blood circulation

Blood VesselsBlood Vessels

The 3 main types of blood vessels are :The 3 main types of blood vessels are :# arteries# arteries# veins# veins# capillaries# capillaries

ArteryArtery VeinVein CapillariCapillarieses

StructurStructuree

Figure 2.4

Figure 2.5

Figure 2.6

FunctionFunction Carries blood out of the heart

Carries blood into the heart

Carries blood from the artery to the vein

Type of Type of blood blood carriedcarried

Carries oxygenated blood( except pulmonary artery )

Carries deoxygenated blood ( except pulmonary vein )

Carries oxygenated blood from the artery and deoxygenated blood to the vein

Rate of Rate of blood blood flowflow

High pressured blood

Low pressured blood

Very low pressured blood

ThickneThickness of ss of blood blood vessel vessel wallwall

Thick, muscular, strong and elastic wall

Thin, less muscular and less elastic wall.

Porous and thin wall ( one cell thick )

Lumen Lumen sizesize

Small Big Very small

BloodBlood• Transport a variety of substances

around the body such as oxygen, carbon dioxide, digested food, urea and hormones.

• Oxygen is carried from the lungs too all parts of the body by the hemoglobin in the red blood cells.

• Carbon dioxide is carried in a pale yellow liquid called plasma.

Comparison between Comparison between oxygenated and oxygenated and

deoxygenated blooddeoxygenated bloodOxygenated

blood# Present

# Not present

# High

# Not present

Deoxygenated Blood

# Not present

# Present

# Very low

# Present

Differences

1. Oxygen

2.Carbon dioxide

3. Concentration ofdigested food

( glucose and amino acid.

4. Waste product ( urea )

Blood circulationBlood circulation•Draw figure 2.8, PAGE 21

• Blood flows from the heart to the lung through an artery and returns to the heart through a vein.

• The oxygenated blood is pumped to the lungs through the pulmonary arteries

•The oxygenated blood leaves the lungs and returns to heart by the pulmonary veins.

•This system of blood circulation is called double circulatory system.

HUMAN BLOODHUMAN BLOOD

Blood consists of ;# plasma# red blood cells# white blood cells# platelets

PlasmaPlasma• Plasma consists of about 90% water

and 10% dissolved substances. It is yellowish fluid with alkaline characteristics.

• Red blood cells, white blood cells and platelets float in plasma.

• The functions of plasma are ;*to transport digested food to cells*to transport waste products like urea*to control body temperature ( 37°C)* to carry hormones.

Red blood cellsRed blood cells1. Have biconcave shape.2. Do not have a nucleus.3. Produced in bone marrow.4. The lifespan of red blood cells is four

months and destroyed in the liver and the spleen

5. Function : transport oxygen to body cells.

White blood cellsWhite blood cells1. Larger in size than red blood cells.2. Have nucleus.3. Do not have a definite shape.4. Produced in the bone marrow and

lymph glands.5. Function ; kill bacteria in the blood ; produce antibodies

PlateletsPlatelets1.1. Small pieces in the blood.Small pieces in the blood.2.2. No definite shape.No definite shape.3.3. Do not have nucleus.Do not have nucleus.4.4. Produced in bone marrow.Produced in bone marrow.5.5. The life of platelets is very short. The life of platelets is very short.

From few hours to nine days.From few hours to nine days.6.6. Function ; to Function ; to clot bloodclot blood in a wound. in a wound.

Blood groupsBlood groups1. Human blood is classified into 4

groups ; a ) A

b) B c) AB d) O

2. A person who donates his bloods blood donor.3. A person who receives blood

recipient.

Blood transfusionBlood transfusion

O, A, B, AB O OA, AB A O,AB, AB B O,B

AB AB O, A, B, AB

Can donate blood to

people with blood group

Peoplewith

blood group

Can receive blood

from people with blood

group

Blood DonationBlood Donation• Anybody who is ;

a) healthyb) weight over 50kgc) ages between 17 and 60

●a donor may give up to 0.5 liters of blood at one time.

How donated blood is stored and handled

• The blood from donor is taken from a vein in the arm.

• It’s collected is sterilized bag containing sodium citrate which prevent blood clotting.

• Then it’s stored in a refrigerator at 5°C for 10 days.

• Blood is then tested for its group and the presence of viruses such as AIDS.

TRANSPORT SYSTEM IN TRANSPORT SYSTEM IN PLANTSPLANTS

TranspirationTranspiration ;a) is a process in plants in which water is lost in the form of water vapour through evaporation from the surface of leaves.b) if too much water evaporated from a plant, the cells of the plant will wilt.

c) water vapour is lost through the stomata of leaves. Gases such as oxygen and carbon dioxide diffuse in and out of the leaf through the stomata during photosynthesis and respiration.d) stomata are pores or openings on the surface of leaves. More stomata are found on the undersurface of leaves.

e) stomata have guard cells to control the opening and closing of a stoma.

□draw figure 2.10, page 26

Rate of Rate of TranspirationTranspiration

1) Factors affecting transpiration are ;◦ temperature◦ wind◦ air moisture◦ light intensity

2) The number of stomata also affects the rate of transpiration

3) Weight photometer is used to estimate the transpiration rate of a plant.

The importance of The importance of transpiration to a planttranspiration to a plant

The role of transpiration is to ;∞ transport water and mineral salts from

roots to the whole plant.∞ cool plants on hot days.

∞ get rid of excess water from plants.

The transport system of flowering plants consists of the :

▪xylemxylem which carries water and mineral salts from the roots to the leaves.

▪ phloemphloem which carries food made in leaves to other parts of a plants.

Draw figure 2.16 ; page 31Draw figure 2.17 ; page 32