BIOM Part 3 :) Flashcards

Question

How does an increase in temperature affect Hb affinity for O2?

Answer 1

Increase in temperature decreases Hb affinity for O2 i.e. more offloaded into tissues (opposite for decrease in temperature) * Higher temperatures weaken bond between O2 & Hb

Answer 2

A. Arterial blood saturation B. Oxyhemoglobin decreases by ~22% as the blood passes through the tissues from arteries to veins C. Oxygen reserve * Oxyhemoglobin remaining in venous blood * Enough to sustain brain & heart for ~4-5 minutes without breathing or CPR * Can also be used when tissue requirements increase e.g. exercise

Answer 3

Mature RBC lack nuclei, mitochondria and ER No protein/enzyme synthesis, or ability to repair membrane * Cannot respire aerobically i.e. the cells that carry O2 cannot use it * RBCs must obtain energy through anaerobic metabolism of glucose * At a certain point in the glycolytic pathway, a side reaction occurs that results in the production of 2,3-DPG * Enzyme that produces 2,3-DPG is inhibited by oxyhemoglobin i.e. when oxyhemoglobin levels decrease (e.g. hypoxia, anemia), 2,3- DPG production is increased * Increased 2,3-DPG concentration increases O2 unloading (shifts curve right)

Answer 4

enzyme that produces 2,3-DPG i.e. when oxyhemoglobin levels decrease (e.g. hypoxia, anemia), 2,3- DPG production is increased * Increased 2,3-DPG concentration increases O2 unloading (shifts curve right)

Answer 5

increases O2 unloading (shifts curve right)

Answer 6

- RBC's take 7 days to develop RBCs age and become fragile Lifespan of 120 days bilirubin produced when old RBCs are destroyed in the spleen

Answer 7

when old RBCs are destroyed in the spleen - breakdown product of heme from Hb - liver enzymes bind bilirubin and it is excreted into bile - phototherapy can also aid in breakdown - circulates in bile, some lost in urine/feces

Answer 8

associated with high blood concentrations of bilirubin from death of RBC (hyperbilirubinemia) skin and whites of eyes have yellow cast healthy newborns - rapid decrease in blood Hb at birth Preemies - inadequate amounts of liver enzymes needed to bind bilirubin so that it can be excreted in the bile (toxic) Phototherapy with blue light

Answer 9

- Inherited defect in Hb, predominant among Mediterranean ancestry - alpha thalassemia: decreased synthesis of alpha Hb chains - Beta thalassemia: impaired synthesis of beta Hb chains - results in excessive destruction of RBCs - Leads to stillbirth, anemia, growth abnormalities, iron overload (leads to heart failure in young adults)

Answer 10

Inherited, recessive disease (2 copies of gene that produces Hb-S instead of Hb-A) Single amino acid substitute in the beta globin chain When deoxygenated, Hb-S polymerizes into long fibers (giving RBC sickle shape), which promote hemolysis Chronic, many clinical complications Lifelong (45 yr life expectancy) heterozygous environmental advantage - high resistance to malaria because plasmodium parasite (carried by mosquitos) cannot live in heterozygous RBCs

Answer 11

straw coloured liquid 92% water ~1% dissolved solutes, trace elements (vitamins), & gases (CO2, O2) ~7% organic molecules * Amino acids * Glucose * Lipids * Nitrogenous waste * Proteins (most produced in liver)

Answer 12

1. albumins 2. globulins 3. fibronogen

Answer 13

- produced in liver - provide osmotic pressure needed to draw water from surrounding tissue fluid into capillaries (maintain blood volume and pressure) - account for most of plasma proteins - albumins along with 9 other proteins account for 90% of plasma proteins (issue for new technology and drug discovery eg. mass spec only detects most abundant proteins) a protein found in blood plasma

Answer 14

- Alpha & beta globulins produced in the liver & function to transport lipids & fat-soluble vitamins * Gamma globulins are antibodies produced by lymphocytes that function in immunity a protein found in blood plasma

Answer 15

- produced in the liver - important for clot formation a protein found in blood plasma

Answer 16

Agglutination (clumping of RBCs) * Occurs when A-type RBCs are mixed with anti-A-type antibodies * Occurs when B-type RBCs are mixed with anti-B-type antibodies

Answer 17

clumping of RBCs - occurs when A-type RBCs are mixed with anti-A-type antibodies - Occurs when B-type RBCs are mixed with anti-B-type antibodies how we determine blood type

