Exam 3 Flashcards
(367 cards)
1
Q
● Some mediators can be both a neurotransmitter and
a hormone
A
Norepinephrine
Epinephrine
Oxytocin
2
Q
Explain Oxytocin as a neurotransmitter and hormone
A
Neurotransmitter: released throughout the brain and
expressed by neurons
Hormone: released from the pituitary gland into blood,
acting on breast and uterine tissue
3
Q
Secrete hormones into interstitial fluid and blood surrounding the secretory cells (TSH for example)
A
ENDO- “Within”
4
Q
Secrete their product into ducts that release into body cavities, lumen of organs, or to outer surface (skin) Sudoriferous (sweat), sebaceous (oil), mucous, salivary, mammary, ceruminous, lacrimal
A
EXO- “Outside”
5
Q
Hormone Receptors are ____ (composition)
A
cellular proteins
6
Q
Occurs when too much hormone present
Reduction of receptors means less sensitivity to the circulating hormone
If not enough receptors, some of the hormone will get metabolized unused…not as effective
A
Receptor Down-regulation
7
Q
Occurs when not enough hormone present Increase of receptors means more sensitivity to the circulating hormone
If more receptors present, better chance at all of the circulating hormone being used
A
Receptor Up-regulation
8
Q
Endocrine Action
● The hormone is distributed in blood and binds to distant target cells (most, but not all hormones)
● Example: _____ pituitary releases thyroid stimulating hormone (TSH) which binds to receptors on cells of the thyroid as no other cells in the body should have receptors for this hormone
A
Anterior
9
Q
Circulating vs Local Hormones
A
● Circulating hormones (the majority) – pass from secretory cells to the interstitial fluid into the blood stream
● Local hormones- act on a neighboring cell or the same cell without entering the bloodstream
10
Q
(the majority) – pass from secretory cells to the interstitial fluid into the blood stream
A
● Circulating hormones
11
Q
- act on a neighboring cell or the same cell without entering the bloodstream
A
● Local hormones
12
Q
the majority of hormones are circulating or local?
A
circulating
13
Q
hormones that act on neighboring cells
hormones that act on same cell
A
Paracrines
Autocrines
14
Q
hormones that act on neighboring cells
A
Paracrines-
15
Q
hormones that act on same cell
A
Autocrines-
16
Q
– tend to linger in blood stream minutes to hours
A
Circulating hormones
17
Q
Local hormones act….
A
quickly
18
Q
Lipid-soluble hormones: Most use….
A
transport proteins (synthesized in the liver)
19
Q
Lipid-soluble hormones: Most use transport proteins (synthesized in the liver)
Make the hormone temporarily ______
Retard the passage of smaller hormone molecules through the kidney filter therefore _______
A
water-soluble
reducing the amount lost in urine
20
Q
Lipid-soluble hormones: Most use transport proteins (synthesized in the liver)
Provide a ready reserve of hormone in the bloodstream or free fraction which is:
A
Free fraction- 0.1-10% are not bound to a transport protein;
these diffuse from capillaries, bind to receptors immediately
21
Q
transported in their free (unbound) form in blood
A
Water-soluble hormones
22
Q
Control of Hormone Secretion
● Regulated by
A
Signals from nervous system
Ex: Nerve impulses to adrenal medullae regulate release of epinephrine
Chemical changes in the blood
Ex: Blood Ca2+ level regulates secretion of parathyroid hormone
Other hormones
Ex: Release of a hormone (ACTH) from the anterior
pituitary stimulates release of cortisol by adrenal cortex
23
Q
Control of Hormone Secretion
● Regulated by
A
Signals from nervous system
Chemical changes in the blood
Other hormones
24
Q
Reverses a change in the controlled condition
Hormone “A” secreted by anterior pituitary
Blood levels of hormone “A” increase
Sends signal to anterior pituitary to stop/slow production of Hormone “A”
A
Negative Feedback
25
Strengthens or reinforces the change in the controlled condition
EX:
Oxytocin causes uterine contractions
Uterine contractions cause oxytocin to be released
Positive Feedback
26
Types of Hormones
● Divided into three major groups based on chemical
structure
Proteins and Polypeptide hormones
Steroid hormones
Tyrosine derivative hormones
27
Types of hormones Divided into three major groups based on...
chemical structure (in this class)
Numerous other ways to classify hormones though
By solubility
By gland
By function
28
The majority of the hormones in the body fall into this
| category
Proteins and Polypeptides
29
Proteins and Polypeptides are made from
the joining of three or more amino acids
30
100+ amino acids joined together
EX's:
Human Growth Hormone
Prolactin
Protein
31
3-99 amino acids joined together
Ex's:
Thyrotropin releasing hormone
Polypeptides
32
Are all water soluble
Can travel unbound in blood
Finds their receptors on the cell membrane
Proteins and Polypeptides
33
Refer to slide 28, 29, and 30 of the ppt
stellar
34
Cholesterol Hormones are known as....
steroid hormones
35
● Derived from cholesterol
| ● Very little concentration of these are stored
Steroid Hormones
36
____ are lipid-soluble
Have to be bound to transport proteins while in blood (because blood is water-based)
Can freely pass through cell membrane
Binds to receptors on the inside of the cell
Steroid hormones
37
Promotes development of male reproductive system and male secondary sex characteristics
Testosterone from testes
38
Promotes growth and development of female reproductive system, female breasts, female secondary sex characteristics
Estrogen
39
Helps to produce “uterine milk” that nourishes growing embryo, helps develop secretory apparatus of breast
Progesterone
40
ovary hormones
estrogen and progesterone
41
adrenal cortex hormones
cortisol and aldosterone
42
kidney hormone
calcitrol
43
● Derived from some form of tyrosine (amino acid)
Thyroid hormones
Triiodothyroinine (T3)
Thyroxine (T4)
Adrenal medullary hormones (catecholamines)
Epinephrine
Norepinephrine
Prolactin Inhibiting Hormone (PIH)
Also known as dopamine
Tyrosine Derivative Hormones
44
Tyrosine Derivative Hormones
thyroid hormones
| adrenal medullary hormones (catecholamines)
45
Prolactin Inhibiting Hormone (PIH) also known as
dopamine
46
dopamine other name
Prolactin Inhibiting Hormone (PIH)
47
Name all of the Tyrosine Hormones then look at page 36 of the PDF
Good little nerd
48
Controls the autonomic nervous system through neural and hormonal approaches
Hypothalamus
49
Location of Hypothalamus:
anterior and inferior to the thalamus
50
Hypothalamus Connected to the posterior pituitary gland by the....
infundibular stalk (axons)
51
There is a partial sheath that wraps up the infundibular stalk from the anterior pituitary gland called the
pars tuberalis
52
These two things entwined become the infundibulum
Pars tuberalis and the infundibular stalk
53
Every hormone synthesized in the hypothalamus is
| transported to the pituitary gland where it will either __ or __?
