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Flashcards in week 13 Deck (53):
1


1)   Which of the following is consistent with homeostasis?

A)  as body temperature rises, sweating occurs to cool the body  
B)  when a person drinks large quantities of water, urine output decreases to raise blood volume
C)  elevated blood glucose levels cause insulin secretion to decline
D)  decreases in blood pressure cause a corresponding decrease in heart rate
E)  as blood pressure falls, blood flow to the heart decreases
 

1)   Which of the following is consistent with homeostasis?

A)  as body temperature rises, sweating occurs to cool the body   *
B)  when a person drinks large quantities of water, urine output decreases to raise blood volume
C)  elevated blood glucose levels cause insulin secretion to decline
D)  decreases in blood pressure cause a corresponding decrease in heart rate
E)  as blood pressure falls, blood flow to the heart decreases
 

2


2) In positive feedback, the initial stimulus produces a response that


A) suppresses the stimulus.
B) has no effect on the stimulus.
C) interferes with the completion of the process.
D) exaggerates the stimulus.   *
E) impedes the stimulus.


2) In positive feedback, the initial stimulus produces a response that


A) suppresses the stimulus.
B) has no effect on the stimulus.
C) interferes with the completion of the process.
D) exaggerates the stimulus.   *
E) impedes the stimulus.

3

3)    An example of a receptor in a negative feedback loop controlling body temperature would be


A) temperature sensors on the skin that detect a stimulus.  
B) sweat glands that increase secretion.
C) regulatory centers that send commands to an effector.
D) effectors that cause blood vessels to dilate.
E) sweat glands that act like effectors.

3)    An example of a receptor in a negative feedback loop controlling body temperature would be


A) temperature sensors on the skin that detect a stimulus.   *
B) sweat glands that increase secretion.
C) regulatory centers that send commands to an effector.
D) effectors that cause blood vessels to dilate.
E) sweat glands that act like effectors.

4

4)   This type of feedback amplifies the effects of a system.

A) negative
B) positive  
C) neutral
D) depressing
E) all of the above

4)   This type of feedback amplifies the effects of a system.

A) negative
B) positive 
C) neutral
D) depressing
E) all of the above

5


 6)    A feedback system consists of three basic components: a control centre, a receptor and a (an)

A)  modulator
B)  generator
C)  integrator
D)  effector  
E)  regulator
 

 6)    A feedback system consists of three basic components: a control centre, a receptor and a (an)

A)  modulator
B)  generator
C)  integrator
D)  effector   *
E)  regulator
 

6


7)    Osmometer cells sense changes in the concentration of blood plasma; therefore, they must be

A)  receptors.   
B)  control centers.
C)  stimulators.
D)  modulators.
E)  effectors.
 


7)    Osmometer cells sense changes in the concentration of blood plasma; therefore, they must be

A)  receptors.    *
B)  control centers.
C)  stimulators.
D)  modulators.
E)  effectors.
 

7


8)    Which of the following is an example of a positive feedback loop?

A) A neuron is stimulated, thus opening membrane channels to allow sodium ions to leak from the extracellular fluid to the intracellular fluid. This causes more membrane channels to open, thus allowing more sodium ions to enter the intracellular fluid.   
B) Baroreceptors notify the brain that the blood pressure has increased. The brain then notifies the blood vessels to dilate, thus lowering the blood pressure.
C) Low levels of glucose in the blood cause the pancreas to release less insulin (a hormone that lowers blood glucose).
D) Elevated body temperature is sensed by cells in the brain. As a result, sweat is produced, and heat is lost as the water in the sweat evaporates.
E)  Receptors detect deficient amounts of calcium ions in the blood.  The receptors notify the parathyroid gland, which then releases a hormone that causes more calcium ions to be retained in the blood.
 

8)    Which of the following is an example of a positive feedback loop?

