IB Biology HL > Immunity and kidneys > Flashcards

Immunity and kidneys Flashcards

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1
Q

What is a disease?

A
  • prolonged change in organism’s
    homeostasis caused by action of particular factors (mutations, trauma, pathogen action)
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2
Q

What is a pathogen?

A
  • an organism (or virus) that infect another organisms leading to development of a disease
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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
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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)
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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
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6
Q

What is the danger of forming blood clots?

A
  • if it occurs inside the vessel, could cause blockages
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7
Q

What are the steps of clotting cascade?

A
  1. platelets release clotting factors
    • platelets = cellular fragments in blood
    • first, form temporary plug
  2. clotting factors produce thrombin
    • conversion of fibrinogen (soluble) to fibrin (insoluble)
  3. fibrin mesh forms
    • platelets and blood cells trapped
    • clot is a gel but with air hardens
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8
Q

What is coronary thrombosis?

A
  • formation of blood clots in coronary arteries
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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
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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
  • smoking
  • high blood cholesterol
  • diabetes
  • obesity
  • no exercise
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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)
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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
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13
Q

What is a polyclonal response?

A
  • many non-self antigens in body when infected
    • different lymphocyte clones activated = polyclonal response
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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
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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
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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
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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)
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18
Q

What is osmoregulation?

A
  • regulation of amount of water and ions in the organism
    • excretion of excess of osmotically active substances
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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
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20
Q

What are osmoregulators?

A
  • majority of animals
  • active regulation of osmotic balance
  • osmolarity at constant level
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21
Q

What are osmoconformers?

A
  • their osmotic balance changes according to the environment (to avoid drying out)
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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
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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
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24
Q

What are examples of osmoconformers?

A
  • shark
    • high concentrations of urea in the body
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25
How does an osmoregulator survive in salty environment?
- ions in environment — hypotonic fish - 1/3 solute concentration of the seawater
26
What are different forms of nitrogenous waste?
- 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
How do contents of blood in renal artery and vein differ?
- 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
How is blood filtered in glomerulus?
- pressure in capillaries high + permeable capillary wall - fluid forced out —> glomerular filtrate (no proteins) - ultrafiltration
29
What are the stages of urine formation?
- ultrafiltration (non discriminating) - size based - selective reabsorption - substances needed are uptaken - regulation - amounts of reabsorption depends on needs
30
How does the structure of glomerulus facilitate ultrafiltration?
- 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
How are sodium and chlorine ions reabsorbed in proximal convoluted tubule?
- 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
How is glucose reabsorbed in proximal convoluted tubule?
- co-transport with Na+ - Na+ down the concentration gradient - the same for amino acids
33
How is water reabsorbed in proximal convoluted tubule?
- osmosis - concentration gradient (Na+ outside by active transport)
34
What is the role of loop of Henle?
- maintaining hypertonic (high solute) conditions in medulla
35
How does loop of Henle fulfils its function?
- 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) - 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
How is the system of loop of Henle called?
- 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
On what does the length of loop of Henle depend?
- longer = more water volume reclaimed - dry habitats, longer - thicker medulla
38
What is the function of ADH? | Antiduretic hormone
- 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 - 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
What are the consequences of dehydration?
- 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
What are the consequences of overhydration?
- water retention in organism - dilution of body fluids - low sodium conc. - swelling of cells - nerve function disruption, headache
41
What is the treatment for kidney failures?
- 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
What is urinalysis?
- 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
What is the role of phagocytes?
- white blood cells - squeeze through capillary walls - engulf pathogens (endocytosis) - digest with lysosomes - infected wounds —> more phagocytes —> formation of pus
44
What is an antigen?
- 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
What is the role of histamines?
- 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
How do histamines cause allergic reaction?
- cells have membrane bound histamine receptors - causes redness, swelling and pain - rashes and anaphylaxis - anti-histamines for allergy taken
47
What is specific immunity?
- production of antibodies to a particular pathogen - antibodies bind to antigens
48
How are antibodies formed?
- lymphocytes recognise specific types of pathogen - many lymphocytes in small quantities —> variety of antibodies - the best reaction employed - lymphocytes produce antibodies
49
What is the first stage of specific immune response?
1. pathogens ingested by macrophages - antigens on macrophges plasma membrane 2. helper T cells bind to antigens 3. helper T cells which have fitting receptors are activated by macrophage 4. 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
50
What is the role of plasma cells in specific immune response?
- 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
What is clonal selection?
- 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
What are blood groups based on?
- different types of antigens on red blood cells - ABO and Rhesus (Rh)
53
What happens when transfusion involves wrong type of blood?
- immune response = agglutination - hemolysis —> RBC destroyed
54
What is the role of antibodies?
- 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
What is immunity?
- presence of antibodies or memory cells - develops when immune system challenged by antigen - secondary response involves more antibodies —> faster
56
How do vaccines work?
- contain attenuated (weakened) version of pathogens - primary immune response - organism produces antibodies and memory cells
57
Why was Jenner’s vaccine experiment unethical?
- when someone had cowpox, smallpox free - infected 8yo with cowpox —> boy recovered - infected with smallpox —> no problems - no preliminary research on animals
58
How was smallpox eradicated?
- 1950s - last case: Somalia, 1977 - success - only humans can transmit it - symptoms emerge quickly - long-lasting immunity
59
What is a zoonosis?
- pathogen which can cross species barrier - tobacco mosaic virus (tobacco, potato, tomato, eggplant, etc.) - tobacco crops damage - animals living close to human (farming)
60
How are monoclonal antibodies produced? | Once the animal is injected
- 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
61
How does a pregnancy test work?
- hCG detected by monoclonal antibodies - antibodies to hCG immobilise at each strip
62
What are antibiotics?
- substances that inhibit growth of microorganisms - block metabolic pathways in prokaryotes - antibacterial - viruses lack metabolism so doesn’t work - discovered in saprotrophic fungi - fungi and bacteria compete for dead organic matter - example: penicillin - produced by Penincillium fungus
63
How did Florey and Chain test penicillin?
- killed bacteria on agar plates - next, 8 mice: 4 treatment, 4 control - next, humans (dangerous and unethical)
64
How can antibiotic resistance be avoided?
- 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
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