Endocrine System Pt. 2 Flashcards
Where is the hypothalamus found
In the Diencephalon
Btwn the ventral brain, caudal to the optic chiasm
What are some of the many nervous system functions the hypothalamus controls?
Appetite control
temp regulation
control of sleep cycles
what does the hypothalamus link together
links the conscious mind with the rest of the body
How is the hypothalamus linked to the endocrine cycle?
Due to its control of the activities of the pituitary gland
The hypothalamus is the missing link btwn what?
nervous and endocrine systems
The pituitary gland is know as what
Master endocrine gland
the pituitary is know as the master gland because
it makes a bunch of hormones
Where is the pituitary gland housed
in the pituitary fos of the sphenoid bone
The pituitary gland is actually two separate glands with completely diff functions. What are the two separate glands called
Anterior pituitary (hypophysis)
Posterior pituitary (neurohypophysis)
Is the anterior pituitary more rostral or more caudal
more rostral
What does the anterior pituitary look like under the microscope
looks more glandular
Is the posterior pituitary more rostral or more caudal
more caudal
what does the the posterior pituitary look like under the microscope
looks like nervous tissue
how many hormones does the anterior pituitary make?
7 different hormones
How many hormones does the posterior pituitary make
doesn’t make any hormones
stores and releases two hormones made in the hypothalamus
Where is the pituitary gland located
in the diencephalon
ventral to the hypothalamus
what is the pituitary gland on and why?
on a stalk
nerves and vessels in the stalk allow the hypothalamus to control the pituitary
what does the portal system link
links the hypothalamus with the anterior pituitary
Modified Hypothalamus neurons secret what where?
hormones into portal blood vessles
The hormones in the portal blood vessels act on what and do what?
act on the anterior pituitary and regulates function
What are the two thing hormones released by the hypothalamus are known as?
Releasing factor or inhibiting factor
The hypothalamus has a more ___________ route to the posterior pituitary
direct
Modified neurons make tow horomones to store in the posterior pituitary
Antidiuretic hormone (ADH)
Oxytocin
Antidiuretic hormone (ADH) prevents what
diuresis
How does ADH prevent diuresis
makes the body conserve water by acting on the kidneys
concentrates the urine
When is ADH released
Hypothalamus detects dehydration
When the osmotic pressure of the blood increases (Hemoconcentration)
Deficiency of ADH causes what specific disease
Diabetes insipidus
What does Diabetes insipidus cause
make large amounts of very dilute urine (polyuria) and makes them drink large amounts of water (polydipsis)
How would you treat Diabetes insipidus
administer ADH
What are the two targets of oxytocin
Uterus and mammary glands
What does oxytocin act on in the uterus
myimetrium
what does oxytocin do in the uterus
causes uterine contractions during breeding and parturition
why would we need uterine contracts during breeding
moves sperm up the ducts
What kind of contractions do we have during breeding
fine contractions
Why would we need uterine contractions during parturition
aids in fetal movement and placenta delivery
what kind of contractions do we have during parturition
strong contractions
What does oxytocin do the mammary glands
cause milk let-down
where does the milk move to and accumulate?
down to the lower parts of the gland and accumulates in the alveoli and small ducts
When nursing occurs (nipple is stimulated) this causes what
cause oxytocin release in the bloodstream
When oxytocin is released into the blood (from nursing) what does that cause
causes myoepithelial cells to contract (cells around the alveoli and small ducts)
what kind of hormone is Growth Hormone (GH)
Somatotropin and somatotropic hormone
What does GH do?
promotes body growth in young animals and helps regulate metabolism
What does GH affect to help young animals grow
mainly muscle and bones
What three things does GH affect to help regulate metabolism
proteins, carbs, and lipids
How does proteins affected by GH help regulate metabolism
promotes anabolism
what is anabolism and what does it provide
synthesis of proteins by cells
provides materials needed for growth and repair
When carbs and lipids are linked, it causes
causes mobilization of lipids from storage and their breakdown aka catabolism
at the same time it inhibits carb breakdown and utilization
What happens to circulating glucose levels (GH)?
Increase (hyperglycemic effect)
this is why insulin and GH have to work together
What does prolactin do?
trigger and maintains lactation
How long does the effect of prolactin continue?
can continue as long as the teat is stimulated (suckle effect)
Once weaning happens, what happens to prolactin
Prolactin production ceases and therefore lactation ceases causing the mammary gland to shrink
what does prolactin do in males?
Jack diddly
What does the Thyroid Stimulating Hormone or Thyrotropic hormone do?
Stimulates the growth and development of the thyroid gland
causes production of thyroid hormone
How is the thyroid stimulating hormone regulated
negative feedback from the target organ - thyroid gland
What does the Adrenocorticotropic hormone (ACTH) do?
stimulates growth and development
how does the ACTH stimulate growth and development
acts on the cortex of the adrenal gland and causes it to release of some of its hormones
How is ACTH regulated
feedback from hormones of adrenal cortex and it can be regulated by the sympathetic system as well
When ACTH is regulated by the sympathetic system, what happens?
Hypothalamus sends a burst of ACTH releasing factor down to the Anterior pituitary and causes ACTH to be released quickly
What does Follicle Stimulating hormone stimulate?
yet another hormone that works in the female
stimulates growth and development of follicles in the ovaries
What does the follicle act as
as an incubator for a single oocyte
this process is known as oogenesis
besides stimulating the growth and development of follicles, what else do the FSH stimulate?
Stimulates the lining cells of follicles to makes estrogens - the female sex hormones
what is estrogen responsible for
for physical/behavioral activity for breeding and pregnancy
What does FSH do in the male
has a similar effect to that of females
stimulates spermatogenesis in the seminiferous tubules of the testes
What does the Luteinizing Hormone (LH) do?
Name once again derived from the effect on female
Completes the process of follicular development
How does LH complete the process of follicular development
as the oocyte keeps growing, it pumps out more estrogens and feeds back to the hypothalamus and the anterior pituitary which causes FSH production to drop and LH production to ramp up
what happens when the oocyte reaches full maturity
LH peaks and ovulation occurs
What does the high levels of LH after ovulation stimulate?
Stimulates cells to develop a corpus luteum in the space left by the ovulated oocyte - CL pumps out progestin hormones (mainly progesterone) aka the pregnancy hormone - keeps female pregnant
What does LH do in males
stimulates cells in the testes called interstitial cells which make testosterone - the male sex hormone
LH can also be known as interstitial cell-stimulating hormone
FSH and LH are known as ____________
gonadtropins
What do gonadotropins stimulate?
Stimulates growth and development of the gonads - ovaries and testes
What is the Melanocyte Stimulating Hormone (MSH) be from?
might actually be a remnant of something used by the body a long time ago
we don’t really know if that is the case for MSH or if it still used today
What does MSH control
mainly controls color changes in pigment cells - melanocytes
Mainly in reptiles, fish, and amphibians - Animals that can rapidly change colors or color patterns
What happens when we administer large amounts of MSH to mammals
it stimulates melanocytes and makes skin darken