Answer 18

Another group of antigens found on RBCs * Rh positive more common than Rh negative * A/B antibodies cannot cross placenta but Rh antibodies can * May cause issues during birth if Rh- mother has an Rh+ positive baby (not an issue during pregnancy when fetal & maternal blood separate) * At birth mother may become sensitized & start to produce antibodies against Rh antigen * During next pregnancy, antibodies can cross placenta & cause RBC hemolysis in fetus (results in Hemolytic Disease in newborn) * Treatment: IV Rh immune globulin (RhIG) after birth of Rh+ baby to destroy fetal cells left in circulation before they elicit immune response

Answer 19

Breaking endothelial lining of vessel exposes collagen proteins from subendothelial connective tissue to blood 3 steps initiated: 1. Vasoconstriction 2. Formation of platelet plug 3. Production of a web of fibrin proteins that penetrate & surround platelet plug

Answer 20

Clot formation: fibringen is converted by thrombin to fibrin * Via extrinsic pathway in vivo * Via intrinsic pathway in vitro

Answer 21

Extrinsic pathway initiated by tissue factor (membrane glycoprotein found in walls of blood vessels & cells of surrounding tissue) * Blood vessel injury results in tissue factor becoming exposed to factor VII & others in the blood, creating a complex * This complex acts as an enzyme to activate factor X * Pathway then generates thrombin which can generate fibrin (important for clotting) from fibrinogen

Answer 22

plasminogen converted to plasmin which digests fibrin (promotes clot dissolution)

Answer 23

Heart attack patients usually treated initially with chewable aspirin to stop platelet clumping (before being evaluated for treatment with angioplasty or clot-dissolving drugs) * One of the most commonly used clot-dissolving medications in US ER departments are TPAs (tissue plasminogen activators) * Also applicable for stroke, blood clots, etc.

Answer 24

ST Elevated Myocardial Infarction Most severe type of heart attack * Artery supplying blood to the heart becomes blocked * Fibrinolytic drugs are the preferred pharmacological class for STEMI treatment because they can achieve reperfusion unlike drugs from other classes * Fibrinolytics act by converting plasminogen to plasmin which in turn cleaves fibrin (results in clot dissolution & restoration of blood flow to ischemic tissues)

Answer 25

Fibrinolytic drugs are the preferred pharmacological class for STEMI treatment because they can achieve reperfusion unlike drugs from other classes Fibrinolytics act by converting plasminogen to plasmin which in turn cleaves fibrin (results in clot dissolution & restoration of blood flow to ischemic tissues)

Answer 26

natural, not learned through experience includes 1st and 2nd line of defense it's non-specific

Answer 27

part of the innate immune system includes physical and chemical surface barriers

Answer 28

internal cellular and chemical defense (if pathogen penetrates barriers) part of innate immune system non-specific

Answer 29

specific defenses 3rd line of defense - immune response (if pathogen survives specific, internal defenses)

Answer 30

uncommited stem cells in bone marrow give rise to progenitor cells for the remaining blood cells and platelets

Answer 31

develop to the megakaryocyte stage in the bone marrow and are released as platelets in circulation

Answer 32

progenitor cells give rise to these cells which are found in circulation

Answer 33

derived from their own lineage of lymphocyte stem cells in the bone marrow, which give rise to lymphocytes in the circulation leukocytes are able to move, squeeze through pores to get to sites - give rise to progenitor cells

Answer 34

fancy name for WBCs includes: Granulocytes and Agranulocytes

Answer 35

Type of leukocyte w lobed nucleus and granular appearance includes: Neutrophils Eosinophils Basophils

Answer 36

Type of leukocyte includes: lymphocytes, monocytes and macrophages

Answer 37

are granulocytes - cells named after morphology and how they stain morphology: lobed nucleus stain: cytoplasmic granules stain blue in hematoxylin dye function in inflammatory reactions and allergies release anticoagulant heparin (slows blood clotting) release histamine (vasodilator increasing blood flow to tissues) basophils found in circulation in low numbers make up <1% of WBC most cells are similar to basophils but are found in the tissues

Answer 38

type of granulocyte morphology: segmented nucleus w 2-5 lobes stain: pink abundance: most abundant leukocyte (make up 54% - 62% of WBCs) function: immunity - early first responder to infections - phagocytose (ingest and kill) 5-20 bacteria during their short (1-2 day) lifespan

Answer 39

1. Roll along the endothelial wall 2. are tethered, captured and activated 3. crawl to exit sites (endothelial cell junctions) 4. exit sites open due to signals btw leukocytes and endothelial cells

Answer 40

Granulocytes Have a bilobed nucleus and stain bright red They Make up 1.3% of white blood cells Function= Defence against parasites Are Are in the G.I. tract urinary and genital epithelia, and they attached to large antibody coded, parasites, and released substances from granules to damage or kill

