Immunity and kidneys Flashcards
1
Q
What is a disease?
A
- prolonged change in organism’s
homeostasis caused by action of particular factors (mutations, trauma, pathogen action)
2
Q
What is a pathogen?
A
- an organism (or virus) that infect another organisms leading to development of a disease
3
Q
What is the role of skin in primary defence?
A
- tough layer (physical barrier)
- sebaceous glands secrete sebum
- skin moisture + low pH
- no fungi and bacteria growth
- sebaceous glands secrete sebum
4
Q
What is the role of mucous membranes in primary defence?
A
- mucous membranes
- thinner and softer
- mucus –> sticky solution of glycoproteins
- pathogens trapped and expelled
- antiseptic properties (anti-bacterial enzyme)
- pathogens trapped and expelled
5
Q
What is blood clotting?
A
- skin is cut —> damage to blood vessels = bleeding
- clotting
- blood from liquid to semi-solid gel
- cuts allow pathogens to enter
6
Q
What is the danger of forming blood clots?
A
- if it occurs inside the vessel, could cause blockages
7
Q
What are the steps of clotting cascade?
A
- platelets release clotting factors
- platelets = cellular fragments in blood
- first, form temporary plug
- clotting factors produce thrombin
- conversion of fibrinogen (soluble) to fibrin (insoluble)
- fibrin mesh forms
- platelets and blood cells trapped
- clot is a gel but with air hardens
8
Q
What is coronary thrombosis?
A
- formation of blood clots in coronary arteries
9
Q
What are the consequences of coronary thrombosis?
A
- heart wall no oxygen and glucose
- no ATP formed
- irregular contractions
- quivering movements = fibrillation
- may be fatal
- no ATP formed
10
Q
What are the causes of coronary thrombosis?
A
- atherosclerosis, coronary occlusion, damage etc.
- atheroma (fatty deposits) develop in arteries
- arterial walls damaged and hardened by calcium salts
- rupture = lesion
- atheroma (fatty deposits) develop in arteries
- smoking
- high blood cholesterol
- diabetes
- obesity
- no exercise
11
Q
How is HIV transmitted?
A
- infected blood: blood transfusions (sharing needles)
- infected semen / vaginal mucus (unprotected sex)
- infected mothers milk (low risk)
- during birth there is a risk —> drugs are given
- infected saliva (almost 0 risk)
12
Q
What is HIV?
A
- human immunodeficiency virus
- attacks lymphocytes
- helper T cells
- number of lymphocytes decreases
- probability of activation of B cells decreases
- less antibodies
- results in AIDS
13
Q
What is a polyclonal response?
A
- many non-self antigens in body when infected
- different lymphocyte clones activated = polyclonal response
14
Q
What are monoclonal antibodies?
A
- antibodies produced (in lab) to target only one type of pathogen
- process
- antigen purified
- injected into animal
- B cells produce antibodies
- many obtained but only some produce the right antibody
15
Q
What are scientific purposes of monoclonal antibodies?
A
- detection of antigen presence in cells, tissues and body fluids
- recognition of antigen position
- catching antigen ion solution
- targeting anti-cancer chemicals
16
Q
What are other uses of monoclonal antibodies?
A
- diagnosis
- HIV detection
- risk of heart attack detection
- hCG-based pregnancy tests
- therapy
- emergency rabies treatment
- anti-cancer therapy
- blood and tissue typing for transplantation
- purification of commercially used proteins
17
Q
What is excretion?
A
- removal of waste products of metabolic reactions
- to external environment (faeces is not excretion - not part of the body)
18
Q
What is osmoregulation?
A
- regulation of amount of water and ions in the organism
- excretion of excess of osmotically active substances
19
Q
What are the functions of excretory system?
A
- maintain volume of extracellular fluid
- maintain ionic balance in extracellular fluid
- maintain pH and osmotic concentration
- excrete toxic metabolic by-products
20
Q
What are osmoregulators?
A
- majority of animals
- active regulation of osmotic balance
- osmolarity at constant level
21
Q
What are osmoconformers?
A
- their osmotic balance changes according to the environment (to avoid drying out)
22
Q
How do insects regulate osmotic balance?
A
- Malpighian bodies – excretory and regulatory functions
- one end in hemolymph (= blood + lymph, no vessels)
- active excretion of uric acid and ions into the tubule
- from hemolymph
- water follows by osmosis
- ions and water reabsorbed in hindgut, waste excreted
23
Q
What are characteristics of excretory system?
A
- two kidneys
- connected to arterial branches of aorta
- blood returned to vena cava by renal veins
- urine transported by ureters to bladder
- urine released via urethra
24
Q
What are examples of osmoconformers?
A
- shark
- high concentrations of urea in the body
25
Q
How does an osmoregulator survive in salty environment?
A
- ions in environment — hypotonic fish
- 1/3 solute concentration of the seawater
26
Q
What are different forms of nitrogenous waste?
A
- ammonia
- most fish
- diluted in water (not toxic)
- urea
- mammals, some fish, marine mammals
- uric acid
- insects, birds, desert animals
- not water-soluble (doesn’t have to be released)
- doesn’t harm the egg
27
Q
How do contents of blood in renal artery and vein differ?
