RB 12 Biology

RBSE Solutions for Class 12 Biology Chapter 24 Man-Blood Vascular, System

RBSE Solutions for Class 12 Biology Chapter 24 Man-Blood Vascular, System

Rajasthan Board RBSE Class 12 Biology Chapter 24 Man-Blood Vascular, System

RBSE Class 12 Biology Chapter 24 Multiple Choice Questions

Question 1.
Human Heart is developed from:
(a) endodermal
(b) mesodermal
(c) exodermal
(d) endomesodermal
Answer:
(c) exodermal

Question 2.
Blood is:
(a) a tissue
(b) not a tissue
(c) liquid tissue
(d) liquid connective tissue
Answer:
(d) liquid connective tissue

Question 3.
At high altitude, Red blood cells will be:
(a) Increase in number
(b) increase in size
(c) decrease in shape
(d) Decrease in the number
Answer:
(a) Increase in number

Question 4.
Contraction of the heart starts from:
(a) left ventricle
(b) Right Atrial
(c) Left auricle
(d) right ventricle
Answer:
(b) Right Atrial

Question 5.
For blood clotting, an important role is played by:
(a) Neutrophils
(b) Thrombocytes
(c) Erythrocytes
(d) Monocytes
Answer:
(b) Thrombocytes

Question 6.
Ventricular contraction is under control of:
(a) AVN
(b) Purkinje fibres
(c) SAN
(d) Papillary muscles
Answer:
(c) SAN

Question 7.
Important ion for Blood clotting is:
(a) K+
(b) Na+
(c) Fe2+
(d) Ca2+
Answer:
(d) Ca2+

Question 8.
The function of Lymph is:
(a) Provide O2 to Brain
(b) Transport of CO2
(c) Returning of WBC to Lymph nodes
(d) provide liquid to blood
Answer:
(d) provide liquid to blood

Question 9.
Normal Blood pressure of Human:
(a) 140/90
(b) 120/80
(c) 110/70
(d) 130/60
Answer:
(b) 120/80

RBSE Class 12 Biology Chapter 24 Very Short Answer Type Questions

Question 1.
Where RBC is formed?
Answer:
Redbone marrow.

Question 2.
Which protein is important for blood clotting?
Answer:
Fibrinogen.

Question 3.
Which blood group is known as Universal Acceptor?
Answer:
AB group.

Question 4.
What is Pace Maker?
Answer:
SA node.

Question 5.
Define cardiac cycle.
Answer:
The sequential changes in the heart from the beginning of one heartbeat & beginning of the second heartbeat.

Question 6.
Which blood group is known as a universal donor?
Answer:
Group O.

Question 7.
What is Plasma?
Answer:
It is the liquid part of the blood which is pale yellow in colour & alkaline in nature. It is 55% of the total blood.

Question 8.
What is Erythroblastosis foetal?
Answer:
It is a disease. It occurs when a wife is Rh– and the husband is Rh+. The infant from these parents have this disease & called as rhesus Child.

Question 9.
Define double blood circulation?
Answer:
In the perfectly four-chambered heart, there is perfect isolation of oxygenated and deoxygenated blood. In such type of heart, the blood passes twice through the hear before body circulation which is called as double circulation.

RBSE Class 12 Biology Chapter 24 Short Answer Type Questions

Question 1.
Write a difference between open and closed circulatory system.
Answer:

  1. Open Circulatory system:
    In open circulatory system liquid flows between cells and tissues, openly i.e. does not flow in closed blood vessels.
    Example: Molluscs and Arthropods.
  2. Closed Circulatory system:
    In a closed circulatory system, the fluid flows within closed vessels.
    Example: Human and Rabbit etc.

Question 2.
Write functions of Blood.
Answer:
Functions of Blood:

  • Transportation of oxygen Haemoglobin found in the RBC transports O2.

  • Transportation of CO2.
  • Transportations of urea & little uric acid as excretory waste up to kidneys.
  • It Transports digested food from ileum up to various body parts.
  • It transports hormones.
  • It protects the body from diseases by destroying the germs.
  • It provides immunity by forming antibodies.
  • It maintains homeostasis in the body.
  • It has a capacity of clotting. Hence, the loss of blood is prevented.
  • It helps to maintain body temperature.
  • Blood is used in various diagnosis techniques.