A) A neuron is stimulated, thus opening membrane channels to allow sodium ions to leak from the extracellular fluid to the intracellular fluid. This causes more membrane channels to open, thus allowing more sodium ions to enter the intracellular fluid.    *
B) Baroreceptors notify the brain that the blood pressure has increased. The brain then notifies the blood vessels to dilate, thus lowering the blood pressure.
C) Low levels of glucose in the blood cause the pancreas to release less insulin (a hormone that lowers blood glucose).
D) Elevated body temperature is sensed by cells in the brain. As a result, sweat is produced, and heat is lost as the water in the sweat evaporates.
E)  Receptors detect deficient amounts of calcium ions in the blood.  The receptors notify the parathyroid gland, which then releases a hormone that causes more calcium ions to be retained in the blood.
 

8


9)    Which of the following cannot be present if homeostasis is maintained?

A)  negative feedback loops
B)  disease or disorder   
C)  positive feedback loops
D) minor fluctuations in a controlled condition such as body temperature
E) changes in the composition of the ECF
 

9)    Which of the following cannot be present if homeostasis is maintained?

A)  negative feedback loops
B)  disease or disorder    *
C)  positive feedback loops
D) minor fluctuations in a controlled condition such as body temperature
E) changes in the composition of the ECF
 

9

10)   In a negative feedback mechanism, the response of the effector

A)  reverses the original stimulus.  
B)  enhances the original stimulus.
C)  has no effect on the original stimulus.
D)  is usually damaging to the body.
E)  creates a cycle that leads away from homeostasis.
 

10)   In a negative feedback mechanism, the response of the effector

A)  reverses the original stimulus.   *
B)  enhances the original stimulus.
C)  has no effect on the original stimulus.
D)  is usually damaging to the body.
E)  creates a cycle that leads away from homeostasis.
 

10

11)  Homeostasis is the condition in which the body maintains

A)  the lowest possible energy usage.
B)  a relatively stable internal environment, within limits.  
C)  a static state with no deviation from preset points.
D)  a changing state, with an unlimited range.
E)  a relatively stable external environment, within limits.
 

11)  Homeostasis is the condition in which the body maintains

A)  the lowest possible energy usage.
B)  a relatively stable internal environment, within limits.   *
C)  a static state with no deviation from preset points.
D)  a changing state, with an unlimited range.
E)  a relatively stable external environment, within limits.
 

11


12)  Interstitial fluid is the fluid

A)  inside blood vessels.
B)  inside cells.
C)  between the cells.   
D)  inside lymph vessels.
E)  that is consumed as part of the diet.
 



12)  Interstitial fluid is the fluid

A)  inside blood vessels.
B)  inside cells.
C)  between the cells.    *
D)  inside lymph vessels.
E)  that is consumed as part of the diet.
 

12


13) Which of the following is not considered to be an extracellular fluid?

A)  the fluid inside cells  
B)  the fluid inside blood vessels
C)  the fluid between cells
D)  the fluid inside lymphatic vessels
E)  the fluid around the brain and spinal cord
 


13) Which of the following is not considered to be an extracellular fluid?

A)  the fluid inside cells   *
B)  the fluid inside blood vessels
C)  the fluid between cells
D)  the fluid inside lymphatic vessels
E)  the fluid around the brain and spinal cord
 

13


14)  Which of the following best describes the endocrine system?

A) It transmits regulatory signals via nerve impulses.
B) It absorbs nutrients.
C) It contains hair, skin, and nails.
D) It produces blood cells that transport oxygen.
E) It transmits regulatory signals via the release of hormones into the blood.  
 

14)  Which of the following best describes the endocrine system?

A) It transmits regulatory signals via nerve impulses.
B) It absorbs nutrients.
C) It contains hair, skin, and nails.
D) It produces blood cells that transport oxygen.
E) It transmits regulatory signals via the release of hormones into the blood.   *
 

14


 15) Which of the following is true of the endocrine system but not the nervous system?