A
- renal artery
- more toxins
- subst. ingested and absorbed, not fully metabolised
- betain pigment (beets), drugs
- nitrogenous waste = urea
- not excretory products (not produced by body)
- excess water (cell respiration, absorbed from food)
- excess salt (absorbed from food)
- osmoregulation
- renal vein
- constant conc. of salts (osmoregulation occurred)
- deoxygenated (kidney metabolism)
- high CO2
- lower glucose conc. (metabolism)
- plasma proteins the same, should not be present
28
Q
How is blood filtered in glomerulus?
A
- pressure in capillaries high + permeable capillary wall
- fluid forced out —> glomerular filtrate (no proteins)
- ultrafiltration
29
Q
What are the stages of urine formation?
A
- ultrafiltration (non discriminating)
- size based
- selective reabsorption
- substances needed are uptaken
- regulation
- amounts of reabsorption depends on needs
30
Q
How does the structure of glomerulus facilitate ultrafiltration?
A
- glomerular filtrate formed
- blood at high pressure —> filtration easier
- ultrafiltration = based on size
- pores in capillary walls = fenestrations
- blocks blood cells
- basement membrane
- covers capillary walls
- negatively charge glycoproteins —> mesh
- plasma proteins stopped (size and negative charge)
- podocytes (specialised epithelial cells)
- inner wall of Bowman’s capsule
- small branches = foot processes
- around capillaries
- narrow gaps —> small molecules blocked
31
Q
How are sodium and chlorine ions reabsorbed in proximal convoluted tubule?
A
- sodium ions
- active transport (pump proteins on outer membrane)
- outside of tubule
- to peritubular capillaries
- chloride ions
- attracted outside by the gradient formed by Na+
32
Q
How is glucose reabsorbed in proximal convoluted tubule?
A
- co-transport with Na+
- Na+ down the concentration gradient
- the same for amino acids
33
Q
How is water reabsorbed in proximal convoluted tubule?
A
- osmosis
- concentration gradient (Na+ outside by active transport)
34
Q
What is the role of loop of Henle?
A
- maintaining hypertonic (high solute) conditions in medulla
35
Q
How does loop of Henle fulfils its function?
A
- ascending limb
- energy to create gradient
- sodium ions out
- between cells in medulla – interstitial fluid
- impermeable to water (stays in filtrate)
- body fluids (interstitial) – 300 mOsm, pumps can create gradient up to 200mOsm = 500mOsm
- descending limb
- permeable to water but not Na+
- filtrate down the descending limb
- at the end interstitial fluid has high conc. Na+ —> water drawn out
- filtrate conc. = interstitial fluid conc. (500mOsm)
- at the end interstitial fluid has high conc. Na+ —> water drawn out
- enters ascending limbs
- pumps raise the conc. of interstitial fluid (700mOsm)
- fluid passing descending limb
- up to 700mOsm
- interstitial fluid conc. can rise up to 1200mOsm
36
Q
How is the system of loop of Henle called?
A
- countercurrent multiplier system
- countercurrent —> fluid flow in different directions
- multiplier —> steeper gradient in medulla
- same in vasa recta
- prevents diluting medulla conc.
- carries water removed from descending limb (with Na+)
37
Q
On what does the length of loop of Henle depend?
A
- longer = more water volume reclaimed
- dry habitats, longer
- thicker medulla
38
Q
What is the function of ADH?
Antiduretic hormone
A
- water in distal convoluted tubule is hypotonic (Na+ way in loop of Henle)
- low solute conc. —> less water absorbed
- DCT and collecting duct low permeability to water
- more urine, less concentrated
- DCT and collecting duct low permeability to water
- solute conc. increases
- high solute conc.
- hypothalamus —> pituitary —> antidiuretic hormone (ADH)
- ADH increases permeability of walls
- water reabsorbed
- high solute conc. in medulla helps
- less urine, more concentrated
—> osmoregulation
39
Q
What are the consequences of dehydration?
A
- insufficient water intake, diarrhoea
- disruption of metabolic processes
- dark urine
- tiredness, lethargy
- increased tissue exposure to metabolic waste
- low blood volume — low pressure
- body temp. regulation
40
Q
What are the consequences of overhydration?
A
- water retention in organism
- dilution of body fluids
- low sodium conc.
- swelling of cells
- nerve function disruption, headache
41
Q
What is the treatment for kidney failures?
A
- result of diabetes or hypertension
- hemodialysis
- kidneys cannot filter blood
- steady amount of blood passes membrane in machine
- waste products pass, blood cells stay
- risk of infection
- kidney transplant
- living or deceased donor
- level of freedom
- recipient can reject kidney
42
Q
What is urinalysis?
A
- osmoregulation, excretion and metabolism disrupted by illness or drugs
- urinary tests
- high glucose + protein —> diabetes
- high protein —> kidney damage
- monoclonal antibody —> drug detection
- microscopic examination —> cells present
- neutrophils (white BC with nucleus visible) —> infection urinary tract
- red blood cells —> bleeding, kidney stone or tumour
43
Q
What is the role of phagocytes?
