homeostasis Flashcards
- Homeostasis refers to
a) Unwavering control of a physiological set point
b) Maintaining a stable internal environment
c) Maintaining a stable external environment
d) A and B
e) A and C
b) Maintaining a stable internal environment
- Some neurons in the vagus nerve terminate on sinoatrial (pacemaker) cells in the heart. These neurons secrete acetylcholine, which ultimately results in a decreased heart rate. This is an example of
a) Endocrine control
b) Neural control
c) Hormonal control
d) Humoral control
b) Neural control
- Under “normal” conditions
a) Set points are generally found within a set range. This allows for minor oscillations around the set point; these minor oscillations are usually ignored
b) Set points are highly variable and internal reactions to set points cannot be predicted with any accuracy at all
c) set points are rigidly adhered to, and when slight deviations occur, the body launches an “all-out effort” to bring the system back to the norm
d) set points are generally found within a set range. Nevertheless, minor oscillations can raise havoc within the system
a) Set points are generally found within a set range. This allows for minor oscillations around the set point; these minor oscillations are usually ignored
- Why is positive feedback useful to the human body?
a) It provides long-term control over the body’s internal conditions.
b) It restores a variable to homeostasis.
c) It helps to maintain a normal range of set point values
d) It can complete a potentially dangerous or stressful process quickly.
d) It can complete a potentially dangerous or stressful process quickly.
- Which of the following statements regarding glycogenolysis is not true?
a) Glycogenolysis releases glucose into the blood.
b) Glycogenolysis helps correct hypoglycaemia.
c) Glycogenolysis is the formation of carbohydrates from monosaccharides
d) Glycogenolysis is stimulated by glucagon.
c) Glycogenolysis is the formation of carbohydrates from monosaccharides
- What is the key role of the kidney in glucose regulation?
a) Production of insulin
b) Reabsorption of glucagon
c) Production of glucose
d) Reabsorption of glucose
d) Reabsorption of glucose
- The pathogenesis of hyperglycemia in type 2 diabetes includes all the following mechanisms except for:
a) Increased glucose production by the liver
b) Impaired insulin secretion
c) Decreased glucose uptake from the skeletal muscle
d) All of the above
d) All of the above
- Glucose moves from the filtrate in the nephron into the bloodstream during normal kidney function. What part of the nephron allows this movement of glucose, and by what mechanism?
a) collecting duct by active secretion
b) distal convoluted tubule by facilitated diffusion
c) glomerulus by ultrafiltration
d) proximal convoluted tubule by selective reabsorption
d) proximal convoluted tubule by selective reabsorption
- The effect of antidiuretic hormone (ADH) on the kidney is to:
a) increase the permeability of the distal nephron to water.
b) Increase the excretion of Na+
c) Increase the excretion of water
d) Increase the diameter of renal artery
a) increase the permeability of the distal nephron to water.
- The body’s core temperature can decrease in response to cold climates. As a response, the body increase its internal temperature to maintain the temperature within a specific range, this is an example of:
a) Feedback inhibition
b) Positive feedback loops
c) Error signal
d) Variation of set point
a) Feedback inhibition
- The measurement of ‘Gain’ refers to:
a) The systems ability to heat up the core body temperature
b) How well the system can correct deviations for the original set-point
c) Negative feedback control mechanisms
d) The narrow range of values within which cells can operate efficiently
b) How well the system can correct deviations for the original set-point
- The body constantly regulates body calcium levels by secreting Parathyroid hormone. Calcium can be classified as what type of stimulus that stimulates hormone synthesis and release:
a) Neural
b) Physical
c) Hormonal
d) Humoral
d) Humoral
- Which of the following is not an appropriate response when activating the heat-loss centre in the hypothalamus:
a) Sweat glands secreting perspiration
b) Skin blood vessels dilating
c) Skeletal muscle shivering
d) A and C
c) Skeletal muscle shivering
- Homeostatic systems are far from perfect and often have oscillate about the set point. An efficient system would:
a) Fluctuate the set-point
b) Minimise the amplitude of the oscillation
c) Have long time lag between receptor and response
d) Have large overcorrections
b) Minimise the amplitude of the oscillation
- Which of the following answers in an immediate response to food consumption and blood glucose:
a) After a meal the body will release insulin to convert glycogen to glucose
b) After a meal the body will release insulin to convert glucose into glycogen
c) After a meal the body will release glucagon to convert glycogen into glucose
d) After a meal the body will release glucagon to convert glucose into glycogen
b) After a meal the body will release insulin to convert glucose into glycogen
- In broad terms and in relation to homeostatic mechanisms, the bodies “effectors” are
a) brain
b) glands
c) muscles
d) both b) and c)
- Homeostatic mechanisms generally respond to?