Be stored (ADH, oxytocin)
Cause another hormone to be synthesized
54
Hypothalamus + Pituitary gland =
regulation of growth, development, metabolism, and homeostasis
55
Hypothalamus Responds to signals from internal AND external environment like...
Temperature, hunger, satiety, blood pressure, levels of hormones, stress
56
Controls daily bodily rhythms such as melatonin secretion
| from pineal gland, cortisol secretion, body temperature
Hypothalamus
57
Collects and combines information from the body and makes changes to correct any imbalances
Hypothalamus
58
Hypothalamic Hormones are Those that have action on the...
and those that get stored in the ...
Anterior Pituitary Gland
Posterior Pituitary Gland
59
Anterior (APG) think
action
60
Posterior (PPG) think
storage
61
From hypothalamus to anterior pituitary gland
```
Hormones produced in hypothalamus, placed into pituitary
portal system (capillaries), transported via portal system down to anterior pituitary gland
```
Once at anterior pituitary gland, these hormones....
CAUSE other hormones to be synthesized in the anterior pituitary
- These hormones are metabolized once their message is received at the anterior pituitary
- Made in small quantities, made only at the request of the body and its feedback systems
62
Hypothalamic Releasing Hormones Function is to...
STIMULATE release of particular anterior pituitary hormones
63
Hypothalamic Releasing Hormones include:
```
● GHRH: growth hormone-releasing hormone
● TRH: thyrotropin-releasing hormone
● CRH: corticotropin-releasing hormone
● GnRH: gonadotropin-releasing hormone
● PRH: prolactin-releasing hormone
```
64
Hypothalamic Inhibiting Hormones
| ● Function is to....
INHIBIT release of particular anterior pituitary hormones
65
● Hypothalamic inhibiting hormones include:
● GHIH: growth hormone-inhibiting hormone AKA somatostatin
● PIH: prolactin-inhibiting hormone
AKA dopamine
66
another name for somatostatin
GHIH or growth hormone-inhibiting hormone
67
another name for dopamine
PIH or prolactin-inhibiting hormone
68
Transport to Posterior Pituitary Gland is From hypothalamus to posterior pituitary gland. Where are these hormones produced vs stored?
Hormones produced in hypothalamus, but stored in the posterior pituitary gland
69
Posterior Pituitary Glan hormones Once produced, these hormones are sent via ____ from the hypothalamus down through the ______, into the posterior pituitary gland, where they are stored for future use
axons
infundibular stalk
70
Examples of Hormones synthesized in the hypothalamus but stored in the posterior pituitary gland
● Oxytocin
| ● Antidiuretic hormone (ADH/Vasopressin)
71
The Pituitary Gland (aka: _____)
hypophysis
72
The Pituitary Gland
● A small, pea-sized endocrine gland located within the
sella turcica of the sphenoid bone
73
sella turcica of the sphenoid bone holds the
pituitary gland
74
Posterior pituitary gland is connected to the hypothalamus
| via the
infundibular stalk
75
Has two separate glandular portions, one intermediate
| portion
pituitary gland
76
Anterior pituitary
| AKA: _______
adenohypophysis or pars distalis
77
Posterior pituitary
| AKA: ________
neurohypophysis or pars nervosa
78
neurohypophysis or pars nervosa aka...
Posterior pituitary
79
adenohypophysis or pars distalis aka....
Anterior pituitary
80
comprises ~ 75% of the total weight of the pituitary gland
The anterior segment of the pituitary gland\
81
The anterior segment of the pituitary gland is composed of:
Pars distalis: glandular tissue (the largest portion)
Pars tuberalis: partially covers the infundibulum (like a sheath)
82
when you see Pars tuberalis think....
Anterior pituitary gland
83
● The anterior pituitary gland produces ____ from 5 specific cell types within the gland
tropic hormones
84
● Once anterior pituitary hormones are synthesized they are....
released into general circulation (venous)
85
● Four of the tropic hormones released from the anterior
| pituitary gland exert their effect on another endocrine gland... the exception is?
-The exception to this is human growth hormone as it acts directly on almost all tissues found in the body, not a particular gland
86
HGH (somatotropin) secreted by these cells
Somatotrophs
87
TSH (thyrotropin) secreted by these cells
Thyrotrophs
88
FSH and LH secreted by these cells
Gonadotrophs
89
PRL (prolactin) secreted by these cells
Lactotrophs
90
ACTH (corticotropin) secreted by these cells
Corticotrophs
91
MSH (melanocyte) secreted by these cells
Corticotrophs
92
Hormones made in the anterior pituitary
GOLF TAMPA - ADH and OXY
93
Also known as somatotropin
Human Growth Hormone (hGH)
94
Most abundant anterior pituitary hormone
Human Growth Hormone (hGH)
95
Secreted by somatotrophic cells (most abundant cell)
Usually secreted in bursts every few hours
Human Growth Hormone (hGH)
96
Starts to decline production after adolescence
Found to be approximately 25% production after age of 70
Human Growth Hormone (hGH)
97
Is produced and released in a pulsatile manner
Characteristic increase during the first two hours of deep sleep
Human Growth Hormone (hGH)
98
increases during first TWO HOURS of DEEP SLEEP
Human Growth Hormone (hGH)
99
Main function is to promote synthesis and secretion of
| small protein hormones called Insulin-like Growth Factors (IGF’s; also known as somatomedins)
Human Growth Hormone (hGH)
100
somatomedin also known as....
Insulin-like Growth Factors (IGF’s; also known as somatomedins)
101
In response to hGH, cells in the liver, skeletal muscle, cartilage, bones synthesize and secrete _____
Enters bloodstream via the liver or may act locally as autocrines or paracrines
IGF’s
102
It is believed that all of the changes seen in the body are due to the presence of these IGF’s, not hGH directly
This means that...
someone can have a normal hGH level but if there is a deficiency in the production of IGF’s, they will have some abnormalities
103
IGF's
Increases protein synthesis
-Increases uptake of amino acids into cells
Decreases protein catabolism
-Decreases breakdown of proteins by limiting use of amino acids for ATP production and instead uses free-fatty acids
Stimulates growth in childhood
-Especially of bone, and muscle
```
Enhances lipolysis (break down of adipose tissue)
- Releases free-fatty acids (FFA’s) into the bloodstream for use as a source of energy in cells rather than glucose
```
Tis True
104
```
Increases protein synthesis
Decreases protein catabolism
Stimulates growth in childhood
Enhances lipolysis (break down of adipose tissue)
Influences carbohydrate metabolism
```
Insulin-like Growth Factors (IGF’s; also known as somatomedins)
105
Insulin-like Growth Factors (IGF’s; also known as somatomedins)
Influences carbohydrate metabolism by...
