Heart Structure and Function

 

Transport in Organisms

Chapter- 6

Biology for 9 & 10

1. What is transpiration?

Ans: The physiological process by which water is carried through plants and then released to the atmosphere in the form of vapour through aerial parts, is called transpiration.

On the basis of aerial parts through which this process occurs, transpiration is categorized into three divisions:

Stomatal

Cuticular 

lenticular

2. What is diffusion?

Ans: The process through which the molecules of any substance are spread from a region of higher concentration to a region of lower concentration is called diffusion.

3. How many kinds of blood cells are there and what are they?

Ans:  Blood is made of three types of cells
          A) Red blood corpuscles or erythrocytes
          B) White blood corpuscles or leucocytes
           C) Platelets or thrombocytes

4. What are the functions of an artery?

Ans: Artery carries oxygenated blood away from the heart to different organs of the body. But pulmonary artery is the exception. This exceptional artery carries deoxygenated blood from heart to the lungs.

5. What is blood pressure?

Ans: Blood pressure is the pressure of the blood against the wall of the arteries.

Such as –

 1. Systolic pressure 

2. Diastolic pressure

6. Describe the measures of keeping the heart sound.

Ans: The heart starts functioning even before a baby is born and continues to so till the last breath. The heart plays an important role both in life and death. In order to keep the heart-healthy, it is necessary to maintain a proper lifestyle and select the right kind of food. Oily or high-fat foods obstruct the proper functioning of the heart. Cholesterol in the blood harms the heart by blocking blood vessels.

Drug and alcohol addiction increases heartbeat and heart functioning. So, the addicted person gets mental pleasure and peace for a while, but it causes serious long-term harm to the heart. Poisoning due to smoking and taking nicotine from tobacco damages the heart. Avoiding a fatty diet, such as - oils, fats, excess carbohydrates and regular exercise can make a person healthy.

7. Describe the process of absorbing water, with a diagram.

Ans: Plants generally, absorb capillary water from the soil through their roots. The diffusion pressure deficit in a cell of a leaf is developed because of transpiration, and then water from the adjacent cell moves towards the cell. In the same way diffusion pressure deficit is developed in the second cell and water moves to it from the adjacent cell. This way, a continuous diffusion pressure deficit is extended up to root hair and a suction force is developed. Because of this suction force, capillary water continues to enter the cell root hair. Water enters the root hair cell through the process of osmosis and diffusion. This way, water is taken up into the root hairs moves through the cortex tissue.

This water movement is called cell to cell osmosis. Then, water moves from the cortex tissue to the endodermis, the pericycle, and finally into the vascular bundles. Water, having entered the vascular bundles, is taken up and flows laterally through the xylem tissue. The water flowing through different branches reaches the leaves and this is accomplished by the active involvement of osmosis and transpiration.

Multiple choice questions.

1. What is the name of the membrane covering the heart?

a) epicardium
b) miocardium
c) pericardium
d) endocardium

2. Arafat saw some swelled raisins in a food (payesh) made of rice, milk and sugar.

In this case, what is the cause of the swelling of these raisins?

A) diffusion
B) absorption
C) osmosis
D) imbibition

Observe table and answer questions 3 and 4.

Name               Blood group
Rafin                    A
Tamim                 B
Tasmia                 AB
Ratul                    O

3. If blood input is necessary for Rafin, from whom he can receive blood?

A) Tamim
B) Tasmia
C) Ratul
D) Tamim and Ratul

4. Tasmia -

i) carries A, B antigen in blood
ii) can donate blood to Rafin
iii) can receive blood from Tamim

Which one is correct?

A) i & ii
B) i & iii
C) ii & iii
D) i, ii & iii

1. A) What is adhesion?

Ans: The characteristics of any material to stick together with water molecules is known as adhesion.

B) What is imbibition?

Ans: The special process of absorbing liquid by dry or half-dry colloidal substance is known as imbibitions. Seeds absorb water before germination in imbibition process.

C) Explain what the effects will be on the process for the absence of constituent S.