a) absolute values, i.e. when variables reach the limits of tolerance
b) changing variables, which therefore tend to oscillate
c) deviations from the set-point
d) both b) and c) are correct
d) both b) and c) are correct
- Oscillation about a set-point for homeostatic variables occurs…..
a) in all non-biological and all biological homeostatic systems
b) only in artificial or non-biological homeostatic systems
c) only in biological systems that are poorly controlled
d) only in biological systems that are well controlled
a) in all non-biological and all biological homeostatic systems
4. Which is the only one of those listed below that is not necessarily a requirement of all homeostatic mechanisms? a) effector b) integrating centre c) sensor d) stimulus
b) integrating centre
- Someone suffering heat stroke is likely to ___________.
a) Be sweating profusely
b) Have a core temperature in excess of 400C
c) Have a surface temperature that is higher than the core temperature
d) All of the above
b) Have a core temperature in excess of 400C
- Imagine it is a very hot day reaching 450C, if standing out in these conditions, and without
homeostatic mechanisms, your normal body temp of 37 0C would rise to ~450C. However,
and after prolonged exposure it only reaches 38. What is the gain here?
a) 1
b) 7
c) 8
d) 38
c) 8
- When attempting to correct for overheating which response is the most crucial?
a) cessation of shivering
b) decreased blood flow to the skin
c) production of a concentrated urine
d) sweating
d) sweating
- If you are becoming increasingly cold, that is, tending toward hypothermia, which is the
most crucial of body’s corrective responses?
a) sweating less
b) sending blood from the core to the periphery
c) shivering
d) increased urine production
c) shivering
- In what place does plasma leave the blood vessels and become filtrate?
a) Collecting tubule
b) Distal convoluted tube
c) Glomerulus
d) Nephron loop
c) Glomerulus
- Where does the majority of glucose, ions and water from the filtrate get reasorbed?
a) Collecting tubule
b) Distal convoluted tube
c) Nephron loop
d) Proximal convoluted tube
d) Proximal convoluted tube
- Where does urea enter the filtrate?
a) Collecting tubule
b) Distal convoluted tube
c) Nephron loop
d) Proximal convoluted tube
c) Nephron loop
- Where in a nephron does ADH regulates water reabsorption?
a) Collecting tubule
b) Distal convoluted tube
c) Nephron loop
d) Proximal convoluted tube
a) Collecting tubule
- When is ADH secreted during maximal levels?
a) During dehydration
b) During over-hydration
c) During sleep
d) During starvation
a) During dehydration
- Aldosterone is secreted by the adrenal cortex to stimulate what?
a) Decreased calcium uptake in the proximal convoluted tubule
b) Decreased sodium uptake in the distal convoluted tubule
c) Increased calcium uptake in the proximal convoluted tubule
d) Increased sodium uptake in the distal convoluted tubule
d) Increased sodium uptake in the distal convoluted tubule
15. Which of the following is/are directly involved in the control over red blood cell concentration in blood? a) the bone marrow b) the kidneys c) the liver d) both a) and b)
d) both a) and b)
- An athlete has taken a hormonal substance to increase the oxygen carrying capacity of their
blood. Which hormone does this directly?
a) adrenaline
b) erythropoietin
c) glucagon
d) oxytocin
b) erythropoietin
- Erythropoietin release is stimulated by
a) falling blood [Ca++]
b) hyperoxia
c) hypoxia
d) low blood [glucose]
c) hypoxia
- The hormone that stimulates release of calcium from bone to increase levels in blood is:
a) calcitonin
b) erythropoietin
c) glucagon
d) parathyroid hormone
d) parathyroid hormone
- PTH (parathyroid hormone) stimulates???
