ICSE Class 10 Biology - Circulatory System

3 principal fluids in our body

blood, tissue fluid, lymph

atleast 2 egs. of non-circulating fluid

synovial fluid in the skeletal joint cavities, vitreous humour in the eye etc.

colour of blood

bright red when taken from an artery or dark red when taken from a vein

volume of blood in our body

5-6 litres

pH level of blood

slightly alkaline, 7.3 to 7.45

the 6 transport/distributory functions of blood

- transport of digested food

- transport of oxygen

- transport of carbon dioxide

- transport of excretory material

- distribution of hormones

- distribution of heat

3 protecting functions of blood

- blood clotting

- its WBCs protect the body by phagocytosis

- produces antitoxins or antibodies

composition of plasma

Water [90-92%]

Proteins [7-8%]

Inorganic salts [1%]

Other substances in traces

The plasma from which the protein fibrinogen has been removed

serum

other name for RBCs

erythrocytes

shape of RBCs

circulae, biconcave disk-like structures

pigment in RBCs

haemoglobin

pigment in RBCs is made up of?

iron-containing part (haemin) and a protein (globin)

name of blood pigment when combined with oxygen

oxyhaemoglobin

name of blood pigment when it carries carbon dioxide

carbaminohaemoglobin

stable compound of the blood pigment and carbon monoxide

carboxyhaemoglobin

average life span of RBCs

120 daya

where are RBCs produced

in the marrow of long bones (especially in the ribs, breastbone, ilium of hip girdle)

old and weak RBCs (except their iron part) excreted as?

a bile pigment named bilirubin

how many RBCs are destroyed in a normal adult?

2 million RBCs per second OR 1% of total RBCs in the body everyday

how are mature mammalian RBCs different from other cells?

they have:

-no nucleus

- no mitochondria

- no endoplasmic reticulum

why are mammalian RBCs devoid of a nucleus?

- loss of nucleus makes the RBCs biconcave, thus increasing their surface area volume ratio for absorbing more oxygen

- space in between RBCs is increased, allowing more RBCs to be accommodated in the space made

why is mitochondria absent in mammalian RBCs?

- prevents RBCs from using the oxygen for themselves; thus all oxygen absorbed from the lungs is transported and delivered to the tissues unconsumed

absence of mitochondria means full transport of glucose in blood plasma, unused by the RBCs

how does no endoplasmic reticulum affect mammalian RBCs?

no ER = increased flexibility of RBCs for them to move thru narrow capillaries

no. of RBCs in newborn infants?

6-7 mil. per mm3

how does sleep affect the RBC count?

RBC count lowered by 5%

how is the RBC count affected by physical activity, pregnancies, and emotional upsets?

it becomes higher

give an example of how altitude affect RBC count

people living at a height of 4200m and above increase their RBCs by 30%

abnormally increased number of RBCs is called?

polycythaemia

abnormally decreased number of RBCs is called?

erythropenia

WBCs aka?

leukocytes

WBCs shape?

irregular, amoeboid

what do WBCs produce and how does it help them with movement? what is this process called?

they produce pseudopodia which helps them squeeze thru the capillary walls into the tissues (called diapedesis)

the 2 categories of WBCs

granulocytes/granular and agranulocytes/non-granular

5 WBC types

granulocytes--neutrophils, eosinophils, basophils

agranulocytes--lymphocytes, monocytes

2 differences between granulocytes and agranulocytes

- cytoplasm contains granules // doesn't contain granules

- nucleus constricted into lobes // single large nucleus

where are WBCs produced?

in the red bone marrow, lymph nodes, and sometimes in the liver and spleen

avg. life span of WBCs

2 weeks

how long do neutrophils live for?

a few hours

how many neutrophils are produced per day?