Answer 41

Second Most devastating, parasitic disease after malaria

Answer 42

Are Agranulocyte they are 2 to 3 times larger than red blood cells and make up 3 to 9% of white blood cells Function = phagocytic Monocytes are the precursors for macrophages monocytes are found in the bloodstream, whereas macrophages are found in the tissues, both our primary tissue scavengers that are larger and more effective than neutrophils they in just 100 bacteria per lifetime and remove debris

Answer 43

Monocytes Are the precursors for macrophages and monocytes are found in the bloodstream, whereas macrophages are found in the tissues they are both primary tissue scavengers that are larger and more effective than neutrophils

Answer 44

reticuloendothelial system And we’re Not associated with white blood cells when first described in different tissues, they acquired different names Microglia And histiocytes for the brain kupfer cells for the liver Osteo clasts for the bone and reticuloendothelial cells for the spleen

Answer 45

Monocytes make up 3 to 9% of leucocytes in the blood, but only stay there for eight hours before they become macrophages monocytes in large and differentiate into macrophages during their eight hour commute from the blood to the tissue

Answer 46

Agranulocytes Only Slightly larger than red blood cells so they’re pretty small they make up 25 to 33% of white blood cells 5% are circulating while the rest are in tissues envountering countering pathogens. The adult body has 1 trillion lymphocytes their function is an immune response they include natural killer cells T lymphocytes also called T cells and B lymphocytes also called B cells

Answer 47

Approximately 1 trillion

Answer 48

25-33% 5% Are circulating in the blood while the rest are in tissues in countering pathogens, they include natural killer cells, T cells and B cells

Answer 49

Natural killer cells Type of lumphocyte Part of the second line of defense, they protect against viral infections, and some cancers. They can respond very quickly compared to other lymphocytes.

Answer 50

1. Destroy target cells (infected or cancerous but not pathogen) by cell to cell contact 2. Can release interference and other cytokines uninfected cells 3. Can release IFNs and other cytokines to enhance the immune response, mediated by other cell types

Answer 51

Antigen: A molecule often on the surface of a pathogen that the immune system recognizes as a specific threat MHC marker; Main tag on every single cell proteins, expressed on the surface of a cell display, both self and non-self antigens they are used primarily in the recognition of pathogens in the immune responses, but also used in self recognition includes MHC1 and MHCII

Answer 52

An MHC marker found on the cell surface of all nucleated cells in the bodies of vertebrates

Answer 53

Found Mostly on macrophages, B cells and dendritic cells also called a APCs

Answer 54

Lymphocytes Have receptors that antigens can be presented to buy antigen presenting cells APCs in order to activate T cells if a helper, T cell, CD4 encounters an APC with a foreign antigen fragment on the MHC II, the T-cell response by secreting cytokines to enhance the immune response not every helper, T cell will bind only ones that recognize specific antigens in a lock and key mechanism. Initial priming of lymphocytes to the antigen occurs in a lymph tissue.

Answer 55

Spleen, lymph nodes, tonsils and gut

Answer 56

1. Threat an invader enters the body and first line of defense isn't enough 2. Detection - a macrophage encounters, engulfs and digests the invader - the macrophage places a piece of the invader (antigen) on its surface with the self (MHC) marker 3. Alert - the macrophage presents the antigen to a helper T cell and secretes a chemical that activates helper T cell - complex set of signals to activate helper T cell (recognition and verification to ensure its responding to non-self) - helper T cell divides and transforms into effector helper T cell 4. Alarm Effector helper T cell activates: A - cell mediated (T cell) response - naive cytotoxic T cell activated B - antibody-mediated/humoral (B cell) response - naive B cell activated

Answer 57

1. Threat 2. Detection 3. Alert 4. Alarm (activation of T or B) 5. Building specific defences 6. Defence

Answer 58

(this is after the alarm step, when an effector helper T cell has just activated naive cytotoxic T cells) 5. Building specific defenses - naive cytocoxic T cell divides into effector cytotoxic T cells and memory cytotoxic T cell 6. Defense - Effector cytotoxic T (CD8) cells targets cells displaying foreign antigen (tissue cells infected with intracellular pathogen) - Binds to MHC-I and kills infected cells by chemical means (perforin forms pores in target cell - gransymes enter pores - target cell apoptosis) 7. Memory T Cells stored for continued surveillance

