Immunology & Immune System PDF

IMMUNOLOGY & IMMUNE SYSTEM 1. Innate Immunity (Natural Immunity) ○ It’s the body’s first line of defense that acts immediately when germs invade. ○ Key Parts: Barriers like skin and stomach acid stop germs from entering the body. Phagocytic Cel...

IMMUNOLOGY & IMMUNE SYSTEM 1. Innate Immunity (Natural Immunity) ○ It’s the body’s first line of defense that acts immediately when germs invade. ○ Key Parts: Barriers like skin and stomach acid stop germs from entering the body. Phagocytic Cells like macrophages and neutrophils "eat" harmful germs. Complement Proteins help attack germs by punching holes in their surfaces. 2. Adaptive Immunity (Memory-Based Immunity) ○ This kicks in after the innate response and specifically targets invaders. ○ Key Parts: B cells make antibodies that latch onto germs and mark them for destruction. T cells find and kill infected cells or help B cells make more antibodies. ○ How It Works: Memory cells remember past infections, so if the same germ comes back, the body can fight it faster. 3. Phagocytosis ○ A process where immune cells engulf (swallow) and digest germs or dead cells. ○ Important steps include presenting pieces of the germs on the cell surface for other immune cells to recognize. 4. Inflammation ○ When your body fights infection, the area becomes red, swollen, and warm. ○ This process helps isolate the area to prevent the spread of germs and promotes healing. 5. Antibodies and Their Role ○ Different antibodies (IgM, IgG, IgA, etc.) have unique roles in defending the body. ○ Primary response: IgM fights the first infection. ○ Secondary response: IgG steps in for faster, stronger defense the next time. PRIONS & MAD COW DISEASE Prions are abnormal proteins that can cause brain diseases in animals and humans. They’re not like regular germs because they don’t have DNA or RNA. Mad Cow Disease (BSE) is a disease in cows that affects their brain and nervous system. Prevention in Cattle: ○ Strict bans on using certain animal products in cattle feed. ○ Careful testing to keep affected animals out of the food supply. Symptoms: ○ Cows: Nervous behavior, weight loss, and difficulty moving. ○ Humans (vCJD): Depression, personality changes, loss of movement control, and eventually death. CANINE & FELINE VIRAL DISEASES 1. Rabies ○ A serious disease that spreads through bites and attacks the brain. ○ Pathway: Starts at the bite site, moves to the nerves, and then the brain. ○ Symptoms in Animals: Strange behavior, inability to swallow, and aggression. ○ Prevention: Vaccines for pets and post-exposure shots for humans. 2. Canine Parvovirus ○ A virus that severely affects a dog’s intestines, causing vomiting, diarrhea, and dehydration. ○ Transmission: Direct contact with an infected dog or contaminated objects. 3. Feline Leukemia Virus (FeLV) ○ Similar to HIV in humans; weakens the immune system, making cats vulnerable to other illnesses. ○ Spread: Through saliva, nasal secretions, and other body fluids. DISEASES FROM FUNGI & PARASITES 1. Fungal Diseases (e.g., Coccidioidomycosis or Valley Fever) ○ Caused by inhaling fungal spores found in soil. ○ Life Cycle: Fungi in the soil release spores, which are inhaled and cause infection in the lungs. ○ Symptoms: Cough, fever, and fatigue. 2. Helminthic Infections (Parasitic Worms) ○ Types: Flatworms (e.g., tapeworms): Live in the intestines, absorb nutrients through their body surface. Roundworms (e.g., heartworms): Live in organs like the heart or intestines. ○ Differences: Pinworms: Cause itching around the anus, common in children. Hookworms: Enter through the skin, can cause anemia by sucking blood. Heartworms: Live in the heart, dangerous for dogs and can lead to death if untreated. PHARMACOLOGY & VACCINES  1. Vaccines ○ Help the body learn how to fight germs without getting sick. ○ Types: Live Attenuated: Contains a weakened version of the virus; strong and long-lasting immunity. Inactivated: Dead virus; safer but may need booster shots. Subunit: Only parts of the germ, very safe. mRNA Vaccines: Provide instructions for cells to make a protein from the virus to trigger an immune response (e.g., COVID-19 vaccines). ○ Herd Immunity: If most people are vaccinated, it stops the disease from spreading easily. 2. Antibiotic Resistance ○ Some bacteria, like Staphylococcus aureus and Salmonella, no longer respond to antibiotics, making infections harder to treat. 3. Why Vaccines Fail: ○ The animal may already be sick. ○ The vaccine could be ineffective due to poor storage or handling. BOVINE & EQUINE DISEASES 1. Bovine Respiratory Disease ○ Affects cows’ lungs and is caused by multiple germs. ○ Factors: Stress and crowded living conditions make it worse. 2. Horse Diseases ○ Strangles: Affects the throat and lymph nodes, highly contagious. ○ West Nile Virus: Transmitted by mosquitoes, can cause swelling in the brain.