1. Human Health & Diseases Class: XII L No: 13
By Mrs. Anjumara Mulla

2. HEALTH
Health does not simply mean absence of disease or physical fitness.
It could be defined as a state of complete physical, mental and social well being & not merely absence of disease or infirmity

3. Concept of Immunology
Immunology is the science which deals with the study of immune system, immune responses to foreign substances & their role in resisting infections.
Any foreign substance invading body & capable of stimulating an immune response is called an antigen.
The protective chemicals produced by immune cells in response to antigens are called antibodies.

4. Types of Immunity

5. Innate Immunity Innate immunity is called natural immunity
Present from birth
Inborn capacity of the body to resist the pathogen
Does not depend on previopus exposure to foreign substances
Also called non specific immunity

6. Barriers of Innate Immunity
Anatomical Barriers: prevent entry of microorganism into the body. It includes skin & mucous membrane. Mucous coating of respiratory tract & GIT, UGT help in trapping microbes entering body
Physiological Barriers: pH, fever, lysozyme is a bacteriolytic enzyme, present in tears which digests bacterial cell walls. Certain cells release interferons INF ( glycoproteins). It makes surrounding cells resistant to viral infections

7. Phagocytic Barriers: brings phagocytosis
Phagocytic Barriers: brings phagocytosis. Neutrophils & phagocytes engulf & destroy invading microbes. Macrophages are large irregular shaped cells that engulf microbes & cellular debris
Inflammatory Barriers: Infection/tissue injury causes redness, swelling, pain & production of heat that may result in fever. This response is due to release of certain chemicals such as histamines & prostaglandins. The chemicals dilate & make blood capillaries more permeable in region of tissue injury. Vascular fluid comes outr of blood vessels. Fluid contains serum proteins which kill bacteria

9. Acquired Immunity/ Specific Resistance
Ability of the body to defend itself against invading foreign agents like bacteria, viruses, toxins & transplanted tissues is called specific resistance.
It is found only in vertebrates

10. Features of Acquired Immunity
Specificity: Highly specific for pathogen
Diversity: It can recognize a vast variety of diverse pathogens or foreign molecules
Discriminaion between self and non-self: it can differentiate between body cells & foreign cells
Memory: when encountered with a pathogen immune system retains memory of this encounter. Second encounter brings quicker & stronger immune response

11. Types 0f Acquired Immunity
Active Acquired Immunity
- Natural Active Acquired Immunity
- clinical or subclinical infection
(you have the disease and become immune)
- Artificial Acquired Immunity
- following vaccination with live or dead
infectious disease microorganism or
injection of their products

12. Types 0f Acquired Immunity
Passive Acquired Immunity
- naturally acquired through mother’s placenta
- naturally acquired by mother’s milk
Artificallly acquired immunity from injection of prepared antibodies from another organism

13. Acquired Immunity
Vaccination
- prevents (and controls) such diseases as Polio, Diptheria, Tetanus, Measles, Mumps, Chickenpox, Hepatitis A and B, and many others
Vaccines work with the bodies nature mechanisms by causing the body to produce antibodies against the microorganisms

14. Cells of acquired or specific Immune System
Lymphocytes: 2 types
B & T lymphocytes
Haematopoiesis
B Lymphocytes are matured in bone marrow
T lymphocytes are matured in thymus
B Lymphocytes produce antibody mediated or humoral immunity
T lymphocytes produce cell mediated cellular immunity

15. Mechanism Of action of T lymphocytes
On coming in contact with an antigen a T- lymphocytes forms a clones of T cells which are similar but they perform different functions
Helper T cells
Killer T cells/
Cytotoxic T cells
Suppressor T cells
Memory T cells

16. Mechanism Of action of B lymphocytes
B lymphocytes are sensitize by both antigens as well as helper T cells
Activated B cells will produce clones to produce plasma cells & memory B cells
Plasma cells produces antibodies which flow in blood
Antibodies have 3 main functions: a) Agglutination
b) Opsonization
c) Neutralization

20. Antigen Presenting Cells
APC engulf invading pathogens & process the antigens
Then the processed antigens are presented on their surface

21. Structure of Antibody

22. Antigen Antibody Complex

23. Antigen Antibody Complex
A branch of immunology which deals with study of antigen- antibody interactions is called serology
Combining sites of antigens are called antigenic determinants ( epitopes)
Combining sites of antibodies are called antigenic determinants ( paratopes)

24. Antigen on Blood Cells
A, B & O blood groups were discovered by Karl Landsteiner in 1900
AB blood group was discovered by Decastallo & Sturli

26. Rh Factor
It is an Ag present on RBC discovered by Landsteiner & Weiner
Rh +ve and Rh –ve
It produces strong immunogenic response

27. Pathogens & Parasites
Pathogenicity is the ability of an organism to enter a host & cause a disease
Parasite is an organism that lives in or on and takes its nourishment from another organism
2 types : a) Ectoparasite
b) endoparasite

