Hormone Physiology Flashcards
1
Q
Gland that has no ducts but have dense capillary network surrounding the secreting cells. It is composed of cells that secrete a chemical substance called hormone. Note that some glands, not considered ______ glands, such as the brain, heart and intestine, also secrete hormones.
A
Endocrine gland
2
Q
Gland that has ducts to carry the secretion (non-hormone) to the body surface (eg. sweat) or to cavity another organ. (e.g. digestive enzymes)
- Secretion have extracellular effects such as those that cause digestion of food. Notice that endocrine secretion, unlike exocrine secretions, have intracellular effects.
A
Exocrine gland
3
Q
Chemical messenger secreted by endocrine glands into the bloodstream and travel to organs all over the body. May be secreted into the blood by organs not considered endocrine glands such as the heart and intestine. It stimulates physiological functions in cells far away from secreting gland. Binds to target cell receptors located on cell membrane or inside the cell. It causes the target cells to produce new proteins or activate enzymes in target cells. It also causes the cels to increase or decrease a cellular activity.
A
Hormone
4
Q
Functions of Hormones
A
Binds to target cell receptors located on cell membrane or inside the cell.
- It stimulates physiological functions in cells far away from secreting gland.
- It causes the target cells to produce new proteins or activate enzymes in target cells.
- It also causes the cells to increase or decrease a cellular activity.
5
Q
A chemical messenger secreted by certain cells that travels from one cell to a nearby cell. It stimulates physiological action in these cells. (ie, causes a receptor cell to increase or decrease its activity) It is also known as local hormone and acts as one.
- Hormone released in a certain distance. Small area.
A
Paracrine.
6
Q
It is released by neurons. Diffuse across narrow synaptic cleft to receptors on postsynaptic neuron or effectors (muscle or gland). Binds to chemical-gated protein receptors on a postsynaptic neuron or effectors. Once bound to the chemical-gated protein receptor, it causes ion channels on the gated-protein to open and ions move into the cell to change the resting membrane potential.
A
Neurotransmitter
7
Q
When a neurotransmitter is secreted by glands such as the adrenal gland, it is called?
A
Neurohormone
8
Q
System that does things in nanoseconds (fast acting). Communicated via electrical system and NT. Release NT at synapse of specific cells. Reacts quickly to external stimuli (millisec). Stops quickly when stimulus stops.
A
Nervous System
9
Q
System that takes very long to do things. Slow acting. It communicates via hormones. It releases hormones into the bloodstream where it is picked by target cells. It reacts slowly to external stimuli (seconds to day). May continue to respond long after stimulus stops.
A
Endocrine System
10
Q
Some chemicals released by the endocrine and non-endocrine glands behaves like hormones and are called _____.
A
Neurohormones
11
Q
Examples of Neurohormones. (7)
A
NE&E. Cholecystokinin. Thyrotropin-releasing hormone. Dopamine. ADH - Antidiuretic hormone (vasopressin) Oxytocin
12
Q
Neurohormones released by SNS. Can be neuro-T and neuro-H.
A
NE&E
13
Q
The endocrine system plays a major role in body ____.
A
homeostasis
14
Q
Functions of the Endocrine System. (4)
A
- It provides the rate at which cells are provided with energy for all their functions. This energy is used in the body’s chemical reaction aka metabolism.
- It regulates the supply of carbohydrate and fatty acids for the body’s metabolism.
- It controls the volume and electrolyte composition of the extracellular fluid.
- It regulates calcium and phosphate for bones and which operate in excitability of nerves and muscles. (Regulate electrons)
15
Q
Note that low Ca++ leads to _____ and _____; too high Ca++ levels lead to ______.
A
weak muscles and lethargy
spasms
16
Q
Major endocrine glands that controls metabolic rate. (2)
A
Thyroid gland & adrenal medulla.
17
Q
Major endocrine glands that controls glucose metabolism. (4)
A
Pancreas, Adrenal cortex and medulla, anterior pituitary.
18
Q
Major endocrine glands that regulates growth and development. (7)
A
Anterior pituitary Thyroid Gonads Adrenal cortex Pancreas Skin Kidneys
19
Q
Major endocrine glands that controls fluid and electrolyte balance. (3)
A
Posterior pituitary, adrenal cortex and kidneys
20
Q
Major endocrine glands that controls Ca++ and phosphate balance. (4)
A
Parathyroid glands, thyroid, skin and kidneys
21
Q
Major endocrine glands that controls responses to life threatening challenge. (3)
A
Adrenal cortex and medulla, thymus
22
Q
Major endocrine glands that controls reproduction and nurturing (5)
A
Anterior pituitary, ovaries, testes, placenta, pineal gland
23
Q
The hypothalamus plays a major role in the maintenance of the internal environment by (2)
A
i. nerve reflex
ii. through the endocrine system
24
Q
Neurohormones Oxytocin and ADH are made in the ______ and released in the ______.
