Brainscape's Knowledge GenomeTM

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


See full index

Physiology Lecture > Cell Signaling and Endocrine System > Flashcards

Cell Signaling and Endocrine System Flashcards

1
Q

What are the 5 types of chemical messengers?

A

Amino acid messengers
Amine messengers
Peptide/Protein messengers
steroid messengers
Eicosanoid messengers

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

what is the amino acid messengers function?

A

functions as a neurotransmitter of the central nervous system

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

where are amino acids synthesized?

A

synthesized in the neuron mostly

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

amino acid messengers are lipophobic and stores in __________ until released?

A

vesicles

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

what are amine messengers derived from?

A

Derived from all amino acids

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

what are amine messengers function?

A

can function as neurotransmitter, paracrine and hormones

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

amine messengers are catecholamines. what are three examples of catecholamines?

A

dopamine, norepinephrine and epinephrine

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

amine messengers are synthesized enzymatically in _________.

A

cytosol

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

serotonin is derived from?

A

tryptophan, precursor for melatonin

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

melatonin

A

hormone secreted by the pineal gland and is important for regulating circadian rhythm

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

what is histamine derived from? what is it involved in?

A

histidine and involved in inflammatory reactions

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

what are peptide/ protein messenger characteristics?

A
  • fewer than 50 amino acids long
  • proteins are long polypeptide chains
  • lipophobic, stored in vesicles until released
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

in post translational modification prepropeptides are formed in the ?

A

lumen of rough endoplasmic reticulum

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

post translational modification is cleaved by?

A

proteolytic enzymes forming propeptide

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

in post translational modification where is propeptide sent to?

A

sent to the Golgi via smooth endoplasmic reticulum

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

what are the steps of post translational modification?

A
  • prepropeptide is formed in the lumen of the rough ER
  • then is cleaved by proteolytic enzymes froming propeptide
  • then propeptide is sent to the golgi via smooth ER
  • propeptide cleaves to peptide on golgi, secondary vesicles released
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are steroid messengers derived from?

A

cholesterol (lipophilic)

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

in steroid messengers, enzymes catalyze cholesterol in the?

A

smooth ER and mitochondria

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

T/F: steroid messengers must be synthesized on demand and released immediately

A

true

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

what are eicosanoid messengers derived from?

A

arachidonic acid (lipophilic)

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

in eicosanoid messgers, phospholipase A2 cleaves _______ _________ from membrane phospholipid.

A

arachidonic acid

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

what two pathways are eicosandoids produced by?

A

cyclooxygenase and lipoxygenase

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

autocines, paracrines, neurotransmitters are trnasported to _____ ____ via ______ _______ and quicly degrade.

A

target cells, simple diffusion

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

how are hormones transported?

A

via circulatory system in dissolved form or via carrier proteins

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

what is the process of signal transduction?

A
  • chemical messengers bind to target cell receptors
  • then the messenger/ receptor binding changes the activity of the cell
  • receptor binds to only 1 messenger
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

affinity

A

the strength of binding between messenger and receptor

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

in singnal transduction, can messengers bind to more than one receptor?

A

yes

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

in signal transduction do target cells have multiple types of receptors?

A

yes

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

what do target cell response to a chemical messenger depend on?

A
  • messenger concentration
  • number of receptors
  • affinity
  • antagonistic messengers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

up regulation

A

increased production of receptors

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

down regulation

A

decreased production of receptors

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

explain the process of intracellular receptors

A
  • lipophilic hormones pass through membrane and bind to receptor in cytoplasm
  • hormone receptor complex binds to hormone response element
  • binging activates or deactivates gene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what are the three membrane bound receptors?

A

channel linked receptors
enzyme linked receptors
G protein linked receptors

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

what is the process of membrane bound receptors?

A
  • lipophocic messenger cannot pass through plasma membrane
  • so it binds to receptors situated within the plasma membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what are examples of channel linked receptors?

A

fast ligand gated ion channel
calcium channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

explain the function of channel linked receptors?

