacemaker, controlling heart rate

myogenic contractions

generated in a muscle without motor neurons

stages of cardiac cycle

atrial systole

ventricular systole

diastole

how chambers behave in atrial systole

atrial contracts, ventricle relaxes

how chambers behave in ventricular systole

atrial relaxes, ventricle contracts

how chambers behave in diastole

atria relaxes, ventricle relaxes

what is the blood flow direction in atrial systole

from atrium to ventricle

what is the blood flow direction in ventricular systole

from ventricle to atrial

what is the blood flow direction in diasytole

into atrial, into ventricle

what is behaviour of valves in atrial systole

AV valve opens, aortic valve closes

what is behaviour of valves in ventricular systole

AV valve closes, aortic valve opens

what is behaviour of valves in diasytole

AV valve opens, aortic valve closes