a) excretion of phosphate by the kidneys
b) increased excretion of calcium by the kidneys
c) decreased uptake of calcium from the gut
d) increased calcium deposition on bone
a) excretion of phosphate by the kidneys
- Declining levels of blood glucose are monitored by the __________________.
a) liver
b) pancreas
c) liver
d) kidney
b) pancreas
- The reabsorption of glucose from the primary filtrate is dependent on…
a) diffusion of glucose from interstitial fluid into blood
b) facilitated diffusion of glucose via GLUT carriers
c) osmosis
d) secondary active transport of glucose
d) secondary active transport of glucose
- The term ‘gluconeogenesis’ means?
a) the release of glucose from glycogen, mostly via the kidney
b) the production of ‘new’ glucose, often from fats or proteins
c) the uptake of glucagon into cells
d) uptake of ‘new’ glucose into cells under the influence of insulin
b) the production of ‘new’ glucose, often from fats or proteins
- Insulin promotes the ………….. of glucose by cells in most tissues, via ……………
a) uptake of glucose, via active transport
b) uptake of glucose, via facilitated diffusion (i.e. GLUT transporters)
c) uptake of glucose, via plain diffusion
d) release of glucose, via active transport
a) uptake of glucose, via active transport
- Blood pressure is increased by all but one of the following, which is?
a) decreased peripheral resistance
b) increase in blood volume
c) increase in cardiac output
d) increase in noradrenaline release
a) decreased peripheral resistance
- Increasing peripheral resistance describes what, and to what end?
a) constriction of blood vessels in the body generally to decrease blood pressure
b) constriction of blood vessels in the body generally to increase blood pressure
c) dilation of blood vessels in the body generally to decrease blood pressure
d) dilation of blood vessels in the body generally to increase blood pressure
b) constriction of blood vessels in the body generally to increase blood pressure
- Angiotensin II stimulates…..
a) peripheral vasoconstriction
b) release of ADH
c) release of aldosterone
d) all of the above
d) all of the above
- Where is renin released from?
a) the heart
b) the bone marrow
c) the kidneys
d) the hypothalamus
c) the kidneys
- Which organ/tissue is most responsible for long term control of blood pressure?
a) the kidneys
b) the heart
c) the liver
d) the bone marrow
b) the heart
- In broad terms and in relation to homeostatic mechanisms, the bodies “effectors” are
a) brain
b) glands
c) muscles
d) both b) and c)
d) both b) and c)
- Homeostatic mechanisms generally respond to?
a) absolute values, i.e. when variables reach the limits of tolerance
b) changing variables, which therefore tend to oscillate
c) deviations from the set-point
d) both b) and c) are correct
d) both b) and c) are correct
- Oscillation about a set-point for homeostatic variables occurs…..
a) in all non-biological and all biological homeostatic systems
b) only in artificial or non-biological homeostatic systems
c) only in biological systems that are poorly controlled
d) only in biological systems that are well controlled
a) in all non-biological and all biological homeostatic systems
4. Which is the only one of those listed below that is not necessarily a requirement of all homeostatic mechanisms? a) effector b) integrating centre c) sensor d) stimulus
b) integrating centre
- Someone suffering heat stroke is likely to ___________.
a) Be sweating profusely
b) Have a core temperature in excess of 400C
c) Have a surface temperature that is higher than the core temperature
d) All of the above
b) Have a core temperature in excess of 400C
- Imagine it is a very hot day reaching 450C, if standing out in these conditions, and without
homeostatic mechanisms, your normal body temp of 37 0C would rise to ~450C. However,
and after prolonged exposure it only reaches 38. What is the gain here?
a) 1
b) 7
c) 8
d) 38
c) 8
- When attempting to correct for overheating which response is the most crucial?
a) cessation of shivering
b) decreased blood flow to the skin
c) production of a concentrated urine
d) sweating
d) sweating
- If you are becoming increasingly cold, that is, tending toward hypothermia, which is the
most crucial of body’s corrective responses?
a) sweating less
b) sending blood from the core to the periphery
c) shivering
d) increased urine production
c) shivering
- In what place does plasma leave the blood vessels and become filtrate?