A
  • functions as a second messenger by binding to calmodulin
  • then calcium calmodulin complex activates protein kinase which alters cellular functioning
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is the function of enzyme linked receptors?

A
  • functions as both as a receptor and an enzyme
  • changes protein activity producing a response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

how does the enzyme linked receptors for tyrosine kinase work?

A

messenger binds to receptor changing conformation which activates tyrosine kinase to catalyze the phosphorylation of intracellular protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

explain the process of G protein linked receptors work?

A
  • bound receptor activates g proteins
  • g protein functions as a link between receptor and other membrane proteins
  • alpha subunit binds with GDP during inactive state
  • messenger binds with receptor which causes g protein to release GDP and bind with GTP and become activated
  • alpha subunit is released
  • alpha subunit binds to ion channel changing conformation which opens/ closes the channel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

explain cAMP second messenger system

A
  • first messenger binds to receptor and actiates Gs protein
  • alpha subunit binds and activates adelylate cyclase which catalyzes conversion of ATP to cAMP
    -cAMP activates protein kinase A which transfers phosphate from ATP to protein causing signal transduction
  • termination of cAMP requires cAMP phosphodiesterase
  • phosphoprotein phosphatase removes phosphate from protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

explain phosphatidylinositol second messenger system

A
  • messenger binds to receptor activating Gs protein, releasing alpha subunit which binds to and activates phospholipase C
  • phospholipase C catalyzes conversion of PIP2 to DAG and IP3
  • DAG activates protein kinase C which catalyzes conversion phosphorylation of proteins
  • IP3 triggers release of calcium from endoplasmic reticulum
  • calcium combines with calmodulin activating protein kinase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

explain the process of signal amplification

A
  • one messenger binds to one receptor
  • several G proteins are activated
  • each G protein activates an adenylic cyclase
  • each adenylic cyclase generates hundreds of cAMP molecules
  • each cAMP activates protein kinase A
  • each protein kinase A phosphorylates hundreds of proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what are the two important control systems to maintain homeostasis?

A

autonomic nervous system and endocrine system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

autonomic nervous system

A

communicates via nerve impulses resulting in rapid short lived responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

endocrine system

A

communicates via hormones resulting in slower prolonged responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what are three components of the endocrine system?

A
  • endocrine cells and glands/organs
  • hormones transported by circulatory system
  • specific target cells that posses receptors that respond to specific hormone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what is the function of the endocrine system?

A
  • reproduction
  • metabolism
  • osmoregulation
  • growth and development
  • digestion
  • sleep/mood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what are two types of endocrine organs?

A

primary and secondary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

primary endocrine organs function?

A

secrete hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

secondary endocrine organ function?

A

secretion is secondary to some other function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what are examples of primary endocrine organs?

A

hypothalamus, pituitary gland, thyroid, pancreas, gonads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what are examples of secondary endocrine organs?

A

heart, liver, skin, stomach, small intestine, kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

hypothalamus

A

forebrain region that coordinates both ANS and activity of pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

what does the hypothalamus control?

A

body temp, thirst, hunger, sleep, emotional activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

pituita (phlegm)

A

protrusion off hypothalamus, divided into anterior lobe and posterior pituitary lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what are two embryonic sources?

A

neurohypophyseal bud and rathkes pouch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

neurohypophyseal bud

A

ventral outgrowth from forebrain derived from neuroectoderm, becomes posterior pituitary lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

another name for posterior pituitary lobe?

A

neurohypophysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Rathkes pouch

A

dorsal outgrowth of roof of mouth, derived from oral ectoderm, becomes anterior pituitary lobe

60
Q

another name for anterior pituitary lobe?

A

adenohypophysis

61
Q

what kind of tissue is the posterior pituitary lobe made of?

A

nervous tissue

62
Q

Describe how the posterior pituitary lobe works

A

-contains axon terminal ends of hypothalamic neurons
- secretes 2 neurohormones into capilaary bed and then into general circulation
- neurosecretory cell bodies within supraoptic nucleus of hypothalamus synthesize oxytocin
- neurosecretory cell bodies within paraventricular nucleus of hypothalamus sythesize ADH

63
Q

what does oxytocin do?