A) directs long term processes such as pregnancy and puberty  
B) communicates via chemical signals
C) regulates activities of muscles and glands
D) A and B are correct.
E) A, B and C are correct.
 

 15) Which of the following is true of the endocrine system but not the nervous system?

A) directs long term processes such as pregnancy and puberty   *
B) communicates via chemical signals
C) regulates activities of muscles and glands
D) A and B are correct.
E) A, B and C are correct.
 

15


16) Which of the following statements about the endocrine system is NOT correct?

A) It uses hormones, which are transported by the blood, to communicate with distant tissues.
B) Its hormones must bind to specific receptor sites in order to have effects on a tissue.
C) It targets are limited to muscles, glands and nerves.   
D) It may take seconds, hours, or days to respond to a stimulus.
E) Its actions may last seconds, hours, or days.
 

16) Which of the following statements about the endocrine system is NOT correct?

A) It uses hormones, which are transported by the blood, to communicate with distant tissues.
B) Its hormones must bind to specific receptor sites in order to have effects on a tissue.
C) It targets are limited to muscles, glands and nerves.    *
D) It may take seconds, hours, or days to respond to a stimulus.
E) Its actions may last seconds, hours, or days.
 

16


17) Which mediator is considered to be both a neurotransmitter and a hormone?

A) insulin
B) norepinephrine (nordrenaline)  
C) thyroid hormone
D) somatotropin
E) aldosterone
 

17) Which mediator is considered to be both a neurotransmitter and a hormone?

A) insulin
B) norepinephrine (nordrenaline)   *
C) thyroid hormone
D) somatotropin
E) aldosterone
 

17


18) Which of the following is NOT an endocrine gland?

A) thyroid gland
B) adrenal gland
C) sudoriferous gland  
D) pituitary gland
E) parathyroid gland
 


18) Which of the following is NOT an endocrine gland?

A) thyroid gland
B) adrenal gland
C) sudoriferous gland   *
D) pituitary gland
E) parathyroid gland
 

18

19) Which of the following does NOT contain endocrine tissue?

A) hypothalamus
B) thymus
C) heart
D) gall bladder  
E) kidney
 

19) Which of the following does NOT contain endocrine tissue?

A) hypothalamus
B) thymus
C) heart
D) gall bladder   *
E) kidney
 

19

20) The anterior pituitary gland responds to gonadotropin releasing hormone (GnRH), but the posterior pituitary gland does not. Why?

A) Only anterior pituitary gland is permeable to GnRH.
B) Only the anterior pituitary gland is vascular.
C) Only the anterior pituitary gland is connected by neurons to the hypothalamus.
D) Only the anterior pituitary gland is connected to a duct carrying GnRH.
E) Only the anterior pituitary gland has receptors for GnRH.   
 

20) The anterior pituitary gland responds to gonadotropin releasing hormone (GnRH), but the posterior pituitary gland does not. Why?

A) Only anterior pituitary gland is permeable to GnRH.
B) Only the anterior pituitary gland is vascular.
C) Only the anterior pituitary gland is connected by neurons to the hypothalamus.
D) Only the anterior pituitary gland is connected to a duct carrying GnRH.
E) Only the anterior pituitary gland has receptors for GnRH.    *
 

20


21) The hypothalamus

A) is a link between the endocrine and nervous systems.   
B) release oxytocin and ADH into the blood but does not produce them.
C) regulates the posterior pituitary gland via releasing and inhibiting hormones.
D) A and B are correct.
E) A, B and C are correct.
 

21) The hypothalamus

A) is a link between the endocrine and nervous systems.    *
B) release oxytocin and ADH into the blood but does not produce them.
C) regulates the posterior pituitary gland via releasing and inhibiting hormones.
D) A and B are correct.
E) A, B and C are correct.
 

21

22) The pituitary gland

A) lies in the cribiform plate of the ethmoid bone.
B) consists of two lobes, the adenohypophysis and the neurohypophysis.   
C) develops from outgrowths of endoderm.
D) A and B are correct.
E) A, B and C are correct.
 

