MCAT Biology Endocrine System

Question 1

The ___is part of the sympathetic nervous system releasing epinephrine and norepinephrine into the blood when stimulated

Answer 1

Adrenal medulla

Question 2

A tropic hormone produced by the anterior pituitary gland that targets the adrenal cortex, stimulating it to release cortisol and aldosterone

Answer 2

Adrenocorticotropic Hormone (ACTH)

Question 3

ACTH is produced by the ___

Answer 3

anterior pituitary gland

Question 4

ACTH target the __

Answer 4

adrenal cortex to release cortisol and aldosterone

Question 5

Also known as the adenohypophysis

Answer 5

Anterior pituitary gland

Question 6

FSH, LH, ACTH, TSH, Prolactin, and growth hormone are all produced and secreted by the

Answer 6

Anterior pituitary gland

Question 7

The anterior pituitary is controlled by releasing and inhibiting factors from the ___

Answer 7

hypothalamus

Question 8

Also called vasopressin

Answer 8

Antidiuretic hormone (ADH)

Question 9

This hormone is produced in the hypothalamus and secreted by the posterior pituitary gland. It targets the kidney tubules, increasing the permeability to water, and thus increasing water retention by the body

Answer 9

Antidiuretic hormone (ADH)

Question 10

A hormone produced by the C-cells of the thyroid gland that DECREASE serum calcium levels

Answer 10

Calcitonin

Question 11

__targets the bones (stimulates osteoblasts) and the kidneys (reduces calcium reabsorption)

Answer 11

Calcitonin

Question 12

___ is the principal mineralcorticoid

Answer 12

Aldosterone

Question 13

___is the principle glucocorticoid

Answer 13

Cortisol

Question 14

___are steroid hormones secreted from the adrenal cortex

Answer 14

Corticosteroids

Question 15

This steroid hormone is released during times of stress, increasing blood glucose levels and reducing inflammation

Answer 15

Cortisol

Question 16

A ductless gland that secretes a hormone into the blood

Answer 16

Endocrine gland

Question 17

A gland that secretes its product into a duct, which ultimately carries the product to the surface of the body or into a body cavity. Some examples include:

• sweat glands (sweat)
• Gastric glands (acid,mucus, protease)
• Liver (bile)
• Sebaceous glands (oil)
• Lacrimal glands (tears)

Answer 17

Exocrine glands

Question 18

A hormone release by the anterior pituitary that targets all cells in the body.

Answer 18

Growth hormone

Question 19

___ stimulates whole body growth in children and adolescents, and increases cell turnover rate in adults

Answer 19

Growth hormone

Question 20

A set of veins that connect a capillary bed in the hypothalamus (the primary capillary plexus) with the capillary bed in the anterior pituitary gland ( the secondary capillary plexus).

Answer 20

Hypothalamic-pituitary portal system

Question 21

Releasing and inhibiting factors from the hypothalamus travel along veins directly affect the cells in the anterior pituitary gland by way of ___

Answer 21

hypothalamic-pituitary portal system

Question 22

The portion of the diencephalon involved in maintaining body homeostasis

Answer 22

Hypothalamus

Question 23

The __controls release of hormones from the pituitary gland

Answer 23

Hypothalamus

Question 24

A form of regulation in which the end result of a series of events inhibits the trigger for that series

Answer 24

Negative feedback

Question 25

Hormones are generally regulated via__

Answer 25

negative feedback

Question 26

Insulin is released when blood glucose levels rise. IT causes the cells of the body to take glucose out of the blood, leading to a drop in glucose levels. The fall in glucose levels stops insulin release

Answer 26

Negative feedback

Question 27

Neurohypophysis =

Answer 27

Posterior pituitary gland

Question 28

A hormone made of amino acids __

Answer 28

peptide hormone

Question 29

__ are generally hydrophilic and cannot cross the plasma membranes of cells, thus the receptor for them must be found on the cell surface

Answer 29

Peptide hormones

Question 30

Binding of a ___ to its receptor usually triggers a second messenger system within the cell

Answer 30

Peptide hormone

Question 31

Which peptide hormone has its receptor on the interior of the cell?