A
Hypothalamus; posterior pituitary gland
25
A part of the CNS that controls thirst and hunger but is also THE MASTER CONTROL OF THE ENDOCRINE SYSTEM.
Hypothalamus
26
In the hypothalamus, synthesis of posterior pituitary hormones and transport occurs via _____.
nerve axons
27
In the hypothalamus, thehHypothalamic hormones is carried in the _____________ portal system.
hypothalamohypophyseal
28
The master endocrine gland and it releases 9 hormones. 2 in the posterior and 7 in the anterior.
Pituitary Gland
29
The _________ has no direct or nervous link with the hypothalamus. The two are connected via capillaries which pass from the hypothalamus to the pituitary in the pituitary stalk. Hypothalamic hormones are secreted into these capillaries and pass into the _________.
anterior pituitary aka adenohypophysis
30
The _______ is derived from the base of the brain and consists of neural tissue that has the cell bodies in the hypothalamus and the axons reaching in the _______.
- These axons deliver oxytocin and vasopressin (ADH) synthesized by the hypothalamus.
posterior pituitary aka neurohypophysis
31
Pituitary hormones are not released in a steady state. GH secreted mainly at ____.
night
32
Pituitary hormones are not released in a steady state. LH peak at _____.
menstrual cycle
33
Pituitary hormones are not released in a steady state. Oxytocin surges during _____ and _____.
labor and nursing
34
The hypothalamus and the cerbral cortex monitor the body's condition and release hormones or inhibit hormone secretion via a _________.
negative feedback system
35
The regulation of synthesis and secretion of hormone is mainly through _____. This system of control keeps the hormone levels within a close range. However, this system allows the endocrine glands to respond to environmental and emotional change action on or in the body.
negative/hormone feedback system
36
The hypothalamus knows that the action is done via _______. They send info about blood up the hypothalamus and pituitary gland. They send info to continue or stop release the hormones.
chemoreceptors
37
Negative fedback system (4 steps)
1. Hypothalamus release hormones to the pituitary gland via releasing hormones,
2. The pituitary gland release stimulating hormones to the end organ to stimulate the organ.
3. The end organ release the hormones and go to the blood.
4. The chemoreceptors detect info from the blood and send info to the hypothalamus/pituitary gland to stop the release of hormones.
38
From the blood, hormones go to the _____.
target cells
39
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to release adrenocorticotropic hormone (ACTH) that targets the adrenal cortex to release glucocorticoid secretion and aldosterone secretion.
Corticotrophin-Releasing hormone (CRH)
40
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to release thyroid stimulating hormone (TSH) that targets the thyroid gland to increase thyroid hormone secretion.
Thyrotropic-Releasing hormone (TRH)
41
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to release growth hormones that targets most body tissues esp liver to increase growth factor secretion to increase growth.
Growth Hormone releasing hormone (GrRH)
42
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to decrease the release of growth hormones that targets most body tissues esp liver to decrease growth factor secretion to decrease growth.
Growth Hormone releasinginhibiting hormone (GrIH)
43
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to release prolactin hormone that targets the breast to increase development of breasts.
Prolactin Releasing hormone (PRH)
44
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to decrease the release prolactin hormone in the breasts to facilitate secretion of milk.
Prolactin Releasing-Inhibiting hormone (PIH)
45
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to release Leutenizing hormones (LH) which stimulate the interstial cell. It targets ovaries and testes to increase ovulation and development of corpus luteum in women.
Gonadotrophin-Releasing hormone (GnRH)
46
Releasing hormone from the hypothalamus that causes the anterior pituitary gland to release Follicle Stimulating Hormone (FSH) that targets ovaries and testes to increase testosterone secretion in men, ovarian follicle growth and spermatogenesis.
Gonadotrophin-Releasing hormone (GnRH)
47
Releasing hormone from the hypothalamus that causes the middle lobe pf the pituitary gland to release melanocyte stimulating hormones (MSH) that targets the skin to deposit melanin by melanocytes.
Melanocyte stimulating hormone releasing hormone. (MSHRH)
48
What triggers the release of insulin (beta cells by pancreas) and glucagon (alpha cells by pancreas) to regulate blood glucose?
