PhysioEx 4: Physiology Lab 4 Test Answers
Which two body systems coordinates and integrates the functions of different physiological systems?
ANSWER : -endocrine system -nervous system
The endocrine system plays a critical role in maintaining what?
ANSWER : -homeostasis
Hormones are secreted from where?
ANSWER : -ductless endocrine glands
endocrine glands
ANSWER : -tissues that have an epithelial origin -secrete hormones into the ECF
What carries hormones to their target cells?
ANSWER : -blood
Where can target cells be located?
ANSWER : -very close to or very far from the source of the hormone
Hormones bind to what and where?
ANSWER : -bind to high-affinity receptors -located on the target cell’s surface, in its cytosol, or in its
nucleus
What is the range in the blood for hormone concentration?
ANSWER : -10^-9 to 10^-12 molar
A hormone-receptor complex can exert a biological action through what?
ANSWER : -signal-transduction cascades and alteration of gene transcription at the target cell
The physiological response to hormones can vary depending on what?
ANSWER : -chemical nature of the hormone -receptor location in the target cell
The chemical structure of the hormone is important in determining what?
ANSWER : -how it will interact with target cells
examples of fast-acting hormones
ANSWER : -peptide -catecholamine
Peptide and catecholamine attach to what and cause what?
ANSWER : -attach to a plasma-membrane receptor -causes a second-messenger cascade in the
cytoplasm of the target cell
cAMP is synthesized from what?
ANSWER : -a molecule of ATP
The synthesis of cAMP makes the cell more what?
ANSWER : -metabolically active -more able to respond to a stimulus
examples of slow-acting hormones
ANSWER : -steroid -thyroxine
Steroid hormones and thyroxine enter what and interact with what?
ANSWER : -enter the target cell -interact with the nucleus
Why do steroid hormones and thyroxine interact with the nucleus?
ANSWER : -affect the transcription of various proteins that the cell can synthesize
Do the organs of the endocrine system function independently?
ANSWER : -no, the activities are coordinated
Positive or negative feedback is important in regulating hormone secretion, synthesis, and effectiveness
at target cells?
ANSWER : -negative feedback
How does negative feedback impact hormones?
ANSWER : -if the body needs a particular hormone, the hormone will be produced until there is too
much of it -once there is too much of the hormone, its release will be inhibited
What is an example of a hormone being regulated by positive feedback?
ANSWER : -oxytocin
Where is oxytocin released from?
ANSWER : -posterior pituitary
oxytocin
ANSWER : -hormone that causes the muscle layer of the uterus (myometrium) to contract during
childbirth
metabolism
ANSWER : -broad range of biochemical reactions occurring in the body
What are the two forms of metabolism?
ANSWER : -anabolism -catabolism
anabolism
ANSWER : -building up of small molecules into larger molecules via enzymatic reactions -energy is stored
in the chemical bonds when larger molecules are formed
catabolism
ANSWER : -breakdown of large molecules into smaller molecules via enzymatic reactions -breaking of
chemical bonds releases energy that the cell can use
Humans are what kind of organisms?
ANSWER : -homeothermic
homeothermic
ANSWER : -need to maintain a fixed body temperature to maintain the activity of the various metabolic
pathways in the body
What is the most important hormone for maintaining metabolism and body heat?
ANSWER : -thyroxine (thyroid hormone…tetraiodothyronine or T4)
Where is thyroxine secreted?
ANSWER : -thyroid gland (in the neck)
The production of thyroxine is controlled by what?
ANSWER : -pituitary gland (hypophysis)
The pituitary gland secretes what?
ANSWER : -thyroid-stimulating hormone (TSH)
The TSH causes the thyroid gland to do what?
ANSWER : -increase in size -secrete thyroxine into the general circulation
If TSH levels are too high, what happens to the thyroid gland?
ANSWER : -enlarges resulting in a goiter
hypothalamus
ANSWER : -participant in thyroxine and TSH production -primary endocrine gland -secretes several
hormones that affect the pituitary gland
What hormone is directly linked to thyroxine and TSH secretion?
