Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Endocrine Physiology > VePHY M3 > Flashcards

VePHY M3 Flashcards

1
Q

Function of thyroid hormones in the body

A

Growth regulation, differentiation, metabolism of lipids, proteins, and carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In these species, the main
lobe of the thyroid is on the midline in the ventral cervical
region with dorso-lateral projections from each side

A

pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

thyroid gland major supply of blood

A

cranial thyroid artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

thyroid gland principal venous drainage

A

caudal thyroid vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

True or False. The thyroid has a rich supply of sympathetic nerves associated with blood vessels thought to regulate the blood supply to the
organ

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Components of thyroid glands in adult animals

A

follicular cells, parafollicular cells, colloid, interstitial CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

common in the dog and may be located anywhere from the larynx to the diaphragm

A

accessory thyroid tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the right lobe of the thyroid is situated slightly cranial to the left lobe and almost touches the caudal aspect of the larynx

A

dogs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

its role is for the synthesis and packaging of
substantial amounts of proteins primarily thyroglobulin

A

Follicular cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

its vascular supply fluctuates considerably depending upon the activity of the gland

A

thyroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

majority of the epithelial cells and the most important functional cells of the thyroid

A

follicular cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

caused by iodine deficiency in the diet

A

diffuse thyroid hyperplasia or goiter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Example of goitrogenic substances

A

thiouracil, sulfonamides, complex anions, plants from family brassicacceae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

the only tissue of the body which is able to accumulate iodine in large quantities and incorporate it into hormones

A

thyroid gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

peptide hormone of the mammalian thyroid that has been shown to be secreted by C-cells

A

calcitonin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

assembly of thyroid hormones within the follicular lumen is made possible by a unique protein

A

thyroglobulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

thyroglobulin is synthesized in?

A

RER of Follicular cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

essential component of thyroid hormones, is incorporated within the molecular structure of thyroglobulin

A

tyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

MIT and DIT combine to form the two biologically active

A

iodothyronines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

essential for maintaining constant blood levels of thyroid hormones in vertebrates under conditions of varied intake of iodine and varying metabolic demand for T4 and T3

A

extracellular storage of thyroglobulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

comprise a second endocrine cell population in the mammalian thyroid gland

A

C cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

active transport of iodine has been shown to be associated with

A

NIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

These other glands have the capacity to actively transport iodide, albeit at a much lower level than the thyroid

A

salivary gland, gastric mucosa, and lactating mammary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

These chemicals effectively block the ability of the gland to synthesize thyroid hormones

A

Perchlorate, Thiocyanate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

accomplished by the coordinated response of the adenohypophysis and hypothalamic nuclei to circulating levels of T4 and T3

A

negative feedback control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

binds to receptors on the plasma membrane of thyrotropic basophils in the adenohypophysis and activates adenylate cyclase

A

thyrotropin releasing hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where does clearance of thyroglobulin from the circulation take place

A

Kupffer cells of liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

incorporated not only into newly synthesized thyroglobulin recently delivered to the follicular lumen but also into molecules already stored in the lumen

A

iodine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

function as coupling enzyme to combine MIT and DIT to form T3

A

thyroperoxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

daily maintenance requirement of iodine of 10 to 15 kg adult dog

A

140

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Most of the iodine in the diets is reduced to iodide in this organ

A

GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which glands clear iodide from plasma

A

thyroid gland, salivary gland, gastric mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

how much is the net daily uptake of iodide in a dog

A

75

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Two-thirds of the iodine is in the form of

A

MIT and DIT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

About one-fourth of iodine is in these forms, all of which are incorporated in thyroglobulin molecules in the follicular colloid

A

T3 and T4

36
Q

About 40 percent of the extrathyroidal T4 in the dog is present in

A

plasma

37
Q

60 percent of extrathyroidal T4 is taken up by which organ

A

liver

38
Q

total plasma equivalent space of distribution of T4 is about

A

12 percent of bw

39
Q

peak concentration usually occurs at about

A

midday

40
Q

most important enzyme in the synthetic pathway of thyroid hormones

A

thyroperoxidase

41
Q

minimum concentration usually at about

A

midnight

42
Q

About 45 percent of the turnover of T4 is via

A

deiodination

43
Q

55 percent of T4 turnover is via

A

fecal excretion

44
Q

70 percent of T3 turnover is via

A

deiodination

45
Q

30 percent turnover of T3 is via

A

fecal excretion

46
Q

ratio of T4 to T3 in thyroglobulin

A

3.6 is to 1

47
Q

ratio of the daily production rates, based on plasma concentration and turnover of T3 and T4

A

2 is to 1

48
Q

stimulates oxygen utilization and heat production by many different cells of the body

A

thyroxine

49
Q

Functions of thyroxine

A

increased utilization of carbohydrates, increased protein catabolism and excretion of nitrogen, oxidation of fats, and loss in body weight