28. Amoebiasis
Causal agent: Entamoeba histolytica is well recognized as a pathogenic amoeba.
Geographic Distribution: Worldwide, with higher incidence of amebiasis in developing countries. 
In industrialized countries, risk groups include male homosexuals, travelers and recent immigrants, and institutionalized populations

30. Transmission 1-driect contact of person to person( fecal-oral)
2- Veneral transmission among homosexual males( oral-anal
3- Food or drink contaminated with feces containing the E.his. cyst
4- Use of human feces (night soil) for soil fertilizer
5- contamination of foodstuffs by flies, and possibly cockroaches

31. Clinical symptoms Asymptomatic infection Symptomatic infection
Intestinal Amebiasis Extraintestinal Amebiasis
Dysenteric Non-Dysenteric colitis Hepatic Pulmonary The extra foci
Liver abscces Acute nonsupprative
Intestinal Amebiasis symptoms: Diarrhea or dysentery, abdominal pain, cramping , anorexia, weight loss, chronic fatigue

32. Prevention
Wash hands thoroughly with soapafter using toilets or changing diaper
Clean bathrooms & toilets often
Avoid raw vegetables growth using human faeces as fertilizer
Drinked boiled water
Avoid eating unhygienically prepared foods

33. Malaria
Malaria is a mosquito borne infectious disease of humans caused by:
Plasmodium falciparum
Plasmodium vivax
Plasmodium ovale
Plasmodium malariae

34. Life cycle of malarial Parasite

35. Symptoms of Malaria

36. Prevention of malaria

37. Filariasis Caused by thread like nematode (roundworm)
Causative agents: Wuchereria bancrofti, Brugia malayi, Brugia timori

38. Life cycle of Filariasis

39. Symptoms of Filariaisis
Edema with thickening of the skin and underlying tissues is the classical symptom of elephantiasis. It usually affects the lower extremities. However, the arms, vulva, breasts and scrotum (causing hydrocele formation) can also be affected. The edema in the extremities, breast or genital area can result in the part becoming  several times its normal size and is due to blockage of the vessels of the lymphatic system.

40. Prevention of Filariasis
Treatment with diethylcarbamine 100mg twice a day for 3 weeks and for 5 days every 6 months
Avoiding mosquito bites, by using mosquito nets

41. Ascariasis
Long, slender almost featureless externally, tapered at both ends.

42. Life Cycle of Ascariasis

43. Symptoms Of Ascariasis
Roundworms in your intestines cause the following symptoms:
nausea
vomiting
irregular stools
stomach or abdominal pain
weight loss

44. Prevention of Aascariasis
The best way to prevent ascariasis is to always:
Avoid ingesting soil that may be contaminated with human feces, including where human fecal matter ("night soil") or wastewater is used to fertilize crops.
Wash your hands with soap and warm water before handling food.

45. Typhoid
Salmonella Typhi, also known as Salmonella enterica serotype Typhi, growing in the intestines and blood. Typhoid is spread by eating or drinking food or water contaminated with the feces of an infected person. Risk factors include poverty as a result of poor sanitation and poor hygiene.

46. Salmonella typhi It is pathogenic Gram –ve bacteria O.M consist of LPS
LPS is made up of O Ag, polysaccharide core and lipid A
PO4 groups determine bacterial toxicity
O Ag is responsible for host immune response & makes it difficult for Abs to recognize
Flagella is with H antigen

47. Symptoms of Typhoid Common symptoms of typhoid fever can include:
a high temperature, which can reach up to 39-40°C ( °F)
headache
muscle aches
stomach pain
feeling sick
loss of appetite
constipation or diarrhoea (adults tend to get constipation and children tend to get diarrhoea)
a rash made up of small pink spots
exhaustion
confusion, such as not knowing where you are or what is going on around you

48. Prevention of Typhoid 2 vaccines are available
Oral Ty21a vaccine (sold as Vivotif Berna)
Injectable Typhoid polysaccharide vaccine (sold as Typhim Vi by Sanofi Pasteur and Typherix by GlaxoSmithKline)

49. Pneumonia
Pneumonia is an inflammatory condition of the lung, especially inflammation of the alveolar when the lungs fill with fluid
Viral pneumonia is commonly caused by Influenza virus (RSV), adenovirus & para influenza
Bacterial pneumonia Streptococcus pneumoniae

50. Symptoms of Pneumonia

51. Prevention Vaccination in both children & adults
Vaccination against H. influenzae & S. pneumoniae in the first year of life have greatly reduced the chances of causing pneumonia in children
When an influenza outbreaks medication such as amantidine, rimantadine,and oseltamivir

52. Common Cold
Also known as nasopharyngitis, acute viral rhinopharyngitis, acute coryza or a cold is viral infectious disease of URT caused primarily by rhinoviruses & coronaviruses
Common symptoms include cough, sore throat, running nose & fever.
Normal adults gets 6-12 infections in a year

53. Prevention of Common Cold
Best way stay away from infected people
Hand washing with plain soap, rinsing, drying physically

54. THANKYOU