9a. transport system in mammals

mass transport system

a transport system in which the bulk moment of fluid occurs in one direction

closed system

blood is contained within the heart and blood vessels and doest’t come into contact directly with tissue cells

tissue fluid

fluid which exchange of substances with tissues occur in

open system

system with open ended blood vessels where blood bathes the tissues directly

single circulatory system

system where the blood flows through the heart once in a complete circuit eg fish

double circulatory system

systems where good travels those though heart in one compete circuit around the body, one circuit to longs one to body eg mammals

different pressures

in the pulmonary and systemic circulation prevents capillaries and alveoli getting damaged, and make sure blood reaches all of the body

blood supply

addicted by vasodilation and vasoconstriction depending on how their respiring

metabolic rate

determines if an animal requires a closed double circulatory system or single open system

capillary

smallest blood vessel, are cross section SA fro exchange with cells, wall only one cell think made from squamous epithelium form networks called beds

artery

carry blood from the heart, thick layer of collagen to withstand pressure and prevent bursting, smooth muscle and elastic fibre maintain pressure, carry oxygenated blood except pulmonary

vein

returns blood to heart, very little elastic fibre or smooth muscle, semilunar velvets prevent back flow, contraction of skeletal muscles helps maintain blood flow, cary deoxygenated blood except pulmonary

venule

slightly wider then capillaries very thin walls of smooth muscle and elastic fibres, cary blood from capillaries to veins

arteriole

smaller vessels divided from arteries, thin wall of smooth muscle and elastic fibres, divert blood flow to different areas of the body by contraction of smooth muscle in wall to restrict blood flow (vasoconstriction), or relaxation of smooth muscle to allow blood flow into capillaries (vasodilation)

artery structure

* high pressure
* thick wall
* narrow lumen
* tunica intima, folded endothelium (allow expansion) of smooth squamous epithelium
* tunica media, thick layer of smooth muscle and elastic fibres
* tunica externa, more collagen to prevent busting
* no valves

capillary structure

* low pressure
* singe layer of cells make up the wall
* narrow lumen 7µm in diameter
* tunica intima, endothelium of single later of smooth squamous epithelium

vein structure

* low pressure
* thin wall that can be compressed
* wide lumen
* tunica intima, endothelium of smooth squamous epithelium
* tunica media, thin layer of smooth muscle and elastic fibres
* tunica externa, less collagen
* semilunar valves to prevent back Flow

tunica intima

inner layer of blood vessel

tunica media

middle layer of blood vessel

tunica externa

outer layer of blood vessel

elastic fibres

stretch to accommodate the volume of blood ejected into arteries during ventricular systole, then recoil during ventricular diastole to maintain pressure and smooth blood flow

smooth muscle

contracts to narrow lumen and maintain pressure during ventricular diastole

vasodilation

relaxation of smooth muscle on wall of arterioles and pre capillary sphincter to increase blood flow in capillaries

vasoconstriction

constriction of smooth muscle in walls of arterioles and pre capillary sphincters to reduce blood flow in capillaries

skeletal muscle

if it contracts it compresses veins , increasing pressure to more blood goes back to the heart

relaxation decompresses veins and reduces pressure which allows greater blood flow from capillaries

smooth endothelium

reduces friction and provides and short diffusion distance in capillaries

low power plan diagram

used to show arrangement of tissues in walls of artery or vein, no internal details or structure of cells shown

high power drawing

used to show individual cells in walls of capillary

increase exchange efficiency

* capillary bed has large total cross sectional surface area
* short diffusion distance
* steep contraction gradient marinated by blood flow

plasma

forced out capillaries into tissues at arteriole end due to high hydrostatic pressure, and enters at venule end due to lower hydrostatic pressure, forms tissue fluid

lymphatic system

drain for excess tissue fluid

colloid osmotic pressure

caused by plasma proteins remaining in blood as their to large to pass though the pores in capillaries, leads to return of water to blood

fenstrations’s

pores in capillary endothelium

oedema

build up of tissue fluid due to body break down of own plasma proteins so colloid osmotic pressure is less

velocity

starts high with blood pressure in arteries but falls as surface area increases at capillaries, increases Adrian in veins due to skeletal muscles

sphygmomanometer

measures blood pressure in kilopascals (kPa) or mmHg

120/80 mmHg

average blood pressure

systolic pressure

due to contraction of muscle in left ventricle in systole, produces a higher reading

diastolic

when the muscle in the left venture id relaxed, produces a lower reading

inflatable cuff

used when measuring blood pressure manually and electronically, inflated until blood flow stops then gradually deflated

1, 3, 2, 4, 6, 5

order statement for how to measure blood pressure:


1. The person should have been sitting down with legs uncrossed for five to ten minutes.
2. Inflate cuff until it exerts sufficient pressure to stop blood flow in the brachial artery.
3. Securely attach the cuff (not too tightly) to the upper left arm which is held supported at heart level
4. Use the stethoscope to listen for the sounds of blood flow and slowly release the pressure from the cuff.
5. When the pulsing sounds disappear the pressure is equal to that in the artery at diastole (diastolic pressure)
6. When pulsing sounds (Korotkoff sounds) are first heard the pressure is equal to that in the artery at systole (systolic pressure)

ABPM ambulatory blood pressure monitoring

patient wears a portable blood pressure monitor in their arm

HBPM home blood pressure monitoring

patient measures own blood pressure at regular intervals at home

hypotension

persistently low blood pressure, typically below 90/0 mmHg

risks of; tiredness and weakness, dizziness and fainting, coma and death

hypertension

persistently higher tax average blood pressure, typically above 140/90 mmHg

risks of; premature morbidity and mortality, damage to endothelium, thrombus formation, damage to blood valves, kidney damage

prehypertension

120/80 mmHg

stage 1 hypertension

140/90 mmHg

stage 2 hypertension

160/100 mmHg

severe hypertension

180/110 mmHg

increases risk of hypertension

* smoking
* been obese
* alcohol
* stress
* age
* make
* sedentary life style

decreases risk of hypertension

* regular exercise
* low salt diet
* low stress