50
Q

increase the heart rate by a direct effect on heart muscle cells

A

thyroxine

51
Q

Effects of thyroxine deficient

A

CNS fail to function, lethargy, dull, mentally deficient, myelin fiber content decreased, cortical neurons smaller and fewer, vascularity of CNS is reduced

52
Q

True or False. The neuronal dysfunction caused by thyroxine deficiency is reversible in the adult animal but not in the
young growing animal

A

True

53
Q

effects of thyroxine excess secretion to animals

A

Nervous, jumpy, irritable and hyperactive

54
Q

These dog breeds are commonly affected with hypothyroidism

A

Doberman pinschers, golden retrievers, beagles

55
Q

is the result of primary diseases of the thyroid gland, especially idiopathic follicular atrophy

A

clinical hypothyroidism

56
Q

closely resembles Hashimotos disease in humans and appears to be genetically conditioned

A

lymphocytic thyroiditis

57
Q

caused by production of autoantibodies directed against
thyroglobulin

A

chronic lymphocytic thyroiditis

58
Q

Many clinical signs associated with hypothyroidism are due to

A

reduction in basal metabolic rate

59
Q

Clinical signs of hypothyroidism in dogs

A

Gain in body weight without an associated change in appetite. Less activite. Reluctance to play or take walks. Difficulty in maintaining normal body temperature. Myxedema. Failure of hair regrowth. Lack of libido. Reduction in sperm count in males and abnormal or absent estrous cyle in females.

60
Q

Clinical signs of hypothyroidism in cats

A

prolonged periods of apathy, poor hair growth, severe seborrhea, and myxedema of the face

61
Q

Hypothyroidism in chicken observed signs

A

small, moderately obese with increased accumulations of abdominal fat, have a small, dry comb, and an abnormally silky plumage

62
Q

other terms for idiopathic follicular atrophy

A

follicular collapse, lymphocytic thyroiditis

63
Q

Severe hypothyroidism and long standing hyperlipidemia may result to

A

atherosclerosis of coronary and cerebral vessels

64
Q

Tx of hypothyroidism

A

oral administration of synthetic thyroxine or triiodothyronine on a daily basis

65
Q

most common in adult cats and often related to adenomas composed of hyperactive follicular cells

A

hyperthyroidism

66
Q

clinical term for a non-neoplastic and non-inflammatory enlargement of the thyroid gland

A

goiter

67
Q

it is a potent thioglycoside from plants excreted in milk

A

goitrin

68
Q

associated with weight loss in spite of a normal or increased appetite and with restlessness and increased activity

A

hyperthyroidism

69
Q

associated with prolonged low-level exposure to thiocyanates produced by the ruminal degradation of cyanogenic glucosides

A

hyperplastic goiter in ruminants

70
Q

Congenital hypothyroidism in domestic animals may be associated with

A

iodine deficient hyperplastic goiter

71
Q

Effects of iodine deficient goiter in foals

A

moderately enlarged thyroids, are weak at birth, and Figure 3-30. Mechanism of action of goitrogens on thyroid hormone synthesis and secretion. (DIT = diiodotyrosine; MIT = monoiodotyrosine; PTU = propylthiouracil; TRH = Thyrotropin releasing-hormone; TSH = Thyroid-stimulating hormone). frequently die within a few days after birth

72
Q

these species with goiter born partially or completely hairless and are
either born dead or die soon after birth

A

calves

73
Q

effects of goiter in newborn pig, goats, and lambs

A

myxedema and hair loss

74
Q

endocrinologically inactive and encountered as an incidental lesion at necropsy

A

multinodular goiter

75
Q

one of the two most common endocrine diseases in adult-age cats

A

hypperthyroidism

76
Q

Congenital goiter is inherited as an autosomal recessive gene in these animals

A

sheep, afrikander cattle, saanen dwarf goats

77
Q

characterized by the inability of the animal to synthesize and secrete adequate amounts of thyroid hormones prior to or at birth

A

congenital dyshormonogenetic goiter

78
Q

plasma half life of T4 in rats

A

12 to 24 hours

79
Q

these species do not synthesize high affinity for transport proteins of T3 and T4

A

rodents, birds, amphibians, fish

80
Q

functions primarily as a prohormone and undergoes a single deiodination of the phenolic ring in extrathyroidal tissues to form the metabolically more active T3

A

T4

81
Q

disrupt one or more steps in the synthesis and secretion of thyroid hormones

A

exobiotics and drugs

82
Q

frequently used for the diagnosis of thyroid diseases in animals

A

thyroid function tests

83
Q

plasma half life of T4 in monkeys and humans

A

5-9 days

84
Q

most direct indicator of hypothyroidism

A

measurement of basal oxygen consumption

85
Q

most sensitive and accurate method for measurement of circulating levels of total thyroxine and triiodothyronine

A

radioimmunoassay

86
Q

a useful and reliable aid in the diagnosis of thyroid disease in animals

A

histological examination of biopsy of thyroid gland

Endocrine Physiology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions