Question
Draw a diagram and describe the immune system found in humans.
✓
Answer
Human immune system is made up of the following structures :
(1) Lymphoid organs
(2) Cells
(3) Tissues
(4) Soluble molecules like antibodies
The immune system recognizes, responds to, and remembers foreign antigens. The immune system plays an important role in allergic reactions, auto-immune diseases and organ transplantation.
Lymphoid Organs : These are the organs in which the generation or maturation and proliferation of lymphocytes takes place. There are two types of lymphoid organs :
(i) Primary Lymphoid Organs : Organs in which immature lymphocytes differentiate into antigen sensitive lymphocytes are called primary lymphoid organs.
Example : Bone marrow and thymus.
(ii) Secondary Lymphoid Organs : After maturation, lymphocytes move to secondary lymphoid organs. Where lymphocytes interact with antigen, which then proliferate in large numbers and become effector cells.
Example : Spleen, lymph nodes, tonsils, paired screw of small intestine and appendix. See the picture for the location of lymphoid organs in the human body.
Bonemarrow is a major lymphoid organ in which lymphocytes and all blood cells are produced.
Thymus is a lobed organ located below the sternum near the heart. The thymus is quite large at birth but as age increases, its size decreases and by puberty it remains very small. Both bone marrow and thymus provide microenvironment for the growth and maturation of Tlymphocytes.
The shape of the spleen is like a bean seed and is large in size. Mainly lymphocytes and phagocytes are found in it. It acts as a blood filter by trapping the micro-organisms produced in the blood. The spleen is a storehouse of red blood cells (RBCs). Lymph nodes are located at different places on the lymphatic system. These lymph nodes are small and solid in size. Lymph glands trap microorganisms or other antigens that enter lymph and tissue fluid. Antigens trapped in lymph nodes are responsible for the activation of lymphocytes present there and the immune response.
Mucosal Associated Lymphoid Tissue : Lymphoid tissue is located within the linings of major pathways such as the respiratory, digestive and genitourinary tracts.
It constitutes approximately fifty percent of the lymphoid tissue of the human body
(1) Lymphoid organs
(2) Cells
(3) Tissues
(4) Soluble molecules like antibodies
The immune system recognizes, responds to, and remembers foreign antigens. The immune system plays an important role in allergic reactions, auto-immune diseases and organ transplantation.
Lymphoid Organs : These are the organs in which the generation or maturation and proliferation of lymphocytes takes place. There are two types of lymphoid organs :
(i) Primary Lymphoid Organs : Organs in which immature lymphocytes differentiate into antigen sensitive lymphocytes are called primary lymphoid organs.
Example : Bone marrow and thymus.
(ii) Secondary Lymphoid Organs : After maturation, lymphocytes move to secondary lymphoid organs. Where lymphocytes interact with antigen, which then proliferate in large numbers and become effector cells.
Example : Spleen, lymph nodes, tonsils, paired screw of small intestine and appendix. See the picture for the location of lymphoid organs in the human body.
Bonemarrow is a major lymphoid organ in which lymphocytes and all blood cells are produced.
Thymus is a lobed organ located below the sternum near the heart. The thymus is quite large at birth but as age increases, its size decreases and by puberty it remains very small. Both bone marrow and thymus provide microenvironment for the growth and maturation of Tlymphocytes.
The shape of the spleen is like a bean seed and is large in size. Mainly lymphocytes and phagocytes are found in it. It acts as a blood filter by trapping the micro-organisms produced in the blood. The spleen is a storehouse of red blood cells (RBCs). Lymph nodes are located at different places on the lymphatic system. These lymph nodes are small and solid in size. Lymph glands trap microorganisms or other antigens that enter lymph and tissue fluid. Antigens trapped in lymph nodes are responsible for the activation of lymphocytes present there and the immune response.
Mucosal Associated Lymphoid Tissue : Lymphoid tissue is located within the linings of major pathways such as the respiratory, digestive and genitourinary tracts.
It constitutes approximately fifty percent of the lymphoid tissue of the human body
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Human female is not fertile after menopause whereas males can produce gametes at any age after puberty. Analyse the statement and schematically represent a comparison between gametogenesis in males and females.
Where do transcription and translation occur inside a living cell? Briefly describe the three steps involved in the process of translation?
Explain the steps involved in the elongation of polypeptide chain during its synthesis.
Match the items of column A with those given in column B.
|
S. No
|
Column A
|
S. No
|
Column B
|
|
(i)
|
Eli Lilly
|
(a)
|
Cotton bollworm
|
|
(ii)
|
Pest resistance
|
(b)
|
Meloidegyne incognitia
|
|
(iii)
|
Crylab
|
(c)
|
Golden Rice
|
|
(iv)
|
CryIAC
|
(d)
|
Humulin
|
|
(v)
|
RNAi
|
(e)
|
Corn borer
|
|
(vi)
|
Vitamin A
|
(f)
|
Bt cotton
|
Draw a diagrammatic sketch of biogas plant, and label its various components given below: Gas Holder, Sludge Chamber, Digester, Dung + water chamber.
What do you understand by energy flow in an ecosystem? Explain the flow of energy through different trophic levels. Draw a diagram of a food chain.
A true breeding pea plant homozygous for axial violet flowers is crossed with another pea plant with terminal white flowers (aavv).
Give the phenotypic ratio of $F_2$ generation.
→Give the phenotypic ratio of $F_2$ generation.
Make a list of any three outbreeding devices that flowering plants have developed and explain how they help to encourage cross-pollination.
Answer the following questions:
Seeds offer several advantages to angiosperms. Describe any three such advantages.
Seeds offer several advantages to angiosperms. Describe any three such advantages.
- Draw the pyramids of biomass in a pond and in a forest. Explain giving reasons why the two pyramids are different.
- Pyramid of energy is always upright. Explain.