Answer 59

(this is after the alarm step, when an effector helper T cell has just activated naive B cells) 5. Building specific defenses - Naive B cell divides into effector B cell and memory cell 6. Defense - Plasma cell (effector B cell) secretes antibodies which neutralize foreign proteins (toxins), trigger release of more complement, and attract more macrophages - antibodies target pathogens or toxins outside of cells by binding to the specific antigen(s) that initiate prior events 7. Continued surveillance - memory B cells stored for continued surveillance - when re-exposed to appropriate antigen, rapidly expand and produce more effector plasma cells and memory cells

Answer 60

many B cells at birth but almost all of them are different B lymphocytes inherit ability to produce particular antibodies --> any given B cell can produce only one type of antibody but they are naive exposure to antigen stimulates B cell to divide many times until large population of genetically identical B cell clones are produced B cells are able to produce close to 2000 antibodies per second

Answer 61

The encounter is remembered in the form of memory cells Primary response: - first exposure to antigen - slower and weaker response - produces mostly IgM antibodies Secondary response: - Lymphocytes clone and memory cells result in faster and stronger response - produces IgG antibodies

Answer 62

Primary response: - first exposure to antigen - slower and weaker response - produces mostly IgM antibodies Secondary response: the thing is remembered! clones are there as warriers to attack - Lymphocytes clone and memory cells result in faster and stronger response - produces IgG antibodies

Answer 63

they target pathogenic bacteria - don't destroy them, just mark them as targets for immunological attack - pathogen may be attacked by innate immune cells (macrophages and neutrophils) - pathogen may be attacked by complement (blood protein defense system)

Answer 64

9 complement proteins (C1-C9) that are inactive in the plasma Proteins become activated when antibodies mark the antigens There are 3 pathways which all lead to same outcome 1. Classical pathway (high level activity triggered by antibody) 2. Alternative pathway (low level, continuous activity) 3. Lectin pathway - similar to classical a type of innate, humoral immunity (always ready to go and found in blood) a type of adaptive, humoral immunity (can be specialized to a pathogen) made up of small, mostly inactive proteins in the blood

Answer 65

1. Classical pathway 2. Alternative pathway 3. Lectin pathway

Answer 66

The complement pathway is made up of small, mostly inactive proteins in the blood When triggered, proteases cleave specific proteins and initiate an amplifying cascade followed by additional cleavages End result: 1. massive amplification of response 2. formation of cell-killing membrane attack complex (MAC)

Answer 67

Membrane attack complex kills cells 1. Recognition C1 2. Activation C4 C2 C3 (in this order) 3. Attack C5 C6 C7 C8 C9

Answer 68

a pathway of the complement pathway starts with antibodies and CI proteins binding to the surface of pathogen

Answer 69

starts with lectins binding to mannose residues on the surface of the pathogen Lectins are carbohydrate-binding proteins that are highly specific for sugar moieties

Answer 70

are carbohydrate-binding proteins that are highly specific for sugar moieties used in lectin pathway of the complement pathway

Answer 71

1. Activation of C1 (classical pathway) 2. C1 catalyses hydrolysis of C4 into C4a and C4b 3. C4b binds plasma membrane and is active 4. C3 cleaved into C3a and C3b - due to intermediate step involving splitting of C2 - alternative pathway also results in cleavage of C3 through a different sequence of events (pathways converge at transport?) 5. C3b converts C5 into C5a and C5b 6. C3a and C5a stimulate mast cells to release histamine - also serve as chemokines (attract macrophages, neutrophils, monocytes and eosinophils) 7. C5, C6, C7, C8 and C9 inserted into bacterial cell membrane to form a MAC = membrane attack complex

Answer 72

membrane attack complex - large pore that kills bacterial cell through osmotic influx of water - formed by C9 units

Answer 73

a defensive process Blood vessels widen 1. Redness - blood flow carries defensive cells and chemicals to damaged tissue, removing toxins 2. Heat - increases the metabolic rate of cells in the injured area to speed healing Capillaries become more permeable 3. Swelling - fluid containing defensive chemicals, blood-clotting factors, oxygen, nutrients and defensive cells seeps into injured area 4. Pain - hampers movement, allowing the injured area to heal

Answer 74

Rest Ice Compression Elevation - how we treat inflammation

Answer 75

in response to tissue damage and stress bruises and torn tissue (acute inflammation) disease states such as arthritis, obesity, etc. (chronic inflammation)

Answer 76

whole body inflammation that causes organ dysfunction (potentially fatal) symptoms: high fever, rapid pulse / respiratory rate, hypotension, hypoxemia, oliguria acidosis treatment: antibiotics, IV fluids septic shock: blood pressure falls so low that organs are not adequately perfused

Answer 77

- Bacteria lipopolysaccharide (component of gram-negative bacteria) that is usually the cause of sepsis - Localized infection: triggers innate immunity - when large amounts enter circulation, inflammatory cytokines are released