a) Collecting tubule
b) Distal convoluted tube
c) Glomerulus
d) Nephron loop
c) Glomerulus
- Where does the majority of glucose, ions and water from the filtrate get reasorbed?
a) Collecting tubule
b) Distal convoluted tube
c) Nephron loop
d) Proximal convoluted tube
d) Proximal convoluted tube
- Where does urea enter the filtrate?
a) Collecting tubule
b) Distal convoluted tube
c) Nephron loop
d) Proximal convoluted tube
c) Nephron loop
- Where in a nephron does ADH regulates water reabsorption?
a) Collecting tubule
b) Distal convoluted tube
c) Nephron loop
d) Proximal convoluted tube
a) Collecting tubule
- When is ADH secreted during maximal levels?
a) During dehydration
b) During over-hydration
c) During sleep
d) During starvation
a) During dehydration
- Aldosterone is secreted by the adrenal cortex to stimulate what?
a) Decreased calcium uptake in the proximal convoluted tubule
b) Decreased sodium uptake in the distal convoluted tubule
c) Increased calcium uptake in the proximal convoluted tubule
d) Increased sodium uptake in the distal convoluted tubule
d) Increased sodium uptake in the distal convoluted tubule
15. Which of the following is/are directly involved in the control over red blood cell concentration in blood? a) the bone marrow b) the kidneys c) the liver d) both a) and b
d) both a) and b
- An athlete has taken a hormonal substance to increase the oxygen carrying capacity of their
blood. Which hormone does this directly?
a) adrenaline
b) erythropoietin
c) glucagon
d) oxytocin
b) erythropoietin
- Erythropoietin release is stimulated by
a) falling blood [Ca++]
b) hyperoxia
c) hypoxia
d) low blood [glucose]
c) hypoxia
- The hormone that stimulates release of calcium from bone to increase levels in blood is:
a) calcitonin
b) erythropoietin
c) glucagon
d) parathyroid hormone
d) parathyroid hormone
- PTH (parathyroid hormone) stimulates???
a) excretion of phosphate by the kidneys
b) increased excretion of calcium by the kidneys
c) decreased uptake of calcium from the gut
d) increased calcium deposition on bone
a) excretion of phosphate by the kidneys
- Declining levels of blood glucose are monitored by the __________________.
a) liver
b) pancreas
c) liver
d) kidney
b) pancreas
- The reabsorption of glucose from the primary filtrate is dependent on…
a) diffusion of glucose from interstitial fluid into blood
b) facilitated diffusion of glucose via GLUT carriers
c) osmosis
d) secondary active transport of glucose
d) secondary active transport of glucose
- The term ‘gluconeogenesis’ means?
a) the release of glucose from glycogen, mostly via the kidney
b) the production of ‘new’ glucose, often from fats or proteins
c) the uptake of glucagon into cells
d) uptake of ‘new’ glucose into cells under the influence of insulin
b) the production of ‘new’ glucose, often from fats or proteins
- Insulin promotes the ………….. of glucose by cells in most tissues, via ……………
a) uptake of glucose, via active transport
b) uptake of glucose, via facilitated diffusion (i.e. GLUT transporters)
c) uptake of glucose, via plain diffusion
d) release of glucose, via active transport
b) uptake of glucose, via facilitated diffusion (i.e. GLUT transporters)
- Blood pressure is increased by all but one of the following, which is?
a) decreased peripheral resistance
b) increase in blood volume
c) increase in cardiac output
d) increase in noradrenaline release
a) decreased peripheral resistance
- Increasing peripheral resistance describes what, and to what end?
a) constriction of blood vessels in the body generally to decrease blood pressure
b) constriction of blood vessels in the body generally to increase blood pressure
c) dilation of blood vessels in the body generally to decrease blood pressure
d) dilation of blood vessels in the body generally to increase blood pressure
b) constriction of blood vessels in the body generally to increase blood pressure
- Angiotensin II stimulates…..
a) peripheral vasoconstriction
b) release of ADH
c) release of aldosterone
d) all of the above
d) all of the above
- Where is renin released from?
a) the heart
b) the bone marrow
c) the kidneys
d) the hypothalamus
c) the kidneys
- Which organ/tissue is most responsible for long term control of blood pressure?
a) the kidneys
b) the heart
c) the liver
d) the bone marrow
b) the heart
• Positive feedback mechanisms tend to enhance the
original stimulus so that the response is accelerated.