Decreasing glucose uptake into the cells (leaving it in the blood for neurons) & increase glycogenolysis
explain the decreasing glucose....
Decreases glucose uptake into cells (to an extent), leaving it in the bloodstream readily available for neurons to use (if needed)
With increased FFA’s, cells will use these as their main energy source
106
Insulin-like Growth Factors (IGF’s; also known as somatomedins)
Influences carbohydrate metabolism by...
Decreasing glucose uptake into the cells (leaving it in the blood for neurons) & increase glycogenolysis
explain glycogenolysis
Also stimulates the liver to release glucose (glycogenolysis) into the blood if serum levels are low (hypoglycemia)
IGF’s attempt to keep glucose available for neurons at all times during states of hypoglycemia
While doing this, they mobilize glucose stores from liver to increase blood glucose levels
107
Insulin secreted in abundance in high blood glucose situations
IGF’s produced and secreted in abundance in low blood glucose situations and -This starts a chain reaction to release more glucose in blood stream from various methods
Insulin-like Growth Factors (IGF’s; also known as somatomedins)
108
_____ stimulates GHRH secretion and inhibits GHIH secretion (hypothalamus) resulting in
Hypoglycemia
Anterior pituitary increases secretion of hGH resulting in increased IGF concentration
-Carbohydrate metabolism and liver glycogenolysis increase blood glucose
109
Hyperglycemia does the opposite of hypoglycemia because it Stimulates the hypothalamus to secrete
Reduced levels of hGH result which also reduces the IGF action... this causes?
GHIH
– plasma glucose levels reduce because the IGF’s are no longer working to keep integral glucose in the blood stream for neurons (there is enough already there)
110
Factors that stimulate hGH secretion: name all 9
| come up with mnemonic
Hypoglycemia
Sympathetic nervous system stimulation (stress, strenuous exercise)
Deep sleep
Decreased serum fatty acids
Increased serum amino acids
Starvation/fasting or protein deficiency
Increased levels of:
- Testosterone
- Estrogen
- Ghrelin – hormone secreted by stomach right before meals
111
Factors that inhibit hGH secretion: name all 9
Hyperglycemia
Increased serum fatty acids
Decreased serum amino acids
Emotional deprivation
Obesity
When plasma T3 and T4 levels are low (thyroid)
hGH (somatotropin) itself (negative feedback)
GHIH (somatostatin)
Aging
112
Describe hypoglycemia's effect on the body followed by hyperglycemia's... look at ppt slide 70 image
draw it out on the board to reinforce
113
ACTH stands for...
Adrenocorticotropic Hormone
114
ACTH (Adrenocorticotropic Hormone ) Secretion is stimulated by:
Corticotropin-releasing hormone (CRH) from hypothalamus which is usually induced by:
Stress-related stimuli:
- Low blood glucose
- Physical trauma
115
ACTH controls production of ____, other glucocorticoids and certain _____ produced by
the cortex of adrenal glands
cortisol
androgens
116
(PRL) stands for
Prolactin
117
Prolactin (PRL)
Secretion is controlled by:
● Prolactin-releasing hormone (PRH)
● Prolactin-inhibiting hormone (PIH) (AKA
dopamine)
118
(PRH) stands for
● Prolactin-releasing hormone
119
Prolactin-inhibiting hormone (PIH) AKA....
dopamine
120
prolactin helps cause two things:
These together cause milk production in pregnant women
Ejection of milk is caused by oxytocin (posterior pituitary)
121
Low levels of estrogen and progesterone just prior to
menstruation inhibits secretion of ____ and
stimulates _____ secretion (this likely accounts for
breast tenderness at this time)
PIH (dopamine); prolactin
122
During the rest of the female cycle: as _____ secretion
| increases, ______ secretion increases
estrogen increases
PIH (dopamine) increases
Prolactin secretion is reduced at this point
123
Prolactin Hypersecretion Is most commonly caused by a
prolactinoma (a benign pituitary adenoma)
Consider this diagnosis if a non-pregnant, non- breastfeeding female complains of a milky breast discharge
Consider this diagnosis in a male with erectile dysfunction with no obvious cause (older, HTN, obese) or a male with milky breast discharge
124
When you hear thyroid hormones in this class think....
T3 / T4
125
iodide issue not making
T3 / T4
126
peroxidase issue... not making iodide to iodine so no
T3 / T4
127
thyroglobulin (TGB) is...
the glue that binds the MIT, DIT, T3, and T4
128
resorption vs reabsorption is PROBABLY on the test
watch out for these key words and differentiate between on the exam
129
FSH
Follicle Stimulating Hormone
130
Gonadotropin-Releasing Hormone (GnRH) from the
| hypothalamus stimulates the anterior pituitary to secrete
FSH
131
___ initiates follicle production in women monthly
& Also stimulates ovarian follicular cells to produce estrogen
& stimulates production of sperm cells in me
FSH
132
FSH is inhibited by negative feedback, seen as
increased serum levels of estrogen (females)
Increased serum levels of testosterone (males)
133
LH
Luteinizing Hormone
134
Gonadotropin-Releasing Hormone (GnRH) from the
| hypothalamus stimulates the anterior pituitary to secrete _____
LH
135
What stimulates the AP to secrete LH?
Gonadotropin-Releasing Hormone (GnRH) from the
| hypothalamus
136
What stimulates the AP to secrete FSH?
Gonadotropin-Releasing Hormone (GnRH) from the
| hypothalamus
137
_____ triggers ovulation in women as well as formation of the corpus luteum and therefore the secretion of progesterone by the corpus luteum... also with FSH stimulates release of estrogen by follicular cells
LH
138
With FSH, LH triggers secretion of estrogen by ovarian
follicular cells
139
LH stimulates cells in the testes to produce and secrete
| testosterone in male... T or F
True
140
● Collective name for group of peptide hormones produced in the skin, the anterior pituitary and other parts of the brain
● Dopamine (PIH) inhibits MSH release from anterior
pituitary only
Melanocyte Stimulating Hormones
141
● In humans, MSH is involved with:
- Pigmentation of skin cells (i.e. increased melanin causing tanned skin) (This MSH is made locally in the skin)
- Possible suppression of appetite
Melanocyte Stimulating Hormones
142
______ inhibits MSH release from anterior
| pituitary only
Dopamine (PIH)
143
TSH
Thyroid Stimulating Hormone
144
Release of _____ from the hypothalamus stimulates the release of Thyroid Stimulating Hormone (TSH) from the anterior pituitary
Thyrotropin Releasing Hormone (TRH)
145
TRH is inhibited by increased levels of ____ in the bloodstream which when reduced, causes a reduced amount of TSH to be produced in the anterior pituitary
T3 and T4; This reduction in TRH and subsequently TSH reduces the amount of T3/T4 to be made
(negative feedback loop)
146
Posterior Pituitary aka...