A

-stimulates contraction of smooth muscles of uterus during labor
- stimulates contraction of myoepithelial cells which release breast milk produced by milk secreting epithelial cells (milk letdown)
- social interactions (pair bonding, strong affinity to mate)

64
Q

what does antidiuretic hormone (ADH) regulate?

A

water conservation

65
Q

explain the process of ADH

A

-sensors in hypothalamus detect and increase in blood osmolarity or decrease in blood volume during times of dehydration
- then a release of ADH causes collecting ducts of nephron to be highly permeable to water which is then returned to the vasculature and increases blood volume and pressure
- solute concentrations become more dilute and ADH release is inhibited

66
Q

how does alcohol inhibit ADH secretion?

A

causes dehydration and hangover associated with alcohol consumption

67
Q

what are symptoms of diabetes insipidus?

A

hypo secretion of ADH, output of copious amounts of urine and intense thirst

68
Q

when you drink alcohol, why do you pee alot?

A

Alcohol is a diuretic, which means it promotes increased urine production. When you drink alcohol, it inhibits the release of antidiuretic hormone, which is responsible for regulating the amount of water reabsorbed by the kidneys. Without enough antidiuretic hormone your kidneys reabsorb less water, leading to increased urine production and more frequent urination.

69
Q

what kind of tissue is the anterior pituitary gland made of?

A

epithelial tissue

70
Q

explain how the anterior pituitary lobe works

A
  • tropin neurohormones are relased by neurosecretory neurons in the hypothalamus
  • adenohypophyseal endocrine cells secrete hormone into general circulation
  • tropin neurohormones may be releasing or inhibiting
71
Q

explain the hypothalamic pituitary portal system works

A
  • connects hypothalamus with anterior pituitary lobe
  • hypothalamus secretes releasing or inhibiting tropin neurohormones into primary capillary bed
  • tropin neurotransmitters travel to anterior lobe via portal vein and enter the second capillary bed
  • tropin neurohormones leaves second capillary bed and stimulates release of hormones by adenohypophyseal endocrine cells
  • if stimulated, adenohypophyseal endocrine cells release hormones into general circulation
72
Q

secretion of tropin neurohormones is regulated by?

A

hypothalamic neural input

73
Q

what is prolactin releasing hormone secreted by?

A

secreted from hypothalamus neurosecetory cells

74
Q

what is the function of prolactin releasing hormone?

A

stimulates lactotrophs within anterior lobe to release prolactin

75
Q

what is the prolactin inhibiting hormone secreted by?

A

secreted by hypothalamus neurosecretory cells

76
Q

what is the function of theprolactin inhibiting hormone?

A

suppresses release of prolactin by lactotrophs

77
Q

when do prolactin concentrations increase?

A

during pregnancy causing mammy gland enlargement

78
Q

what is sustained PH release stimulated by?

A

infant suckling

79
Q

what is the growth hormone releasing hormone secreted by?

A

hypothalamus neurosecetory cells

80
Q

what is the function of the growth hormone releasing hormone?

A

stimulates somatotrophs within the anterior lobe to release growth hormone

81
Q

what does growth hormone do in the liver?

A

stimulates the production of insulin like growth factors

82
Q

what does insulin like growth factors in concert with growth hormone do?

A

stimulates growth, cell reproduction and regeneration (muscle and bone cell)

83
Q

what is the growth hormone inhibiting hormone secreted by?

A

secreted by the hypothalamus nuerosecretory cells

84
Q

what is the function of the growth hormone inhibiting hormone?

A

inhibits release of growth hormones by somatotrophs

85
Q

T/F: growth hormone secretion has a circadian cycle that is highest during sleep and decreases with age

A

true

86
Q

interstitial growth

A

increased length

87
Q

appositional growth

A

increased thickness

88
Q

epiphyseal plate

A

main site of longitudinal growth of the long bones

89
Q

what effects do growth hormones have in children?

