Now, lets move a little bit to some
of the higher brain structures.
The brain stem and the hypothalamus.
Cause this are integratedly involved in
the autonomic nervous system response.
The brain stem in fact is the major controller for
many of the different homeostatic mechanisms
that we’ve discussed.
The respiratory centers are
located in the brain stem.
And so this is the spot that we are going to
send and receiving information based upon
what the chemoreceptors tell us
about PO2, PCO2 and hydrogen ions.
This are just the rate of breathing, the depth of
breathing and controls the respiratory muscles.
The cardiovascular system is also in the brainstem.
Here is where you have the information from both the
sympathetic and parasympathetic nervous systems.
Will control things like the rate of the heart
and vascular resistance via the blood vessels.
Then you have a number of smaller reflex centers.
One, can be controlling the bladder. And you have
the other ones that control things like vomiting.
Other ones that control swallowing. There are number
of brain stem reflexes that are controlled
at this particular level.
The hypothalamus is the other component of the brain
that involves a lot of the regulatory features.
So let’s go through some of the most important nuclei now.
And throughout the course, we will be revisiting
this important nuclei as they come up
in relation to the organ system involved.
Well, the paraventricular nucleus is very important, in that,
it releases a couple of posterior pituitary hormones.
Oxytocin and anti-diuretic hormone
also known as arginine vasopressin.
These are important for the things like water balance.
The anterior and preoptic areas of the hypothalamus,
this is involve for thermoregulation,
controlling things like sweating and shivering.
Some of our blood vessel control for
dilating or constricting the skin.
Receives some of the information
from our healing cold receptors.
The supraoptic nucleus, this is also important for releasing
oxytocin, antidiuretic hormone and arginine vasopressin.
The suprachiasmatic nuclei, this is really
important for controlling our circadian rhythms.
We have varying isolations in some of our hormone release
base upon of its day or night.
And this is an important spot in which this occurs.
It is gonna get some feedback from the eyes. And so,
it has some photoreceptor input to this specific area.
So they did know some of that
information about what time and date is.
And if there are some resetting in
that inherit clock in the hypothalamus.
If we look more now at the lateral hypothalamus,
here is where we are going to look at areas that are
involves in thirst and hunger.
And so, this will control our ability to wanting
taking more fluid if we are dehydrated.
Also allows us to taking food when
we are hungry for our GI Tract.
The posterior hypothalamus, this is more involved
in relaying signals as well as the mammillary body
that helps with some of those visual memories along with
the amygdala and couple other structures in that close area.
So these are not necessarily the memories that you
are think of fond childhood memories.
these are more are visceral responses.
We also have other pos spots in the hypothalamus
that controls specific behaviors.
And this will be related to both
emotions as well as circadian rhythms.
And then finally, the things about when we’re full or
some endocrine control of our various hormones
in our hypothalamic pituitary access.