High blood glucose level. Inhibited by decreased blood glucose level.
49
What triggers the release of parathyroid hormone (PTH) and 1,25 dihydroxycholecalciferol (by parathyroid and kidney) to regulate plasma concentration of Ca++?
Low Ca++ in the blood.
50
You have high blood Ca++ level. What endocrine gland is involved and what hormone does it secrete to regulate plasma concentration of Ca++?
Thyroid gland (parafollicular cells) release Calcitonin.
51
You have low serum Na+ and/or high K+ renin from the kidneys. What endocrine gland is involved and what hormone does it need to secrete to regulate Na+ and K+ serum concentration?
Adrenal Cortex release Aldosterone.
52
The patient is suffering from hypoxia. What endocrine gland is involved and what hormone does it need to secrete to produce and release RBC?
Kidneys release erythropoietin
53
The point at which a hormone initially influences the activity of a cell. The hormones act like keys that fit into a specific lock.
The Receptor
54
Two major groups of hormones.
1. Steroid (lipid-soluble) hormones
| 2. Non-steroid (water-soluble) hormones
55
Major group of hormone that is from cholesterol and fat. Its made by adrenal gland and gonads. It changes DNA activity. It goes directly inside the cell in which the cell receptor resides. When the hormone receptor binds it goes to the DNA and the DNA opens and we get transcription-translation and we get protein which carries out the work/job. (regulate calcium, etc) It takes a long time to work (slow; 2weeks)
- These hormones are fat-soluble so they penetrate cell wall readily and bind with receptor in the cytosol.
Steroid hormones
56
What hormone is a non-steroid hormone by type but it BEHAVES like steroid hormones?
Thyroid hormones
57
Hormones that are small and act by binding to cell membrane receptors. The hormone is the 1st messenger and the cAMP generated by the hormone acts as the 2nd messenger.
Non-steroid hormones aka water-soluble hormones
58
2nd messenger system by non-steroid hormones.
The first messenger activates the receptor, then the receptor activates a protein that creates ATP and cAMP (the second messenger) the cAMP activates the protein inside and it will do the job. This mechanism is faster than steroid mechanism and acts immediately.
59
In non-steroid hormones, the first messenger (which is the hormone) cannot go in the cell so it a message to ______. (2nd messenger)
cAMP (Cyclic adenosine monophosphate)
60
Hormones are secreted by endocrine glands and pass into the _____ which transport them through the circulation.
capillaries
61
_______ in the blood is able to interact with target cells but is also exposed to enzymes that can metabolize it.
Free hormone
62
Thyroxine, corticosteroids, and other lipid hormones are transported bound to ______. As the portion of the free hormones is used up, more is released by the plasma.
proteins
63
Hormones such as _______(4) are transported in the plasma in free state and have short half-life.
NE, E, insulin, ADH
64
The time for the plasma concentration to fall to one-half its highest plasma volume.
hormone half-life
65
2 main ways in which hormones act on cells.
1. Increase amount of an enzyme present
| 2. Regulate the level of activity of already formed enzymes
66
True or false;
| Hormone secretion is turned off once it has served its purpose.
True
67
Most hormones are taken up and degraded by the ____ and ____; then excreted in the ____ or _____.
liver and kidney
| bile or urine
68
Some hormones are degraded by ___ ; they bind it and act on.
cells
69
Metabolism by the liver usually makes hormones _______ so that they can be cleared from the body via kidneys or bile.
water soluble
70
Liver problem may _______ of hormones and cause the hormone to build up in the body. This build up may cause adverse results.
prevent metabolism
71
Cirrhosis of the liver in males may cause the build up oestrogen, which leads to enlarged male breasts called _____.
gynaecomastia
72
Rate of hormone removal
Metabolic clearance rate (MCR)
73
The length of time required to clear 50% of released hormone from the blood.
One half-life
74
Typical stress response include elevated ____ and _____ levels.
Epinephrine and Glucocorticoid
75
Initial response to stress called ________ is mediated by increased secretion of NE and E which prepare the body for flight-fight.
(alarm reaction)
76
Increased secretion of NE and E cause increase blood glucose aka ___________.
glyconeolysis.
77
In stress, aldosterone and angiotensin levels also rise causing ____ and _____.
increased BP and water retention
78
The receptor of ______ is similar to the receptor for adrenal steroids, vit A and vit D.
thyroid hormones
79
Tissues that are esp sensitive to thyroid hormones. (4) It increases the basal metabolic rate of these organs.
-The organ that is less responsive to these hormones is the brain.
