Midterm Questions

Question 1

Changes in ionized calcium within the cell regulate a protein called?

Answer 1

Calmodulin

Question 2

One anatomic feature that efficiently directs hormones to their target tissues

Answer 2

Portal circulation

Question 3

consists of blood flow from capillaries in one organ to a vein and then to capillaries in another organ

Answer 3

Portal circulation

Question 4

During transport, these prohormones are cleaved to yield AVP or oxytocin, and their binding proteins,
called

Answer 4

Neurophysins

Question 5

Define Endocrinology

Answer 5

It is the study of communication within a living organism by means of hormones.

Question 6

Define hormones

Answer 6

are the chemical messengers of the endocrine system

Question 7

Define Hormones

Answer 7

are the chemical messengers of the endocrine system

Question 8

Define Feedback Control

Answer 8

It is the regulation of hormonal secretion from an endocrine gland by an effect of the circulating hormones that the gland itself produces.

Question 9

Discuss the Hypothalamic-Pituitary-Thyroid Axis

Question 10

Hormonally active form of testosterone in male

Answer 10

Dihydrotestosterone

Question 11

Forms the junction between the pars distalis and pars nervosa

Answer 11

Pars intermedia

Question 12

Communication involves secretion of hormones from a cell directly into the surrounding extracellular space; the hormone then interacts with adjacent or nearby cells without being transported by
blood

Answer 12

Paracrine communication

Question 13

delivers very high concentrations of the hormone to its target site

Answer 13

Paracrine communication

Question 14

Communication involving secretion of peptides or other neurotransmitter molecules by neurons.

Answer 14

Neurocrine communication

Question 15

is a specialized form of paracrine function in which the
chemical messenger is transferred to a target cell via a
synapse or neuromuscular junction

Answer 15

Neurocrine communication

Question 16

Cyclic AMP is derived from ATP through the action of?

Answer 16

Adenylate cyclase

Question 17

Are enzymes that catalyze the conversion of inactive proenzyme to active enzymes.

Answer 17

Kinases

Question 18

The fact that 80 to 90% of the blood supply for the adenohypophysis comes from the

Answer 18

portal circulation

Question 19

The placenta of the mare also produces a gonadotropin called

Answer 19

equine chorionic gonadotropin (eCG)

Question 20

is synthesized by the endometrial cups of the
uterus, which in mares begins to develop about
day 36 of pregnancy

Answer 20

equine chorionic gonadotropin (eCG)

Question 21

One of the most common endocrinopathies in cat

Answer 21

Hyperthyroidism

Question 22

The fibers also contain their respective carrier protein called?

Answer 22

Neurophysins

Question 23

Prolactin is synthesized, processed, packaged, stored, and released by?

Answer 23

Lactotropes

Question 24

A disease caused by excess growth hormone secretion

Answer 24

Acromegaly

Question 25

(Enumerate) Several characteristics of hormone

Answer 25

1. They are present in the blood and other extracellular fluids in low concentrations. 2. The existence of mechanisms that direct hormones to their target cells and tissues.

Question 26

(Enumerate) Few hormones are produced without feedback regulation

Answer 26

1. Equine Chorionic Gonadotropin (eCG) 2. Progesterone 3. Estrogen

Question 27

(Enumerate) Second messenger of hormones

Answer 27

1. Cyclic AMP (cAMP) 2. Calcium 3. Phosphotidylinositides

Question 28

(Enumerate) Initial steps in signal transduction are as follows

Answer 28

1. Hormone binds to receptor on the outer surface of the plasma membrane. 2. Receptor binding activates intramembranous regulatory proteins. 3. Stimulatory regulatory proteins increase adenylate cyclase activity. 4. Adenylate cyclase catalyzes formation of cyclic AMP from ATP.

