Question 1

Chemical substances, secreted by cells into the extracellular fluids, regulate the metabolic function of other cells in the body are called ________.
A) enzymes
B) hormones
C) antibodies
D) proteins

Accepted Answer

Hormones are chemical substances secreted by cells into the extracellular fluids that regulate the metabolic function of other cells in the body. Enzymes, antibodies, and proteins all have different functions in the body, but do not necessarily have a regulatory role over other cells.

Question 2

All of the following hormones are produced by the thyroid gland EXCEPT ________. A) calcitonin B) OT C) T₃ D) T₄

Accepted Answer

The thyroid gland produces hormones such as thyroxine (T4), triiodothyronine (T3), and calcitonin. However, oxytocin (OT) is not produced by the thyroid gland. Choices C and D are not valid options as they seem to be typing errors.

Question 3

Which endocrine gland also performs exocrine functions?
A) pituitary gland
B) thymus
C) thyroid gland
D) pancreas

Accepted Answer

The pancreas performs both endocrine and exocrine functions. The endocrine functions include the production of insulin and glucagon, while the exocrine functions involve the secretion of digestive enzymes into the small intestine.

Question 4

The posterior lobe of the pituitary gland is NOT a true endocrine gland because ________.
A) in adults it is not functional
B) it does not produce hormones, rather it stores hormones from the hypothalamus for release
C) it is strictly part of the neural system and has nothing to do with hormonal release
D) it is unable to function as endocrine tissue because it is part of the nervous system due to its location

Accepted Answer

The posterior lobe of the pituitary gland does not produce hormones itself, but rather stores hormones that are produced in the hypothalamus and transported to the posterior pituitary for release into the bloodstream. Therefore, it is considered to be a neuroendocrine organ rather than a true endocrine gland.

Question 5

The darkly stained cells in the posterior lobe of the pituitary gland are called ________.
A) chromophobes
B) acidophils
C) chromophils
D) pituicytes

Accepted Answer

Pituicytes are the glial cells found in the posterior lobe of the pituitary gland, which can appear darkly stained in histological sections. They support the function of the neurohypophysis but are not hormone-producing cells themselves.

Question 6

Which two systems regulate homeostasis?
A) immune and endocrine
B) lymphatic and endocrine
C) muscular and endocrine
D) nervous and endocrine

Accepted Answer

Both the nervous and endocrine systems regulate homeostasis. The nervous system uses electrical impulses to quickly respond to changes in the body, whereas the endocrine system uses hormones to regulate the body's functions more slowly over a longer period of time. Together, they work to maintain a stable internal environment for the body's cells.

Question 7

Which of the following hormones is secreted by the pars intermedia?
A) ADH
B) MSH
C) OT
D) none of the above

Accepted Answer

The hormone secreted by the pars intermedia is melanocyte-stimulating hormone (MSH). ADH and OT are secreted by the posterior pituitary gland. None of the hormones are secreted by the anterior pituitary gland.

Question 8

Which cells of the parathyroid glands turns colorless when prepared with histological stains?
A) C cells
B) oxyphil cells
C) follicular cells
D) chief cells

Accepted Answer

Oxyphil cells are the only cells in parathyroid glands that turn colorless when prepared with histological stains.

Question 9

All of the following are regions of the adrenal cortex EXCEPT ________.
A) zona medulla
B) zona fasciculata
C) zona glomerulosa
D) zona reticularis

Accepted Answer

The adrenal cortex has three distinct regions: the zona glomerulosa, which produces mineralocorticoids such as aldosterone; the zona fasciculata, which produces glucocorticoids such as cortisol; and the zona reticularis, which produces androgens such as testosterone. There is no region called the zona medulla in the adrenal cortex. The medulla is a separate part of the adrenal gland that produces catecholamines such as epinephrine and norepinephrine.

Question 10

CT is produced by which cells of the thyroid gland?
A) C cells
B) chromophils
C) pituicytes
D) follicle cells

Accepted Answer

CT (calcitonin) is produced by C cells (also called parafollicular cells) located in the thyroid gland.

Question 11

All of the following are parts of the anterior pituitary gland EXCEPT ________.
A) pars nervosa
B) pars distalis
C) pars intermedia
D) pars tuberalis

Accepted Answer

The pars nervosa is actually part of the posterior pituitary gland, not the anterior pituitary gland. The pars distalis, pars intermedia, and pars tuberalis are all parts of the anterior pituitary gland.

Question 12

An important regulator of electrolyte concentrations in extracellular fluids is ________.
A) cortisol
B) aldosterone
C) insulin
D) glucagon

Accepted Answer

The hormone aldosterone is released by the adrenal gland in response to low sodium or high potassium levels in the blood. Aldosterone promotes reabsorption of sodium and excretion of potassium in the kidneys, which helps regulate electrolyte concentrations in extracellular fluids. Cortisol, insulin, and glucagon do not have a direct role in electrolyte regulation.