Skeletal muscles
Heart
Liver
Kidney
80
2 cell types of the thyroid gland.
1. Follicular cells
| 2. Parafollicular cells
81
Cell type of thyroid gland that produce T4 and T3 in response to TSH from the pituitary gland.
Follicular cells
82
Cell type of thyroid gland that produce calcitonin.
Parafollicular cells
83
Primary function of T4 and T3.
Increase body`s metabolic rate.
84
Signs and effects of T4 and T3. (10)
↑ O2 consumption
↑ heat production
↑ HR and conduction strenght
↑ respiratory rate
↑ breakdown of carbohydrate, fats, and protein for fuel
Stimulation of appetite
Promotes alertness, bone growth and remodeling
Development of integumentary system
Stimulation of pituitary gland to release growth hormone
Promotion of foetal nervous sys & skeletal development.
85
How does follicular cells produce T3 and T4
Follicular cells trap iodine and synthesize thyroglobulin (TGB; a protein made mainly from tyrosine amino acid). TGB binds to iodine and form T3 and T4.
86
More than 99% of T3 and T4 are transported in the blood bound to the carrier protein _______.
thyroid-binding globulin (TBG)
87
Other than thyroid hormones, what else does the thyroid gland secrete?
Calcitonin
88
Hormone that antagonizes the action of parathyroid hormone. It promotes calcium deposit and bone formation by osteoblasts.
Calcitonin
89
The adrenal gland consists of (2)
```
Adrenal cortex (80-90%)
Adrenal medulla
```
90
Part of adrenal gland that produces steroid hormones that are essential for life.
Adrenal cortex
91
Cells in the adrenal cortex (3)
Zona glomerulosa
Zona fasciculata
Zona reticularis
92
Cells in the adrenal cortex that produce mineralocorticoids
Zona glomerulosa
93
Cells in the adrenal cortex that produce glucocorticoids
Zona fasciculata
94
Cells in the adrenal cortex that secrete androgens
Zona reticularis
95
Regulate the secretion of steroid hormones
negative feedback control
96
3 hormones produced by the adrenal cortex
mineralocorticoids
glucocorticoids
androgens
97
Hormone produced by the adrenal cortex that control water and electrolytes (Na+ and K+) in the body. 95% of activity of this hormone is due to aldosterone.
Mineralocorticoids
98
Hormone produced by the adrenal cortex that regulate metabolism and stress response.
Glucocorticoids
99
Glucocorticoid activities (5)
1. Break down protein (muscle fibres) to produce energy
2. Form glucose from amino acids and lactic acid (particularly in the liver)
3. Break down triglycerides and release fatty acids to use as fuel
4. Mediate stress, inflammation response
5. Depress immune response
100
Hormone produced by the adrenal cortex that contributes to libido but effect is not that significant.
Androgen
101
Major androgens secreted is ________.
dehyroepiandrosterone (DHEA)
102
The adrenal medulla consists of hormone producing cells called ____.
chromaffin
103
Cells that receive direct innervation from the preganglionic neurons of the sympathetic nervous system. These postganglionic cells release NE & E.
chromaffin cells
104
epinephrine makes up about ___% of the secretion from the cells.
80%
105
Hormones that increase pumping and force of contraction of the heart, increase BP, dilate airways and increase blood levels of glucose and fatty acids.
NE&E
106
____ secreted by the preganglionic neuron onto the adrenal medulla, causes chromaffin cells to increase output of E and NE.
Ach (acetylcholine)
107
Hypoglycaemia stimulates the medulla to______ E&NE secretion.
increase
108
Gland that is both endocrine and exocrine.
Pancreas
109
Cell types of Pancreatic Islets (4)
1. Alpha cells
2. Beta cells
3. Delta cells
4. F cells
110
Hormone secreted by alpha cells. Targets primarily liver.
1. Increases blood glucose levels when it falls below normal
2. Stimulates production of glucose from non-carbohydrate sources
3. Stimulates glycogen breakdown and the release of glucose in the blood
4. Stimulated in response to high amino acid in the blood following a high protein meal
Glucagon
111
Hormone secreted by beta cells.
1. Stimulates cells to absorb glucose from blood.
2. Stimulates muscle and adipose tissues to store glycogen and fat.
3. Surpresses breakdown of stored glucose
4. Antagonises the effect of glucagon
5. Kidneym brain. liver and RBC takes up glucose without the aid of insulin.
Insulin
112
Hormone secreted by delta cells. Targets stomach, intestines, and pancreatic islet cells. It modulates digestion, nutrient absorption, and glucagon and insulin secretion.
somatostatin
113
What is secreted by F cells?