neurohypophysis
147
The ____ segment of the pituitary gland
| comprises ~ 25% of the total weight of the gland.... doesn't synthesize it stores and releases
posterior pituitary gland
148
posterior pituitary gland is composed of neural tissue and these two particulars:
● Pars Nervosa- nerve tissues encompassing the “bulbar” part of the posterior pituitary
● Infundibular stalk- connection to the pituitary gland
149
nerve tissues encompassing the “bulbar” part of the posterior pituitary (with axons storing oxytoxicin and ADH)
Pars Nervosa
150
connection to the pituitary gland
Infundibular stalk
151
The ____ pituitary does not synthesize
hormones but rather it stores and releases hormones sent to it by the hypothalamus
Which hormones are stored?
posterior
Antidiuretic Hormone (ADH) (also known as vasopressin)
Oxytocin
152
Contains the axons and axon terminals of more than 10,000 hypothalamic neurosecretory cells
Posterior Pituitary
153
produces oxytocin
paraventricular nucleus (in hypothalamus)
| from picture not slides maybe not testable
154
produces ADH
supraoptic nucleus (in hypothalamus)
| from picture not slides maybe not testable
155
● Produced in the hypothalamus, stored in the posterior pituitary gland
● “Against urination” – decreases urine production/excretion
Antidiuretic Hormone (ADH; Vasopressin)
156
● Normal urine output daily is 1-2 liters, without ADH this increases 10 FOLD!!! to 20 liters a day!!!! (FOOT STOMP)
-Alcohol inhibits release of ADH – “Breaking the seal” urinate more, end up dehydrated after drinking (FOOT STOMP)
Antidiuretic Hormone (ADH; Vasopressin)
157
Also causes vasoconstriction of arterioles (causing an increase in blood pressure) hence the alternative name vasopressin
Antidiuretic Hormone (ADH; Vasopressin)
158
Amount of ADH secreted varies with ___ and ___
blood osmotic pressure and blood volume
159
High blood osmotic pressure stimulates ______ in the hypothalamus
osmoreceptors
160
Osmoreceptors are a type of ____ that measure osmotic pressures; which measure the pressure solutes are causing ____
baroreceptor
inside the plasma
161
Causes of high osmotic pressure
Dehydration
Hemorrhage
Diarrhea
Excessive sweating
162
These osmoreceptors activate the production and release of ADH from ______ in hypothalamus
These same neurosecretory cells send a signal to the ______ to release the ADH it already has stored
ADH is released to find its target tissues
neurosecretory cells
posterior pituitary
163
```
Antidiuretic Hormone (ADH):
Mechanism of action and regulation of secretion
```
```
1
2
3
4
5
6
```
1. High blood osmotic pressure stimulates hypothalamic osmoreceptors
2. Osmoreceptors activate the hypothalamic neurosecretory cells that synthesize and release ADH
3. Nerve impulses liberate ADH from axon terminals in the PPG into the bloodstream
4. Kidneys retain more water, which decreases urine output
5. Sudoriferous (sweat) glands decrease water loss by perspiration from the skin
6. Arterioles constrict, which increases BP
164
IN what other ways is ADH secretion altered?
```
● Pain, stress, trauma, anxiety
● Drugs:
Morphine
Tranquilizers
Some anesthetics (hence post op monitor)
Nicotine
```
165
During delivery of a child, stretching of the cervix stimulates release of oxytocin from posterior pituitary
This in turn enhances the contraction of the uterus What type of action is this?
positive feedback
166
After delivery of the child, _____ stimulates milk ejection or “let-down” from the mammary glands.... which is increased by?
Oxytocin
Increased by the suckling stimulus of the newborn
167
Very little is known about the purpose of oxytocin in males and non-pregnant females, but is it believed to be linked to....
Believed (and being researched) to be involved with the ability to emotionally/socially bond with others
168
Control of Thyroid Hormone Secretion
_______ from the hypothalamus stimulates Thyroid Stimulating Hormone (TSH) secretion from the anterior pituitary gland
Thyrotropin releasing hormone (TRH)
169
Control of Thyroid Hormone Secretion
Thyroid hormone synthesis/secretion occurs within the thyroid gland in the presence of
TSH: Thyroid Stimulating Hormone
170
Control of Thyroid Hormone Secretion
_____ feedback causes the hypothalamus to stop or slow production of TRH which then causes the anterior pituitary to stop or slow release of
Negative
TSH
171
Control of Thyroid Hormone Secretion
Anything that increases cellular energy demand causes an increase in T3/T4 production: T or F?
TRUE
172
Control of Thyroid Hormone Secretion:
Cold environment, hypoglycemia, high altitude, pregnancy all do what to T3/T4 production?
INCREASE.... metabolic demand or cellular energy demand increased requiring more T3/T4
173
A butterfly shaped gland weighing approximately 30 grams (is the largest of the “pure” endocrine glands)
Thyroid Gland (Macroscopic)
174
(is the largest of the “pure” endocrine glands)
Thyroid Gland (Macroscopic)
175
Lateral lobes (wings) on each side of the trachea projecting upward to just below the larynx
Thyroid Gland (Macroscopic)
176
Thyroid Gland (Macroscopic)
Lobes connected by an ____ located anterior to the trachea
isthmus
177
Approximately 50% of thyroid glands have a ____ in the center extending superior from the isthmus, this is called the ____
third lobe
pyramidal lobe
178
_____ are the functional units of the thyroid
Follicles
179
A follicle is a sphere with its wall consisting of follicular cells: THE INSIDE IS CALLED?
This inside of this unit is called the colloid
180
_____ cells reside in between follicles and produce _____?
Parafollicular; calcitonin
181
No direct action on thyroid
Made in the thyroid but not considered to be a “thyroid hormone”?
calcitonin produced by Parafollicular cells
182
- The inactive form of thyroid hormone
| - Much more abundant, but less potent
Tetraiodothyronine (Thyroxine, T4)
183
- The active form of thyroid hormone
| - Much more potent, less abundant
Triiodothyronine (T3)
184
(not a “thyroid hormone” only made in the thyroid)
Made in small quantities by parafollicular cells, helps to regulate calcium levels of the blood
Calcitonin
185
What are the hormones produced in the Thyroid gland?
