PHYS: Hypothalamus Flashcards
(26 cards)
What controls the set point and core temperature of the body?
Hypothalamus
It recieves infor about the current temperature and decides what to do
What is normal body temp:
98.6 (or 36.7 degrees in the morning)
What are 3 types of thermoreceptors?
- Cutaneous (skin)
- Visceral
- Hypothalamic
Which body temperature (hands, feet, oral, core) does not change over a variety of temperatures?
CORE Temperature! stays the same
Cutaneous thermoreceptors are sensitive to?
The cold –> they have 10x as many cold receptors, cause the biggest threat to our skin is cold temperatures
Thermoreceptors in our gut sense?
food that is ingested that may change our body temperature (ex. ice cream)
Where are thermoreceptors located in the hypothalamus?
Pre-Optic + Superoptic region of hypothalamus!
Neuron thermoreceptors in the hypothalamus are sensitive to?
Heat! have 10x more warm receptors
Becuase in your brain, heat is your biggest threat
Which thermoreceptors are classified as detecting “core” temperature?
Brain (Hypothalamus) + Viscera
How does the hypothalamus have the ability to control the body set point?
Cause it can activate hormones, autonomic sympathetics, behavioral changes (shivers)
What happens to our core temperature when we sleep + exercise?
When we sleep our temperature decreases (decreases in set point) and when we exercise our core temperature increases.
The anterior hypothalamus responses to ______.
heat
The posterior hypothalamus responds to ________.
cold
(for example. if it is cold outside the posterior hypothalamus becomes active to make me wanna warm up)
Babies have ________ which leads to them losing heat very fast. Therefore, they need a lot of adipose tissue to insulate their tiny baby bodies :)
High surface area
What area is responsible for shivering, in order to increase heat production?
Dorsomedial posterior hypothalamus
How does brown adipose tissue lead to heat production?
Uncoupiling proteins
How do we lose heat?
- Evaporation –> insensible (respiratory) + sweating (controlled)
- Convection –> Mvmt of molecules away from contact (heat rises)
- Conduction–> transfer of heat w/ 2 things touching eachother
- Radiation –> losing heat to the walls (w/out touching them)
What determines how much heat we lose?
How much blood is sent to the skin determines how much heat moves from blood to external environment.
*more blood sent to skin = more heat given off = appear flushed (like me :))
What is the innervation of a sweat gland?
Sympathetic cholinergic
*Instead of the usual NE, Ach is used as the neurotransmitter to bind to a muscarinic receptor
In the process of sweating, as the blood flows next to the sweat gland, what is reabsorbed?
Na+, Cl-, and water
How do we increase heat production?
Shivering + Non-shivering thermogenesis
What is the definition of a fever?
A controlled increase in body temperature.
(the set point of the body increases)
When we get an infection (endotoxins), our immune cells release what that helps raise our hypothalmic set point for temperature to kill them off?
Prostaglandin E2
In a fever, why do we suddenly feel so cold?
Because our body temperature is now lower than our temperature set point.
