BLOOD CIRCULATION AND TRANSPORT

The human blood circulatory system consists of the heart, a network of blood vessels and blood

The functions :1. To transport nutrients, oxygen and water2. To transport carbon dioxide and waste

product3. To bring hormones to the whole body

The human circulatory system is a double circulatory system Each complete circuit, the blood must flow

through the heart twice The pulmonary circulation – transports

blood between the heart and the lungs. The systemic circulation – transports blood

between the heart and other parts of the body

The Heart Organ that pumps blood throughout

the body by its alternating contractions and relaxations of the muscles

Wall of the heart Cardiac muscles Oxygen and nutrients

are supplied to the cardiac muscles by coronary arteries

Can be divided to four chambers auricles/ atrium

(upper chambers) ventricles (lower

chambers)

Septum Divides the heart into

the right and left halves Walls of atrium is

thinner than the ventricles

Tricuspid valve Between right atrium

and right ventricles Mitral/ Bicuspid valve

Between left atrium and left ventricles

Semilunar valves Beginning of aorta and

pulmonary artery

Blood vessels

Charateristics Artery Vein Capillary

Function Carries blood away from heart

Carry blood to the heart

Connects artery to vein

Wall Thick muscular wall

Thin muscular wall

Very thin wall, only one cell thick

Lumen Narrow Fairly wide Very Narrow

Charateristics Artery Vein Capillary

Valves Absent (except in pulmonary artery)

Present Absent

Rate of blood flow

Quick rate, high pressure

Slow rate, low pressure

High rate, high pressure

Oxygen content Oxygenated blood (except in pulmonary artery)

Deoxygenated blood (except in pulmonary veins)

Oxygenated blood to the tisseDeoxygented blood from the tissue

Blood vessels

Path of blood flow1. Oxygenated blood is carried from the lungs by

the pulmonary vein to the heart.2. Oxygenated blood is carried from the heart by

the aorta and arteries to the whole body.3. Deoxygenated blood is carried from the whole

body by the vein and vena cava to the heart.4. Deoxygenated blood is carried from the heart

by the pulmonary artery to the lungs.

Blood transport substances in our body

Substances ExampleTransport from

Transport to

Respiratory gases

Oxygen Lungs Tissues

Carbon dioxide Tissues Lungs

Excretory products

Urea Liver Kidneys

End products of digestion

Glucose Small intestineLiver and tissues

Amino acids Small intestineLiver and tissues

Mineral saltsCalcium Small intestine Bones and teeth

IronSmall intestine and liver

Bone marrow

Blood – A mixture of liquid blood plasma, red blood cells, white blood cells, blood platelets, and dissolved substances.

55% is plasma and 45% is blood cells

Plasma : Liquid – pale yellow colour Functions

1. Transport digested food, mineral salts and vitamins to the body cells

2. Transport waste substances like carbon dioxides, water, urea

3. Maintain the pH of the blood4. Maintain body temp at 37°C

Blood Cells Made up of red blood cells, white blood

cells and platelets. Produced in bone marrow Old red blood cells and platelet is

destroyed in the liver or spleen.

Red blood cells White blood cells Platelets

Round, biconcave Irregular shape Irregular shape, fragments of cells

No nucleus Big nucleus No nucleus

Life span – 120 days Life span – 2 to 4 days Life span – 4 days

Transport oxygen Protect body against diseases

Blood clotting

Blood group Based on ABO system There are four main groups called A, B, AB,

and O. Blood transfusion

Donor’s blood must be compatible with the recipient's blood.

If incompatible, agglutination will occur – can cause fatal blockages in the recipient’s blood vessels.

Compatible Incompatible

Blood O can safely donate blood to anyone. Universal donors

Blood AB can safely receive blood from anyone Universal recipents

Blood typePopulation percentage (approx.)

O 40.77%

A 31.79%

B 21.98%

AB 5.51%

Blood donation: Treatment for accident

cases, canser victims, haemophiliacs, gastrointestinal bleeding, surgery, childbirth.

Storage and handling of donated blood: Collected in sterilised container contained

anticoagulant solution Tested for ABO group Screening for HIV, hepatitis and other

sexually transmitted diseases Date of expiration should be added

Storage and handling of donated blood: Blood can be stored for 10 days at 5°C –

longer if glucose is added Blood can be stored for 42 days under

refrigeration, or up to 10 years of frozen Frozen plasma can be kept for up to one

year If frozen, plasma and red blood cells should

be thawed in a water bath at a temperature not exceeding 38°C

Wilting Occurs in non-woody plants Rate of loss of water is greater

than the intake of water Cells lose their turgidity

(stiffness) and the plant droops

Transpiration Evaporation of water from the

aerial parts of the plants

Stomata Pores in the epidermis of the leaves

and stems

Stomata A pair of bean- shaped guard cells

bound each stoma. Most stomata open during the day

and close at night.

Function of stomata : Allow gases to diffuse in and out

of the leaf. During photosynthesis, carbon

dioxide diffuse into the leaf and oxygen diffuse out to the atmosphere.

During transpiration, water vapour will diffuse out when the stomata opens.

Factors affecting transpiration rate:

Roles of transpiration Produce pulling force

which enables to transport water and minerals from roots to all parts of the plant

To cool the plant

Vascular tissues of a plant Two types

of vascular tissues ; xylem and phloem.

Xylem Transport water and minerals

from roots to the stem and leaves

Provides supports for the plants

Consists mainly of vessels – elongated tubes with thick walls, strengthened by lignin

Phloem Transport synthesized

food Consist mainly of sieve

tubes. Sieve tubes – living

cells without nucleus. Transverse walls are

perforated by pores – sieve plates.

Each sieve tubes has a companion cell