Question 3.
Write an account of human blood groups.
Answer:
Blood Groups:

  • In human beings, blood varies from person to person on the basis of surface antigens on RBCS, blood can be divided into various groups.
  • Antigens are also called as agglutinogen and they stimulate the formation of antibodies. Chemically, antigens are mucopolysaccharide (glycoprotein),
  • Group “O” blood can be donated to persons with any other blood group and hence “O” group individuals are called ‘Universal donors’. Persons with “AB” group can accept blood from persons with AB as well as the other groups of blood. Therefore, such persons are called ‘Universal recipients’.

  • The antibodies are also called agglutinin and are made up of globulin protein.
  • There is a reaction between similar antigen & antibody which is called agglutination.
  • It results in clumping of RBC which may be fatal.

There are two main systems to classify the human blood –

  1. ABO System
  2. Rh-system

1. ABO System:

  • It was discovered by Landstenier (1900).
  • According to it, there are two types of natural antigens on the RBCs namely A and B. Similarity, two types of natural antibodies in the plasma namely anti-A or a and anti-B or b.
  • According to the ABO system, human blood is of four types as per below table.

 

2. Genetics of ABO System:

  • Burn Stein (1924 – 25) First explained that ABO blood groups in human beings are a hereditary character.
  • ABO system is controlled by three genes. Hence, it is an example of multiple gene inheritance.

Question 4.
Explain the Rh system.
Answer:
Rh System:

  • Landsteiner and Weiner (1940) discovered the Rh factor in Rhesus monkey. Rh antigen is found on the surface of RBC.
  • Such individuals are called Rh-positive (Rh+) and those without this antigen are called Rh-negative (Rh–). Rh antigen is, also called an Rh factor. It is controlled by a dominant gene.
  • If Rh+ blood is transfused to the Rh person than it produces agglutinin. It is called Isoimmunization.
  • According to it, human blood is of two types:

Erythroblastosis foetal:

  • This disease occurs when the husband is Rh+ and the wife is Rh–. In this case, the foetus will be Rh+.
  • Rh antigens of the foetus do not get exposed to the Rh-ve blood of the mother in the first pregnancy as the two types of blood are well separated by the placenta. However, during the delivery of the first child, there is a possibility of exposure of the maternal blood in small amounts to the Rh+ blood from the foetus.
  • In such cases, the mother starts preparing antibodies against Rh antigen in her blood.
  • In case of her subsequent pregnancies, the Rh antibodies from the mother (Rh-ve) can pass into the blood of the foetus (Rh+) and destroy the foetal RBCs. This could be fatal to the foetus or could cause severe anaemia and jaundice to the baby.
  • This condition is called Erythroblastosis foetal.

  • This can be avoided by administering anti-Rh antibodies to the mother immediately after the delivery of the first child. A baby suffering from this disease is called “Rhesus baby”.
  • Generally, they born before stipulated gestation period and have blood deficiency complete blood transmission of a newborn can be done to save the life of the child.
  • A newborn can also be saved by giving a mother Rh-antibody injection just before 72 hours of delivery.

Question 5.
Give differences between Artery and Vein.
Answer:

Question 6.
Define double circulatory and its significance.
Answer:
Blood clotting or Blood coagulation or double circulatory:

  • Blood exhibits coagulation or clotting as a result of an injury or trauma. This is a protective mechanism which prevents excessive loss of blood. Factors which induce clotting are known as Inducer and which inhale motion function clotting is called anticoagulant. In clotting, fibrinogen thrombin, platelets and total 13 factors are involved.

This process occurs in three steps:
1. Formation of prothrombin:

  • Normally these factors remain inactive and become active on bleeding. The platelets break on-air contact and release inactive thromboplastin. It forms active thrombin in the presence of Ca++, factors VI and Factors VII and X and Ca++ together called prothrombin activator.

2. Conversion of Prothrombin into Thrombin:

  • Prothrombin is a protein found in plasma Thrombin activator converts it into Thrombin.

3. Conversion of Fibrinogen into fibrin and formation of Clot:

  • Fibrinogen is a soluble protein found in plasma and it changes into fibrin with the help of thrombin which is a non-soluble and fibrous protein.
  • These fibrin monomers soon assemble and form a net at the wound. This network with entangled blood cells forms a clot.
  • The liquid oozes out of the clot which is called serum.
  • The serum is plasma without fibrinogen. Normally, clotting takes about 6-10 minutes.
  • There is no blood clotting inside the blood vessels because the blood contains an anticoagulant called heparin.