ANSWER : -thyrotropin-releasing hormone (TRH)
Where is TRH secreted from?
ANSWER : -hypothalamus
The TRH stimulates what to produce what?
ANSWER : -stimulates anterior pituitary -produces TSH which then stimulates the thyroid to produce
thyroxine
When circulation levels of thyroxine are low, what happens?
ANSWER : -hypothalamus secretes more TRH
Why does the hypothalamus secrete more TRH?
ANSWER : -to stimulate the pituitary gland to secrete more TSH
The increase in TSH further stimulates what?
ANSWER : -secretion of thyroxine from the thyroid gland
The increased levels of thyroxine influences what to do what?
ANSWER : -influences hypothalamus -reduce production of TRH
How does the TRH travel from the hypothalamus to the pituitary gland?
ANSWER : -hypothalamic-pituitary portal system
hypothalamic-pituitary portal system
ANSWER : -specialized arrangement of blood vessels that consists of a single portal vein that connects
two capillary beds -transports many hormones from the hypothalamus to the pituitary gland
The hypothalamus primarily secretes what kind of hormones?
ANSWER : -tropic hormones
Tropic hormones stimulate what?
ANSWER : -secretion of other hormones
What are examples of tropic hormones?
ANSWER : -TRH: stimulates the release of TSH from the pituitary gland -TSH: stimulates production of
thyroxine -ACTH -CRH
What was the purpose of this physioex?
ANSWER : -investigate the effects of thyroxine and TSH on a rat’s metabolic rate
The metabolic rate will be indicated by what?
ANSWER : -amount of oxygen the rate consumes per time per body mass
How many experiments will you perform on how many rats?
ANSWER : -4 experiments -3 rats
thyroidectomized rat
ANSWER : -rat whose thyroid gland has been surgically removed
hypophysectomized rat
ANSWER : -rat whose pituitary gland has been surgically removed
propylthiouracil
ANSWER : -drug that inhibits the production of thyroxine
What does soda lime do?
ANSWER : -absorbs the carbon dioxide given off by the rat
insulin
ANSWER : -hormone produced by the beta cells of the endocrine portion of the pancreas
Insulin is vital to the regulation of what?
ANSWER : -plasma glucose levels or “blood sugar”
Glucose absorbed from the blood is used for what?
ANSWER : -fuel for metabolism -stored as glycogen
Glycogen is stored in what types of cells?
ANSWER : -muscle and liver cells
How much glucose consumed during a meal is stored as glycogen?
ANSWER : -0.75
When glucose levels in the plasma fall below a certain value, the alpha cells of the pancreas are
stimulated to release what?
ANSWER : -glucagon
glucagon
ANSWER : -hormone that stimulates the breakdown of stored glycogen into glucose which is released
back into the blood
When the pancreas doesn’t produce enough insulin, what results?
ANSWER : -type 1 diabetes mellitus
When the pancreas produces sufficient insulin but the body fails to respond, what results?
ANSWER : -type 2 diabetes mellitus
What organs filter the excess glucose out of the plasma?
ANSWER : -kidneys
Inability of body cells to take up glucose from the blood is also a result from what?
ANSWER : -skeletal muscle cells undergoing protein catabolism
A patient with FPG values greater than or equal to 126 mg/dl in two FPG tests is diagnosed with what?
ANSWER : -diabetes
FPG values between 110 and 126 mg/dl indicate what?
ANSWER : -impairment or borderline impairment of insulin-mediated glucose uptake by cells
FPG values less than 110 mg/dl is considered what?
ANSWER : -normal
follicle-stimulating hormone (FSH)
ANSWER : -anterior pituitary peptide hormone that stimulates ovarian follicle growth
Ovarian follicles produce and secrete what?
ANSWER : -estrogen
Estrogen is what kind of hormone?
ANSWER : -steroid hormone
Estrogen affects what?
