Lecture & Vodcast 1 -- Exam 5 Flashcards
The ______________ is responsible for processing the body’s sensory input like light and temperature
hypothalamus
The ______________ in the brain recognizes stress
hypothalamus
The pituitary sits on the ___________ bone
sphenoid
What tissue type is the anterior pituitary made of?
oral epithelium
What tissue type is the posterior pituitary made of?
neural tissue
What connects the hypothalamus to the pituitary gland?
hypothalamus stalk
What is the first symptoms of a pituitary tumor vision issues?
optical chiasm is being compressed by tumor
___________ signaling is when signal molecule travels to act far from where it was made
endocrine
_____________ signaling is when signal molecules acts on neighboring cells
paracrine
_____________ signaling is when signal molecules act on the cell that secreted it
autocrine
_______________ signaling is when signal molecules produced in CNS act somewhere else in to body
neuro-endocrine
What are 2 examples of peptide/protein hormones?
growth hormone (GH)
Adrenocorticotropic hormone (ACTH)
_______________ hormones are synthesized as pre-hormones, stored in secretory vesicles, and are released when intracellular Ca2+ rises
Peptide/protein
____________ hormones are derived from tyrosine
Amine
What are 2 examples of amine hormones?
epi/norepinepherine (EPI/NOREPI)
thyroid hormone (TH)
___________ hormones are derived from cholesterol
steroid
What are 2 examples of steroid hormones?
cortisol
testosterone
____________ hormones are synthesized in cytoplasm and mitochondria and not stored long term
steroid
_________ hormones are not synthesized as pre-hormones and are not stored long term
amine
Increased concentration of ______ causes release of peptide/protein hormones
Ca2+
What are the 3 types of G-coupled protein receptors peptide/protein hormones use?
Gs
Gq
Gi
What hormone type can freely pass through cell membranes via passive diffusion?
steroid hormones
What hormone is transported in blood bound to proteins because they have a short half life?
steroid hormones
What hormone interacts with intracellular receptors and doesn’t have cell membrane receptors?
steroid hormones
What hormone acts as a gene inducer or supressor?
steroid hormones
What are the 2 negative feedback mechanisms used to regulate hormone secretion?
- physiological regualted
- hypothalamic regulated
How can hormone secretion be physiologically regulated?
The physiological effect of the hormone (glucagon raising BG) causes release of a compound which enters blood and can tell endocrine glands to turn off secretion
Hypothalamic regulation of hormone secretion has a _______ loop and _______ loop
long loop
short loop
How can hormone secretion be hypothalamiclly regulated?
hormone can act on the target organ but also loop back and effect glands/organs back upstream to cut them off
____________ ___________ from the hypothalamus tells the pituitary gland to release hormones
release hormones (RH)
What is the role of hypothalamohypophyseal portal vessels?
blood vessels that deliver release hormones to ANTERIOR pituitary
What is the role of the median eminence?
location where releasing hormones enter the blood stream (hypothalmic stalk)
What are the 5 hormones the anterior pituitary releases?
prolactin (PRL)
thyroid stimulating hormone (TSH)
LH & FSH
ACTH
growth hormone (GH)
Why are hypothalamic releasing hormones secreted in pulses?
to make sure a new membrane receptor is always present
What is the second messenger pathway of Gs receptors?
- activate adenylyl cyclase
- cAMP
- PKA
- rise in intracellular calcium
- release hormone
What is the second messenger pathway of Gq receptors?
- PLC
- IP3
- rise in intracellular calcium and PKC
- release hormone
What is the second messenger pathway of Gi receptors?
PLA blocks stimulatory pathway to prevent release of hormone from cell
What kind of receptor does insulin have?
intracellular tyrosine kinase domains
What kind of receptor does growth hormone have?
intracellular tyrosine kinase domains with JAKs
The hypothalamic hormone, CRH, stimulates pituitary hormone ______
ACTH
The hypothalamic hormone, TRH, stimulates pituitary hormone ______
TSH
The hypothalamic hormone, dopamine, inhibits pituitary hormone ______
PRL
The hypothalamic hormone, GnRH, stimulates pituitary hormone ______
FSH/LH
The hypothalamic hormone, GHRH, stimulates pituitary hormone ______
GH
The hypothalamic hormone, GHIH (somatostatin), inhibits pituitary hormone ______
GH
A __________ endocrine disease affects what adrenal gland, thyroid and gonads
primary
A ___________ endocrine disease affects the pituitary gland
secondary
A ____________ endocrine disease affects the hypothalamus
tertiary
How is stimulation by the hypothalamus of the posterior pituitary different than the anterior
posterior is neural tissue so the hypothalamus axons stretch all the way into the pituitary
What 2 hormones are secreted by the posterior pituitary?
