Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
SBI4U Homeostasis Unit Test
Name: _______________________________
Date: _______________________
Instructions: You have 70 minutes to complete all test questions in the space
provided.
A. Fill in the blank questions: (12 marks) – 9 minutes
1. _______________ breaks down neurotransmitters within the synapse so
that the postsynaptic receptors are available for the next signal.
Acetycholinesterase K/U
2. _____________ are located at one end of a neuron, they are the primary
site for receiving signals from other neurons. Dendrites (K/U)
3. ___________________ is a primary neurotransmitter of the sympathetic
nervous system which increases heart rate, blood pressure, and produces
other “fight-or-flight” responses. Norepinephrine (K/U)
4. _____________________ are neurons located in the CNS. Interneurons
(K/U)
5. During __________________ there is a facilitated diffusion of sodium ions,
whereas during ________________there is a facilitated diffusion of
potassium ions, of the action potential. Depolarization, Repolarization
K/U
6. Molecules called _______________________ relay messages across the
synaptic cleft between the two neurons. Neurotransmitters (K/U)
7. ___________________increase the speed at which action potentials travel
and provide insulation to the axon. Myelin sheath (K/U)
8. Stress tends to promote _____________ activity of the sympathetic
nervous system and secretion of epinephrine thereby ____________
gluconeogenesis. (T/I) increased, stimulating
9. Increased glucagon secretion will stimulate the liver to ___________________
gluconeogenesis and glycogenolysis which ultimately works to _______________
plasma glucose levels. (T/I) increase, increase
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
B. Multiple-Choice questions: (21 marks) K/U – 21 minutes
Use the diagram to your right to answer questions 1-3.
1. Which structure produces secretions that regulate E and H?
a) A
b) B
c) C
d) D
2. Which two structures secrete substances that control the
menstrual cycle?
a) A and F
b) B and H
c) C and D
d) E and I
3. Which letter indicates the organ that produces insulin and glucagon?
a) H
b) G
c) B
d) F
4. The function of the urinary system is to maintain a blood pH of approximately
a) 7.1
b) 6.9
c) 7.2
d) 7.3
5. The continuous production of metabolic wastes establishes a steep
concentration gradient across the plasma membrane causing wastes to diffuse
out of cells and into the ___________________.
a) intracellular fluid
b) extracellular fluid
c) interstitial fluid
d) both b and c
6. The drainage of the urinary bladder is controlled by:
a) sphincters
b) urethra
c) ureters
d) the cortex
7. ____________________ is produced in the liver from the breakdown of excess
amino acids that are the building blocks of proteins
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
a) Ureters
b) EPO
c) NH2
d) Urea
8. Each kidney is composed of _________ to ____________ nephrons
a) one thousand to two thousand
b) two thousand to three thousand
c) one million to two million
d) two million to three million
9. In the nephron, as the water concentration in the filtrate _____________, the
chloride ion concentration in the filtrate ______________.
