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