22) The pituitary gland

A) lies in the cribiform plate of the ethmoid bone.
B) consists of two lobes, the adenohypophysis and the neurohypophysis.    *
C) develops from outgrowths of endoderm.
D) A and B are correct.
E) A, B and C are correct.
 

22


23) The anterior pituitary gland

A) contains two cell types and secretes four different hormones.
B) is regulated largely by positive feedback mechanisms and hormones from the pineal gland.
C) regulates the function of some other endocrine glands by secreting hormones called tropins.  
D) A and B are correct.
E) A, B and C are correct.
 


23) The anterior pituitary gland

A) contains two cell types and secretes four different hormones.
B) is regulated largely by positive feedback mechanisms and hormones from the pineal gland.
C) regulates the function of some other endocrine glands by secreting hormones called tropins.   *
D) A and B are correct.
E) A, B and C are correct.
 

23

24) Which of the following is correct?

A) Only females produce prolactin.
B) Increased levels of stress may cause increased secretion of ACTH.  
C) MSH is required for normal thyroid function in humans.
D) LH inhibits ovulation.
E) TSH stimulates calcitonin production.
 

24) Which of the following is correct?

A) Only females produce prolactin.
B) Increased levels of stress may cause increased secretion of ACTH.   *
C) MSH is required for normal thyroid function in humans.
D) LH inhibits ovulation.
E) TSH stimulates calcitonin production.
 

24

25) The posterior pituitary gland

A) is also called the adenophysis.
B) contains pituicytes and the axons of neurons that originate in the hypothalamus.   
C) synthesizes ADH and OT.
D) releases ADH and OT into the hypophyseal artery.
E) All of these are correct.
 

25) The posterior pituitary gland

A) is also called the adenophysis.
B) contains pituicytes and the axons of neurons that originate in the hypothalamus.    *
C) synthesizes ADH and OT.
D) releases ADH and OT into the hypophyseal artery.
E) All of these are correct.
 

25

26) The hormone oxytocin

A) is made by females, but not males.
B) inhibits uterine contractions.
C) stimulates ejection of milk from the breast.   
D) may be responsible for arousal before sexual intercourse.
E) helps retain the attachment between the placenta and the uterus.
 

26) The hormone oxytocin

A) is made by females, but not males.
B) inhibits uterine contractions.
C) stimulates ejection of milk from the breast.    *
D) may be responsible for arousal before sexual intercourse.
E) helps retain the attachment between the placenta and the uterus.
 

26

27) The thyroid gland

A) lies posterior and superior to the larynx.
B) contains follicular cells that secrete calcitonin.
C) contains parafollicular cells that secrete T3/T4.
D) helps regulate metabolism and Ca2+ levels.   
E) is embedded within the parathyroid gland.
 

27) The thyroid gland

A) lies posterior and superior to the larynx.
B) contains follicular cells that secrete calcitonin.
C) contains parafollicular cells that secrete T3/T4.
D) helps regulate metabolism and Ca2+ levels.    *
E) is embedded within the parathyroid gland.
 

27

A) are embedded within the thyroid gland.
B) contain chief cells, which secrete PTH.
C) are controlled by negative feedback mechanisms.
D) A and B are correct.
E) A, B and C are correct.   

A) are embedded within the thyroid gland.
B) contain chief cells, which secrete PTH.
C) are controlled by negative feedback mechanisms.
D) A and B are correct.
E) A, B and C are correct.    *

28


29) The adrenal glands

A) lie superior and medial to the kidneys.
B) have an inner medulla derived from embryonic ectoderm.
C) have an outer cortex that secretes hormones critical to maintenance of homeostasis.
D) A and B are correct.
E) A, B and C are correct.   
 