Ans: Here the constituent S is sunlight. The process mentioned in the stem is known as photosynthesis. The main element of photosynthesis is light, chlorophyll, water and CO2. If one of these element is absent then the photosynthesis process will be stopped. So without sunlight the photosynthesis process will be stopped and no oxygen will emit in the atmosphere. Without oxygen living animal and human cannot live. Everything will be destroyed. So, with constituent S in the stem photosynthesis process will be destroyed.

D) Analyze the problems that may develop in the plant if the element X does not reach the region Y.

Ans: In the stem the element X is water and Y region is leaf. If water doesn't flow to leaves then the photosynthesis and transpiration process will be stopped. 

Photosynthesis is the process by which plants produce their food with sunlight, Chlorophyll, water and CO2. Without photosynthesis plants can not exit. On the other hand transpiration is the process by which plants emit water vapour. This process is useful for metabolic activities of plants. It helps plants to conduct mineral salts and it controls the temperature of plants. So if X element does not reach Y regions plants will die.

2. Mr. Hasan is 50 years old. He serves in a socio-economic institution. He is feeling headache, palpitation, restless. His 7 years old daughter Moon feels joint pain, and her skin turned swollen and reddish. They consulted a doctor. After some tests the doctor advised necessary measures.

A) What is blood?

Ans: Blood is a viscous, slightly alkaline and salty fluid.

B) Explain how white blood cells protect body.

Ans: White blood corpuscles are known as guard of human body. There are 5 - 10 thousand white blood corpuscles in cubic milliliter. White blood corpuscle engulfs the germs by spreading pseudopodia. This process is named phagocytosis. It also produces antibody. In this process white blood corpuscles save human body.

C) Explain the causes of Mr. Hasan's disease.

Ans: Mr. Hasan feels headache, palpitation, restless. These are the symptoms and signs of hypertension. A normal adult person possesses the systolic pressure 120 and diastolic pressure 80 or below it is considered as the desired measure. When systolic and diastolic pressures rise more than the normal pressure is called hypertension. The reasons behind hypertension of Mr. Hasan.

1. May be Mr. Hasan's parents had got this problem.

2. Another reason is that he suffers from tension or he has smoking habit.

3. Another reason can be his body weight is much or he takes excessive salt in food and fatty diet.

4. Diabetes and cholesterol are also the reason of hypertension.

D) Which disease is incurable from the problems mentioned? Explain.

Ans: These are the signs and symptoms of rheumatic fever. Between those two diseases hypertension is incurable and Rheumatic fever is curable. Rheumatic fever is the result of a streptococcus infection. If we can detect it in the preliminary step, it can be prevented by using penicillin. If the parents have hypertension, it can be transferred to the offspring and generation to generation. For the reason, hypertension is incurable. But it can be controlled by taking medicine regularly and balanced diet.

Q. 1. Why the Pituitary Gland is called the main Hormone producing gland?

The pituitary gland is the main hormone-producing gland. Despite being small in size, the pituitary gland secretes several hormones which help in the growth and regulation of the functions of reproductive organs, breast milk secretion, contraction of the uterus etc. Some of these pituitary hormones have an influence on the other endocrine glands. It is also called the master gland.

Q.1. What is blood?

Ans: Blood is just a red fluid, but it is more accurately called a fluid tissue. It consists of a fluid in which are suspended blood cells and platelets. Blood is a type of liquid connective tissue. 

Difference between Red Blood Cells and White Blood Cells:

Red blood cell:

a) contains haemoglobin

b) no nucleus

c) circular, biconcave in shape

d) transports oxygen

White blood cell:

a) haemoglobin absent

b) nucleus present

c) irregular in shape

d) phagocytosis or production of antibodies

Red Blood Cells are wheel-shaped. 

They have no nucleus.

They are red in colour because of the haemoglobin inside them.

Red Blood cells are the body's oxygen carriers. They carry oxygen from the lungs to all the cells of the body.

White Blood cells are larger than red cells.

They all have a nucleus.

They can change shape.

White cells protect us from disease. White cells called phagocytes can eat up the germs that cause disease.

* Fibrinogen and prothrombin play an important part in the clotting of blood. 

Haemoglobin is a special kind of protein containing iron.

Q.2. How many kinds of blood cells are there and what are they?

