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