Question 13

The parathyroid glands maintain adequate levels of blood calcium. This is accomplished by ________.
A) antagonizing the synthesis of calcitonin
B) blocking the action of growth hormone
C) activating osteoclasts so that calcium will be released
D) none of the above

Accepted Answer

The parathyroid glands secrete parathyroid hormone (PTH) which activates osteoclasts to break down bone tissue in order to release calcium into the blood. This results in an increase in blood calcium levels.

Question 14

Which region of the adrenal gland is regulated by the sympathetic nervous system?
A) adrenal medulla
B) zona fasciculata
C) zona reticularis
D) zona glomerulosa

Accepted Answer

The adrenal medulla is regulated by the sympathetic nervous system and secretes catecholamines such as epinephrine and norepinephrine in response to stress or danger. The other regions of the adrenal gland are regulated by different hormones or factors. The zona glomerulosa is regulated by the renin-angiotensin-aldosterone system, the zona fasciculata is regulated by adrenocorticotropic hormone (ACTH) from the anterior pituitary gland, and the zona reticularis is regulated by ACTH and other factors such as androgens.

Question 15

What connects the pituitary gland to the hypothalamus?
A) brain stem
B) midbrain
C) infundibulum
D) thalamus

Accepted Answer

The infundibulum is a small stalk-like structure that connects the pituitary gland to the hypothalamus. The brainstem, midbrain, and thalamus do not directly connect to the pituitary gland.

Question 16

In a negative feedback mechanism the response is ________ the stimulus.
A) to reduce
B) no change to
C) to enhance
D) none of the above

Accepted Answer

In a negative feedback mechanism, the response is to reduce the stimulus. This means that the body is attempting to maintain homeostasis by decreasing the output of a system in response to a detected increase in a particular variable. This allows the body to maintain a stable internal environment despite changes in external conditions.

Question 17

All of the following are effects of calcitonin EXCEPT ________.
A) increases blood calcium levels
B) stimulates osteoblasts to store calcium
C) inhibits osteoclasts
D) decreases blood calcium levels

Accepted Answer

Calcitonin decreases blood calcium levels by inhibiting osteoclasts and stimulating osteoblasts to store calcium. It does not increase blood calcium levels.

Question 18

Which region of the adrenal gland produces and secretes cortisol?
A) zona reticularis
B) adrenal medulla
C) zona glomerulosa
D) zona fasciculata

Accepted Answer

The zona fasciculata of the adrenal gland is responsible for producing and secreting cortisol.

Question 19

Which region of the adrenal cortex secretes aldosterone?
A) zona fasciculata
B) zona glomerulosa
C) zona reticularis
D) none of the above

Accepted Answer

Aldosterone is secreted by the zona glomerulosa of the adrenal cortex.

Question 20

What hormone produced by the thymus gland is essential for the maturation of the immune system?
A) calcitonin
B) triiodothyronine
C) tymosin
D) parathyroid hormone

Accepted Answer

Tymosin is the hormone produced by the thymus gland that is essential for the maturation of the immune system. It plays a vital role in the development of T-cells, which are responsible for identifying and attacking foreign invaders in the body.

Quiz 33: Endocrine System

Chemical substances, secreted by cells into the extracellular fluids, regulate the metabolic function of other cells in the body are called ________.

All of the following hormones are produced by the thyroid gland EXCEPT ________.

Which endocrine gland also performs exocrine functions?

The posterior lobe of the pituitary gland is NOT a true endocrine gland because ________.

The darkly stained cells in the posterior lobe of the pituitary gland are called ________.

Which two systems regulate homeostasis?

Which of the following hormones is secreted by the pars intermedia?

Which cells of the parathyroid glands turns colorless when prepared with histological stains?

All of the following are regions of the adrenal cortex EXCEPT ________.

CT is produced by which cells of the thyroid gland?

All of the following are parts of the anterior pituitary gland EXCEPT ________.

An important regulator of electrolyte concentrations in extracellular fluids is ________.

The parathyroid glands maintain adequate levels of blood calcium. This is accomplished by ________.

Which region of the adrenal gland is regulated by the sympathetic nervous system?

What connects the pituitary gland to the hypothalamus?

In a negative feedback mechanism the response is ________ the stimulus.

All of the following are effects of calcitonin EXCEPT ________.

Which region of the adrenal gland produces and secretes cortisol?

Which region of the adrenal cortex secretes aldosterone?

What hormone produced by the thymus gland is essential for the maturation of the immune system?