29) The adrenal glands

A) lie superior and medial to the kidneys.
B) have an inner medulla derived from embryonic ectoderm.
C) have an outer cortex that secretes hormones critical to maintenance of homeostasis.
D) A and B are correct.
E) A, B and C are correct.    *
 

29


30) An eight-year old child spent the day eating sweets.  He ate cookies for breakfast, ice cream for lunch and lollies for dinner.  How did his body maintain his blood glucose level within normal range?

A) by increasing glucagon secretion
B) by increasing cortisol secretion
C) by increasing insulin secretion   
D) by increasing hGH secretion
E) by increasing ACTH secretion
 

30) An eight-year old child spent the day eating sweets.  He ate cookies for breakfast, ice cream for lunch and lollies for dinner.  How did his body maintain his blood glucose level within normal range?

A) by increasing glucagon secretion
B) by increasing cortisol secretion
C) by increasing insulin secretion    *
D) by increasing hGH secretion
E) by increasing ACTH secretion
 

30



31)  The fight-or-flight response

A) is the body’s immediate response to a real or perceived threat to survival.
B) elevates heart and respiration rates and blood glucose level.
C) decreases urinary and digestive functions.
D) activates the renin-angiotensin-aldosterone pathway.
E) All of these are correct.   
 


31)  The fight-or-flight response

A) is the body’s immediate response to a real or perceived threat to survival.
B) elevates heart and respiration rates and blood glucose level.
C) decreases urinary and digestive functions.
D) activates the renin-angiotensin-aldosterone pathway.
E) All of these are correct.    *
 

31

32)  Which of the following disorders and hormonal imbalances is correctly matched?

A) diabetes insipidus: decreased insulin response
B) acromegaly: excessive hGH secretion after epiphyseal plates close  
C) diabetes mellitus: decreased ADH secretion
D) pheochromocytoma: excessive thyroid hormone production
E) cretinism: excessive cortisol production
 

32)  Which of the following disorders and hormonal imbalances is correctly matched?

A) diabetes insipidus: decreased insulin response
B) acromegaly: excessive hGH secretion after epiphyseal plates close   *
C) diabetes mellitus: decreased ADH secretion
D) pheochromocytoma: excessive thyroid hormone production
E) cretinism: excessive cortisol production
 

32

33)    The underlying pathogenic mechanism for both type 1 and type 2 diabetes is  

A) pancreatic β cell destruction.
B) lack of insulin receptors.
C) lack of exercise and chronic overeating.
D)
E) pancreatic α cell destruction.
E)  impaired glucose transport into cells.    
 


33)    The underlying pathogenic mechanism for both type 1 and type 2 diabetes is  

A) pancreatic β cell destruction.
B) lack of insulin receptors.
C) lack of exercise and chronic overeating.
D)
E) pancreatic α cell destruction.
E)  impaired glucose transport into cells.     *
 

33


34)   Which of the following manifestations would you not expect to observe in a person suffering from type I diabetes mellitus?

A) glycosuria
B) decreased appetite   
C) hyperglycaemia
D) increased thirst
E)  polyuria
 

34)   Which of the following manifestations would you not expect to observe in a person suffering from type I diabetes mellitus?

A) glycosuria
B) decreased appetite    *
C) hyperglycaemia
D) increased thirst
E)  polyuria
 

34

35)   Soon after a meal rich in carbohydrates, the concentration of glucose in the blood vessels leading to and from the liver was measured.   Which of the following would be CORRECT?

A)  the glucose content of the blood entering and leaving the liver would be much greater than normal.
B)  the glucose content of the blood entering the liver would be higher and the blood leaving the liver would contain much less glucose than normal.    
C)  the glucose content of blood leaving the liver remains about the same but there would be a greater glucose content of blood entering the liver.
D)  the glucose content of the blood entering and leaving the liver remains fairly constant and is not affected by the a meal of carbohydrates.
E)  none of the above.
 

35)   Soon after a meal rich in carbohydrates, the concentration of glucose in the blood vessels leading to and from the liver was measured.   Which of the following would be CORRECT?