T3
T4
Calcitonin
186
Synthesis of T3 and T4: describe or draw the entire process:
● Follicular cells pull iodide ions from the blood stream
● Follicular cells are also producing thyroglobulin (TGB) (glycoprotein-carbon chain of many amino acids)
-TGB is produced in endoplasmic reticulum
-Packaged in the Golgi apparatus
-Released by exocytosis into the lumen (colloid)
● Iodide requires oxidation to make iodine (the useable form for thyroid hormone synthesis)
-Perioxidase oxidizes the iodide into iodine (I2)
● At this point there is now TGB and iodine (I2) roaming in the colloid
● Simultaneously TGB and iodine begin to react with each other forming bonds (at the tyrosine portions of TGB)
- One iodine to one tyrosine = monoiodotyrosine (MIT)
- Two iodines to one tyrosine = diiodotyrosine (DIT)
●These MIT and DIT molecules continue to form bonds to one another
- MIT + DIT = T3 (3 iodine molecules)
- DIT + DIT = T4 (4 iodine molecules)
187
Describe and or draw the Secretion of T3 and T4
Secretion of T3 and T4
● The colloid is then pulled back into the follicular cells by pinocytosis
-This colloid contains the T3 and T4
● Once back in the follicular cell, this colloid is engulfed by a lysosome which digests the TGB and cleaves off the T3 and
T4
● This T3 and T4 is sent out of the cell, into the interstitial space, into the bloodstream
-Because they are weak in terms of water solubility, more than 99% of both T3 and T4 are then bound to transport proteins (thyroxine- binding globulin; TBG) in the blood stream
● They are then sent to their target cells
188
** TGB and TBG are two different things***
| T or F? What are they?
True
● TGB – Thyroglobulin
-This is the “glue” binding the MIT, DIT, T3, T4
● TBG – Thyroxine Binding Globulin
-This is the transport protein found in the blood stream that carries the T3/T4 to their target cells after synthesis of them is complete
189
This is the “glue” binding the MIT, DIT, T3, T4
● TGB – Thyroglobulin
190
This is the transport protein found in the blood stream that carries the T3/T4 to their target cells after synthesis of them is complete
● TBG – Thyroxine Binding Globulin
191
Actions of Thyroid Hormones (T3/T4)
● Increase basal metabolic rate (BMR)
- BMR is the rate of _____ consumption under normal conditions
- When increased, BMR causes metabolism of ____?
● Stimulates synthesis of additional __ pumps
- This causes increased ___ production and consumption by the constant turnover of the Na+ and K+
- These reactions release heat as a byproduct This heat helps to raise and maintain the body temperature
● oxygen
carbohydrates, proteins, and lipids
● Na+/K+
ATP
192
What are the Actions of Thyroid Hormones (T3/T4)?
1. Increase BMR
2. Stimulate synthesis of Na/K pumps
3. Helps to regulate metabolism
4. Can enhance actions of some catecholamines
5. Works with hGH and insulin to accelerate body growth
193
Actions of Thyroid Hormones (T3/T4)
● Helps to regulate the metabolism
-Stimulates ___ synthesis
- Increases use of glucose and fatty acid for __
- Increases ___ and enhances cholesterol excretion
● Can enhance actions of some catecholamines I.e. __ and ___
-T3 and T4 upregulate ____ receptors in the presence of these substances
--The up-regulation can explain why hyperthyroid patients experience....?
● protein
ATP production
lipolysis
● Epinephrine and Norepinephrine
beta adrenergic
increased heart rates, and blood pressure
194
Actions of Thyroid Hormones T3/T4
● Works with hGH and insulin to accelerate what? in which two systems mainly?
Deficiency of T3/T4 in fetal growth, infancy or childhood causes what?
body growth; Nervous and skeletal systems mainly
severe mental retardation and stunted bone growth
195
____cells reside outside of the follicular cells but still within the thyroid
Parafollicular
196
Parafollicular Cells Synthesizes and secretes ?
calcitonin (calci-tone-it-down)
197
(calci-tone-it-down)
calcitonin
198
High levels of serum Ca2+ and HPO42 stimulate secretion of?
calcitonin
199
Low levels of serum Ca2+ and HPO42 inhibit secretion?
calcitonin
200
The process of using/losing a substance
Taking flour off the shelf for use (it’s yours, you are just now using it)
Resorption
201
Example: The breakdown of bone by osteoclasts in order to increase plasma Ca2+
Resorption
202
The process of gaining something (whether for the first time or again)
Using some of the flour, and then putting the unused portion back on the shelf
Absorption/Reabsorption
203
Example: Osteoblasts absorbing/reabsorbing the Ca2+ from blood to build bone matrix
Absorption/Reabsorption
204
** Osteoclasts crush (break down), Osteoblasts build**
yup
205
The cells that break down bone and release it into blood circulation
osteoclasts (inhibited by calcitonin)
206
The cells that reabsorb calcium and store it in bone matrix
osteoblasts (Increased by calcitonin)
207
Closes certain channels from absorbing calcium from food you eat
calcium absorption in the intestines (Decreased by calcitonin)
208
Prevents cells in distal convoluted tubule from reabsorbing more calcium
calcium loss in the urine (increased by calcitonin)
209
Prevents cells in distal convoluted tubule from reabsorbing more calcium
calcium loss in the urine (increased by calcitonin)
210
Parathyroid GLANDS located ON the
thyroid gland
211
Four small glands attached to the posterior surface
| of the thyroid gland
Parathyroid Glands (As if they were stuck onto it, not part of it)
212
______ are the functional component of the Parathyroid gland
Principal cells (AKA Chief cells)
213
These secrete parathyroid hormone (PTH)....
Principal cells (AKA Chief cells)
214
High levels of serum Ca2+ inhibit secretion of?
Principal cells (AKA Chief cells) secretion of PTH
215
Low levels of serum Ca2+ stimulate secretion
Principal cells (AKA Chief cells) secretion of PTH
216
Where are the parathyroid glands located on the thyroid gland?
Four small glands on the POSTERIOR... two superior and two inferior
217
Increases osteoclasts
-The cells that break down bone and release it into blood circulation
Inhibits osteoblasts
-The cells that reabsorb calcium and store it in bone matrix
Increases calcium absorption in the intestines
-Opens certain channels that cause absorption of calcium from food you eat
Decreases calcium loss in the urine
-Stimulates the cells in distal convoluted tubule to reabsorb more calcium
Parathyroid Hormone (PTH) from parathyroid gland
218
Parathyroid Hormone (PTH) from parathyroid gland causes the following:
Increases osteoclasts
Inhibits osteoblasts
Increases calcium absorption in the intestines
Decreases calcium loss in the urine
EXPLAINED FURTHER BELOW
Increases osteoclasts
-The cells that break down bone and release it into blood circulation
Inhibits osteoblasts
-The cells that reabsorb calcium and store it in bone matrix
Increases calcium absorption in the intestines
-Opens certain channels that cause absorption of calcium from food you eat
Decreases calcium loss in the urine
-Stimulates the cells in distal convoluted tubule to reabsorb more calcium
219
Pair of flattened, pyramidal-shaped glands located
| superior and adjacent to the kidneys (retroperitoneal)
Anatomy of the Adrenal Glands
220
Each usually measures 3-5cm in height by 2-3cm in width and usually less 1cm thick
Anatomy of the Adrenal Glands
221
Each adrenal gland has two distinct section:
Adrenal cortex- large and peripherally located
| Adrenal medulla- smaller and centrally located
222
Adrenal gland is covered by? and is highly ___?