ADH and oxytocin
Hypertrophy is the enlargement of _______
cells
Hyperplasia is the increased replication of _______
cells
What are the 4 jobs of growth hormones?
- promote linear growth
- reduce adipose tissue (fat loss)
- enhance lean body mass (increase muscle)
- stimulation of immune system
What 2 common hormones are NOT important in fetal development and only appear after you are born?
GH and T3
What type of hormone is GH?
protein/peptide hormone
__________ store mature GH in the pituitary until GHRH stimulates the cell to release the GH
somatotroph
Hypothalamic releasing hormones trigger __________ _________ systems in target cells which includes Ca2+, cAMP, and PKC
second messenger
What are the 2 stimuli for GH secretion?
exercise and sleep
- mainly sleep
Why does GH increase during exercise and sleep?
GH increases blood glucose so its release during these “fasting conditions”
Why can GH interact with PRL and hCS receptors?
they all share similar structure
Does GH increase or decrease blood glucose?
increase
In the muscle, what is GH’s affect on amino acid uptake?
increases amino acid uptake (for protein synthesis)
- building muscle
In the muscle, what is GH’s affect on protein synthesis?
increased protein synthesis
In the muscle, what is GH’s affect on glucose uptake?
decrease
In the muscle, what is GH’s affect on muscle mass?
increase
In the liver, what is GH’s affect on protein synthesis?
increase
In the liver, what is GH’s affect on gluconeogenesis?
increase (release more glucose into blood)
In the liver, what is GH’s affect on somatmedin production?
increase (for production of somatmedins IGF1&2)
What are the 2 somatmedins?
IGF-1
IGF-2
In adipose tissue, what is GH’s affect on glucose uptake?
decreases uptake
In adipose tissue, is GH lipogenic or lipolytic?
lipolytic (breaks down fat)
Why is GH considered diabetogenic?
decreases glucose uptake
** opposes insulin
What is the somatomedin hypothesis?
GH cannot act alone, it must induce the secretion of IGF-1 & 2
What is the affect of somatomedins (IGFs) on linear and tissue growth?
increase
Somatomedins function is known as __________ because it stimulates the building of bone and tissue
anabolic
GH directly differentiates precursor cells but GH indirectly induce cell expansion because GH requires __________ to do this
somatomedins (IGFs)
The duel collaboration of IGF and GH results in increased __________ and increased __________
growth
hypertrophy (enlargement of cells)
What hormone can increase and inhibit GH secretion and why?
gonadal steroids (mainly estrogen)
at first accelerates linear growth then closes the epiphyseal plates (stops growth)
Why does the somatomedins (IGF-1) peak during puberty?
increased growth
increased secretion of GH and IGF-1 which causes increased linear growth
What hormone secreted by the hypothalamus regulates GH so no GH is secreted from pituitary vesicles?
somatostain
What kind of receptor does somatostatin use on GH vesicles in the pituitary?
Gi (inhibit the release of intracellular Ca2+)
What are the two ways negative feedback can inhibit GH secretion?
- GH autocrinley inhibit itself
- IGF can inhibit release of GHRH in hypothalamus by stimulating the production of somatostain
Does stress inhibit or promote GH secretion?
promote
need BG for sympathetic response
What is high glucose and free FAs affect on GH release?
inhibits GH release
How does somatostatin’s Gi receptor inhibit GH secretion?
Gi opens K+ channels which hyperpolarizes the cell which keeps the Ca2+ channels closed so hormone vesicles are not exocytosed
How does GHRH’s Gs receptor cause release of GH from pituitary?
- adenyly cyclase
- cAMP
- open Na+ channels to depolarizes cell
- Ca2+ channels open
- rise in intracellular Ca2+
Decreased GH secretion from pituitary results in the lack of what hormone?
IGF
- smaller statue
Giantism is when excess GH is present __before/after__ closure of epiphyses
before
- occurs before adulthood
Acromegaly is when excess GH is present __before/after__ closure of epiphyses
after
- protruding features
Why does Acromegaly (excess GH) cause infertility?
PRL and GH share a receptor
2 ways to test for acromegaly is serum _____ levels and ________ tolerance tests
IGF
glucose