Question 29

(Enumerate) Tropic Hormones

Answer 29

1. Thyrotropin or Thyroid stimulating hormone (TSH) 2. Luteinizing hormone (LH) 3. Follicle stimulating hormone (FSH) 4. Prolactin, Adrenocorticotropin (ACTH) 5. Growth hormone or Somatotropin

Question 30

(Enumerate) Cells in Neurohypophysis

Answer 30

1. Pituicytes 2. Nonmyelinated axons

Question 31

(Enumerate) The primary stimuli for oxytocin release from storage sites in the neurohypophysis are

Answer 31

1. Distention of the reproductive tract, particularly in the pregnant female. 2. Stimulation of the mammary gland by the young 3. Audiovisual contact with the offspring

Question 32

(Enumerate) Components of the endocrine system that communicate by routes other than blood vessels

Answer 32

(PANS) Paracrine Autocrine Neurocrine Solinocrine

Question 33

(Enumerate) FUNCTIONS OF HORMONES

Answer 33

(3M's & G) 1. maintenance of pregnancy 2. maintain homeostasis 3. Metabolism 4. Growth and development

Question 34

A single hormone can affect a single function, give example

Answer 34

erythropoietin on hemoglobin synthesis by erythrocytes

Question 35

single hormones having multiple actions, give example

Answer 35

1. thyroxine on enzyme synthesis 2. erythropoiesis 3. bone turnover 4. carbohydrate 5. lipid metabolism

Question 36

multiple hormones having single actions, give example

Answer 36

1. regulation of lactation by prolactin 2. placental lactogens 3. corticosteroids 4. thyroxine 5. sex steroids 6. oxytocin

Question 37

multiple hormones producing multiple actions, give examples

Answer 37

1. reproductive steroids 2. oxytocin 3. parturition 4. fetal development 5. corticosteroids on pregnancy

Question 38

(Enumerate) Characteristics of hormone

Answer 38

1) single hormone can affect a single function 2) single hormones having multiple actions 3) multiple hormones having single actions 4) multiple hormones producing multiple actions

Question 39

the hormonally active form of testosterone in the male

Answer 39

Dihydrotestosterone

Question 40

negatively controls PTH secretion

Answer 40

Ionized calcium

Question 41

glucose negatively controls _________ and positively controls _________ secretion

Answer 41

glucagon insulin

Question 42

the volume of extracellular fluid negatively controls __________ production by feedback mechanism

Answer 42

aldosterone

Question 43

(Enumerate) few hormones are produced without feedback regulation. Those produced by the?

Answer 43

placenta, such as : 1. equine chorionic gonadotropin (eCG) 2. progesterone 3. estrogens

Question 44

These hormones affect other hormones

Answer 44

tropic hormones

Question 45

(Enumerate) four criteria for assay validity

Answer 45

(i) specificity (ii) accuracy (iii) precision (iv) sensitivity

Question 46

is often the result of an autoimmune process whereby the thyroid gland is invaded by immune cells and the hormone-secreting cells are destroyed

Answer 46

Primary hypothyroidism

Question 47

can be due to insufficient secretion of TSH, but it should be distinguished from “hypothyroxinemia”, which can be produced by concurrent disease, e.g., hyperadrenocorticism, malnutrition, and certain drugs.

Answer 47

Secondary hypothyroidism

Question 48

Anatomical subdivisions of the pituitary gland:

Answer 48

1. Adenohypophysis (anterior pituitary) 2. Neurohypophysis (posterior pituitary)

Question 49

Three parts of the adenohypophysis

Answer 49

1. the pars distalis 2. the pars tuberalis 3. the pars intermedia

Question 50

is the largest part of the adenohypophysis

Answer 50

pars distalis

Question 51

pars distalis five populations of cells

Answer 51

(i) thyrotropes (ii) gonadotropes (iii) lactotropes (iv) corticotropes (v) somatotropes

Question 52

which secrete the “tropic” hormones that regulate function of other endocrine glands

Answer 52

corticotropes

Question 53

regulate other nonendocrine organs and tissues

Answer 53

somatotropes

Question 54

is an upward extension of the adenohypophysis and is attached to the infundibulum

Answer 54

pars tuberalis

Question 55

forms the junction between the pars distalis and pars nervosa and is the source of melanocyte-stimulating hormone (MSH)

Answer 55

pars intermedia

Question 55

In cattle, pigs, and rats, ACTH produced by the pars intermedia is cleaved into what?