tissue capsule
Highly vascularized
223
describe the gross transverse cross section of the adrenal gland I.e. larger layers from superficial to deep
capsule, cortex, medulla
224
describe the microscopic section of the adrenal gland from superficial to deep
```
Capsule
Zona Glomerulosa
Zona Fasciculata
Zona Reticularis
Medulla
```
225
Hypothalamus releases _______ which targets the anterior pituitary (for control of adrenal cortex hormone section)
corticotropin-releasing hormone (CRH)
226
Anterior pituitary produces and releases ____ in response to CRH, which has the following. actions on the adrenal cortex: Zona Glomerulus, Fasciculata, Reticularis
adrenocorticotropic hormone (ACTH)
Zona Glomerulus – mineralcorticoids are produced and secreted
Zona Fasciculata – glucocorticoids are produced and secreted
Zona reticularis – certain androgens are produced and secreted
227
Secretes mineralocorticoids
-Aldosterone (most notable)
Affects mineral homeostasis in the body
- Promotes the reabsorption of sodium in the kidneys
- ----Brings water with the sodium (helps to increase blood volume)
- Promotes the loss of (secretion, excretion) of
- ----Potassium (K+) into the urine
- ----Hydrogen (H+) into the urine
Zona Glomerulosa – outer zone
228
Aldosterone secretion is stimulated by both:
- Elevated serum potassium and hydrogen levels
- Low blood pressure
- ----Via the renin-angiotensin-aldosterone system (RAAS)
229
Aldosterone inhibited by both:
- Low serum levels of potassium and hydrogen
| - High blood pressure
230
** This is not an all or nothing response, it’s not on or off. There is fluctuation of aldosterone levels in the body constantly**
SWEET BEAT
231
Renin-Angiotensin-Aldosterone System
Blood pressure is low this occurs:
This is recognized by the kidneys as well by reduced pressure coming into them
---Kidneys secrete renin in response to this
232
Renin-Angiotensin-Aldosterone System
Circulating renin causes the conversion of ____ (normal constituent of blood) into ______
angiotensinogen into angiotensin-I
233
Renin-Angiotensin-Aldosterone System
_____ is made by the liver and dumped into circulation regularly
Angiotensinogen
234
Renin-Angiotensin-Aldosterone System
Angiotensin-I circulates into the lung vasculature where it encounters _____
angiotensin converting enzyme (ACE)
235
Renin-Angiotensin-Aldosterone System
ACE splits angiotensin-I now making ______
Angiotensin-II then circulates causing numerous things to occur
angiotensin-II
236
Angiotensin-II increases blood pressure by numerous
| pathways..... which ones?
Stimulates the production of aldosterone
Causes increase in sympathetic activity
Causes arteriolar vasoconstriction
Causes release of antidiuretic hormone (ADH)
237
Secretes glucocorticoids
- ----Cortisol (95%)
- ----Corticosterone
- ----Cortisone
Zona Fasciculata – middle zone
238
Affects numerous biological functions
- ----Glucose levels
- ----Helps to regulate metabolism
- ----Inflammatory response
- ----Immune system
- ----Blood pressure
- ----Nervous system
- ----Sleeping
Zona Fasciculata – middle zone
239
____ help the body regain homeostasis after a "Stress" event
Glucorticoids
--Very effective if stressor is removed
--Over-reaction occurs if stressor not removed
240
Function of glucocorticoids? Name all Six
```
Stimulates protein catabolism
Stimulates gluconeogenesis
Stimulates lipolysis
Suppression of immune response
Acts as an anti-inflammatory
Inhibition of bone formation
```
241
WHat is the majority of the pars distalis made up of?
Cells that create HGH or somatotropin. So it’s made of SOMATOTROPHIC cells
242
Protein / Polypeptide Hormones made in the Hypothalamus
```
TRH
CRH
GHRH
GHIH
GRH
```
What about PIH and PRH? Dopamine is a Tyrosine Derivative Hormone!
243
Protein / Polypeptide Hormones created in the thyroid
Calcitonin
244
promotes deposition of calcium into bones; decreases serum calcium levels
Calcitonin (Protein / Polypeptide )
245
Protein / Polypeptide Hormones created in the Pancreas
Glucagon
| Insulin
246
Increases synthesis and secretion of glucose from the liver
Glucagon (Protein / Polypeptide )
247
Protein / Polypeptide Promotes entry into cells; helps to control carbohydrate metabolism
Insulin
248
Hormones created in the Parathyroid glands
PTH (Protein / Polypeptide )
249
Increase calcium absorption by the gut and the kidneys; breaks down bone matrix to in order to increase serum calcium levels
PTH (Protein / Polypeptide )
250
Protein / Polypeptide Hormones created in the Placenta
Human Chorionic Gonadotropin Hormone (HCG)
Human somatomammatropin
251
Promotes growth of the corpus luteum and therefore the growth of progesterone... also the secretion of estrogen by follicular cells
Human Chorionic Gonadotropin Hormone (HCG) (Protein / Polypeptide )
252
Promotes development of some fetal tissues as well as enlargement of mothers breasts
Human somatomammatropin (Protein / Polypeptide )
253
Protein / Polypeptide Hormones created in the kidneys
Renin
| Erythropoietin (EPO)
254
catalyzes conversion of angiotensinogen to angiotensin (acts an enzyme)
Renin
255
Increases erythrocyte production
Erythropoietin (EPO) (Protein / Polypeptide )
256
Protein / Polypeptide Hormones created in the Heart
Atrial-natiuretic peptide hormone (ANP)
257
increases sodium excretion by the kidneys, reduce blood pressure
Atrial-natiuretic peptide hormone (ANP) (Protein / Polypeptide )
258
Protein / Polypeptide Hormones created in the stomach
gastrin
259
stimulates hydrogen chloride secretion by parietal cells to aid in digestion
gastrin (Protein / Polypeptide )
260
Protein / Polypeptide Hormones created in the small intestines
Secretin
| Cholecystokinin
261
Stimulates pancreas to release bicarbonate
Secretin (Protein / Polypeptide )
262
Stimulates gall bladder contraction and release of pancreatic enzymes
Cholecystokinin
263
Protein / Polypeptide Hormones created in adipocytes
Leptin
264
inhitibits appetite, stimulates thermogenesis
Leptin (Protein / Polypeptide )
265
Where in the body are all of the steroid hormones created (listed in this class at least)?
