circulatory system ch3

NIK/ASASI/2013

Functions :

Transport ;

1. Metabolic wastes

2. Oxygen

3. Hormones

4. Nutrients

Helps ;

1. Regulate body temperature

2. Stablize pH

3. Defends against invading microorganism

4. Maintains homeostatic balance

Composition and functions of blood

- 45% cellular elements

- 55% plasma

Cellular elements

Components Functions

Erythrocytes (RBC) Transport oxygen and carbon dioxide (respiratory gases)

Leukocytes (WBC) Helps in immunity and defense

Platelets Blood clotting

Plasma

Water Solvent

Ions (electrolytes) - Osmotic balance between blood and - interstitial fluid - pH buffer - regulation of membrane permeability

Plasma proteins; consist of

Components Functions

Albumin Osmotic balance

Fibrinogen Blood clotting

Immunoglobin Body defense

Substances transport by blood ( nutrients, respiratory gases, hormones) 10%

CHAPTER 3 : CIRCULATORY SYSTEM

NIK/ASASI/2013

- Lack nuclei and mitochondria

- Biconcave

- Thinner centre

- Formed in bone marrow

Composition ;

- 4 polypeptides chains

- 4 heme groups (organic compound)

Heme group has iron to bind with oxygen

RBC ;

- Circulate in blood for 3 to 4 months

- Worn out RBC broken down at liver with the helps of enzymes

- Iron from the RBC back to bone marrow : to make other RBC

! Usually, granulocytes names, end with ‘phil’

While agranulocytes names end eith ‘cytes’

leukocytes

agranulocyte

monocytes

lymphocytes

granulocytes

neutrophil

basophil

eosinophil

Erythrocytes

Provide high TSA for

gases exchange

Leukocytes (WBC)

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Adaptations

- Irregular shape

- Nucleus constricted into two lobes

- Cytoplasm contain granules ; bluish black

Functions

- Helps fight against infections

- Release histamine

- Phagocytes which fight bacteria

- Phagocytic action causes

formation of phagosome

Secretion of hydrolitic enzymes

- Phagocyte

Basophil

Histamine - dilates blood vessels - Allow other WBC to go to tissues

Neutrophil

Eosinophil

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- Fights parasitic protozoans and worms

- Reduce allergy attacks

- Phagocytes

- Fight bacteria which enter the body through wound

- Help heal tissue by removing debris (dead cells)

Phagocytic actions :

- Use intermediary (opsonising)

- Intermediaries are antibodies and complement

- Bind to the microbe via pattern recognition

- Key cell in immunity

- Defends body

- Produce antibodies (protein)

- Fight viruses and cancer cells

- Functions in blood clotting together with the plasma protein fibrinogen

Monocytes

Pattern recognition receptors - Recognize pathogens

Lymphocytes

Platelets

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BLOOD CLOTTING MECHANISM :

Invertebrate

- Some don’t have CS (small and aquatic)

- Have open CS

- Have closed CS

Those without CS, has Gastrovascular cavity (GvC)

In Cnidarians, GvC acts as CS digestive organs

Clotting factors in

plasma Clumped platelets Damaged cells

Activators

thromboplastin

Calcium ions, Ca2+ Vitamin K

Prothrombin (inactive

plasma protein)

Thrombin (active plasma

protein which act as enzyme)

Fibrinogen

(soluble)

Fibrin(insoluble)

Fibrin form a mesh of fibres across the wound, sealing

wound and preventing further loss of blood

form

Circulatory system (CS)

Vertebrate

- Closed CS

NIK/ASASI/2013

Circulation helped by contractions of muscles of the body wall

Flatworms

- No need circulation

- Flattned body allows effective diffusion of gases

- Have branched intestine to spread nutrients to cell

Open and closed CS have 3 components:

- Fluid (blood/lymph)

- Tubes (blood vessels)

- Muscular pump (heart)

Open CS

- Heart pumps blood into vessels that have open ends

- Blood contained in body cavity

- Cannot differentiate blood and lymph so it is named as haemolymph

Open CS in mollusc

- Heart has 3 chambers

Two atria - Receive haemolymph from the gills

Ventricle - Pump haemolymph rich in oxygen into blood vessels - Vessels conduct haemolymph into large sinuses in haemocoel.

- After haemolymph bath the body cells, it passed to vessels which lead back to the gills to

receive oxygen again.

Haemocoel

- Space between the organs with the open CS

- Contained haemolymph

Open CS in arthropods

- Some arthropods have haemocyanin (piment)

- Haemocyanin turns blue when oxygenated

- Arthropod has tubular heart

In grasshopper,

- When tubular heart pump(contract), haemolymph to move into body cells

- Haemolymph brings along nutrients

- When heart relaxes, haemolymph return back to heart through tiny pores called ostia

- Ostia has valves to prevent backflow

Open CS

Haemolymph consist of - Blood - Lymph - Interstitial fluid

NIK/ASASI/2013

- more haemolymph circulate during movement : provide nutrients for cell energy

Closed SC

- blood in vessels, does not mixes with interstitial fluid

invertebrate : earthworm

- has two main blood vessels

- Dorsal and ventral blood vessels

Dorsal and ventral blood vessels connect via the 5 pairs of contractile blood vessels (heart)

Contraction of these vessels and body muscle helps circulation of blood.

Vertebrate

Fish

- Single circulation of blood

- Heart has one atrium and one ventricle

- Each chamber has its own chamber

Atria has sinus venous

- Collection chambers

Ventricle has conus arterious

- Pumping chambers

Flow of contraction

1. Blood in the heart is deoxygenated

2. When blood pump out of conus arterious, the blood is oxygenated (respiratory capillaries)

3. Blood then travel to body cells

4. Body cells used up oxygen

5. Blood enter systemic capillaries

6. Deoxygenated blood enters the heart again

sinus venous

atrium ventricle conus

arterious

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However, there is a problem in the circulation

- Blood lose pressure from the heart while travel through the gills

- Making the circulation from gills a bit slow

- Rate of oxygen transfer to the body is limited/slow

Conclusion : single circulation suitable for fish but not to other active vertebrates

Closed CS (Double Circulation)

Separate circulation of oxygenated blood and deoxygentaed blood

To supply blood with oxygen, blood in mamals and reptiles have to pass pulmonary circuit

Blood in amphibians have to pass pulmocutaneous circuit

blood then pass oxygen to cells of mammals, reptiles and amphibian through systemic circuit

double circulation : higher pressure then single circulation

Amphibian circulatory system

- Two partially partitions heart

- Right and left

Respiratory

capillaries Systemic

caplillaries

Sinus venosus ventricle

Conus arterious

atrium B

O

D

Y

G

I

L

L

S

Mammals, reptiles Amphibians

Blood receives oxygen from

Pulmonary circuit Pulmocutaneous circuit

Delivers oxygenated blood through

Systemic circulation

circulatory system ch3

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