Thirst and Hunger

The human body is composed of ___ water

60%

Why is water important?

It regulates a variety of bodily functions, like digestion and circulation and helping us maintain an appropriate bodily functions

What does water form and for what?

Saliva to being the process of digesting our food

With regard to our circulatory system, how does water help?

It helps to deliver oxygen throughout the body which helps the heart to pump the blood more good throughout your body

What can drinking hot water do?

Increase blood circulation through your body

What can a cold shower do?

Cause your blood vessels on the surface of your body to constrict which warms the core of your body

Water is essential to …?

Brain functioning

Why do you need water in the brain?

To manufacture hormones and neurotransmitters

Why is water important to taste?

Because it helps form saliva which keeps the taste buds moistened and allows chemical molecules involved in taste to bind to the tongue

Why is water important to smell?

It keeps the mucosal membranes moist so odorants can bind to the olfactory receptors which allows the receptors in your nose to sense them

How do we maintain how much water must be in our cells?

We must balance our intake of water with water loss throughout the day

How do we lose water in our body?

Through sweating, normal digestive processes. and when you breathe

What are the two types of thirst that we experience?

Hypovolemic and osmotic thirst

What type of thirst is common or rare?

Hypovolemic is rare and osmotic thirst is extremely common

When does hypovolemic occur?

If there is a drop in blood pressure

What happens when there is a drop of blood pressure?

Your blood cannot transport oxygen and nutrients to your cells throughout your body

Hypovolemic thirst is most likely to occur..?

A hemorrhage, vomiting, or excessive sweating and diarrhea

How does your body know that you need in order to satisfy hypovolemic?

Due to sensors located in the largest blood vessels of your body called baroreceptors

What do baroreceptors detect?

Changes in pressure in these large blood vessels. I there is a drop they cause your blood vessels to constrict 

What do baroreceptors send a message to?

Your brain to drink water  to replace lost fluid in order to raise your blood pressure as well

Several hormones are released in response to hypovolemic, like..?

The pituitary gland releases vasopressin, which causes your kidneys to slow down urine production and your cells to reabsorb the water already in you

Apart from the pituitary gland, what other hormones are released in hypovolemic?

Your heart decreases the release of ANP-atrial natriuretic peptide

What does ANP-atrial natriuretic peptide promote?

The excretion of water and salt by the kidneys

When your kidneys produce angiotensin II, what does it do?

Increases blood pressure but at the same time makes you thirsty so that you are more likely to drink

What is osmotic thrist?

It relates to maintaining the balance between the water and solutes in your body fluids

When is osmotic thirst triggered?

When you lose more water than salt so the fluid content within your cells decrease 

What is the sensor for osmotic thirst?

The OVLT-organum vasculosum laminae terminals

What is the role of OVLT resides?

To detect the concentration of solutes in the body

What does the OVLT sense?

If there is a depletion of water in your body

When we experience osmotic thirst, not only is vasopressin released but the …?

hypothalamus also sends a message using the sympathetic nervous system to stop the digestive processes so that salvation stops 

What is a hormone related to an osmotic thirst?

Histamine 

How many phases is the feeding cycle divided into?

2 phases

What is the first phase of the feeding cycle?

The absorptive phase

What is the absorptive phase?

It occurs for a few hours after you eat, your body uses the nutrients you just ate to run on rather than burning stored energy

What is the fasting pahse?

It is when we do not feel hungry and we do not eat

What happens during the fasting phase?

The glucose level in our blood falls and our body must use its energy stored to function

What is most of the food we ingest used for?

Breathing and maintaining appropriate body heat

Based on what you know about sensory specific satiety, one of the best ways to lose weight is to..?

Limit your food choices at any given meal

What is the main energy source that your body uses?

Glucose

If you eat ____, it takes energy for your body to break these down to form glucose

Protein or complex starches

What is one important hormone the pancreas produces?

Insulin

What does insulin play an important role in?

In transporting glucose from your blood into your cells to be used for energy

Without insulin, your cells can’t what?

Takin in sufficient nutrients to survive

What does insulin balance?

Balances the amount of glucose that is in your system

When you take too much glucose, what does insulin do?

Convert the excess glucose into glycogen which is stored in your liver and muscles for use in the short term

During the fasting phase, what does your body do when it needs to access the glucose that is stored as glycogen?

It produces glucagon which converts the glycogen back to glucose for immediate use

What is the most common type of hunger?

Glucoprivic hunger

What is glucoprivic hunger?

It occurs when we have a low supply of glucose cycling through our body

Besides glucoprivic hunger, what is another type of hunger?

Lipoprivic hunger

When we are experiencing lipoprivic hunger, what do we crave?

Foods that are high in fatty acids like ice cream or junk food

Besides lipoprivic and glucoprivic hunger, what is another type of hunger?

Amnioprivic hunger

What might amnioprivic hunger lead you to do?

Wander around the kitchen to see what you want

What are you missing in amnioprivic hunger?

An essential amino acid

What type of hunger do pregnant women experience the most?

Amnioprivic hunger, their body searches for a nutrient they they need to satisfy the fetus (craving)

What does the arcuate nucleus of the hypothalamus monitor?

Your nutrient levels and will trigger you to feel hungry if there is a deficiency in these levels 

What is ghrelin?

It is released in response to low levels of either glycogen or glucose in the body and induces hunger

Where is ghrelin produces?

In the stomach, other parts of the digestive tract, and in the hypothalamus of the brain

Besides ghrelin, what also induces hunger?

Neurotransmitters 

When your stomach sends a signal to your hypothalamus to tell you to eat, what else does it send?

Two different signals to your brain to tell you to stop eating

What hormone decreases hunger?

Leptin

After you eat, what happens with leptin levels?

They increase and they inhibit the firing of neuropeptide Y so you feel full 

What percentage of americans are obese?

40%

What could be a reasons for obesity?

Damage to the ventromedial hypothalamus and to the paraventricular nucleus 

True or False: The amount of food you ingest is perfectly correlated with the amount you will weigh and this is true for everyone

False

Damage to the ____ can cause undereating

Lateral hypothalamus

The hypothalamus clearly plays a large role in weight management as damage to the ____ causes overeating whereas damage to the ____ causes undereating

Ventromedial hypothalamus, lateral hypothalamus

When do we tend to eat more?

When we are in a group

The best way to lose weight is to…?

Eat alone and only have one or two items that you are eating at that meal