Cascade Theory:

  • Blood clotting can be explained with the help of the cascade theory. The 13 clothing factors participate as follows:
    • Intrinsic Factors
    • Extrinsic Factors


The names of 13 clothing factors participate as follows:

Question 7.
Write differences between blood and Lymph.
Answer:

RBSE Class 12 Biology Chapter 24 Essay Type Questions

Question 1.
Describe the external structure of Heart with the help of a well-labelled diagram.
Answer:
The external structure of Heart:

  • The heart is situated in the thoracic cavity in between the lungs obliquely towards the left side.
  • The anterior end of the heart is broad & it is called as a base. The posterior end is narrow & it is called an apex.
  • The heart is covered by the pericardium.
  • There is a pericardial cavity between the pericardium & heart which is occupied by pericardial fluid. This fluid protects the heart from shocks & keeps the heart moist.

  • The walls of the heart are consist of three layers
    1. Epicardium-outermost
    2. Myocardium-middle layer & it is made up of Cardiac muscles.
    3. Endocardium-Inner layer
  • The anterior part of the heart is called an auricular part & the posterior part is called a ventricular part. There is a coronary sulcus between these 2 parts.
  • The auricular pair is smaller & less muscular. It is divisible into 2 equal left & right auricles with the help of an interauricular septum.
  • During the embryonic stage, the interauricular septum bears an oval pore, the foramen ovals. This pore get closed later & its scar is called as fossa ovals.

  • The ventricular part is larger & more muscular. Aoblique inter ventricular septum divides the ventricular part into unequal left & right ventricles.
  • The interventricular septum is visible from outside ventrally. A coronary artery is situated along the interventricular septum.
  • The left auricle receives two pulmonary veins through a single slit-like & valve-less aperture. They bring oxygenated blood. In human beings, both the pulmonary veins open through 4 small apertures into the left auricle.
  • The left auricle opens into a left ventricle through an auriculo-ventricular aperture which is guarded by a bicuspid or mitral valve.
  • The left ventricle opens into the left systemic arch and the opening is guarded by three semi-lunar valves.
  • The right auricle receives two prevails & one post-carnival which open through separate & valve-less apertures.
  • The right auricle has a membranous eustachian valve and a sign-auricular node (S-A node). In addition, it receives a coronary sinus. Its opening is guarded by a Thebesian valve.
  • The right auricles open into the right ventricle and this opening is guarded by a tricuspid valve.
  • The right ventricle leads into a pulmonary arch & it’s opening is guarded by 3 semi-lunar valves.
  • Both the pulmonary arch & systemic arch cross each other & remain connected with the help of ligament asterism.
  • During the embryonic stage. both the pulmonary & systemic arches remain connected by a ductus arteriosus which is also called as ductus Bocelli.
  • Later on, this duct gets closed. Both the ventricles are provided with papillary muscles which form pocket-like column cornea.
  • Thread-like chordate tending remains attached between the papillary muscles & the bicuspid tricuspid valves. The chordee tending & the papillary muscles prevent the reverse-opening of the valves.
  • There is an auriculo-ventricular node (A-V node) in the tip of the interventricular septum. The AV node gives out two bundles of which further divide to form Purkinje’s. fibres.

Question 2.
Describe the internal structure of the Heart with the help of a well-labelled diagram.
Answer:
The internal structure of Heart:

  • The heart is situated in the thoracic cavity in between the lungs obliquely towards the left side.
  • The anterior end of the heart is broad & it is called as a base. The posterior end is narrow & it is called as an apex.
  • The heart is covered by the pericardium.
  • There is a pericardial cavity between the pericardium & heart which is occupied by pericardial fluid. This fluid protects the heart from shocks & keeps the heart moist.