Answer 55

1) α- MSH 2) Corticotropin-like intermediate lobe peptide, or CLIP

Question 56

parts of the adenohypophysis of the dog and horse significant source of ACTH, and tumors of thIs part can lead to spontaneous hyperadrenocorticism in these species

Answer 56

pars intermedia

Question 57

Two parts of the neurohypophysis:

Answer 57

1. infundibulum or pituitary stalk 2. pars nervosa (posterior or neural lobe)

Question 58

(Enumerate) Hormones produced in the hypothalamus and stored in and released from the neurohypophysis are nonapeptides and include:

Answer 58

1. oxytocin 2. arginine vasopressin 3. lysine vasopressin 4. arginine vasotocin

Question 59

All hypophysiotropic hormones are peptides except

Answer 59

dopamine (prolactin release-inhibiting hormone)

Question 60

(Enumerate) The synthetic stimulatory hypophysiotropic hormones are:

Answer 60

(i) Thyrotropin-releasing hormone (TRH) (ii) Gonadotropin-releasing hormone (GnRH) (iii) Corticotropin-releasing hormone (CRH) (iv) Growth hormone-releasing hormone (GHRH)

Question 61

cholesterol side-chain cleavage enzyme

Answer 61

CYP11A1

Question 62

17α-hydroxylase/17, 20-lyase

Answer 62

CYP17A1

Question 63

21-hydroxylase

Answer 63

CYP21A2

Question 64

11β-hydroxylase

Answer 64

CYP11B2

Question 65

aldosterone synthase

Answer 65

CYP18B2/18-HSD

Question 66

aromatase

Answer 66

CYP19A1

Question 67

CYP11A1

Answer 67

cholesterol side-chain cleavage enzyme

Question 68

CYP17A1

Answer 68

17α-hydroxylase/17, 20-lyase

Question 69

CYP21A2

Answer 69

21-hydroxylase

Question 70

CYP11B2

Answer 70

11β-hydroxylase

Question 71

CYP18B2/18-HSD

Answer 71

aldosterone synthase

Question 72

CYP19A1

Answer 72

aromatase

Question 73

is a single-chain polypeptide hormone

Answer 73

Prolactin

Question 74

Prolactin is produced by widely dispersed pituitary gland cells called

Answer 74

lactotropes or mammotropes

Question 75

prolactin is under inhibitory control by this hormone

Answer 75

dopamine

Question 76

in some old and new literature, prolactin is called luteotropic hormone (LTH)?

Answer 76

luteotropic hormone (LTH)

Question 77

Atrophy of adrenal cortex caused by this Hormone Deficiency

Answer 77

ACTH

Question 78

(Enumerate) General depression of metabolism of fat, carbohydrates, and protein caused by these Hormone Deficiency

Answer 78

Adrenal steroids, STH, TSH, ACTH, gonadotropins

Question 79

Hormone Deficiency of Prolactin and STH; others like ACTH and TSH to lesser degree causes

Answer 79

Cessation of lactation

Question 80

this hormone appears to reduce growth hormone secretion independently of GHRH and by blocking GHRH action

Answer 80

Somatostatin

Question 81

is an important mediator of growth hormone action and is produced by many cells, particularly those of the liver

Answer 81

Insulin-like growth factor-1 (somatomedin C)

Question 82

is secreted by cells of the central nervous system and is involved mainly with fetal tissue development

Answer 82

Insulin-like growth factor-2

Question 83

(Enumerate) The gonadotropes have specific membrane receptors for GnRH. The intracellular messengers include

Answer 83

ionized calcium IP3 DAG

Question 84

HORMONES OF THE NEUROHYPOPHYSIS

Answer 84

Arginine Vasopressin and Oxytocin

Question 85

antidiuretic hormone or ADH

Answer 85

Arginine vasopressin

Question 86

(Enumerate) The primary stimuli for oxytocin release from storage sites in the neurohypophysis are:

Answer 86

1. distention of the reproductive tract, particularly in the pregnant female 2. stimulation of the mammary gland by the young 3. audiovisual contact with the offspring

Question 87

functions of oxytocin

Answer 87

1. inducing parturition 2. increase uterine contraction 3. treatment of retained placenta, metritis, and in some cases agalactia

Question 88

The adenohypophysis arises from an evagination of the ectodermal roof of the oropharynx (i.e., a mouth cavity) commonly called

Answer 88

Rathke’s pouch.

Question 89

Adrenocorticotropin is a 39-amino acid peptide derived from a much larger precursor called

Answer 89

proopiomelanocortin (POMC)

Question 90

Whatever the chemical nature of hormones they all have several characteristics in common. First, they are present in the blood and other extracellular fluids in low concentrations.