A
  • increases calcium retention
  • increases muscles mass through sarcomere hypertrophy
    -promotes lipolysis
  • stimulates growth of all external organs (excluding brain)
  • reduced uptake and retention of glucose by liver
  • contributes to the maintenance and function o pancreatic islets
  • stimulates the immune system
  • increases deiodination of t4 to t3 (thyroid hormones)
90
Q

what is the result of hyper secretion of growth hormone in children?

A

gigantism, abnormally but proportionally tall (epiphyseal plates are still active)

91
Q

what is the result of hyper secretion of growth hormone in adults?

A

acromegaly, overgrowth of bones in the face, feet and hands (long bones cannot grow because plates are closed), appositional growth of bone only

92
Q

what is the result of hyposecretion of growth hormone in children? in adults?

A

-pituitary dwarfism, abnormally but proportionally short (can be treated to some degree)
-in adults there is no problem regarding growth

93
Q

Achondroplasia

A

connective tissue disorder

94
Q

what is thyrotropin releasing hormone secreted by?

A

secreted by the hypothalamus neurosecertory cells

95
Q

what is the function of thyrotropin releasing hormone?

A

stimulates thyrotrophs within the anterior lobe to released thyroid stimulating hormone

96
Q

what does thyroid stimulating hormone do?

A

stimulates the thyroid gland to secrete thyroid hormones (T3 AND T4)

97
Q

what do thyroid hormones do?

A

increases metabolism, promotes growth and development

98
Q

what happens if thyroid hormone blood levels increase?

A

suppresses the release of thyroid regulating hormone by hypothalamus neurosecretory cells and thyroid stimulating hormones by thyrotrophs

99
Q

what is corticotropin releasing hormine secreted by?

A

hypothalamus neurosecretory cells

100
Q

what is the function of corticotropin releasing hormone?

A

stimulates corticotrophs within the anterior lobe to release adrenocorticotropic hormone

101
Q

what does the adrenocorticotropic hormone do?

A

stimulates adrenal cortex to release glucocorticoid hormones (ex. cortisol)

102
Q

when is cortisol released?

A

in response to stress

103
Q

what happens when cortisol levels rise?

A

suppresses corticotropin releasing hormone and adrenocorticotropic hormone release

104
Q

what is gonadotropin releasing hormone secreted by?

A

hypothalamus neurosecretory cells

105
Q

what is the function of gonadotropin releasing hormone?

A

stimulates gonadotrophs within the naterior lobe to release follicle stimulating hormone and luteinizing hormone

106
Q

what does follicle stimulating hormone do?

A

promotes egg and sperm development and stimulates the ovary to secrete sex hormone estrogen and the testes to secrete testoserone

107
Q

what does luteinizing hormone do?

A

stimulates ovulation and secretion of sex hormone estrogen and progesterone in females and androgens in males

108
Q

what happens when estrogen and androgen levels rise?

A

suppresses gonadotropin releasing hormone release

109
Q

what is the difference between short and long negative feedback loops?

A

short negative feedback loops involve direct inhibition of hormone secretion by the product of the process it regulates and occur relatively quickly, while long negative feedback loops involve multiple steps and regulatory factors, occurring over a longer time frame.

110
Q

pineal gland

A

endocrine tissue that secretes neurohomone melatonin

111
Q

why is melatonin important?

A

manages your circadian rhythm, levels raise at night, and used as a sleep agent

112
Q

where is the thymus gland located?

A

anterior superior mediastinum (in front of the heart and behind the sternum)

113
Q

what does the thymus gland do?

A

secretes thymosin

114
Q

what does thymosin do?

A

promotes the maturation of T lymphocytes

115
Q

when is the thymus gland largest and most active?

A

during neonatal and pre adolescent periods

116
Q

when does the thymus gland begin to atrophy?

A

early teens years (replaced by adipose tissue in adults)

117
Q

where is the thyroid gland located?

A

lies below the thyroid cartilage of the larynx and is surrounded by a connective capsule

118
Q

what extends from the capsule to divide the thyroid into irregular lobes?

