2.1 Blood Circulation
Transcript of 2.1 Blood Circulation
Blood circulatory system
The function of blood circulatory systems are to:i. Supply oxygen to all body.ii. Eliminate carbon dioxideiii. Transport waste product like carbon dioxide and urea for elimination.
Artery Vein
a) Humans have a close blood circulatory system.
b) Blood is carried to the heart by vein blood vessel and pump out from the heart through artery blood vessel.
Artery
Vein
Artery – the blood vessel that carries blood out of the heart
Vein – the blood vessel that carries blood into the heart
Blood capillaries
Blood capillaries-Act as connectors that joint the blood vessel of arteries to veins
CO2 blood
O2 blood
Go to body
The heart is a muscular organ which contract and relaxes without stopping to pump and circulate blood to the whole body.
The heart has four large chambers:i. Left atriumii. Right atriumiii. Left ventricleiv.Right ventricle
Left atrium and right atriumare situated at the upperpart of the heart
Left ventricle and right ventricle are situated at the lower part of the heart.
The space in the atrium is smaller than in the ventricle.
The wall of ventricle is thicker and stronger than atrium
The wall of left ventricle is thicker and more muscular compared to right ventricle.
This is because strongerpressure is needed by the left ventricle to pump the blood to our body.
The valve in the heart enable blood to flow in one direction only. Blood is prevented from flowing back.
There are 3 types of valve inthe heart:i. Tricuspid valveii. Bicuspid valveiii. Semi lunar valve
The left chamber of the heartcontains oxygenated bloodThe right chamber containsdeoxygenated blood.
TYPE OF VALVE POSITION FUNCTIONTricuspid Between the right
atrium and right ventricle
Prevents blood in the right ventricle from flowing back to the right atrium
Bicuspid Between the left atrium and the left ventricle
Prevents blood in the left ventricle from flowing back to the left atrium
Semilunar At the base of the pulmonary artery and the aorta
Prevents blood leaving the heart from flowing back
TYPE OF BLOOD VESSEL
FUNCTION
Pulmonary artery Carries deoxygenated blood from the heart to the lungs
Pulmonary vein Carries oxygenated blood from the lungs to the heart.
Aorta Carries oxygenated blood from the heart to the whole body.
Vena cava Channels deoxygenated blood from all parts of the body to the right atrium.
Four blood vessels are connected to the heart:
Right ventricle
S
Vena cava
TricuspidValve
Right atrium
Left ventricle
Bicuspid valveLeft atrium
Semilunar valve
Pulmonaryveins
Vena cava
Aorta Pulmonaryartery
1. The vena cava caries deoxygenated blood from all the body to the right atrium.
2. When it is filled with blood, the wall of the right atrium will contract and push the blood through the tricuspid valve into the right ventricle.
3. When the right ventricle is filled with blood, its wall will contract and push the blood through the semilunar valve into the pulmonary artery and go to the lungs.
4. Gaseous exchange takes place in the lungs. Carbon dioxide diffused out and oxygen diffused into the blood.
5. Oxygenated blood then flows from the lungs into the left auricle through the pulmonary vein. 6. The left auricle wall contracts and pushes blood through the bicuspid valve into the left ventricle.
7. The contraction of the left ventricle wall pushes blood through the semilunar valve into the aorta.
8. The aorta then carries the blood to the whole body.
The pathway of blood circulation:
Vena cava
Right auricle
Tricuspid valve
Right ventricle
Semilunar valve
Pulmonary artery
Semilunar valve
Left ventricle
Bicuspid valve
Left auricle
Pulmonary vein
Lungs
Aorta
Whole body
Video : Heart 1
Video: Heart 2
Blood vessels in humans
Blood vessels are tubes in the body that channel blood
3 types ofblood vessels
Artery
Vein
Blood capillary
Artery Vein Blood capillaryStructureFunction Carries
blood out of heart
Carries blood into the heart
Carries blood from artery to vein
Type of blood carried
Oxygenated blood (except pulmonary artery)
Deoxygenated blood (except pulmonary vein)
Oxygenated blood (artery)Deoxygenated blood (vein)
Rate of blood flow
High pressure blood flow faster
Low pressure blood flow slowly
Blood flows very slowly to enable diffusion process
Artery Vein Blood capillary
Thickness of blood vessel wall
Has thick, muscular and elastic.
Has thin less muscular and less elastic.
Has porous and thin wall to enable gas exchange
Lumen size
Small Big Very small
Existence of valve
No Yes No
Oxygenated blood Deoxygenated bloodDifference
PresentNot present
High
Not presentArtery and pulmonary
vein
OxygenCarbon dioxide
Concentration of digestion
food (glucose)
Waste product(urea)
Blood vessel that carries it
Not presentPresentVery low
PresentVein and
pulmonary artery
Deoxygenatedblood
Vein Artery
Blood capillary
Oxygenatedblood
Relationship between artery, vein and blood capillary
Cell
Vena cava andveins
Arteries andaorta
1. Heart disease is caused by:a. Damage to the valve in the heartb. Failure of the ventricle and atrium muscular wall to contract
c. Blockage of blood supply to the heart as a result of cholesterol deposits.
The importance of maintaining a healthy heart is toa. Avoid contracting heart disease. If serious can cause deathb. Ensure that our body cells get enough supply of oxygen