Answer 78

defensive process - infection leads to fever - teething also results in fever - exogenous pyrogens cause the release of IL1 and FN which signal to receptors in hypothalamus to decrease heat loss and increase heat production resulting in increased temp = fever

Answer 79

immune system functions by distinguishing "self" from "non-self"

Answer 80

a failure of immune system to recognize and tolerate self-antigens there are over 40 autoimmune diseases, affecting 5-7% of the population

Answer 81

( in relation to autoimmune diseases) 1. an antigen that does not normally circulate in the blood may become exposed to the immune system 2. A self-antigen that is otherwise tolerated may be altered by combining with a foreign haplen 3. Antibodies may be produced that are directed against other antibodies 4. Antibodies produced against foreign antigens may cross-react with self-antigens 5. Self-antigens may be presented to helper T cells together with MHCII 6. Autoimmune diseases may result when there is inadequate activity of regulatory (suppressor) T lymphocytes

Answer 82

acquired immune deficiency syndrome caused by human immunodeficiency virus HIV - infects and destroys helper T cells in the gastrointestinal mucosa decreased immunological function and greater suceptibility to opportunistic infections and cancer

Answer 83

retrovirus that causes AIDS genetic code carried in RNA reverse transcriptase transcribes viral RNA into complementary DNA for viral replication

Answer 84

antiretroviral therapy inhibits reverse transcriptase, suppressing HIV replication indefinitely ART is not a cure! - HIV viral DNA integrates itself into host DNA of memory helper T cells - when ART drugs not stopped, virus reappears - not all individuals with AIDS have access to ART drugs

Answer 85

2 different pathways 1. Abnormal responses by B cells 2. Abnormal responses by T cells

Answer 86

One of the pathways of allergies - hay fever, asthma and most other allergies caused by IgE immediate hypersensitivity - Not allergic: allergen stimulate Th1 cells to secrete IFNg and IL2 Allergic: allergen stimulates Th2 cells to secrete IL4 and IL13 which stimulate plasma cells to secrete IgE antibodies instead of IgG Plasma cells bind to mast cells and basophils, stimulating them to release hestamine and other cytokines (produces immune reaction ie. trouble breathing, itching, sneezing)

Answer 87

delayed hypersensitivity - hours to days because the reaction is mediated by lymphokines instead of antibodies ex. contact dermatitis due to poison ivy - get hives hours to days late

Answer 88

(antidiuretic hormone) /vasopressin synthesized in the hypothalamus & stored in posterior pituitary increases water retention/reabsorption by kidneys creates more water in blood (decreased osmolality) and less water / more concentrated urine

Answer 89

is increased plasma osmolality - increased release of ADH by posterior pituitary - - stimulates more resorption from the kidneys in order to increase the water in the blood, concentrate/decrease water loss from urine and decrease blood osmolality via this negative feedback response

Answer 90

when there;s low plasma osmolality - stimulates decrease in water reabsorption in the kidneys (creates less water in blood, more in urine - dilute pee)

Answer 91

Mutation in ADH gene resulting in no ADH production (so no retention of water by kidneys and very high plasma osmolality) * Excessive thirst * Excess dilute urine * Diabetes insipidus (kidneys cannot conserve water)

Answer 92

Generally, ADH follows a circadian rhythm in children i.e. ADH levels increase at night * Increased absorption of water * Decreased production of urine

Answer 93

* Babies – 75% * Women – 50% * Men – 60% * Elderly men & women – 45%

Answer 94

2/3 intracellular 1/3 extracellular

Answer 95

- Drinking fluid & water in food (2250 mL) * Water produced by metabolism (250 mL) 2500mL total

Answer 96

- Urine (1500 mL) * Feces (100 mL) * Sweat (200 mL) * Lungs (700 mL)

Answer 97

A human can survive for 3 minutes without air * In a harsh environment, a human can survive for 3 hours without shelter * A human can survive for 3 days without water * A human can survive for 3 weeks without food

Answer 98

Iran, 2004 * A 97 year old woman survived for 8 days without food or water, under the rubble of her home, after an earthquake Mexico City, 1985 * Newborn babies trapped in wreckage of hospital after an earthquake, rescued 4-7 days later & nearly all survived * Known as the “Miracle Babies”

Answer 99

Dessert mammals: * Arabian camel * Desert rodents * Antelopes Marine mammals Hibernating mammals

Answer 100

- Survive without water in desert for several days in hot & dry environment * May be active under these conditions * Cannot halt the function of their kidneys * Lipid stored in hump * Lipid metabolism provides a significant amount of metabolic water * Dry food provides some water (even dry hay) * Kidneys efficient at water recovery - Primarily used for racing