Answer 31

Thyroxine which is hydrophobic enough to enter the cell easily

Question 32

The ___ is made of nervous tissue and stores and secretes two hormones made in the hypothalamus

Answer 32

Posterior pituitary gland

Question 33

The posterior pituitary gland is controlled by action potentials from the ___

Answer 33

hypothalamus

Question 34

The hypothalamus makes __ and___ which are stored in the posterior pituitary gland

Answer 34

Oxytocin and ADH

Question 35

A hormone derived from ___

Answer 35

cholesterol

Question 36

___ are generally hydrophobic and can easily cross the plasma membranes of cells, thus receptors for them are found intracellularly

Answer 36

Steroid hormone

Question 37

Once the ___ binds to its receptor, the complex acts to regulate transcription in the nucleus

Answer 37

Steroid hormone

Question 38

A tropic hormone produced by the anterior pituitary gland that targets the thyroid gland, stimulating it to produce and release thyroid hormone

Answer 38

Thyroid stimulating hormone (TSH)

Question 39

__ is produced and secreted by follicle cells in the thyroid gland.

Answer 39

Thyroxine (thyroid hormone)

Question 40

____targets all cells in the body and increases overall body metabolism

Answer 40

Thyroxine

Question 41

A hormone that controls the release of another hormone

Answer 41

Tropic hormone

Question 42

If signaling molecules modify the activity of the cells which secreted them this is ___

Answer 42

autocrine activity

Question 43

T cell secretes interleukin 2, which binds to receptors on the same T cell to stimulate increased activity

Answer 43

Autocrine activity

Question 44

The hydrophilicity of peptide hormones means they can't cross the biological membrane and thus are required to communicate with the interior of the target cell by way of a __

Answer 44

second messenger cascade

Question 45

The two subgroups of peptide hormones are __ and _

Answer 45

polypeptides and amino acid derivatives

Question 46

An example of a polypeptide hormone is __

Answer 46

insulin

Question 47

___is secreted by the beta cells of the pancreatic islets of Langerhans in response to elevated blood glucose

Answer 47

Insulin (polypeptide hormone)

Question 48

___ are derived from single amino acids and contain no peptide bonds

Answer 48

Amino acid derivatives (hormones)

Question 49

___ is the parent amino acid for the catecholamines (which include epinephrine) and the thyroid hormones

Answer 49

Tyrosine

Question 50

___ incorporate iodine into their structure. enter the cell, bind to DNA, and activate transcription of genes involved in energy mobilization

Answer 50

Thyroid hormones

Question 51

___ are hydrophobic molecules synthesized from cholesterol in the smooth endoplasmic reticulum

Answer 51

Steroids

Question 52

The small hydrophobic steroid hormones exert their effects upon target cells by ___

Answer 52

diffusing through the plasma membrane to bind with a receptor in the cytoplasm

Question 53

Because peptide hormones modify the activity of existing enzymes in the cytoplasm their effects are exerted___

Answer 53

rapidly minutes to hours from time of secretion

Question 54

Because steroid hormones must be transported as a steroid hormone-receptor complex into the nucleus and modify transcription to change the amount and/or type f proteins in the cell, their effects are exerted__

Answer 54

slowly, over a period of days, and persist for days to weeks

Question 55

Steroids regulating water balances and other processes are secreted by the ___

Answer 55

adrenal cortex

Question 56

Regulation of release of peptide hormones?

Answer 56

Stored in vesicles until a signal for secretion is received

Question 57

Mechanism of effect of peptide hormones?

Answer 57

Bind to receptors that generate second messengers which result in modification of enzyme activity

Question 58

Site of synthesis of steroid hormones

Answer 58

Smooth ER

Question 59

Regulation of release of steroid hormones?

Answer 59

Synthesized only when needed and then used immediately, not stored

Question 60

The function of calcitonin is to ___

Answer 60

prevent serum [Ca2+] from peaking above normal levels, and the amount of calcitonin secreted is directly proportional to increases in serum [Ca2+] above normal.

Question 61

When serum [Ca2+] is elevated, ___

Answer 61

calcitonin is secreted