• True – clotting example where speed of response is
important
• Without some sort of negative feedback mechanism, it
would be impossible to keep our body chemistry in
balance.
• True – need to return to set point if in excess
Responsiveness is the ability to sense changes in the
environment and then respond to them.
True – otherwise we would not survive
Moving from a tropical climate to a temperate climate
means that the body temperature set point will need to
adjusted.
True – Normal body temperature set-point is slightly higher
in long term residents of the tropics
• Fanning yourself makes you warmer
True – Muscle contraction generates heat
• If you are stranded in the snow, you should resist
urinating to help maintain your body temperature.
• True – the bladder is a reservoir for heat in the core
1.WHAT IS THE DEFINITION
OF HOMEOSTASIS?
a) The ability to maintain relatively stable external
conditions even though the inside world
changes continuously
b) When the output shuts off the original effect of
the stimulus
c) The response enhances the original stimulus so
that the response is accelerated
d) The ability to maintain relatively stable internal
conditions even though the outside world
changes continuously
1.WHAT IS THE DEFINITION
OF HOMEOSTASIS?
a) The ability to maintain relatively stable external
conditions even though the inside world
changes continuously
b) When the output shuts off the original effect of
the stimulus
c) The response enhances the original stimulus so
that the response is accelerated
d) The ability to maintain relatively stable internal
conditions even though the outside world
changes continuously
2. GENERALLY WHAT IS THE RESULT OF THE NEGATIVE FEEDBACK PROCESS? A) to keep the body's blood sugar level high B) to control body movement C) to regulate excretion via the kidneys D) to maintain homeostasis
D) to maintain homeostasis
3. WHICH ONE OF THE FOLLOWING SYSTEMS RESPONDS FASTEST TO ENVIRONMENTAL STIMULI? A) immune B) lymphatic C) muscular D) nervous
D) nervous
- HOMEOSTASIS IS THE
CONDITION IN WHICH THE
BODY MAINTAINS ________.
A) a dynamic state within an unlimited range,
depending on circumstances
B) a relatively stable internal environment, within limits
C) the lowest possible energy usage
D) a static state with no deviation from preset points
B) a relatively stable internal environment, within limits
- WHICH OF THE FOLLOWING
IS AN EXAMPLE OF A NEGATIVE
FEEDBACK MECHANISM?
a) During labor, as uterine contractions begin,
levels of the hormone, oxytocin, continuously
rise to further stimulate more contractions.
b) The thyroid gland releases thyroid hormone
under the influence of the hormone TSH. TSH
release decreases when thyroid hormone
levels reach their set point.
c) An individual who is incapable of synthesizing
thyroid hormone will often develop an
enlarged thyroid gland due to continuous TSH
stimulation.
b) The thyroid gland releases thyroid hormone
under the influence of the hormone TSH. TSH
release decreases when thyroid hormone
levels reach their set point.
- WHICH OF THE FOLLOWING
STATEMENTS IS THE MOST CORRECT
REGARDING HOMEOSTATIC
IMBALANCE?
A) It is considered the cause of most diseases.
B) Positive feedback mechanisms are overwhelmed.
C) Negative feedback mechanisms are functioning
normally.
D) The internal environment is becoming more stable.
A) It is considered the cause of most diseases.
7. OF THE FOLLOWING HEAT-PROMOTING MECHANISMS, WHICH APPEARS TO BE MOST EFFECTIVE IN ADULTS? a) Constriction of cutaneous vessels b) Shivering c) Increased metabolic rate d) Thyroxine secretion
b) Shivering
1. DESCRIBE THE OPPOSING WAYS THAT THE MUSCULAR SYSTEM AND INTEGUMENTARY SYSTEM ACT AS EFFECTORS IN THE REGULATION OF BODY TEMPERATURE. (2 MARKS)
• The integument cools the body through evaporation of
sweat (1) while the muscular system warms the body by
shivering which generates heat (1).
- DESCRIBE THE THREE (3)
MECHANISMS FOR
MAINTAINING BODY
TEMPERATURE? (3 MARKS)
• Heat loss where heat is actively lost to the environment
through redirection from core to peripheral areas (1)
• Heat generation through activation of the muscular
system (1)
• Heat conservation where heat is moved away from the
peripheral to the core of the body.