A
- white blood cells
- squeeze through capillary walls
- engulf pathogens (endocytosis)
- digest with lysosomes
- infected wounds —> more phagocytes —> formation of pus
- engulf pathogens (endocytosis)
44
Q
What is an antigen?
A
- cells recognise belongings of organism (self or non-self)
- cells possess distinctive surface molecules
- molecule that triggers immune response = antigen
- non-specific immunity
- all non-self objects attracted the same way
45
Q
What is the role of histamines?
A
- response to allergens (infection)
- produced by white blood cells
- mast cells (connective tissue)
- basophils (blood)
- vasodilation (dilation of blood vessels)
- increased capillary permeability
- more leukocytes
46
Q
How do histamines cause allergic reaction?
A
- cells have membrane bound histamine receptors
- causes redness, swelling and pain
- rashes and anaphylaxis
- causes redness, swelling and pain
- anti-histamines for allergy taken
47
Q
What is specific immunity?
A
- production of antibodies to a particular pathogen
- antibodies bind to antigens
48
Q
How are antibodies formed?
A
- lymphocytes recognise specific types of pathogen
- many lymphocytes in small quantities —> variety of antibodies
- the best reaction employed
- lymphocytes produce antibodies
49
Q
What is the first stage of specific immune response?
A
- pathogens ingested by macrophages
- antigens on macrophges plasma membrane
- helper T cells bind to antigens
- helper T cells which have fitting receptors are activated by macrophage
- T cells bind to B cells
- only B cells with matching receptors are activated
- B cells activated by binding of T cells or by release of signalling protein by T cells
- only B cells with matching receptors are activated
50
Q
What is the role of plasma cells in specific immune response?
A
- plasma cells = mature B cells
- produce antibodies
- a lot of rough endoplasmic reticulum (rER)
- synthesis and transport of antibodies
- only some genes expressed —> same proteins
51
Q
What is clonal selection?
A
- activated B cells divide (mitosis)
- plasma cells produce the same antibody = clonal selection
- some clones of B cells —> memory cells
- inactive unless the same pathogen comes
52
Q
What are blood groups based on?
A
- different types of antigens on red blood cells
- ABO and Rhesus (Rh)
53
Q
What happens when transfusion involves wrong type of blood?
A
- immune response = agglutination
- hemolysis —> RBC destroyed
54
Q
What is the role of antibodies?
A
- destruction of pathogens
- opsonisation - pathogen recognisable and easily engulfed
- neutralisation of viruses and bacteria
- preventing from docking to host cells (cannot enter cells)
- neutralisation of toxins
- binding to toxins from pathogens
- activation of complement
- proteins make hole in membrane of pathogen
- water and ions go in —> cell lyses
- agglutination
- sticking together of pathogen
- don’t enter cells, easier to ingest
55
Q
What is immunity?
A
- presence of antibodies or memory cells
- develops when immune system challenged by antigen
- secondary response involves more antibodies —> faster
56
Q
How do vaccines work?
A
- contain attenuated (weakened) version of pathogens
- primary immune response
- organism produces antibodies and memory cells
57
Q
Why was Jenner’s vaccine experiment unethical?
A
- when someone had cowpox, smallpox free
- infected 8yo with cowpox —> boy recovered
- infected with smallpox —> no problems
- no preliminary research on animals
58
Q
How was smallpox eradicated?
A
- 1950s
- last case: Somalia, 1977
- success
- only humans can transmit it
- symptoms emerge quickly
- long-lasting immunity
59
Q
What is a zoonosis?
A
- pathogen which can cross species barrier
- tobacco mosaic virus (tobacco, potato, tomato, eggplant, etc.)
- tobacco crops damage
- animals living close to human (farming)
60
Q
How are monoclonal antibodies produced?
Once the animal is injected
A
- antibody obtained by injecting antigen to mouse
- blood spleen taken —> many antibodies present
- hybridoma cells = B cells + myeloma cells (cancer)
- different variations
- only one has the wanted antibody
- once desired one found —> clones
- cultured in fermenter
- different variations
61
Q
How does a pregnancy test work?
A
- hCG detected by monoclonal antibodies
- antibodies to hCG immobilise at each strip
62
Q
What are antibiotics?
A
- substances that inhibit growth of microorganisms
- block metabolic pathways in prokaryotes
- antibacterial
- viruses lack metabolism so doesn’t work
- block metabolic pathways in prokaryotes
- discovered in saprotrophic fungi
- fungi and bacteria compete for dead organic matter
- example: penicillin
- produced by Penincillium fungus
63
Q
How did Florey and Chain test penicillin?
A
- killed bacteria on agar plates
- next, 8 mice: 4 treatment, 4 control
- next, humans (dangerous and unethical)
64
Q
How can antibiotic resistance be avoided?
A
- antibiotics only for serious bacterial infections
- completing courses of antibiotics
- high standards of hygiene in hospital (no cross-infection)
- no antibiotics in animal feeds for growth
- new types of antibiotics needed