  • The walls of the heart are consist of three layers
    1. Epicardium-outermost
    2. Myocardium-middle layer & it is made up of Cardiac muscles.
    3. Endocardium-Inner layer
  • The anterior part of the heart is called an auricular part & the posterior part is called a ventricular part. There is a coronary sulcus between these 2 parts.
  • The auricular pair is smaller & less muscular. It is divisible into 2 equal left & right auricles with the help of an interauricular septum.
  • During the embryonic stage, the interauricular septum bears an oval pore, the foreman ovals. This pore get closed later & its scar is called as fossa ovals.
  • The ventricular part is larger & more muscular. Aoblique interventricular septum divides the ventricular part into unequal left & right ventricles.
  • The interventricular septum is visible from outside ventrally. A coronary artery is situated along the interventricular septum.
  • The left auricle receives two pulmonary veins through a single slit-like & valve-less aperture. They bring oxygenated blood. In human beings, both the pulmonary veins open through 4 small apertures into the left auricle.
  • The left auricle opens into a left ventricle through an auriculo-ventricular aperture which is guarded by a bicuspid or mitral valve.
  • The left ventricle opens into a left systemic arch and the opening is guarded by three semi-lunar valves.
  • The right auricle receives two prevails & one post-carnival which open through separate & valve-less apertures.
  • The right auricle has a membranous eustachian valve and a sign-auricular node (S-A node). In addition, it receives a coronary sinus. Its opening is guarded by a Thebesian valve.
  • The right auricles open into the right ventricle and this opening is guarded by a tricuspid valve.
  • The right ventricle leads into a pulmonary arch & it’s opening is guarded by 3 semi-lunar valves.
  • Both the pulmonary arch & systemic arch cross each other & remain connected with the help of ligament asterism.
  • During the embryonic stage. both the pulmonary & systemic arches remain connected by a ductus arteriosus which is also called as ductus Bocelli.
  • Later on, this duct gets closed. Both the ventricles are provided with papillary muscles which form pocket-like column cornea.
  • Thread-like chordate tending remains attached between the papillary muscles & the bicuspid tricuspid valves. The chord tending & the papillary muscles prevent the reverse-opening of the valves.
  • There is an auriculo-ventricular node (A-V node) in the tip of the interventricular septum. The AV node gives out two bundles of His which further divide to form Purkinje’s fibres.

Question 3.
Explain the working mechanism of the Human Heart.
Answer:
Working of Heart:

  • The heart functions as a pump & it keeps the blood circulating in the whole body. The rhythmic contraction of the heart is called a heartbeat. Each heartbeat has two parts:
    1. Systole
    2. diastole
  • During diastole, the heart receives blood from the veins & during systole it pumps the blood into the arteries.
  • The heart contracts were alternate i.e. when the auricular part contracts, the ventricular part relaxes & vice versa.
  • The number of heartbeats in adult man is 72 per minute.

Mechanism of heartbeats:

  • The heartbeats begin by the self-contraction of the S-A node. Hence, the S-A node is also called a pacemaker.
  • The S. A. node consists of cardiac muscles and nerve cells. Hence, the heartbeat begins by the contraction of the cardiac muscles Therefore, the heart is also called as myogenic.
  • Firstly, the S. A. node contracts, as a result of both the auricles contract. Soon the stimulus of contraction gets transmitted to the A. V. node & from the A.V. node to all over the ventricles with the help of bundle of His & Purkinje’s fibres. It results in ventricular contraction.

Question 4.
Write the mechanism of Blood clotting.
Answer:
Blood clotting or Blood coagulation:

  • Blood exhibits coagulation or clotting as a result of an injury or trauma. This is a protective mechanism which prevents excessive loss of blood. Factors which induce clotting are known as Inducer and which inhale motion is function clotting is called anticoagulant. In clotting, fibrinogen thrombin, platelets and total 13 factors are involved.

This process occurs in three steps:
1. Formation of prothrombin:

  • Normally these factors remain inactive and become active on bleeding. The platelets break on-air contact and release inactive thromboplastin. It forms active thrombin in the presence of Ca++, factors VI and Factors VII and X and Ca++ together called prothrombin activator.

2. Conversion of Prothrombin into Thrombin:

  • Prothrombin is a protein found in plasma Thrombin activator converts it into Thrombin.

3. Conversion of Fibrinogen into fibrin and formation of Clot:

  • Fibrinogen is a soluble protein found in plasma and it changes into fibrin with the help of thrombin which is a non-soluble and fibrous protein.
  • These fibrin monomers soon assemble and form a net at the wound. This network with entangled blood cells forms a clot.
  • The liquid oozes out of the clot which is called serum.
  • The serum is plasma without fibrinogen. Normally, clotting takes about 6-10 minutes.
  • There is no blood clotting inside the blood vessels because the blood contains an anticoagulant called heparin.

Cascade Theory:

  • Blood clotting can be explained with the help of the cascade theory. The 13 clothing factors participate as follows:
    • Intrinsic Factors
    • Extrinsic Factors


The names of 13 clothing factors participate as follows:

Question 5.
Describe a lymphatic system.
Answer:
Lymphatic system:

  • It is made by Lymph, Lymph vessel and Lymph nodes.