A

trabeculae

119
Q

what hormones are produced by the thyroid?

A

T3- triiodothyronine
T4- tetraiodothyronine (thyroxine)

120
Q

what is the functional unit of the thyroid gland?

A

follicle

121
Q

describe the structure of the follicle

A
  • single layer of simple cuboidal follicular cells surrounding a lumen.
  • lumen filled with colloid produced and secreted by follicular cells
122
Q

what does colloid consist of?

A

mainly of thyroglobulin (thyroid gland, precursor and storage form of thyroid hormone)

123
Q

T/F: thyroid gland is synthesized in RER and enters colloid in via exocytosis

A

True

124
Q

what are located between follicles in the thyroid gland?

A

calcitonin producing cells (C cells)

125
Q

what does calcitonin do?

A

lovers blood calcium levels

126
Q

In the thyroid gland, iodine is actively transported from blood into follicular cell via?
Then sent passively into colloid via?

A

Na+/I- symporter, pendrin transporter

127
Q

explain the synthesis of thyroid hormones

A
  • tyrosine residues of thyroid gland are iodinated
  • 1 iodine forms MIT, 2 iodide ions form DIT
  • 2 iodinated tyrosines (MIT or DIT) on the same thyroid gland covalently bond
  • 2 DITs combine and form T4, 1 MIT and 1 DIT form to make T3.
  • they are attached to the thyroid gland and stored
128
Q

explain the secretion of thyroid hormones

A
  • Thyroid secreting hormone binds to follicular cell membrane-bound receptors which activates cAMP secondary messenger system
  • phosphorylated proteins causes endocytosis of iodinated thyroid gland from colloid via phagocytosis
  • once inside cell, vesicle fuses with lysosome
  • various proteases cleave thyroid gland to produce free T3 and T4
  • T3 and T4 pass through membranes and bind with carrier proteins in blood
129
Q

deficiency of iodine lead to decreatsed production of T3 and T4, this enlarges the tissue and will cause?

A

goitre

130
Q

what is caused by the hyper secretion of thyroid hormones?

A

hyperthyroidism (graves disease)

131
Q

What are symptoms of graves disease?

A

-elevated metabolic rate, sweating, raid/ irregular heart rate, nervousness, weightloss, oily skin and bulged eyes

132
Q

how is graves disease corrected?

A

thyroid gland removal or ingestion of radioactive iodine to destroy most active thyroid cells

133
Q

what is the result of underproduction of thyroid hormones?

A

hypothyroidism

134
Q

hyperthyroidism can cause congenital thyroid abnormalities and autoimmune disorders such as?

A

hashimotos thyroiditis

135
Q

what are symptoms of hypothyroidism?

A

abnormal weight gain, tiredness hairloss, dry skin, bradycardia

136
Q

cretinism

A

severly stunted physical and mental growth due to untreated congential deficinecy of thyroid hormones

137
Q

how is hypothyroidism treated?

A

hormone replacement therapy

138
Q

where is the parathyroid glands located?

A

located on the surface of the thyroid gland

139
Q

what is the function of parathyroid glands?

A

secretes parathyroid hormone (helps regulate Ca2+ levles by increasing blood Ca2+ levels)

140
Q

hypocalcemia

A

low blood Ca2+ levels

141
Q

hypercalcemia

A

high blood Ca2+ levels

142
Q

adrenal glands location?

A

located above the kidneys

143
Q

what are the three layers of the adrenal cortex?

A

zona glomerulosa
fasciculata
reticularis

144
Q

mineralocorticoids, function?

A

cells of the zona glomerulosa. regulate Na+ reabsorption and K secretion from kidneys

145
Q

sex hormones from the adrenal cortex. function?

A

cells of the zona fasciculata and reticularis. stimulates sex drive in femials

146
Q

glucocorticoids, function?

A

cells of the zona fasciculata and reticularis. regulates response to stress

147
Q

adrenal medulla

A

Physiology Lecture (4 decks)

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