Human Anatomy and Physiology : Human Anatomy and Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #21 : Systems Physiology

A baseball player is taking exogenous steroids for 1 year. Which of the following organs will be suppressed? 

Possible Answers:

Heart

Kidneys

Adrenal glands

Liver

Lungs

Correct answer:

Adrenal glands

Explanation:

Steroids, when taken exogenously, diminish the production of steroids in the body. This can lead to atrophy of the adrenal glands (responsible for producing cortisol-stress steroid hormone). Thus, when patients are taking steroids for whatever reasons (sports, chemo, infection and etc) it is important for the steroids to be tapered off and not removed immediately since the body needs time to begin to reproduce the hormone again. 

Example Question #31 : Systems Physiology

Which of the following mechanisms is not typically associated with endocrine hormones?

Possible Answers:

They travel in the bloodstream

They are long lasting

They are indirect

They are fast acting

Correct answer:

They are fast acting

Explanation:

When thinking of hormones, it helps to remember that they are generally slow acting, indirect, and long lasting. All endocrine hormones travel through the bloodstream in order to reach their target cells. It can help to compare the activity of hormones to the activity of neurotransmitters, which are fast acting and have immediate effects on their target cell. Consider the effects of acetylcholine release at a neuromuscular junction in comparison to growth hormone release into the blood. The muscle twitch is much more transient and quick to react, whereas the effects of growth hormone can take much longer to appear.

Example Question #32 : Systems Physiology

Which of the following hormones binds to transmembrane receptors on the target cell?

Possible Answers:

Aldosterone

Estrogen

Testosterone

Thyroid hormone (T4)

Epinephrine

Correct answer:

Epinephrine

Explanation:

All steriod hormones are lipid soluble and will thus bind either nuclear or cytoplasmic receptors. Most peptide hormones are water soluble and cannot diffuse through the plasma membrane of the target cell; they must bind to receptors embedded in the cell membrane. The one exception to this rule is thyroid hormone. It is a peptide hormone, but is a lipophilic tyrosine derivative and binds to nuclear receptors.

Example Question #33 : Systems Physiology

Which of these is an example of a positive feedback loop?

Possible Answers:

Oxytocin release during childbirth causes uterine contractions

Blood pressure increases so heart rate decreases

High blood sugar produces an insulin response

Body temperature falls which causes shivering

Correct answer:

Oxytocin release during childbirth causes uterine contractions

Explanation:

A positive feedback loop features further deviation from normal. In the case of childbirth, oxytocin produces uterine contractions, which then causes more oxytocin to be released and more uterine contractions to occur until the baby is delivered. A negative feedback loop returns the body to normal conditions.

Example Question #34 : Systems Physiology

What type of communication occurs when a chemical messenger diffuses across the synaptic cleft formed between the presynaptic neuron and the target cell? 

Possible Answers:

Endocrine 

Neural or synaptic 

Paracrine 

Autocrine 

Exocrine 

Correct answer:

Neural or synaptic 

Explanation:

Neural or synaptic communication occurs when a neurotransmitter (or chemical messenger) diffuses across the synaptic cleft of the presynaptic neuron and postsynaptic neuron or target cell. Examples of these neurotransmitters include acetylcholine and norepinephrine. Endocrine communication occurs when chemical messengers are released into the blood stream. These chemical messengers are called hormones. 

Example Question #35 : Systems Physiology

The secretion of the parathyroid hormone is controlled by the plasma concentration of __________

Possible Answers:

calcium 

growth hormone

cortisol 

sodium 

thyroid-stimulating hormone 

Correct answer:

calcium 

Explanation:

The secretion of hormones can often be controlled by concentrations of nutrients, ions, and other molecules. The secretion of parathyroid hormone is regulated and controlled by the concentration of calcium found in the plasma. The function of parathyroid hormone is to increase the concentration of calcium in the blood. This is done by breaking down bone and increasing calcium reabsorption in the kidneys and intestine. 

Example Question #36 : Systems Physiology

Calcitonin is secreted by the __________.

Possible Answers:

thyroid gland

adrenal cortex 

hypothalamus 

parathyroid gland

thymus gland

Correct answer:

thyroid gland

Explanation:

Calcitonin, thyroxine, triiodothyronine are the hormones that are secreted by the thyroid. The c-cells of the thyroid secrete calcitonin. The function of calcitonin is to decrease the concentration of calcium in the blood by activating osteoblasts and/or deactivating osteoclasts, ultimately storing the calcium from the blood into bone.

Example Question #37 : Endocrine And Reproductive Physiology

Which hormone is responsible for regulating blood calcium levels when they become too low?

Possible Answers:

Thyroid stimulating hormone (TSH)

Melatonin

Cortisol

Parathyroid hormone (PTH)

Calcitonin

Correct answer:

Parathyroid hormone (PTH)

Explanation:

The correct answer is parathyroid hormone (PTH). PTH is secreted by the parathyroid gland when calcium levels become too low and acts to increase levels to normal range.

Calcitonin is also involved in calcium regulation, but is secreted by the thyroid gland when calcium levels become too high. Calcitonin reduces the action of the parathyroid gland and PTH until calcium levels are reduced to normal range. Thyroid stimulating hormone (TSH) causes the thyroid gland to grow in size in an attempt to make more hormones if iodine levels become too low. Melatonin is synthesized in the pineal gland and is important for the regulation of the sleep cycle. Cortisol is secreted by the adrenal cortex, and increases blood glucose levels, and has other effects.

Example Question #791 : Human Anatomy And Physiology

Which of the following hormones is created in the hypothalamus, then sent to the pituitary gland?

Possible Answers:

Adrenocorticotropic hormone

Prolactin

Oxytocin

Thyroid-stimulating hormone

Correct answer:

Oxytocin

Explanation:

The pituitary gland can be further divided into the anterior and posterior pituitary gland. The anterior pituitary gland creates and secretes its hormones, but the posterior pituitary gland does not create its hormones. Instead, the hormones secreted by the posterior pituitary gland are created in the hypothalamus, and are then sent to the pituitary gland. The two hormones made in the hypothalamus are antidiuretic hormone (ADH) and oxytocin.

Adrenocorticotropic hormone (ACTH), prolactin, and thyroid-stimulating hormone (TSH) are synthesized and secreted from the anterior pituitary.

Example Question #792 : Human Anatomy And Physiology

Which of the following hormones is not produced by the anterior pituitary gland?

Possible Answers:

Prolactin

Anti-diuretic hormone

Growth hormone

Follicle-stimulating hormone

Luteinizing hormone

Correct answer:

Anti-diuretic hormone

Explanation:

The anterior pituitary produces six hormones: follicle-stimulating hormone, luteinizing hormone, prolactin, growth hormone, adrenocorticotropic hormone, and thyroid-stimulating hormone.

The posterior pituitary releases only two hormones: anti-diuretic hormone (vasopressin) and oxytocin.

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