THE BLOOD-FILTERING STRUCTURE OF THE KIDNEY IS CALLED THE \_\_\_\_\_\_\_. a) glomerular capsule b) renal tubule c) glomerulus d) nephron
c) glomerulus
THE URINE-FORMING UNITS OF THE KIDNEY ARE THE \_\_\_\_\_\_\_. a) glomerular capsules b) renal tubules c) glomeruli d) nephrons
d) nephrons
NEPHRONS ARE FOUND MOSTLY IN THE \_\_\_\_\_\_\_\_\_\_ . a) Renal medulla b) Renal cortex c) Renal capsule d) Renal sinus
b) Renal cortex
PODOCYTES ARE PART OF THE \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ a) Filtration slits b) Juxtaglomerular apparatus c) Glomerular capsule d) Proximal convoluted tubule
c) Glomerular capsu
WHICH OF THE FOLLOWING GENERAL FUNCTIONS CAN BE ASSIGNED TO THE RENINANGIOTENSIN SYSTEM? a) Water conservation b) Blood pressure elevation c) Lowering blood sodium levels d) Both a and b
d) Both a and b
WHAT WOULD BE THE
EFFECT ON URINE OUTPUT IF
SODIUM CHANNELS IN THE
TUBULE CELLS WERE
INHIBITED?
a) The volume would increase.
b) The volume would decrease, then quickly resume
c) The volume would decrease by half the sodium
concentration.
d) The volume would decrease by one-tenth the sodium
concentration.
a) The volume would increase.
WHY DO HIGH LEVELS OF
POTASSIUM STIMULATE
ALDOSTERONE SECRETION?
a) Aldosterone stimulates potassium secretion at
potassium-specific pumps.
b) Aldosterone stimulates the sodium-potassium pump to
reabsorb sodium while simultaneously secreting
potassium.
c) Aldosterone stimulates the sodium-potassium pump to
secrete sodium while simultaneously reabsorbing
potassium.
d) High levels of potassium accompany high levels of
sodium.
b) Aldosterone stimulates the sodium-potassium pump
to reabsorb sodium while simultaneously secreting
potassium.
DRINKING TOO MUCH
ALCOHOL RESULTS IN A
HEADACHE THE NEXT DAY.
WHY DOES THIS HAPPEN?
a) Alcohol stimulates pain receptors in the brain.
b) Alcohol stimulates sodium reabsorption.
c) Alcohol stimulates aldosterone secretion.
d) Alcohol inhibits ADH secretion
d) Alcohol inhibits ADH secretion.
HOW DOES ADH
CONTRIBUTE TO THE
FORMATION OF
CONCENTRATED URINE?
a) ADH increases the permeability of the ascending limb
of the nephron loop to water.
b) ADH increases the permeability of the descending
limb of the nephron loop to water.
c) ADH increases the permeability of the collecting duct
to water by stimulating the insertion of aquaporins
into the luminal membrane.
d) ADH decreases the permeability of the collecting
duct to water by inhibiting the insertion of aquaporins
into the luminal membrane.
c) ADH increases the permeability of the collecting duct
to water by stimulating the insertion of aquaporins into
the luminal membrane.
WHEN URINE ENTERS THE COLLECTING DUCT, IT IS \_\_\_\_\_\_\_\_\_ TO THE BLOOD. a) Hypotonic b) Hypertonic c) Isotonic d) Isosmotic
a) Hypotonic
PREDICT THE OUTCOME OF AN
OVERDOSE OF THE HORMONE
ERYTHROPOIETIN.
a) The blood viscosity increases to levels that may
induce heart attacks or strokes.
b) The oxygen-carrying capacity remains unchanged
despite elevated red blood cell counts.
c) Red blood cell counts remain unchanged, but the
number of reticulocytes increases.
d) Blood viscosity levels decrease while oxygen-carrying
capacity increases.
a) The blood viscosity increases to levels that may
induce heart attacks or strokes.