Answer 101

Thermoregulate by panting * Core body temperature = 36.5-38.5°C

Answer 102

- No panting * Core body temperature = 34.5-40.5 °C Turn off thermoregulation for water conservation * Supercooling at night * Overheating during day

Answer 103

- Small, arid desert-adapted species * High oxygen consumption & respiratory water loss * Survive without drinking water (even when available) * Maintain body temperature * Obtain water from dry food & metabolism * Live in colonies underground – moist air in burrows reduces respiratory water loss * Nocturnal (avoid heat of day) * Produce very dry feces

Answer 104

Fresh water = 0.1% dissolved salts Human body = 0.9% dissolved salts Sea water = 3.5% dissolved salts When humans drink salt water, we become dehydrated

Answer 105

Marine mammals have no access to fresh water Only salt water (3.5% dissolved salts) * Obtain water from food (krill, fish, plankton) & metabolism * Produce very concentrated urine

Answer 106

Grizzly bears hibernate for half of the year & live completely off of stored fat reserves * Burn up to 8000 calories/day * Do not eat, defecate, drink, or urinate * Reduce their metabolic rate & heart rate * Metabolic water from lipids balance respiratory water loss * Urea recycled to produce protein * Water reabsorbed from bladder

Answer 107

Essential organs for life * Excrete metabolic waste products * Involved in other homeostatic processes * Water & electrolyte regulation * Acid-base (pH) balance * Major blood vessels associated (renal artery & vein)

Answer 108

- Water & electrolyte regulation * Acid-base (pH) balance

Answer 109

ureters drain urine from kidneys by peristalsis urinary bladder for urine storage urethra drains bladder

Answer 110

- Renal cortex * Renal medulla * Major arteries & veins * Papillae of the renal medulla (renal pyramids) * Renal pelvis connected to ureter

Answer 111

Horses = triangular shape Cows - lumpy Dog = kidney bean shape

Answer 112

Functional unit of the kidney * Blind-ended microscopic tubules * Each human kidney contains >1 million nephrons * Nephrons are lost with age & cannot be replaced * All regions associated with networks of peritubular capillary vessels

Answer 113

Each human kidney contains >1 million nephrons - 80% of nephrons are cortical * 20% of nephrons are juxtamedullary (i.e. dip into the medulla)

Answer 114

1. Blood enters the glomerulus 2. Blood is filtered through the nephron 3. Urine exits out the collecting duct

Answer 115

1. Bowman’s/glomerular capsule (contains glomerulus) 2. Proximal convoluted tubule 3. Loop of Henle 4. Distal convoluted tubule

Answer 116

Collecting ducts play an essential role in water retention but are not normally considered to be part of the nephron

Answer 117

180L fluid/day enters Bowman’s capsule * 1.5L fluid/day is excreted as urine

Answer 118

1. Filtration 2. Reabsorption 3. Secretion

Answer 119

- First part of urine formation - Movement of fluid from blood to lumen of nephron * Only takes place in “renal corpuscle” where glomeruli & Bowman’s capsule allow for bulk flow of fluid Blood hydrostatic pressure forces blood plasma out of the glomerulus into Bowman’s capsule Inner layer of Bowman’s capsule made up of podocytes * Intricate interdigitation of pedicels * Filtration slits/diaphragms * Act as filters * Negatively charged * Major barrier to proteins (plasma protein = 7%, glomerular filtrate protein = 0.03%) * Mutations in slit proteins results in proteinuria (protein in urine) * Smaller plasma solutes easily enter glomerular filtrate

Answer 120

Only takes place in “renal corpuscle” where glomeruli & Bowman’s capsule allow for bulk flow of fluid filtration slits between podocytes of Bowman's capsule act as filters

Answer 121

It's the primary filter for urine formation Inner layer of Bowman’s capsule made up of podocytes * Intricate interdigitation of pedicels * Filtration slits/diaphragms

Answer 122

btw podocytes of bowman's capsule Act as filters * Negatively charged * Major barrier to proteins (plasma protein = 7%, glomerular filtrate protein = 0.03%) * Mutations in slit proteins results in proteinuria (protein in urine) * Smaller plasma solutes easily enter glomerular filtrate

Answer 123

= ~180L/day in healthy men & ~150L/day in healthy women * Equivalent to the entire blood volume being filtered every 40 mins * Most of this is recovered since daily urine volume = ~1.5L/day

