Module 10 PY 413

arcuate nucleus of hypothalamus

"master area" for control of appetite

Sham feeding experiments

-Everything an animal eats leaks out of a tube connected to the stomach or esophagus -Do not produce satiety

Cholecystokinin (CCK) limits meal size in two ways:

1) constricts the sphincter muscle between the stomach and the duodenum, which facilitates stomach distention 2) stimulates the vagus nerve causing cells there to release a neurotransmitter that is a shorter version of the CCK

water is absorbed by the digestive tract and pumped through the blood. This takes about ____ minutes

15

1) intruders invade the body 2) leukocytes (white blood cells) attack them 3) leukocytes release small proteins called __________ that attack intruders 4) __________ also stimulate the vagus nerve, which sends signals to the __________ 5) chemicals called prostaglandins increase *necessary for fever*

3) cytokines 4) cytokines hypothalamus

Physiological changes such as shivering, sweating, and changes to blood flow to the skin depend on areas in and near the:

Hypothalamus

The areas important for detecting osmotic pressure and the salt content of the blood include:

OVLT and subfornical organ (SFO)

in addition to its role in wakefulness, _______ has two roles in feeding 1): 2):

Orexin 1) increases animals' persistence in seeking food 2) responds to incentives or reinforcement in general

What is the primary area for controlling physiological mechanisms of temperature regulation?

POA/AH

Homeothermic

Physiological mechanisms maintain a nearly constant body temperature Mammals and birds

Homeostasis

Temperature regulation and other biological processes that keep body variables within a fixed range

cholecystokinin

a hormone that is secreted by cells in the duodenum in the presence of food

set point

a single value that the body works to maintain

sodium-specific hunger

a strong craving for salty foods -develops automatically to restore solute levels in the blood

Vasopressin is also known as

antidiuretic hormone (ADH)

After damage to the POA/AH, mammals can still regulate body temperature but only by __________ mechanisms.

behavioral

Poikilothermic

body temperature matches the temperature of their environment Amphibians, reptiles, and fish

OVLT receives input from receptors in the ________ as well as receptors in the _________ ________

brain digestive tract

osmotic thirst

caused by neurons detecting their own loss of water triggered to help restore the normal state kidneys excrete more concentrated urine to rid the body of excess sodium

angiotensin II is like vasopressin in that it:

constricts blood vessels

splanchnic nerves

convey information about the nutrient contents of the stomach

vagus nerve

conveys information about the stretching of the stomach walls to the brain, providing a major basis for satiety

high levels of insulin _______ appetite

decrease

Loss of NPY leads to _______ eating

decreased

the lateral preoptic area and the surrounding parts of the hypothalamus control ___________

drinking

______ is the first digestive site that absorbs a significant amount of nutrients

duodenum

CCK helps to ____ a meal

end

basal metabolism

energy used to maintain a constant body temperature while at rest

lactase

enzyme that breaks down lactose

_______ is the only known hunger hormone

ghrelin

aldosterone

hormone produced by adrenal glands when body's sodium reserves are low causes the kidney, salivary glands, and sweat glands to retain salt

Vasopressin

hormone that raises blood pressure by constricting blood vessels released by the posterior pituitarty

arcuate nucleus of the hypothalamus has on set of neurons sensitive to ______ signals and a second set sensitive to ______ signals

hunger satiaty

bleeding or sweating induces ___________ thirst

hypovolemic

melanocortin

important for limiting food intake, and deficiencies of this receptor lead to overeating

ventromedial hypothalamus (VMH)

inhibits feeding and therefore damage to this nucleus leads to overeating and weight gain

prolonged high or prolonged low ________ levels increase eating, but for different reasons

insulin

lateral hypothalamus controls:

insulin secretion, alters taste responsiveness, and facilitates feeding in other ways

The POA/AH monitors body temperature partly by monitoring ____.

its own temperature

_______ triggers the onset of puberty

leptin

overweight people already produce plenty of leptin the problem is that they become:

less sensitive to it

Glucagon stimulates the ________ to convert some of its stored glycogen to glucose

liver

aldosterone indicates ______ sodium and angiotensin II indicates low ________ _________

low blood volume

Insulin, diet drugs, and other procedures affect eating largely by altering input to the ____________ receptors

melanocortin

Who would drink more pure water - someone with osmotic thirst or someone with hypovolemic thirst?

osmotic

eating salty foods causes _________ thirst

osmotic

animals with ______ thirst need water, animals with ______ thirst can't drink much pure water because it would dilute its body fluids

osmotic hypovolemic

duodenum

part of the small intestine adjoining the stomach

negative feedback

processes that reduce discrepancies from the set point

ghrelin

released by the stomach during a period of food deprivation

in hypovolemic thirst, you must restore _______ as well as water

salt

preoptic area/anterior hypothalamus (POA/AH)

send output to the hindbrain's raphe nucleus, which controls physiological mechanisms

CCK produces _____-term effects

short

leptin

signals your brain about your fat reserves provides long-term indicator of whether you have been overeating or undereating

You also increase secretion of vasopressin while you are ____________.

sleeping

Cytokines

small proteins released by leukocytes to help attack intruders

ghrelin triggers ______ ______

stomach contractions

usually, the main signal to end a meal is:

stomach distention

vagus is to ______ as splanchnic is to ______

stretching nutrients

the ________ nucleus and the ________ nucleus (PVN) control the rate at which the posterior pituitary releases vasopressin

supraoptic paraventricular

what two messages limit drinking to not much more than you need

swallowing distention of the stomach

POA/AH also receive input from _________ _________ in the skin and spinal cord.

temperature receptors

osmotic pressure

tendency of water to flow across a semipermeable membrane from the area of low solute concentration to the area of higher concentration

Allostasis

the adaptive way in which the body changes its set points depending on the situation

fever is not a part of the illness; it is a part of:

the body's defense against the illness

Insulin and glucagon are pancreatic hormones that regulate:

the flow of glucose

GABA, neuropeptide Y (NPY) and agouti-related peptie (AgRP)

transmitters that block the satiety actions of the paraventricular nucleus

When you lose a significant amount of body fluid from bleeding, sweating, or diarrhea, which two hormones constrict blood vessels?

vasopressin angiotensin II