NCERT Class 11 Biology Chapter 18 Notes Body Fluids And Circulation- Download PDF Notes

The chapter body fluid and circulation deals with special fluid within the body to transport material from cell to cell. The NCERT Class 11 Biology chapter 18 notes covers a brief outline of the chapter Body Fluid and Circulation. The main topics covered in Body Fluid and Circulation Class 11 notes are blood, plasma, blood groups, lymph (tissue fluid), circulatory pathways, Human Circulatory System, double circulation, Electrocardiograph (ECG), regulation of cardiac activity, and disorders of the circulatory system. Download the CBSE Notes for Class 11 Biology, Chapter 18, PDF to use offline anywhere. Students must go through each topic in the body fluid and circulation in Class 11 Notes Biology in the easiest and most effective way possible with the help of NCERT Notes for Class 11.

Class 11 Biology chapter 18 notes also cover the basic knowledge in the chapter. Body fluids and circulation NCERT Notes for Class 11 Biology help you revise these major concepts given in the NCERT Book in a short period of time during the CBSE Board exam preparation. CBSE Class 11 Biology Chapter 18 notes will help you with quick revision. The Body Fluids and Circulation chapter covers all headings of NCERT. CBSE Class 11 Biology chapter 18 notes also contain important examples that have been frequently asked in the various exams. Having revision notes and NCERT Solutions for Class 11 Biology Chapter 18 handy is beneficial to save you time.The NCERT Class 11 notes pdf can be downloaded through the link given below.

Also, Students can refer,

• NCERT Solutions for class 11 biology chapter 18 Body Fluid and Circulation.
• NCERT Exemplar Class 11 Biology Chapter 18 Solutions Body Fluid and Circulation

NCERT Class 11 Chapter 6 Class Notes

Body Fluids and Circulation

More Complex organisms Use special fluid for Transport materials inside the body. Blood is the most commonly used body fluid by higher organisms including humans. Lymph is a special type of fluid that also helps in the Transport of certain substances.

Blood

• Study of blood: Haematology
• Special Connective tissue Consisting of a fluid matrix, Plasma, and Formed element

Composition of Blood:

• Liquid Part: Matrix- Plasma (55%)
• Solid Part: Blood Corpuscles- RBC, WBC, Platelets (45%)

Plasma:

• Straw coloured
• Viscous fluid

Composition of Plasma:

• Water: 90-92%
• Protein: 6-8%

Major Proteins:-

Fibrinogen:

• Largest Plasma Protein
• Help in blood clotting

Globulin:

• Destroy Bacteria, Virus and Toxic substance
• Produced and secreted by the liver and lymphoid organ

Albumin:

• Smallest Plasma Protein
• Help in maintaining blood colloidal osmotic pressure (BCOP)

Formed Element:

• Erythrocytes, leucocytes, and platelets are collectively called Formed elements.

Erythrocytes (Red blood corpuscles):

• Most abundant cell in the blood.
• A healthy adult man has 5 to 5.5 million RBC per mm³ in blood.
• Formed in red bone marrow in adult
• Mammalian RBC is biconcave, circular, and non-nucleated.
• Red coloured respiratory pigment haemoglobin is present.
• 12 to 16 gm of haemoglobin present in 100 ml of blood.
• The average lifespan of 120 days after that is destroyed in the spleen.

Leucocytes (White blood corpuscles):

• Colourless due to lack of haemoglobin.
• Total Leucocyte count- 6000 to 8000 per mm³.
• Based on the nucleus and nature of the cytoplasm. Leucocytes are of two types

Granulocytes:

• Granules are present in the cytoplasm which can be stained by the specific dye
• Multilobed nuclei and lobes are connected by protoplasmic strands.
• Produced in the bone marrow.
• Are of three types: Acidophils, Basophils, Neutrophils.

Agranulocytes:

• Agranular cytoplasm
• Lobes are not present in the nucleus and are called mononuclear WBC
• Produced in bone marrow
• Are of two types: Monocytes, Lymphocytes

Platelets: (Thrombocytes)

• Cell fragments produced by megakaryocytes.
• Normally Present in blood 1,50,000-3,50,000 per mm³.
• Release substances involved in coagulation or clotting of blood.

Blood Groups

• Various types of Grouping of blood has been done.
• Two of these – The ABO and Rh are widely used.

Blood Group and Donor Compatibility

• Group ‘O’ blood can be donated to any person with any other blood group.
• ‘O’ Blood group individuals are called Universal Donor
• ‘AB’ Blood group person can accept blood from a person with any blood group
• ‘AB’ Blood group individuals are called Universal recipient

Rh Grouping:

• Discovered by Landsteiner & Weiner in Rhesus monkey.
• Rh antigen is due to a dominant gene.
• If one of the gametes contains the Rh gene its offspring become Rh +ve
• Rh antigen found on the surface of RBCs.