Answer 124

Determined by glomerular blood hydrostatic pressure in the glomerular capillaries lood hydrostatic pressure can change (e.g. with exercise), but GFR is relatively constant at 125mL/min (both kidneys) Relatively stable GFR ensures constant flow of glomerular filtrate, allowing reabsorption to occur & waste to be eliminated

Answer 125

↑ blood pressure → afferent arteriole constricts & efferent arteriole dilates

Answer 126

↓ blood pressure → afferent arteriole dilates & efferent arteriole constricts

Answer 127

(This is for filtration) Juxtaglomerular cells Macula densa cells Mesangial cells Sympathetic nerve fibres

Answer 128

part of juxtaglomerular apparatus involved in filtration smooth muscle cells in the afferent arteriole

Answer 129

part of juxtaglomerular apparatus sensory cells in a region of the distal convoluted tubule

Answer 130

part of juxtaglomerular apparatus involved in filtration connect juxtaglomerular and macula densa cells i.e. communication

Answer 131

associated with afferent arterioles; redirect blood from kidney to other organ systems involved in filtration part of Juxtaglomerular Apparatus

Answer 132

Renin-Angiotensin System 1. Blood pressure falls 2. Juxtaglomerular cells secrete renin into the blood 3. Renin acts on angiotensinogen to produce angiotensin I (ANGI) 4. ANGI is converted into ANGII by angiotensin converting enzyme (ACE) 5. ANGII is a vasoconstrictor 6. Blood pressure increases (draw it out!!)

Answer 133

Stimulates aldosterone secretion from adrenal cortex * Acts with aldosterone to increase salt & water retention by kidneys (increases blood volume)

Answer 134

- Blood flows from the glomerulus into the peritubular capillaries * Blood vessels, after going through the glomerulus, continue winding around the nephron * Blood vessels send more water/solutes into the nephron as needed * Blood vessels draw water/solutes out of the nephron as needed

Answer 135

second step of filtration After filtrate leaves Bowman’s capsule, it is modified by reabsorption * Substances in the nephron tubules flow back into blood Excess K+ from glomerular filtrate returned/reabsorbed into peritubular capillaries (blood) in proximal convoluted tubule * ~65% of salt & water in original glomerular ultrafiltrate reabsorbed across proximal tubule & returned to vascular system * ~20% returned to vascular system by reabsorption through descending limb of loop of Henle

Answer 136

During reabsorption Excess K+ from glomerular filtrate returned/reabsorbed into peritubular capillaries (blood) in proximal convoluted tubule Tight junctions of the proximal convoluted tubule cells are leaky → paracellular transport Transportation can also occur through the cell → transcellular transport

Answer 137

Last step of urine formation Opposite of reabsorption * Active transport of substances from the peritubular capillaries into the tubular fluid

Answer 138

Glomerulus = 300 Os Proximal tubule = 300 Os bottom of loop of Henle = 1200 Os Top of loop of Henle = 200 Os Distal confoluted tubule = 100 - 300 then Top of collecting duct = 300 Bottom of collecting duct = 1200

Answer 139

Sets up hyperosmotic environment in renal medulla (juxtamedullary nephrons) so that urine concentration can occur Includes descending loop of henle and ascending loop of henle follws proximal tubule

Answer 140

* Thin-walled * Filtrate becomes very concentrated (from 300 to 1200 mosm/L as it reaches loop turn) * Allows water to be drawn out i.e. impermeable to salt & permeable to water

Answer 141

* Thick-walled * Rich in mitochondria * Salt actively extruded & sent back into interstitial fluid i.e. permeable to salt & impermeable to water * Concentration (osmolality) decreases from 1200 back to 300 mosm/L

Answer 142

(of loop of Henle) 1. Descending limb is passively permeable to water, making the concentration in the tubule more concentrated 2. Extrusion of salt from ascending limb makes the surrounding interstitial fluid more concentrated 3. Deepest region in the medulla reaches a concentration of ~1200-1400 mosm/L

Answer 143

Several nephrons drain into each collecting duct * Under influence of ADH, water drawn out of filtrate by osmosis from medullary collecting duct into blood * I.e. ADH must be present to make urine hyperosmotic (more concentrated than blood)

Answer 144

ADH! (hyperosmotic = more concentrated than blood)

Answer 145

1. ADH/vasopressin (AVP in diagram) binds receptor 2. Signals cAMP 3. Inserts AQP2(aquaporins) on apical side 4. Water absorbed by osmosis (basolateral side) into blood

Answer 146

Blood vessels associated with nephron loop (peritubular capillaries associated with cortex portion of nephron, vasa recta associated with medulla portion of nephron) Act as counter current exchange system (not the same as counter current multiplier) Diffusion of salt and water changes the salt concentration of the interstitial fluid in the renal medulla Therefor, maintains standing osmotic gradient

