Circulatory system

doesn't include blood groups, lympatic sysytem or dideases

plasma components

H20 - 91%

Nutrients

ions

waste

gases

proteins

structure of blood

plasma ,leucocytes, thrombocytes, and erythroytes

leucocytes

white flood cells (1%) - larger than red, protect the body from infection by removing dead or injured cells

Thrombocytes

platlets - small fragments of cells with no nucleus forming scaffolds for coagulation of blood forming clots

erythroytes

RBC - boncave shape, don’t contain a nucleus meaning flexability to travel through blood vessels

transporting oxygen from lungs to cells in the body.

average persons hematocrit

40 - 50% of volume

what is a anitgen

substance that makes a certain protein ( antibody)

Oxygen location in blood

3% in plasma ( due to it insolubility)

97% in Oxyhaemoglobin (Hb02)

Oxygen combines into haemoglobin where

gas exchange -diffuse into the blood

when does oxyhaemoglobin break down

When conc 02 levels are low

why are RBC suited for oxygen transport

contain haemoglobin = able to combine with 02

no nucleus, more room for haemoglobin

biconcave discs increases SA

CO3 location in blood

7–8% in plasma

22% combined in globin part of Hb

70% as bicarbonate ions

when does carbaminohaemoglobin breaks down

when blood reaches the alveoli for gas exchange -diffuse into the alveolus.

Arteries

carry blood away from the heart

Arteries structure

smooth muscle and elastic fibres - no valves

vasoconstriction.

narrowing of blood vessels - contraction of muscular walls

vasodilation.

widening of blood vessels - relaxation of muscular walls

Capillaries

link between the arteries and veins - microscopic blood vessels that

form network carrying blood close to every cell in the body

Veins

carry blood towards the heart

what can’t veins do

don’t have muscular walls and not able to change diameter

why do veins have valves

low blood pressure so the valves help prevent the blood from flowing backwards.

systole.

cotnracts and pumps blood

diasole

relaxes and fills with blood

Atrial systole

atriums contracts opening valves and pumping blood into ventricles

ventricular systole.

ventricles contract, valves close pumping blood into arteries

cardiac output calc

heart rate x stroke volume

what does the medulla do

contains certain nerves thaty regulate how fast the heart beats

blood clotting

protects invading micro-organism as it creates a scab over the wound preventing entry of pathogens -

caused by dammaged veins

plattlet plug

damaging of wall releasing collagen attracting plattlets to injured area forming aggluination agglutination

coagluation

process blood becoming gel-like

coagulation vs agglutination

A= clumping together of micro-organisms or BC

C = process blood becoming gel-like - clot

clot

fribrin forming a mesh that traps blood

clot retraction

mesh threads contract becoming denser and stronger pulling danmaged blood vessel together.

blood cloothing steps

1. vasconstriction

2. plattlet plug

3. coagulation

4. clot retraction