Lymph:

  • Lymph flows in fluid form in the Lymphatic system. Blood gets filtered in blood capillaries due to blood pressure, that is called as Lymph.
  • It is colourless transluscent & alkaline vascular tissue.
  • It is similar to plasma but the lymph is without RBC & platelets.
  • The lymph has less amount of protein, Ca++ & Phosphorus than the plasma.
  • The lymph is a carrier of nutrients, hormones etc.
  • It contains specialized lymphocytes which are responsible for immune responses of the body.

Lymph vessels:

  • The lymph vessels are similar to the veins which carry lymph.
  • In lymph vessels, the lymph always flows from the organs towards the heart. They have less pressure than veins.
  • Lymph vessels are lined by endothelial cells and have a thin layer of smooth muscle, and adventitia that binds the lymph vessels to the surrounding tissue.

Main lymph vessels are as follows:
1. Thoracic Duct:

  • The main vessel of the lymphatic system, passing upwards in front of the spine and draining into the left innominate vein near the base of the neck. The thoracic duct is the largest lymphatic vessel of the lymphatic system of the body. It is approximately 40 cm in length in adults and approximately 5 mm in width at its abdominal origin.

2. Right Lymphatic duct:

  • The right lymphatic duct drains lymph from the right upper limb, the right side of the thorax and right halves of head and neck. The thoracic duct drains lymph into the circulatory system at the left brachiocephalic vein between the left subclavian and left internal jugular veins.

3. Lymph Nodes:

  • There are lymph nodes in many regions of the lymph vessels.
  • These nodes have a network of lymphocyte granules.
  • They are situated close to the large blood vessels in the head, neck, armpits, groins etc.
  • Tonsils are also lymph nodes.

Functions of the Lymphatic system:

  • Lymph acts as an intermediate between blood & the tissues. It takes digested food & O2 from the blood & provides to the tissues. Similarity, it takes excretory substances, hormones etc from the tissues & conveys them to the blood.
  • The lymphatic system helps in the circulations of absorbed substances particularly fatty acids & glycerol.
  • The digested fats are absorbed into the lacteals of the ileum.
  • The WBC found in the lymph destroy the germs.

Question 6.
Write the different diseases concerned with the blood circulatory system.
Answer:
Diseases related to heart and circulatory system
1. Hypertension or High Blood Pressure:

  • The BP in human beings is expressed as Sp/DP mm of Hg. The normal value is 120/80 mm of Hg.
  • An increase in SP/DP. Both are called as hypertension.
  • It adversely affects brain, kidneys & heart.

2. Coronary Artery Disease (CAD):

  • It is also called as Atherosclerosis. It is caused by deposition of calcium, fats, fibrous material in the arteries supplying blood to the heart muscles. As a result, the artery lumen becomes narrow.

3. Heart Failure:

  • It is also termed as congestive heart failure. Heart failure is different than a heart attack. In a heart attack, the heartbeat stops suddenly. The heart failure is usually caused by the insufficient blood supply to the heart muscles. The main Symptom is congestion of the lungs.

4. Angina:

  • It is normally caused due to coronary thrombosis. As a result, the Cardiac muscles fail to get proper oxygen and nutrients.
  • There is severe pain in the chest migrating towards the left arm.
  • Also termed as angina pectoris.

5. Myocardial Infarction (MI):

  • Mi is also called a heart attack.
  • It occurs when the coronary artery gets blocked, normally because of coronary thrombosis. The cardiac muscles get
  • damaged because of less blood supply and the heart fail to function with full capacity.

6. Valvular Disease:

  • It is because of the malfunctioning of the cardiac valves, as a result, the blood starts flowing in the opposite direction.
    There is a mixing of oxygenated & deoxygenated blood.

7. Ventricular Fibrillation:

  • In this disease, the ventricular muscles contraction disorganized. The quivers instead of pumping.

8. Pericarditis:

  • It is caused due to bacterial infection in the pericardium. There is inflammation in the pericardium and increased amount of pericardial fluid. It causes more pressure on the heart which may be fatal.

9. Coronary Thrombosis:

  • The intravascular blood clot is called as thrombus & its formation is called thrombosis. When the thrombus forms in the coronary artery, it is termed as coronary thrombosis. It may result in a heart attack.

10. Heart Block:

  • It is caused due to malfunction of Bundles of His. As a result, the impulses generate in the S-A node fail to spread all over the ventricles. Hence, there is no/poor ventricular contraction.

11. Rheumatic Heart Disease:

  • It is caused by the infection of Streptococcus viridin bacteria. The heart valves do not work properly and cardiac muscles become weak.

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