WHAT RESPONSE WOULD
YOU EXPECT AFTER
TRAVELING TO HIGH
ALTITUDE FOR TWO WEEKS?
a) Blood levels of oxygen would remain depressed for
the duration.
b) A surge in iron release from the liver would occur.
c) The kidneys would secrete elevated amounts of
erythropoietin.
d) There would be no change in blood composition.
c) The kidneys would secrete elevated amounts of
erythropoietin.
THE TARGET ORGAN OF ERYTHROPOIETIN IS THE \_\_\_\_\_\_\_. a) kidney b) liver c) thymus d) red bone marrow
d) red bone marrow
WHICH OF THE FOLLOWING
IS AN INDIRECT EFFECT OF
PTH?
a) Increasing osteoclast activity
b) Increasing calcium absorption in the intestines
c) Increasing calcium reabsorption in the kidney
d) Activating vitamin D
b) Increasing calcium absorption in the intestines
WHAT ARE THE EFFECTS OF
PTH?
a) Increase osteoclast activity
b) Increase Ca2+ reabsorption in the kidney
c) Increase Ca2+ absorption in the intestine
d) All of the above
d) All of the above
A 65 YEAR OLD WOMAN SUFFERING FROM
OSTEOPOROSIS SHOWS NO CALCITONIN
IN HER BLOOD. HOW SHOULD THIS BE
INTERPRETED?
a) She is not secreting calcitonin and that is causing her
osteoporosis.
b) PTH levels are obscuring the calcitonin level
c) She is deficient in calcium
d) Calcitonin is not secreted in adults, so this result is of
no importance
d) Calcitonin is not secreted in adults, so this result is of
no importance
DISCUSS WHY ERYTHROPOIETIN IS NOT USEFUL IN CASES OF DROWNING (4 MARKS)
• EPO is a long term solution to hypoxia (1) where the
body creates more erythrocytes (1) to deliver oxygen
to the tissues (0.5).
• Drowning is complete starvation of oxygen (0.5)
leading to anoxic conditions (0.5) so oxygen needs to
be restored to the lungs to save the person’s life (0.5)
EXPLAIN HOW PTH RELEASE IS TRIGGERED IN
THE HUMAN BODY AND THE OUTCOME OF ITS
SECRETION.
( 5 MARKS)
• When calcium levels in the body drop below 9
mg/100ml (1), the parathyroid gland (0.5) is stimulated
to release parathyroid hormone (1).
• This stimulates osteoclasts in the bone matrix (1) to
degrade bone (0.5) and release calcium ions into the
blood (0.5) to return calcium levels to between 9 – 11
mg/100ml (0.5)
WHEN THE PANCREAS RELEASES INSULIN IN DIRECT RESPONSE TO BLOOD GLUCOSE, THIS IS AN EXAMPLE OF \_\_\_\_\_\_\_\_\_\_ STIMULATION. a) humoral b) neural c) hormonal d) negative feedback
a) humoral
HIGH BLOOD GLUCOSE LEVELS ARE DETECTED IN THE PANCREAS BY WHAT CELLS USING WHICH TRANSPORTERS? a) Alpha cells using GLUT 2 b) Alpha cells using GLUT 4 c) Beta cells using GLUT 2 d) Beta cells using GLUT 4
c) Beta cells using GLUT 2
WHICH OF THE FOLLOWING
IS NOT AN ACTION OF
GLUCAGON?
a) Release of glucose to the blood by liver cells
b) Transport of glucose into most body cells
c) Synthesis of glucose from lactic acid
d) Breakdown of glycogen
b) Transport of glucose into most body cell
HYPOGLYCEMIA IS A PROBLEM WITH WHICH HORMONE? a) Insulin b) Glucagon c) Calcitonin d) Parathyroid hormone
a) Insulin
WHAT DOES THE GLUCOSE
TUBULAR MAXIMUM
REPRESENT?
a) The concentration of glucose at which insulin
stimulates cells to uptake more glucose
b) The concentration of glucose at which the collecting
duct stops reabsorbing glucose and excretes the
glucose in the urine
c) The concentration of glucose at which the nephrons
stop reabsorbing glucose and excretes excess
glucose in the urine
d) The concentration of glucose at which the kidneys
stop producing filtrate
c) The concentration of glucose at which the nephrons
stop reabsorbing glucose and excretes excess
glucose in the urine
WHY IS GLUCOSE IN THE
URINE AN INDICATOR OF
DIABETES MELLITUS?
a) Glucose occupies all the transport carriers, thus
becoming saturated, as a result it is no longer
reabsorbed.
b) Because diabetics cannot regulate their glucose.
c) When blood glucose is high, it is secreted in the urine.
d) Because diabetics have high levels of glucagon.
a) Glucose occupies all the transport carriers, thus
becoming saturated, as a result it is no longer
reabsorbed.