Kidneys, Adrenal Cortex (zona glomerulosa), Testes, Ovaries
266
Kidneys, Adrenal Cortex (zona glomerulosa), Testes, Ovaries... List the steroid hormones made in each
Kidneys - Calcitriol (Inc intestinal absorption of calcium)
Adrenal Cortex (ZG) - Cortisol (protein, carb, & fat metabolism; inflammatory effects
Adrenal Cortex (ZG) - Aldosterone - (increases renal absorption, and potassium and hydrogen ion secretion)
Testes - Testosterone - (male development)
Ovaries - Estrogen (Growth & development of female reproductive system, female breasts, etc)
Ovaries - Progesterone ("uterine milk" nourished embryo, helps develop secretory apparatus of breasts)
267
How do glucocorticoids Stimulate protein catabolism?
Essentially from all cells except the liver
These liberated amino acids travel to liver where they participate in gluconeogenesis
268
Explain how a glucocorticoid Stimulates gluconeogenesis
Liver converts amino acids to glucose
269
Explain how a glucocorticoid Stimulates lipolysis
Stimulates shift from carbohydrate catabolism to lipid catabolism
Liberates fatty acids also used in gluconeogenesis in the liver
270
Explain how a glucocorticoid Suppression of immune response- presence of glucocorticoids cause
Marked decrease in number of eosinophils (type of WBC) as well as atrophy of lymphatic tissue
--Leads to a decreased number of lymphocytes and plasma cells
------These cells produce numerous anti-bodies
------With a reduced level of these cells, the body’s ability to fight infections is greatly reduced
271
Explain how a glucocorticoid Acts as an anti-inflammatory
Inhibits synthesis of precursor to prostaglandins and leukotrienes
Inhibits production of interleukin-2 and proliferation of T-
lymphocytes
Inhibits release of histamine and serotonin from mast cells and platelets
272
Explain how a glucocorticoid causes Inhibition of bone formation
Decreases Type I collagen (major component of bone matrix)
Decreases osteoblast activity
Decreases intestinal absorptions of calcium
273
What is the inner zone of the adrenal gland?
Zona Reticularis - inner zone
274
What is made in the Zona Reticularis - inner zone?
Secretes small amounts of weak androgens:
- Dehydroepiandrosterone (DHEA)
- Androstenedione
- Dihydrotestosterone (DHT)
275
Converted in testes to testosterone for males
Portion converted to estrogen in women (various tissues)
weak androgens secreted from Zona Reticularis
276
Weak androgenic effect on its own
Precursor to numerous hormones
Androstenedione, testosterone, dihydrotestosterone (DHT), estrogen
Dehydroepiandrosterone (DHEA)
277
\Weak androgenic effect on its own
Can be converted to Testosterone or estrone (precursor to estradiol)
Androstenedione
278
More potent androgen than testosterone
Made from conversion of testosterone
Is active in tissues where testosterone is not
Dihydrotestosterone (DHT)
279
Middle region of the adrenal gland
The Adrenal Medulla
280
functional unit of the adrenal medulla
Chromaffin Cell
281
Chromaffin Cell Synthesizes and secretes:
catecholamines
Epinephrine (more potent, more abundant)
Norepinephrine (precursor to epinephrine)
282
These cells are considered modified sympathetic ganglion of the autonomic nervous system (ANS)
Chromaffin Cell
283
Stimulation of sympathetic nervous system sends signal down through splanchnic nerves
These nerves synapse at the chromaffin cells
Signals....
epi/norepi to be released
284
Catecholamines intensify sympathetic responses
| throughout the body
True
285
Catecholamines do what to the body?
Increase heart rate, force of contraction, cardiac
output, blood pressure
Increases blood flow to heart, liver, skeletal muscles
Dilates airways to lung tissue
Causes liver and skeletal muscle to convert glycogen
into glucose
Vasodilation (lungs, brain, heart, skeletal muscle)
Vasoconstriction (GI, kidneys, skin)
286
What is pheochromocytoma?
a tumor that's usually benign of the chromaffin cells
| causes a lot of sympathetic NS responses
287
pancreas is 95% what?
Exocrine
288
pancreas is 5% what?
Endocrine
289
Islets of langerhans where?
exocrine acini
290
raises blood glucose levels
glucagon
291
____ receptors in pancreas sense low blood glucose
glucose (to stimulate glucagon)
292
Glucagon performs the following:
glycogenolysis (break down of liver glycogen)
Gluconeogenesis (liver uptake of AA's to convert into glucose)
Lypolysis (breakdown of triglycerides into FFA's and glycerol
293
How is glucagon regulated?
negative feedback from serum glucose levels
294
lowers blood glucose levels
insulin
295
What are the 4 types of islet cells?
A - 20% secrete glucagon
B - 75% secrete insulin
D - 4% secrete somatostatin (GHIH)
F - (aka PP cell) - 1% secrete pancreatic polypeptide
296
What is the exocrine acinus?
where the endocrine cells of the pancreatic islets are located (Islets of Langerhans)
297
what is GDIP (aka GIP) and what triggers it?
GDIP = Glucose-Dependent Insulintropic Peptide aka Gastric Inhibitory Peptide whcih is triggered BY presence of food in the small intestine
298
What does GDIP aka GIP trigger?
release of insulin from the pancreas
299
what does insulin perform?
Facilitates glucose uptake into cells
Stimulates glycolysis (metabolism of glucose for ATP)
Stimulates glycogenesis (excess glucose into glycogen in liver)
Promotes triglyceride and protein synthesis
300
how is insulin regulated?
negative feedback from serum glucose levels (decrease levels in hypoglycemia)
301
explain how SOMATOSTATIN acts in paracrine manner
how about endocrine manner?
paracrine: stops release of insulin and glucagon
endocrine: inhibits release of hGH
302
What does the following:
Inhibits somatostatin release
Inhibits gallbladder contraction
Inhibits secretion of bicarb and certain enzymes from pancreas
Appetite suppression potentially
Pancreatic polypeptide
303
Pancreatic polypeptide
What does the following:
Inhibits somatostatin release
Inhibits gallbladder contraction
Inhibits secretion of bicarb and certain enzymes from pancreas
Appetite suppression potentially
304
hypoglycemia inhibits release of insulin, increases release of Glucagon which...
acts on?
glucose then released by and then stimulates release of?
hypoglycemia inhibits release of insulin, increases release of Glucagon which...
acts on hepatocytes (liver cells)
hepatocytes which increases blood glucose and stimulates the release of insuliln
305
Blood sugar immediately after a meal: Insulin
hyperglycemia does what?
inhibits glucagon (alpha cells)
stimulates release of insulin by Beta Cells
306
Where does insulin act on the body?
glucose into cells
glycogenesis (conversion glucose into glycogen)
increase uptake of AA's to increase protein synthesis
speeds up synthesis of FFA's (lipogenesis)
307
Glucagon is which cell
Alpha cells
308
Insulin is which cell
Beta cells
309
Ovaries synthesize and secrete
estrogen, progesterone, INHIBIN, and RELAXIN
310
When do INHIBIN and RELAXIN get produced in large quantities?
when pregnancy occurs (otherwise negligible levels)
311
INHIBIN inhibits what?