125 billion

explain leukemia

cancer of the tissue forming WBCs whose number increases manifold at the cost of RBCs; usually a fatal disease

what is leukopenia?

abnormal decrease in the number of WBCs

neutrophil characteristics

- 55 to 70%

- 3 to 4 lobed nucleus

- granular cytoplasm

- stain with neutral dyes

neutrophil function

phagocytosis

eosinophil characteristics

- 1 to 3% (no. increases with allergies)

- 2 lobed nucleus

- large cytoplasmic granules

- stain dark red with eosin (acid dye)

eosinophil function

- phagocytosis

- produce antitoxins

- concerned with allergens

basophil characteristics

- 0.5 to 1%

- indistinctly lobed nucleus

- stain with basic dyes (e.g methylene blue)

basophil functions

release histamine for inflammation which dilates blood vessels

lymphocyte characteristics

- 20 to 35%

- single large nucleus

- smallest WBC

- produced in bone marrow and lymph glands (spleen, tonsils etc.)

lymphocyte function

produce antibodies

monocytes characteristics

- 3 to 8%

- kidney shaped, large nucleus

- largest of WBCs

- transforms into a microphage at the site of infection

monocyte function

ingest germs

mention the function of WBCs

- phagocytosis

- inflammation

- formation of antibodies

what indicates some infection in the body?

an abnormal increase in WBC count up to about 50,000 or more per mm3of blood

inflamed spot characteristics

local heat, redness, swelling, pain etc.

pus composition

pus is mainly composed of dead WBCs together with the tissue cells destroyed by the bacteria

platelets aka?

thrombocytes

platelets shape

minute, oval or round

platelets no.

200,000 to 400,000 per mm3 of blood

where are platelets derived from?

giant cells called megakaryocytes in the red bone marrow

how are platelets budded off from the megakaryocytes?

budded off in a manner such that each one is completely surrounded with membrane

platelets lifespan

3-5 days

where are platelets destroyed?

in the spleen

what is the spleen?

a lymphatic organ located in the abdomen

clotting aka?

coagulation

what is the first substance involved in blood clotting? how is it formed?

injured tissue cells and platelets at the site of the wound, disintegrate to release thrombokinase

thrombokinase aka?

thromboplastin, Factor X, Stuart factor

how is thrombin formed?

thrombokinase acts as an enzyme and with the help of calcium ions in the blood converts prothrombin (inactive) in the blood plasma to thrombin (active)

what is essential for prothrombin production

fat-soluble Vitamin K

how is fibrin formed?

thrombin along with calcium ions reacts with soluble fibrinogen in the blood plasma to form insoluble fibrin

fibrin function

the microscopic threads of fibrin are sticky and form a mesh network at the wound to trap the blood cells

what is serum?

clear, watery and yellowish part of blood without fibrinogen and blood cells

blood clot aka?

thrombus

define blood transfusion

the injection of blood into the body of patients undergoing surgical operation

who discovered the concept of blood grouping?

Karl Landsteiner

antigens

special proteins on the surface of RBCs

2 types of antigens

Antigen A & B

antibodies

complementary proteins in blood plasma

universal donor

O type blood

universal recipient

AB type

which antigens do people with Rh+ blood have

D antigens

heart location

right in the centre between the two lungs above the diaphragm

heart size and dimensions

roughly the size of a closed fist in adults; 12 cm in length and 9 cm in width

pericardium

double walled membranous covering around the heart

pericardial fluid location

in the pericardial cavity of the pericardium

pericardial fluid function

reduces friction during heartbeats and prevents mechanical injuries

anterior/superior vena cava function

to bring deoxygenated blood from the upper regions of the body to the heart (right atrium)

posterior/inferior vena cava function

to bring blood from the lower parts of the body to the heart (right atrium)

how many pulmonary veins are there and where do they end?

4 pulmonary veins (2 from each lung) end in the left atrium

pulmonary vein function

to bring oxygenated blood to the heart (left atrium)

pulmonary artery origin

right ventricle

pulmonary artery function

carries deoxygenated blood to the lungs for oxygenation

aorta origin

left ventricle

aorta function

carries oxygenated blood and supplies it to all parts of the body

coronary artery function

supply oxygenated blood to the heart muscles

coronary artery origin

base of the aorta

what is deadening of heart muscles?

when there is a blockage in any coronary artery or in any one or more of their branches there is 'deadening' of the corresponding area of the heart muscles

what does deadening of heart muscles lead to?

myocardial infarction/heart attack

coronary vein function

carry blood from heart walls and pour it into the right auricle

what is angina pectoris?

chest pain due to insufficient supply of blood to the heart muscles