- Targets pancreas, gallbladder.
- Inhibits the release of bile and digestive enzymes.
pancreatic polypeptides
114
Hormone secreted by pancreas and/or stomach and SI that targets the stomach and stimulates acid secretion and gastric motility.
Gastrin
115
What makes up glucocorticoids? (3)
Cortisol + corticosterone + cortisone
116
A hormone secreted by the ovaries that targets the anterior pituitary gland. It inhibits FSH secretion.
Inhibin
117
Precursor of calcitriol (skin and liver version)
skin - cholecalciferol
| liver - calcidiol
118
Precursor of angiotensinogen II
angiotensinogen (liver)
119
Hormone secreted by the kidneys and liver that targets the red bone marrow. It promotes RBC production and increases O2 carrying capability of blood.
Erythropoietin
120
Hormone secreted by the liver that targets the small intestine and liver. It promotes iron absorption and mobilization.
Hepcidin
121
Hormone secreted by the liver that prolongs and mediates action of growth hormone.
Insulin-like growth factor 1
122
Hormone secreted by the kidney that targets the small intestine. It increases blood Ca++ level mainly by promoting intestinal absorption of Ca2+.
Calcitriol
123
Hormones that is secreted by the heart that targets the kidney. They lower the blood volume and pressure by promoting Na+ and water loss.
Atrial natriuretic peptide and brain natriuretic peptide.
124
Hormone that is secreted by the stomach and small intestine that targets the gallbladder and brain. It controls bile release and appetite suppression.
Cholecystokinin
125
Hormone that is secreted by the stomach and small intestine that targets the brain. It stimulates hunger and initiates feeding.
Ghrelin
126
Hormone that is secreted by the stomach and small intestine that targets the brain. It produces sense of fullness and terminates feeding.
Peptide YY
127
Hormone that is secreted by the stomach and small intestine that targets the origin and coordintes secretion and motility in diff regions of the digestive tract.
Other enteric hormones
128
Hormone that is secreted by the adipose tissue that targets the brain. It limits appetite over long term.
Leptin
129
Hormone that is secreted by the bone tissues that targets the pancreas and adipose tissue to stimulate pancreatic beta cells to multiply. Increases insulin secretion, enhances insulin sensitivity of various tissues, and reduces fat deposition.
Osteocalcin
130
Hormone that is secreted by the placenta that targets many tissues of mother and fetus that stimulate fetal development and meternal body adaptations to pregnancy, also prepare mammary glands for lactation.
Estrogen and progesterone
131
A condition in which large volumes of urine are formed due to hyposecretion of ADH.
diabetes insipidus
132
With too much blood Ca+ what can happen to the body?
brain and heart cells dont function normally resulting to mental disturbance and stopping of the heart.
133
With too little blood Ca+ what cab happen to the body?
nerve cells become overactive sometimes to the degree that they send muscles too many impulses causing spasms.
134
Hypersecretion of glucocorticoids. Women > men.
- Noticeable features include buffalo hump in the upper back that develop because of redistribution of body fat.
- Individuals have increased BS levels and suffer frequent infection.
Cushing's syndrome
135
Hyposecretion of glucocorticoids. REduced cortical hormone levels result in muscle weakness, reduced BS, nausea, loss of appetite, and weight loss.
Addison's disease.
136
Oversecretion of the thyroid hormones dramatically increases metabolic rate. Food material is burned by the cells at an excessive rate, and these individuals tend to lose weight, have increased appetite, and show signs of nervous irritability.
Hyperthyroidism
137
Undersecretion of thyroid hormones caused by a number of diff conditions such as painless enlargement of the thyroid gland called simple goiter.
Hypothyroidism
138
Hyposecretion of thyroid hormones during formative years. Low metabolic rate, retarded growth, and sexual development, and mental retardation.
Cretinism
139
Later in life, deficient thyroid hormone secretion.
Myxedema
140
1. Hypersecretion of GH during early yrs. The child grows into giant size.
2. Hyposecretion of GH during early yrs.
gigantism
| pituitary dwarfism
141
The anterior gland secretes too much GH after normal growth yrs.
Acromegaly
142
Low BS levels - High BS levels
Hypoglycemia - Hyperglycemia
143
If pancreatic islets secretes too little insulin.
Type I diabetes mellitus.
144
Best hidden endocrine glands in the body. Little masses of hormone-producing tissue are scatted among the enzyme-producing acinar tissue.
Pancreatic islets or Islets of Langerhans