a) decreases, increases
b) increases, decreases
c) decreases, decreases
d) increases, increases
10. ________________ is secreted by the anterior pituitary gland and increases
the permeability of the distal tubule and collecting duct
a) EPO
b) ADH
c) LH
d) Testosterone
11. A human skeleton is shown in the photograph. The elongation of structures
A and B was stimulated by a hormone produced by the
a) islets of Langerhans
b) liver
c) pituitary gland
d) adrenal gland
12. The primary endocrine organs include the following….
a) Hypothalamus, liver, adrenal cortex
b) Hypothalamus, liver, small intestine
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
c) Hypothalamus, pineal gland, adrenal cortex
d) Hypothalamus, GI tract, adrenal cortex
12. The anterior pituitary gland is known to secret the following hormones…
a) Luteinizing hormone (LH), follicle stimulating hormone (FSH),
prolactin
b) Lipid hormone (LH), follicle stimulating hormone (FSH), prolactin
c) Parathyroid hormone (PTH), follicle stimulating hormone (FSH),
prolactin
d) Antidiuretic hormone (ADH), follicle stimulating hormone (FSH),
prolactin
13. The hormone oxytocin…
a) Is secreted by the hypothalamus and stimulates uterine contractions
and milk ejection by mammary glands in females
b) Is secreted by the hypothalamus and has an unknown function in
males
c) Is secreted by the posterior pituitary gland and stimulates uterine
contractions and milk ejection by mammary glands in females
d) Is secreted by the parathyroid glands and stimulates uterine
contractions and milk ejection by mammary glands in females
14. The hypothalamus is connected to the posterior pituitary gland by which
of the following
a) Infundibulum
b) Capillary bed
c) Anterior pituitary
d) Paraventricular nucleus
15. Calcitriol (or vitamin D3) is produced in the sin and kidneys. It’s main
function is to
a) Promote secretion of acid by intestine
b) Promotes absorption of calcium by intestine
c) Inhibits absorption of calcium by intestine
d) Inhibits secretion of acid by intestine
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
16. The adrenal cortex secretes a number of hormones all referred to as
adrenocorticoids. These include the following
a) Sex-corticoids, mineralocorticoids, and glucocorticoids
b) Sex hormones, mineralocorticoids, and glucocorticoids
c) Catecholamines, mineralocorticoids, and glucocorticoids
d) Catecholamines, sex-corticoids, and glucocorticoids
17. Excess thyroid hormones in the blood
a) Induce strong positive feedback, thereby decreasing TRH and TSH
release into the blood
b) Induce strong positive feedback, thereby increasing TRH and TSH
release into the blood
c) Induce strong negative feedback, thereby increasing TRH and TSH
release into the blood
d) Induce strong negative feedback, thereby decreasing TRH and TSH
release into the blood
18. Thyrotropin releasing hormone (TRH) is known to
a) Inhibit the release of TSH from the posterior pituitary
b) Stimulate the release of TSH from the posterior pituitary
c) Stimulate the release of TSH from the anterior pituitary
d) Inhibit the release of TSH from the anterior pituitary
19. Tropic hormones of the hypothalamus and anterior pituitary include the
following
a) Prolactin releasing hormone (PRH), prolactin inhibiting hormone
(PIH), and growth hormone releasing hormone (GHRH)
b) Prolactin releasing hormone (PRH), thyrotropin releasing hormone
(TRH), and growth hormone releasing hormone (GHRH)
c) Prolactin releasing hormone (PRH), thyroid stimulating hormone
(TSH), and growth hormone releasing hormone (GHRH)
d) Prolactin releasing hormone (PRH), tetraiodothyronine (T4), and
growth hormone releasing hormone (GHRH)
20. The secondary endocrine organs include the following
a) Heart, kidneys, thymus, liver, and skin
b) Heart, kidneys, digestive organs, liver, and skin
c) Heart, kidneys, ovaries, organs, liver, and skin
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
d) Heart, kidneys, parathyroid glands, liver, and skin
C. Matching (6 marks) K/U – 6 minutes
Column A
i.
Synaptic cleft (c)
Column B
a. Carries information about the environment to
the brain
ii.
Sympathetic
Nervous System (d)
b. Involved in processing of somatic sensory and
motor information
iii.
Refractory period (f)
c. A junction between two neurons
iv.
Cerebrum (b)
d. Associated with the “flight or fight” response
v.
Sensory neuron (a)
e. Supports the brain, cushions delicate brain
structures and helps to transport nutrients and
waste products
vi.
Cerebrospinal fluid
(e)
f. The time required before another action
potential can be produced
Match the following words to the diagram below (8 marks) K/U – 8 minutes
Thymus (6)
Parathyroid glands (1)
Pituitary gland (5)
Pancreas (7)
Testis (4)
Thyroid glands (2)
Ovaries (female) (8)
Adrenal glands (3)
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
D. Short answer questions:
1. Explain how nerve impulses travel faster along axons covered by myelin
sheath than they do along non-myelinated neurons. Ensure to support your
answer with a detailed diagram (3 marks) K/U – 3 minutes
The 3 stages of an action
potential only take place at the
Nodes of Ranvier and then the
action potential slides through
the myelinated portion of an
axon thus increasing its
propagation time.