FSH to develop follicles
312
RELAXIN does what?
relaxes cartilage of the pubic symphesis for baby passage & widens cervix (relaxes)
313
testes produce what?
testosterone and inhibin
314
inhibin in males testes does hat?
inhibits FSH so therefore INHIBIN will INHIBIT spermatogenesis (lower levels still reduce rate of spermatogenesis)
315
what does the pineal gland secrete
melatonin
316
ANP and BNP (Atrial Natiuretic Peptide aka A-type and there is also B-type) what do they do?
when blood pressure stretches heart they decrease blood pressure
317
Adipose tissue secretes what?
Leptin and Adiponectin
Leptin (satiety)
Adiponectin (reduce insulin resistance)
318
Leptin from adipose tissue does what?
(satiety) or feeling of it
319
Adiponectin from adipose tissue does what?
(reduce insulin resistance)
320
skin releases what?
cholecalciferol (forms Vitamin D)
321
Thymus does what with age?
larger and more active EARLY in LIFE, but over time it will ATROPHY
322
Thymus hormones
Thymosin
Thymic humoral factor
Thymic factor
Thymopoietin
323
Liver secretes what?
IGF-1
Angiotensinogen
Thrombopoietin
Hepcidin
324
blocks release of iron into bloody fluids and produced by liver?
Hepcidin
325
GI tract hormones?
Gastrin
CCK (Cholecystokinin)
GDIP AKA GIP
Secretin
326
Gastrin is secreted by
stimulated by?
Function?
G cells of the stomach
ingestion of protein, stomach distention & VAGAL STIMULATION***
Promotes H+ from gastric parietal cells
stimulates growth of gastric mucosa
327
what is bone resorption?
using/ losing so osteoclasts will break down bone to increase serum calcium levels
328
what is bone absorption/reabsorption?
osteoblasts are absorbing the calcium from the blood to build bone matrix
329
resorption
using/losing
330
reabsorption/absorption think
gaining something
331
vagal stimulation helps G cell in stomach secrete
gastrin
332
secreted by I cells of the small intestines
Cholecystokinin (CCK)
333
Stimulated by fatty meals w/ protein
Cholecystokinin (CCK)
334
monoglycericdes and fatty acids along with
| small peptides and amino acids stimulate
Cholecystokinin (CCK) from small intestine
335
Function of Cholecystokinin (CCK)
Gallbladder contraction
slows gastric empyting
stimulates secretion of pancreatic enzymes
stimulates growth of exocrine pancreas and the gallbladder
****thought to provide SATIETY (fullness)
336
thought to provide SATIETY
Cholecystokinin (CCK)
337
secreted by K cells of the small intestine
Glucose-dependent Insulinotropic Peptide (AKA Gastric Inhibitory Pepetide) GDIP AKA GIP
338
stimulated by presence of these in luminal:
```
Glucose (carbs)
Fatty Acids (Fats)
Amino Acids (Proteins)
```
Glucose-dependent Insulinotropic Peptide (AKA Gastric Inhibitory Pepetide) GDIP AKA GIP
339
Function of: Glucose-dependent Insulinotropic Peptide (AKA Gastric Inhibitory Pepetide) GDIP AKA GIP
Stimulates release of insulin
Inhibits H+ ion secretion by gastric mucosa
340
secreted by S cells of the small intestine
Secretin
341
stimulated by ph < 4.5 in luminal contents
secretin
342
Function of secretin
pancreatic bicarb
biliary bicarb (gall baldder)
inhibit effects of gastrin
343
secretin inhibits
gastrin
344
found in all cells of body EXCEPT RBC's
eicosanoids (act locally i.e. paracrine or autocrine)
345
two major types of eicosanoids
Prostaglandins (PG's)
| Luekotrienes (LT's)
346
stimulates chemotaxis of WBC's and mediates inflammation
Leukotrienes (LT's)
347
in any tissue that has mast cells and in platelets
histamine
348
physical trauma to cells containing it and
| immune response to allergens causes their release
histamine
349
major problem caused function of histamine?
contraction of smooth muscle in lungs creating problems breathing as well as dilation of blood vessels in general that lower BP
(also stimulates gastric acid secretion)
350
synthesized by cells in the INTESTINES, brain, CNS
serotonin
351
estimated that 90% of this is made in the intestines
serotonin
352
"good" stress
eustress
353
eustress
good stress
354
harmful stress
distress
355
the bodies attempt to counteract all stress
General Adaptation Syndrome (GAS)
356
what controls the bodies attempt to stress
hypothalamus
357
What are the three stages of the stress response?
Alarm Stage
Resistance Reaction
Exhaustion Response
358
What happens in the alarm stage of GAS stress response
release of glucocorticoids (cortisol)
- decreases lymphocytes and eosinophils (impair of immune response)
- increase of SNS
359
What happens in the Resistance Reaction stage of GAS stress response?
normally occurs and is the "recovery" phase
- Glucocorticoids decline
- Immune system repenishes
- decrease of SNS
- Parasympathetic stimulated PNS
360
What happens in the Exhaustion Response stage?
the stressor was not removed or resistance reaction phase was not sufficient, so body goes to the exhaustion response phase
body cannot "cope" with stress
prolonged cortisol
prolonged SNS
mental and physical illnesses
Fatigue, depression, anxiety
stomach ulcers, bowel changes
361
Aging endocrine
hGH production decreases (atrophy)
T3/T4 production reduced due to...
worn out thyroid
causes reduction in metabolism (more fat)
hypothyroidism
ALTHOUGH TRH/TSH increases as we age (no negative feedback loop)
362
worn out atrophied thyroid decreases metabolism
ALTHOUGH TRH/TSH increases as we age (no negative feedback loop)
363
increased PTH levels as we age
calcitrol and calcitonin levels reduced also leading to bone injury
364
adrenal cortex becomes fibrous as we age leading to....
decreased cortisol and aldosterone release
| **Although.... MEDULLA is unaffected
365
aging and the pancreas causes
insulin released more slowly (if at all) and glucose sensitivity decreases (due to oversuse)
so it causes....
HYPERGLYCEMIA
366
Ovaries and Testes decrease in size, but differ in what they do as we age
Ovaries STOP RESPONDING to gonadotrophins leading to decrease ESTROGEN leading to osteoporosis, hyperlipidemia, atherosclerosis
Testes decrease size but still produce testosterone in viable levels
-usually same # of sperm just lack quality
367
All the cells or hormones that provide satiety or fullness?
CKK & Leptin