ANSWER : -female body and homeostasis -stimulation of bone growth and protection against
osteoporosis
osteoporosis
ANSWER : -reduction in the quantity of bone -decreased bone mass -increased susceptibility to fractures
After menopause, what happens to the ovaries?
ANSWER : -stop producing and secreting estrogen
What is one of the effects and potential health problems of menopause?
ANSWER : -loss of bone density (osteoporosis and bone fractures)
What secretes calcitonin?
ANSWER : -C cells in the thyroid gland
calcitonin
ANSWER : -peptide hormone -counteracts development of osteoporosis -inhibits osteoclast activity
-stimulates calcium uptake and deposition in long bones
ovariectomized rats
ANSWER : -rats that no longer produce estrogen because their ovaries were surgically removed
T score
ANSWER : -quantitative measurement of the mineral content of bone -indicator of the structural
strength of the bone -screen for osteoporosis
normal T score
#ERROR!
osteopenia T score
ANSWER : -1.0 to -2.49
osteoporosis T score
ANSWER : -2.5 and below
What secretes cortisol?
ANSWER : -adrenal cortex
Cortisol is important in the body’s response to what?
ANSWER : -stress
Cortisol release is stimulated by what?
ANSWER : -adrenocorticotropic hormone (ACTH)
adrenocorticotropic hormone (ACTH)
ANSWER : -tropic hormone released by the anterior pituitary
ACTH release is stimulated by what?
ANSWER : -corticotropin-releasing hormone (CRH)
corticotropin-releasing hormone (CRH)
ANSWER : -tropic hormone from the hypothalamus
Increased levels of cortisol negatively feed back to inhibit what?
ANSWER : -release of both ACTH and CRH
hypercortisolism
ANSWER : -increased cortisol in the blood
Cushing’s syndrome
ANSWER : -if the increased cortisol in the blood is caused by an adrenal gland tumor -iatrogenic -“steroid
diabetes”: results in hyperglycemia
iatrogenic
ANSWER : -physician induced
Which of the following is INCORRECTLY matched with its secreting organ? a) TRH – hypothalamus b) TSH
– posterior pituitary c) thyroxine – thyroid gland d) triiodothyronine – thyroid gland
ANSWER : TSH – posterior pituitary
A decrease in the level of thyroxine would increase the secretion of _______. a) neither TSH nor TRH b)
TSH c) TRH d) both TSH and TRH
ANSWER : D
A hypophysectomized rat is missing its ______. a) pituitary gland b) thyroid gland c) adrenal gland d)
hypothalamus
ANSWER : pituitary gland
Thyroxine is a __________. a) hormone that works through a second-messenger system b) slow-acting
hormone that enters the nucleus c) hormone that enters the nucleus d) slow-acting hormone e)
slow-acting hormone that works through a second-messenger system
ANSWER : B
Which of the following hormones is regulated by a positive feedback mechanism? a) oxytocin b)
thyroxine c) TRH d) TSH
ANSWER : A
Which rat(s) was euthyroid without any injections? a) the normal rat and the hypophysectomized rat b)
the hypophysectomized rat c) the normal rat d) the thyroidectomized rat
ANSWER : C
An abnormally high level of which of the following will result in goiter? a) thyroxine b) either TRH or TSH
c) TSH d) TRH e) either thyroxine or TRH
ANSWER : C
Why did the TSH have NO effect on the BMR of the thyroidectomized rat? a) the metabolism of the rat is
already too low b) the metabolism of the rat is already too high c) the rat is missing its pituitary gland d)
the rat is missing its thyroid gland
ANSWER : D
The injection of TSH resulted in goiter in ________. a) the hypophysectomized rat b) the normal rat c)
the thyroidectomized rat d) the normal rat and the hypophysectomized
ANSWER : D
Propylthiouracil injections resulted in goiter formation in _________. a) the normal rat b) the
thyroidectomized rat c) the hypophysectomized rat d) the normal rat and the hypophysectomized rat
ANSWER : A
Glucose is stored in the human body as ________. a) glucagon b) insulin c) glycogen d) plant starch