Answer 147

Urine moves from renal pelvis /kidney) to ureter * Smooth muscle in walls carry out peristalsis * Peristalsis waves move urine toward bladder * Backflow of urine from bladder prevented by flap valve

Answer 148

a flap valve

Answer 149

When the one way valve btw ureter and bladder is not working right, backflow of urine into the kidneys may occur

Answer 150

= normal urine - Sterile * Pale to dark yellow * Rapidly populated by bacteria (source of ammonia odour) * pH range: 4.5-8.2

Answer 151

The following should not be found in the urine: - protein, - glucose -blood cells - hemoglobin - bile

Answer 152

CKD - the severity/stage of CKD is inversely proportional with the GFR ie. the higher the stage, the lower and least efficient the GFR is >10% of people (>20 million) aged 20+ in the US have CKD * More common among women * >35% of people aged 20+ with diabetes have CKD * >20% of people aged 20+ with hypertension have CKD

Answer 153

>10% of people (>20 million) aged 20+ in the US have CKD * More common among women * >35% of people aged 20+ with diabetes have CKD * >20% of people aged 20+ with hypertension have CKD

Answer 154

DIALYSIS! includes: Blood removed for dialysis Arterial pressure monitor Blood pump Heparin pump (to prevent clotting) dialyzer inflow pressure monitor dialyzer (filter) venous pressure monitor air trap and air detector air detector clam filtered blood returned to body

Answer 155

= KIDNEY STONES! - Hard objects formed by the kidneys containing crystalized minerals/waste products (concentrations exceed solubility) * Increased incidence with dehydration * Large stones in calyces or pelvis may obstruct urine flow * Small stones (<5mm) pass into ureter and can cause severe pain * If medications do not cause stone to pass, individual may need - lithotripsy (shock waves to shatter stone) * Surgery may be required if lithotripsy is unsuccessful

Answer 156

- Calcium stones – calcium phosphate/ calcium oxalate * Struvite stones – crystals of magnesium ammonium phosphate (may result from UTIs) * Uric acid stones – occur in individuals with gout * Cysteine stones – occur in individuals with cystinuria

Answer 157

Uncontrolled urination due to loss of bladder control includes: - STRESS urinary incontinence and - URGENCY incontinence

Answer 158

urine leakage due to increased abdominal pressure (sneezing, laughing, coughing) * Occurs in females when pelvic floor no longer provides adequate support to urethra due to childbirth or aging * Occurs in males as a result of prostate cancer treatment

Answer 159

uncontrolled contractions of detrusor muscle

Answer 160

Diagnosis through urodynamic testing and cystometric tests (test bladder pressure and compliance)

Answer 161

Characterized by: * Polyuria (large urine volume from 3-10L/day) * Polydipsia (drinking a lot of fluids) * Urine is dilute (hypotonic concentration of <300mOsm) * 2 major types of diabetes insipidus: 1. Central diabetes insipidus 2. Nephrogenic diabetes insipidus

Answer 162

Characteristic of Diabetes insipidus - large urine volume from 3-10L/day

Answer 163

Characteristic of diabetes insipidus means drinking a lot of fluids

Answer 164

means dilute urine concentration of <300mOsm

Answer 165

- Inadequate secretion of ADH * Treated with Desmopressin (synthetic ADH)

Answer 166

- Inability of the kidneys to respond to ADH * Individuals must drink a lot of water to prevent dehydration

Answer 167

Hyperkalemia: plasma K+ concentration >5mEq/L * Results in nausea, weakness, and EKG changes

Answer 168

Hypokalemia: plasma K+ concentration <3.5mEq/L * Results in heart arrhythmias and muscle weakness * Caused by some diuretics, vomiting, metabolic alkalosis, or excessive aldosterone secretion

Answer 169

Plasma K+ concentration should normally be between 3.5-5mEq/L if below = hypokalemia if above = hyperkalemia

Answer 170

Acute Mountain Sickness Occurs when individuals move to high elevations without being adequately acclimatized (involves the respiratory and renal systems) * Respiratory system acclimates through hyperventilation * Kidneys will acclimate by undergoing diuresis, resulting in hypovolemia (decreased blood volume) which helps mitigate AMS symptoms * Done in response to decreased ADH and aldosterone secretion, and increased natriuretic hormone secretion

Answer 171

Acetazolamide (inhibits carbonic anhydrase) * Decreases renal absorption of bicarbonate (and water), producing mild diuretic effects and metabolic acidosis * Acidosis promotes hyperventilation which aids acclimatization