135 Flashcards
(34 cards)
What is used to distinguish between T and B cells
Molecules on their cell surface
How does the antibody elimination of pathogen occur (B-cell mediated)
Pathogen is opsonised
Faster phagocytosis
Antibodies recruit complement proteins
Causes formation of membrane attack complex
Hole forms in pathogen’s membrane
Pathogen destroyed
Draw and label a diagram of HIV and state how HIV infects the body
HIV infects T helper cells
-GP120 binds to CD4
-GP41 binds to CXCR4 on surface of Th
HIV destroys T helper cells
B and Tc cell-mediated immunity lost
3 methods for detection of HIV infection
Antibodies to HIV (‘seroconversion’)
-ELISA
-Chromogenic substrates
-Immunochromatography
-Latex particle agglutination
Detection of HIV viral RNA
-Polymerase chain reaction
-PCR amplifies a target DNA sequence
-Window period detection of HIV using RT-PCR
Detection and monitoring of HIV infection by analysis of T helper cell number
-Flow cytometry and fluorescence-activated cell sorting (FACS)
- Flow cytometry and FACS using more than one fluorochrome
How does an ELISA test work
- HIV antigen e.g. p24, gp41 bound to well
- Patient serum added. Anti-HIV antibodies bind to antigen
- Anti-human antibody binds to anti-HIV antibodies. Enzyme linked
- Substrate added, converted to coloured product by enzyme
What are the symptoms of multiple myeloma
Anaemia
Weakness
Tachycardia
Recurrent infection
Bone pain/factures: Osteoclasts dissolves bone, activity up-regulated in MM, factures of long bones, ribs and vertebrae
Diagnosis of multiple myeloma
-Cancerous proliferation of a clone of immunoglobulin-producing plasma cells in the bone marrow
-Large amount of one immunoglobin produced
-Detect via cellulose acetate electrophoresis
-Malignant plasma cells stay in bone marrow and activate osteoclasts
-Bone broken down
What is autoimmunity
Autoimmunity occurs when the bodies immune system fails to recognise self and attacks self cells.
What is pernicious anaemia
Absorption of vitamin B12 requires combination with intrinsic factor made by gastric parietal cells.
In pernicious anaemia there are autoantibodies against gastric parietal cells so less B12 absorbed.
Vitamin B12 is needed to synthesis DNA. Red blood cell production requires rapid DN synthesis
Therefore less RBC, less O2 transport
What is a barrier and exciter filter in transmitted light fluorescence microscopy
Barrier filter - enables visible fluorescent light to pass to eye
Exciter filter - maximum amount of appropriate wavelength light reaches specimen
Draw and label the gastrointestinal tract
Draw and label a diagram of the stomach
Draw and label a diagram of the structure of the stomach wall
Draw and label a diagram of the gastric pit
Draw and label a diagram of the small intestine
Draw and label a diagram of the layers of the small intestine
Draw and label a diagram of the section of a villus
What is an ulcer
Break in the lining of the gut which fails to heal it is often inflamed which causes more acid secretion
Symptoms: upper abdominal pain, nausea, vomiting
Treatment: Antibiotics and proton-pump inhibitors to reduce formation of HCl in the stomach
How can H.pylori survive in the stomach’s low pH
H.pylori produces enzyme urease. Urea is broken down by urease to form ammonia and carbon dioxide. The ammonia and further formed HCO3- (from ammonia and water) neutralises stomach acids
Cause, symptoms, diagnosis, treatment of coeliac disease
Cause: Sensitivity to gliadin - component of gluten in wheat, barley, rye
-TTGA attaches to gliadin peptides followed by phagocytosis leading to immune destruction of intestinal mucosa
Symptoms: Diarrhoea, weight loss
Diagnosis: By biopsy of small intestine mucosa and ELISA
Treatment: Remove gluten from the diet
Crohn’s disease
Chronic inflammatory disease affecting small intestine where submucosa is thickened
Symptoms
-Diarrhoea (may contain blood)
-Abdominal pain
-Tiredness
-Weight loss
Diagnosis
-Intestinal biopsy, fecal tests, barium meal, CT/MRI scan
Treatment
Surgery, corticosteroids, antibiotics, but no cure
What is 3 problems with having a mutation in the CFTR
-It is a chloride ion channel
-Important in sweat production
-Important in intestinal chloride ion secretion
What does high mucus viscosity cause in cystic fibrosis
Lungs - chest infections, inflammation, structural changes
GI tract - exocrine ducts in pancreas blocked
Pancreas - ducts containing secretory juices blocked by viscous mucus
Why is there increased sweat in people with CF
CFTR facilitates movement of Cl- from the sweat to the cytoplasm of the cell. So without CFTR, Cl- stays on surface of skin, combines with Na+ to give NaCl