In non-myelinated axons the
action potential stages take
place through the whole axon
thus taking more time to reach
the next neuron.
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
2. Hassan visited his psychiatrist and was told that his serotonin levels are
low. His doctor explained to him that serotonin is a naturally occurring
neurotransmitter that affects individual’s emotions and their moods. A lack of
serotonin has been associated with conditions such as phobias, schizophrenia,
depression, and aggressive behaviors. The doctor showed him a chart with
some of the drugs that might affect his serotonin levels.
Drug
Effect
Hallucinogens (LSD, ecstasy)
React directly with the serotonin receptors to
produce the same effect of serotonin
Clozapine
Prevents serotonin from binding to the postsynaptic
membranes
Prozac, Zoloft, Paxil
Cause serotonin to remain longer in the brain
a) Why is Prozac prescribed for people with depression? (2 marks) A – 2
minutes
Prozac increases serotonin levels in the brain what results in a more positive
mood.
b) Which drug should not be prescribed by someone experiencing
depression? (2 marks) A – 1 minute
Clozapine
3. Aside from filtering blood to remove wastes, what are the other functions of
the kidneys? (7 marks) K/U – 5 minutes
In addition to filtering blood to remove toxic waste products, the kidneys also
control water balance, pH, and levels of sodium, potassium, bicarbonate, and
calcium ions in the blood. They also secrete the hormone EPO that stimulates red
blood cell production and activates vitamin D production in the skin.
4. List the organs that compose the urinary system (4 marks) K/U – 2 minutes
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
–
–
–
–
two kidneys,
two ureters,
one urinary bladder and
one urethra.
5. Diabetes mellitus is known to affect around 4-6% of the adult population
and is the 7th leading cause of death in the United States. Are both forms
(both insulin dependent and non-insulin dependent) caused by persistent
hypoglycemia or hyperglycemia? Expand on your answer by explaining
how or where the system breaks down. (5 marks) A – 5 minutes
Level 4 Answer- Student not only states that it is hyperglycemia but also
clearly explains exactly how the system breaks down to cause this condition.
The primary sign of either form is hyperglycemia. This is due to reduced
insulin activity which is caused in part by reduced glucose uptake and
utilization by many tissues, as well as increased glucose output by the liver.
The increased glucose output is caused by increased gluconeogenesis and
glycogenolysis and reduced glycogen synthesis. Glucagon secretion is usually
elevated because the glucose permeability of alpha cells in the pancreas
(which secretes glucagon) is insulin dependent. This lack of insulin slows
down the ability of glucose to enter these cells, which makes them behave as
if the glucose level is lower than it actually is.
6. Hyposecretion of cortisol is also known as Addison’s disease. Explain how
this disease is caused by relating it to feedback loops discussed in class. (5
marks) A – 5 minutes
Level 4 answer: Student should be able to clearly explain the process of
the way in which all the hormones and organs are involved. They may
draw feedback loops to show the process more clearly.
Addison’s disease is characterized by hypoglycemia and poor tolerance of
stress. It is usually a result of destruction of the adrenal cortex and so
there is a defect in the secretion of aldosterone. Aldosterone normally
promotes sodium retention and potassium secretion by the kidneys.
Addison’s disease therefore involves having excess sodium secretion and
potassium retention, which by altering plasma sodium and plasma levels
results in cardiac arrhythmias and other neuromuscular signs.
Kasia Hirniak, Emily Colangelo and Ezgi Cetinkaya
E. Labeling:
1. Please CLEARLY label on the diagram below the following structures (3
marks) K/U - 3 minutes
-Cortex
Cortex
-Medulla
-Pelvis
Medulla
Pelvis