Ans: Blood is made of  3 types of cells

a) Red blood corpuscles or erythrocytes are produced by the bone marrow. 

b) White blood corpuscles or leucocytes are colourless and do not contain haemoglobin.

There are two main kinds of white blood cells :

i) lymphocytes and

ii) phagocytes

c) platelets or thrombocytes are true cells but fragments of cytoplasm from certain bone marrow cells. They play a part in the clotting of blood.

Functions of blood:

a) Red blood corpuscles transports oxygen as oxyhaemoglobin to the cells.

b) Hormone is a bio-chemical substance which is produced in ductless glands. It mixes with the blood directly and circulated to the different organs of the body. It helps in different important biological processes.

c) Blood carries all the waste products and eliminates  (urea, uric acid and CO2).

d) Heat is produced in the body tissues, especially in the muscles and liver. As a result, the temperature varies in different organs but blood helps to maintain uniform body temperature by distributing it throughout the body.

Fibrinogen and prothrombin play an important part in the clotting of blood.

Haemoglobin is a special kind of protein containing iron. It is a type of coloured pigment. 

Heart Structure and Function

Educator SharminFebruary 04, 2021

Heart Structure:

1) Describe the internal structure of the heart.

Ans: The heart is a triangular-shaped, hollow, muscular pumping organ. The mammalian heart has four chambers: the two upper chambers are called atria. Below which are two large chambers known as the ventricles.
Blood from various parts of the body is returned to the right atrium. Blood from the head, neck and arms is returned to the right atrium by a large vein called the common anterior or superior vena cava.
Blood from the other parts of the body is brought back by the inferior vena cava.
When the right atrium contracts, the blood flows into the right ventricle. Between the right atrium and the right ventricle is the tricuspid valve, which contains of three flaps.

2) How the heart pumps blood?

The heart pumps blood in the following ways-

a) When the heart is relaxed, both sides fill up with blood from the veins.

b) Then the atria contract. The veins also contract where they join the atria. So blood is forced into the ventricles through the valves.

c) A fraction of a second later, the ventricles contract. The valves between the atria and ventricles close. So the blood is squeezed into the arteries.

d) The heart relaxes again, and fills up with blood.

3) Differences between artery, vein, and capillary.

Artery:

a) Carry blood away from the heart

b) Blood under great pressure in arteries, hence it flows fast, in spurts, reflecting the rhythmic pumping action of the heart.

c) Have thick and elastic muscular walls

d) Have no valves

e) Carry red oxygenated blood (exception: pulmonary arteries which carry deoxygenated blood from the heart to the lungs).

Veins:

a) Carry blood towards the heart

b) Blood is not under great pressure in veins, hence it flows more slowly and smoothly.

c) Have relatively thin, slightly muscular walls.

d) Have semi-lunar valves along their lengths to prevent back flow of blood.

e) Carry bluish-red deoxygenated blood (exception: pulmonary veins which carry oxygenated blood from the lungs to the heart).

Coronary Heart Disease

Educator SharminApril 30, 2020

Coronary Heart Disease:

The coronary arteries lie on the outside of the heart and carry blood to the muscles in the walls of the heart. If these arteries become blocked or narrowed by, for example, the build-up of fatty deposits in the arteries, the blood supply to the heart muscles can be greatly reduced. This can cause 2 problems:

a) angina

b) heart attack

Angina pectoris literally means chest pain.
Blood flow to the heart muscles is sufficient at rest.
Obstructions in the coronary arteries can be caused by arteriosclerosis, a condition where the arterial walls are thick and hard.  In one form of this condition, known as atherosclerosis, fatty material is deposited in the lining of the arteries.

 The rough inner surface of such an affected artery increases the risk of a blood clot being trapped in it. The formation of a local blood clot in an artery is called thrombosis. If it occurs in the coronary arteries, the supply of blood and oxygen to the heart muscles may be completely cut off, resulting in a heart attack.

White Blood Cells:

White blood cells are irregular in shape and fewer in number than red blood cells. There are 4 - 10 thousand white blood cells per cubic milliliter of blood. White blood cells are produced in the bone marrow and lymphatic glands. Their average viability is 1 - 15 days.

They are colourless but contain a nucleus. White blood cells contain DNA. White blood cells can change shape and can move from one place to another.