A STABLE BLOOD PRESSURE
IS MAINLY GENERATED BY
WHICH THREE
PHYSIOLOGICAL FACTORS?
a) Plasma proteins, glomerular filtration, and hormones
b) Renin, angiotension II and anti-diuretic hormones
c) Colloid osmotic pressure, skeletal muscles and heart
rate
d) Cardiac output, peripheral resistance and blood
volume
d) Cardiac output, peripheral resistance and blood
volume
BARORECEPTORS DETECT CHANGES IN \_\_\_\_\_\_\_\_\_\_. a) blood O2 levels b) stretch in arterial walls c) blood CO2 levels d) blood H+ levels
b) stretch in arterial walls
AN INCREASING LUMEN DIAMETER IS TERMED \_\_\_\_\_\_\_\_\_\_, AND OCCURS WHEN SMOOTH MUSCLE \_\_\_\_\_\_\_\_\_\_. a) vasodilation, relaxes b) vasodilation, contracts c) vasoconstriction, relaxes d) vasoconstriction, contract
a) vasodilation, relaxes
CAPILLARY COLLOID
OSMOTIC PRESSURE
CREATED BY __________
TENDS TO __________.
a) blood volume; push fluids out of the capillary
decreasing systemic blood pressure
b) nondiffusable plasma proteins; draw fluids into the
capillary increasing systemic blood pressure
c) interstitial fluid; draw fluids out of the capillary
decreasing systemic blood pressure
d) proteins in the interstitial fluid; push fluids into the
interstitial fluid increasing systemic blood pressure
b) nondiffusable plasma proteins; draw fluids into the
capillary increasing systemic blood pressure
IF A PERSON STANDS UP SUDDENLY FROM THE PRONE
(LYING) POSITION THEY MAY FEEL A SUDDEN DIZZY OR
LIGHTHEADEDNESS. WHICH OF THE FOLLOWING IS THE
LEAST LIKELY PHYSIOLOGICAL RESPONSE TO THIS
SITUATION?
a) increased sympathetic output to the heart
b) faster heart rate and greater heart contractility
c) increased parasympathetic nerve impulses to the
heart
d) increasing peripheral resistance due to
vasoconstriction
c) increased parasympathetic nerve impulses to the
heart
HYPERTENSION CAN BE TREATED WITH WHICH OF THE FOLLOWING DRUGS? a) ACE inhibitors b) Beta blockers c) Diuretics d) All of the above
d) All of the above
WHAT ACTION/S COULD YOU TAKE IF
A DIABETIC IS SUFFERING FROM A
HYPOGLYCAEMIC EVENT?
(2 MARKS)
• Hypoglycemia is low blood glucose (0.5)
• Give the person something sugary to eat (1) to return
their blood sugar levels to the normal range (0.5)
A PATIENT LOST A LOT OF BLOOD DURING
SURGERY AND HIS BLOOD PRESSURE DROPPED FROM
120/80 TO 90/50. DESCRIBE HOW THE KIDNEYS
RESPOND TO THIS CHANGE IN BLOOD PRESSURE.
(6 MARKS)
• When arterial blood pressure declines, special cells in
the kidneys release the enzyme renin (0.5) into the
blood. Renin triggers a series of enzymatic reactions
that produce angiotensin II (0.5), which is a potent
vasoconstrictor (0.5) which will increase peripheral
resistance and thereby BP (1). It also stimulates the
adrenal cortex to secrete aldosterone (0.5), a hormone
that enhances renal reabsorption of sodium (1), and
prods the posterior pituitary to release ADH, which
promotes more water reabsorption (1). As sodium
moves into the bloodstream, water follows; thus both
blood volume and blood pressure rise (1).
