Download MBBS Physiology Presentations 54 Hematology Immunity 1 Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Physiology 54 Hematology Immunity 1 PPT-Powerpoint Presentations and lecture notes

Immunity

Learning Objectives

? Introduction to Immunity

? Innate Immunity

? Lymphoid Tissue


Introduction to Immunity

Immunitas : Freedom from

Immunity is the ability of body to destroy potentially hazardous/harmful

foreign substances, if entered in body, that is it provides FREEDOM from any

foreign invader.

Types of Immunity

Depending on presence-since birth or after birth

Innate (Non specific immunity) - present since birth

Acquired (Specific immunity) - develop afterwards

Humoral Immunity

Cellular Immunity

Acquired

Immunity




Innate Immunity

Innate (Non specific immunity)-

It denotes to nonspecific protection mechanisms that come

into play immediately or within hours of an antigen's

appearance in the body. These mechanisms include-

1) Physical barriers:

2) Chemical barriers:

3) Cellular Components:

4) Proteins:

Natural killer cells

Natural killer cells (also known as Nk cells, K cells, and killer cells) are a type of lymphocyte

which does not undergo processing, show much faster immune reaction and thus a

component of innate immune system.

Interferon

Interferons are named after their ability to "interfere" with

viral replication within host cells.


Alternate pathway of complement system

Lymphoid Tissue

Lymphoid tissue are the sites of processing to form

immunocompetent lymphocytes and storage.

Primary lymphoid tissue (Central lymphoid tissue )

Secondary lymphoid tissue (Peripheral lymphoid tissue)


Primary Lymphoid Tissue-Thymus

Thymus increases in size from

birth (10-15 gm to 40 gm at

puberty) in response to postnatal

antigen stimulation and regresses

thereafter, still, minimal T

lymphopoiesis continues

throughout adult life.

Primary Lymphoid Tissue-Thymus

1) Formation of specific surface receptors during Maturation:

2) Development of `Tolerance to self antigen proteins':


Secondary Lymphoid Tissue-Spleen

This is the body's largest

lymphatic organ.

It is a large encapsulated organ in

left upper part of abdomen, the

outer capsule is fibro-elastic. Like

the thymus, the spleen has only

efferent lymphatic vessels. The

germinal centers are supplied by

arterioles.

Secondary Lymphoid Tissue ? Lymph Nodes

500-600 lymph nodes in the

human body are grouped in

clusters in different regions as

at the base of limbs, abdominal

and neck areas , where lymph is

collected from regions of the

body likely to sustain pathogen

contamination from injuries.


Secondary Lymphoid Tissue ? Lymphoid follicles

Lymph

Lymph, (lymph = clear fluid)

Fluid filters out of capillaries and drains into lymphatic vessels to become lymph and circulates

throughout the lymphatic system.

Lymph is same as interstitial fluid, the fluid around tissue cells. Lymph eventually drains into

venous blood.
Self Assessment

Immunity is the ability of body to ............................potential y hazardous/harmful foreign substances.

Innate immunity denotes to ............. protection mechanisms that come into play ....................of an antigen's

appearance in the body.

Natural kil er cells are a type of lymphocyte which does not undergo ........................

Interferons are named after their ability to "interfere" with .........................................within host cells.

........................... is the body's largest lymphatic organ.

Tolerance to self antigen proteins develop in .......................

Thank you