A)  the glucose content of the blood entering and leaving the liver would be much greater than normal.
B)  the glucose content of the blood entering the liver would be higher and the blood leaving the liver would contain much less glucose than normal.     *
C)  the glucose content of blood leaving the liver remains about the same but there would be a greater glucose content of blood entering the liver.
D)  the glucose content of the blood entering and leaving the liver remains fairly constant and is not affected by the a meal of carbohydrates.
E)  none of the above.
 

35


36)   Symptoms of hypoglycaemia include:

A)  hunger, mental confusion, and diaphoresis    
B)  flushed skin and dehydration
C)  rapid respirations and fruity smelling breath
D)  tachycardia and polyuria
E)   all of the above
 


36)   Symptoms of hypoglycaemia include:

A)  hunger, mental confusion, and diaphoresis     *
B)  flushed skin and dehydration
C)  rapid respirations and fruity smelling breath
D)  tachycardia and polyuria
E)   all of the above
 

36

37)   The signs and symptoms of hypoglycaemia reflect the fact that:

A)  muscle cells need glucose for normal function.
B)  glucose is the only source of energy for nervous tissue.   
C)  hypoglycemia decreases cerebral blood flow.    
D)  hypoglycemia inhibits the release of counterregulatory hormones such as the catecholamines. 
E)  all of the above.
 


37)   The signs and symptoms of hypoglycaemia reflect the fact that:

A)  muscle cells need glucose for normal function.
B)  glucose is the only source of energy for nervous tissue.    *
C)  hypoglycemia decreases cerebral blood flow.    
D)  hypoglycemia inhibits the release of counterregulatory hormones such as the catecholamines. 
E)  all of the above.
 

37


38)   If you knew a person was suffering from an overdose of insulin, the best remedial step would be to give the person

A)  unsweetened tea.
B)  large amounts of cold water.
C)  a saline solution drink.
D)  a non-diet soft drink.    
E)  none of the above.
 

38)   If you knew a person was suffering from an overdose of insulin, the best remedial step would be to give the person

A)  unsweetened tea.
B)  large amounts of cold water.
C)  a saline solution drink.
D)  a non-diet soft drink.    
E)  none of the above.
 

38

39)   A characteristic common to all hormones is that they:

A)  exert their effects by altering the rate of a body reaction  
B)  are secreted at a uniform rate
C)  must be produced in large quantities to exert their effects
D)  always exert their actions at the site of secretion
E)  none of the above
 

39)   A characteristic common to all hormones is that they:

A)  exert their effects by altering the rate of a body reaction   *
B)  are secreted at a uniform rate
C)  must be produced in large quantities to exert their effects
D)  always exert their actions at the site of secretion
E)  none of the above
 

39

40)    Hormones reach their target organs by:

A)  travelling through the bloodstream  
B)  paracrine mechanisms in which they act locally on cells other than those that produced the hormone
C)  autocrine action in which they regulate the action of the cell producing the hormone
D)  all of the above mechanisms
E)  none of the above mechanisms
 


40)    Hormones reach their target organs by:

A)  travelling through the bloodstream   *
B)  paracrine mechanisms in which they act locally on cells other than those that produced the hormone
C)  autocrine action in which they regulate the action of the cell producing the hormone
D)  all of the above mechanisms
E)  none of the above mechanisms
 

40


41)   The chemical mediators of the endocrine system must bind to ___________________ on target cells before they can initiate changes in those cells.
 

41)   The chemical mediators of the endocrine system must bind to ___________________ on target cells before they can initiate changes in those cells.

Answer: receptors

41


42) The chemical mediators used by the endocrine system are called __________________.
 


42) The chemical mediators used by the endocrine system are called __________________.

Answer: Hormones

42


43) ___________________________ glands secrete small amounts of chemical mediators into the interstitial fluid; other glands secrete products directly into ducts.

 



43) ___________________________ glands secrete small amounts of chemical mediators into the interstitial fluid; other glands secrete products directly into ducts.