ANSWER : C
Which hormone stimulates the breakdown of polymerized glucose? a) glycogen b) insulin c) glucagon d)
plant starch
ANSWER : C
Glucose remains in the bloodstream as a result of ______. a) type 2 diabetes mellitus b) type 1 diabetes
mellitus c) type 1 diabetes mellitus and diabetes insipidus d) type 1 and type 2 diabetes mellitus e)
diabetes insipidus
ANSWER : D
Excess glucose can be found in the urine ________. a) when the transport maximum for reabsorption in
the kidney tubules is exceeded, as a result of type 1 diabetes or as a result of type 2 diabetes b) as a
result of type 2 diabetes c) as a result of type 1 diabetes d) when the transport maximum for
reabsorption in the kidney tubules is exceeded
ANSWER : A
In this experiment, optical density is measured using a _________. a) thermocycler b)
spectrophotometer c) caliper d) microscope
ANSWER : B
Using this assay, glucose concentration is _______. a) directly proportional to optical density b) inversely
proportional to the volume of blood sampled c) inversely proportional to optical density d) directly
proportional to the volume of blood sampled
ANSWER : A
Which of the patients tested was (were) in the diabetic range? a) patients 3 and 4 b) patients 3 and 5 c)
patient 3 d) patients 3, 4, and 5
ANSWER : B
Which of the patients tested was (were) in the borderline range for insulin-mediated glucose uptake? a)
patients 2 and 3 b) patient 3 c) patient 2 d) patient 4 e) patients 2 an 4
ANSWER : E
Peptide hormones include which of the following? a) estrogen b) calcitonin c) follicle-stimulating
hormone and estrogen d) follicle-stimulating hormone and calcitonin e) follicle-stimulating hormone
ANSWER : D
Which of the following is INCORRECTLY matched with one of its functions? a) FSH – stimulates ovarian
follicle growth b) estrogen – provides protection against osteoporosis c) calcitonin – inhibits osteoblast
activity d) all of the above are matched correctly
ANSWER : C
Which of the following is INCORRECTLY matched with its primary secreting organ? a) estrogen – ovaries
b) calcitonin – thyroid gland c) FSH – ovaries d) all of the above are matched correctly
ANSWER : C
Inhibiting osteoclast activity would prevent _______. a) osteoporosis b) ovariectomy c) osteopenia d)
osteopenia and osteoporosis
ANSWER : D
Replacement therapies for which two hormones were tested in this experiment? a) saline and calcitonin b) saline and estrogen c) FSH and calcitonin d) FSH and estrogen e) estrogen and calcitonin
ANSWER : E
Which of the following showed the greatest improvement in vertebral bone density for the rats? a) FSH
b) estrogen c) saline d) calcitonin
ANSWER : B
The baseline T score for the rats was indicate of ________. a) osteoporosis, because their ovaries were
removed b) osteopenia, because their ovaries were remvoed c) osteopenia, because their anterior
pituitary was removed d) osteoporosis, because they were postmenopausal e) osteoporosis, because
their anterior pituitary was removed
ANSWER : A
Which of the following improved the vertebral bone density of the rats? a) FSH b) estrogen c) saline d)
both calcitonin and estrogen e) calcitonin
ANSWER : D
The target cells for the hormone ACTH are located in the ________. a) posterior pituitary b) anterior
pituitary c) adrenal cortex d) hypothalamus
ANSWER : C
Tropic hormones include which of the following? a) cortisol, ACTH, and CRH b) ACTH c) CRH d) both
ACTH and CRH e) cortisol
ANSWER : D
Which of the following is NOT characterized by high levels of cortisol in the blood? a) Addison’s disease
b) Cushing’s syndrome c) iatrogenic Cushing’s syndrome d) Cushing’s disease
ANSWER : A
Iatrogenic Cushing’s syndrome is _______. a) a result of treatment with glucocorticoid hormones b)
often referred to as “steroid diabetes” c) physician induced d) all of the above are correct
ANSWER : D