Class Notes (836,517)
Canada (509,851)
Psychology (7,783)
PSYB64H3 (93)
Lecture 6


4 Pages
Unlock Document

Janelle Leboutillier

PSYB64 Lecture 6 TEMPERATURE REGULATION, HUNGER AND THIRST HOMEOSTASIS -homeostasis is the physiological equilibrium of the body -set point for the body is 37 degrees Multiple Thermostats in the Body -hypothalamus holds the most sensitive one -brainstem holds next sensitive; has a bigger range for set temperature -spinal cord is least sensitive; large range of temperatures before putting in place the mechanisms to cause change -endotherms: produce our own body heat -ecotherms: “cold- blooded”; lizards, etc Surface to Volume Ratios Affect Temperature Regulation -smaller animals have a larger surface body- ratio; more difficult for them to maintain the core temperature, requires more effort How We Regulate: HOMEOSTASIS Deviations in Human Core Temperature -fever -heat stroke; elderly or younger children; the core temperature increases due to a failure to compensate -hypothermia; can be beneficial to people who are having cardiac arrest; decreases swelling in the brain & helps the heart slow & not need as much oxygen -blood vessels constrict & lose heat; people with Raynon’s disease have it to the extreme; white waxy like appearance of skin; fingers and toes go into spasms because of the lack of blood flow Brain Mechanisms Responsible for Temperature Regulation -pre- optic area and posterior hypothalamus -infancy regulation: rat babies continue moving their position to regulate heat (ie. centre of the litter, t the outside of the litter, then back in, etc) THIRST -thirst, in comparison to temperature, there are two types of fluid we need to think about -intra and extra cellular fluid -67% fluid is intracellular; 33% extracellular -interstitial fluid is the fluid between the cells Osmosis -causes water to move to keep water properly proportioned Sources of Intake and Loss of Fluids -foods can have fluids -intaking about 2.5 L of water each day -lose about 2.5 L each day; a balance Thirst: Regulation of the Body’s Fluid -osmotic thirst: an osmotic drop in the intracellular fluid -or hypovolemic thirst: result of a drop of blood volume -example: eating a bag of salty chips; osmotic thirst, too much salt, need more water to regulate -example: losing blood; car accident, being sick (vomiting); hypovolemic thirst Mechanisms of Osmotic Thirst -found in the OVLT Mechanisms of Hypovolemic Thirst -baroreceptors in the heart and the kidneys measuring blood pressure -kidneys will reserve any remaining fluids Regulation of Thirst -ADH; anti- diuretic hormone is released for both kinds of thirst -renin affects angiotensin; angiotensin II more important; angiotension II constricts blood vessels & sends a message to aldosterone that tells the kidneys to retain sodium Thirst & Sports Drinks -so, sodium helps to retain fluids -hyonatremia: sodium concentration is lower than normal -diabetes insipidus: abnormal functioning of ADH; water retention is not normal -high blood pressure: most people who take high blood pressure medication are
More Less

Related notes for PSYB64H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.