Rh incompatibility (mismatching) is a condition in which the Rh-ve blood of a pregnant mother will have Rh+ve blood of the fetus. The blood of the mother and foetus are separated by the placenta, hence the RH antigen of the foetus does not get exposed to the RH negative blood of the mother in the first pregnancy. It is also possible that during the delivery of this first child, the blood of the mother can be exposed in small amounts to the blood of the foetus. In this case, the body of the mother develops antibodies against the RH in her blood. In the case of her subsequent pregnancies, the Rh antibodies from the mother (Rh-ve) can leak into the blood of the fetus (Rh+ve) and destroy the fetal RBCs. This could cause severe anaemia and jaundice to the baby and the condition is called erythroblastosis foetalis.

Lymph (TISSUE FLUID)

• Blood passes through the capillaries in tissues. A fluid along with small water-soluble substances move out into the spaces in between the cells of tissues which is known as the interstitial fluid or the tissue fluid or the lymph. The lymph contains the same composition as that of plasma. The main function of lymph is the exchange of gases and nutrients.

Circulatory Pathways

• Two types of circulatory pathways.

Human Circulatory System

= Heart+ Blood vessels+ Blood.

Human Heart:

• Origin- Mesodermal
• Position- in the thoracic cavity between two lungs, Slightly tilted to left
• Covering- Double-walled Pericardium

Structure-

Conducting System of Heart:

Cardiac Cycle:

• The sequential event in the heart which is cyclically repeated is called the cardiac cycle.

• Stroke Volume: 70 ml in 1 Cardiac Cycle.
• Cardiac Output: Stroke volume× Heart rate

70 × 72 = 5040ml = 5 litre

Electrocardiograph (ECG):

• In the following figure, the electrical excitation which is also known as the depolarization of the atria is represented by the P-wave. As a result of it, the contraction of both the atria occurs.
• The depolarisation of the ventricles is represented and initiated by the QRS complex. After Q, the systole phase begins and the contraction starts.
• The ventricles from an excited to a normal state, also known as repolarisation is shown by the T-wave. The end of the systole is also denoted by the end of the T-wave.

Double Circulation

• Blood flow via a strictly fixed route through blood vessels - Arteries and veins.
• Arteries and veins consist of three-layer:

Inner- Tunica intima

Middle- Tunica media

Outer- Tunica Externa

• Tunica media is comparatively thin in Veins.
• The systemic circulation gives us essential nutrients, O2, and other essential substances to the tissues and takes off CO2 and other harmful substances.
• The vascular connection present between the digestive tract and liver is called the hepatic portal system.
• Hepatic Portal vein carries blood from intestine to liver before going into the systemic circulation.

Regulation of Cardiac Activity

• Human Heart is Myogenic
• Auto regulated by the specialized muscle (Nodal tissue)
• Neural signals through The sympathetic nerves (part of ANS) can increase the rate of heartbeat
• Parasympathetic neural signals decrease the rate of heartbeat, speed of conduction of action Potential and thereby the cardiac output.
• Adrenal medullary hormones Can also increase cardiac output.

Disorders of The Circulatory System

High Blood Pressure (Hypertension):

• Normal BP is 120/80 mm of Hg - Systolic Pressure-120 and Diastolic pressure-80.
• If BP increase more than 140/90 mm of Hg then called Hypertension

Coronary Heart Disease: Caused by deposition of ca+², Fat, Cholesterol, and fibrous tissue in arteries

Angina Pectoris: Pain in heart muscles

Heart Failure: Condition when the heart is not pumping blood effectively to meet the needs of the body

Cardiac arrest: Heart stops beating.

Heart Attack: Death of heart muscle due to inadequate blood supply.

Chapter-Wise NCERT Class 11 Notes Biology

Significance of NCERT Notes for Class 11 Biology chapter 18

Class 11 Body Fluid and Circulation Notes will be helpful to revise the chapter and explain the main topic covered in the chapter. These Notes for Class 11 Biology chapter 18 are also beneficial for covering the core concepts of the CBSE Biology Syllabus in Class 11 as well as for competitive exams such as AIPMT, AIIMS, NEET, and other similar exams. Class 11 Biology chapter 18 notes pdf download can be utilized for offline preparation.

Subject Wise NCERT Exemplar Solutions

• NCERT Exemplar Class 11 Solutions
• NCERT Exemplar Class 11 Maths
• NCERT Exemplar Class 11 Physics
• NCERT Exemplar Class 11 Chemistry
• NCERT Exemplar Class 11 Biology

Subject Wise NCERT Solutions

• NCERT Solutions for Class 11 Mathematics
• NCERT Solutions for Class 11 Chemistry
• NCERT Solutions for Class 11 Physics

• NCERT Solutions for Class 11 Biology