Answer: Endocrine

43

44)   The electrolyte critical for thyroid hormone synthesis is ________________________.
 

44)   The electrolyte critical for thyroid hormone synthesis is ________________________.

Answer: Iodide

44


45)  __________________________ , also known as islets of Langerhans, are the endocrine tissues of the pancreas.
 

45)  __________________________ , also known as islets of Langerhans, are the endocrine tissues of the pancreas.

Answer: Pancreatic islets

45

46) Hormones, such as insulin and glucagon, which have opposing effects are described as ______.

 

46) Hormones, such as insulin and glucagon, which have opposing effects are described as ______.

Answer:  antagonistic

46

47)   Glucagon is secreted by ____________________ cells of the Islets of Langerhans. 
 


47)   Glucagon is secreted by ____________________ cells of the Islets of Langerhans. 

Answer: alpha cells

47

48)   The adrenal __________________ releases adrenalin (epinephrine) and noradrenalin (norepinephrine).
 


48)   The adrenal __________________ releases adrenalin (epinephrine) and noradrenalin (norepinephrine).

Answer: medulla

48

49)   Hormones act on specific _________________ tissues.
 


49)   Hormones act on specific _________________ tissues.


Answer: target

49


50)   The hormone responsible for milk production is _________________________.

50)   The hormone responsible for milk production is _________________________.

Answer: prolactin

50


51) Approximately 30 minutes after falling from a tree, a ten year-old boy arrives at the emergency department of PMH by ambulance.   He has suffered a head injury that includes his pituitary gland being completely severed from its attachment to the hypothalamus of the brain.

(a) What immediate homeostatic consequence will the staff of the Emergency Department have to manage in relation to the death of his pituitary gland tissues?        

(2 marks)

 

51) Approximately 30 minutes after falling from a tree, a ten year-old boy arrives at the emergency department of PMH by ambulance.   He has suffered a head injury that includes his pituitary gland being completely severed from its attachment to the hypothalamus of the brain.

(a) What immediate homeostatic consequence will the staff of the Emergency Department have to manage in relation to the death of his pituitary gland tissues?         (2 marks)

Answer: - Marked increase in diuresis (uncontrolled)       (1mark)
               - leading to dehydration              (1mark)

51


52)  Explain why hyperglycemia occurs in type I diabetes mellitus and give TWO complications.                                                      (5 marks)


 

52)  Explain why hyperglycemia occurs in type I diabetes mellitus and give TWO complications.                                                      (5 marks)

Answer:
Lack of insulin → cells not to be able to take up glucose → hyperglycemia.
Complication → blindness, MI, stroke, renal disease, foot ulcer
 

52

53)   Cells communicate with one another using a language of chemicals.  List one role each of the following plays in cellular communication.


a. hormones
b. cell membranes
c. receptor molecules           (3 marks)

 

 

Answer:
A)  Hormones attach to cells and influence their activity in some specific fashion.
B)  Cell membranes contain the receptor molecules for those hormones that use membrane-bound receptors to achieve their effects.
C)  Receptor molecules are chemicals that hormones bind to.  Specific receptors are used to identify target cells to a given hormone.  The hormone-receptor complex initiates the response of the target cells.

 

53

54)   Hormone Z, responsible for maintaining normal blood levels of chemical A, binds to membrane-bound receptors on its target cells.  These target cells use G-protein and cyclic AMP to carry out the response of hormone Z.  Predict the consequences if a drug is taken that inhibits the action of cyclic AMP.            (1 mark)


 

54)   Hormone Z, responsible for maintaining normal blood levels of chemical A, binds to membrane-bound receptors on its target cells.  These target cells use G-protein and cyclic AMP to carry out the response of hormone Z.  Predict the consequences if a drug is taken that inhibits the action of cyclic AMP.            (1 mark)

Answer:     If the action of cyclic AMP is inhibited, then the action of hormone Z is inhibited.