Introduction to Human Anatomy and Physiology Notes + Feedback Loops

Introduction to Human Anatomy and Physiology Notes (1-22) - Feedback Loops (23-40)

Anatomy vs Physiology

Anatomy = structure (what it looks like). Physiology = function (what it does)

Homeostasis

Keeping the inside of the body stable and normal

Levels of organization

Atoms, molecules, macromolecules, organelles, cells, tissues, organs, organ systems, organism

Cell

The basic living unit

Tissue

Group of cells working together

Organ system

Group of organs working together

Metabolism

All the chemical reactions in the body; needs ENERGY (from food)

Differentiation

A cell becomes specialized for one job by turning genes on and off

Respiration

Using oxygen, getting rid of carbon dioxide

Absorption vs Assimilation

Absorption = taking substances in. Assimilation = changing them into forms the body can use

Excretion

Removing wastes

Set point

The target value the body tries to stay at

Normal range

The range where the body works best

Feedback loop order

Stimulus, receptor, control center, effector, response

Receptor

Senses the change

Control center

Decides what to do (usually the brain)

Effector

Muscle or gland that does the response

Negative feedback

Reverses the change and brings the body back to normal

Positive feedback

Makes the change bigger until something finishes (childbirth, blood clotting)

Body too hot example

Receptors in skin and brain, brain control center, you sweat and cool down

Vital signs

Basic body measurements: temperature, pulse, breathing, blood pressure

Hyponatremia

Too little sodium (salt) in the blood, often from drinking too much water

Glucose

Sugar in the blood

Set point

90 mg per 100 mL (normal blood sugar)

Pancreas:

Organ that controls blood sugar

Beta cells

Release insulin

Alpha cells

Release glucagon

Insulin

Lowers blood sugar by making cells and the liver take in glucose

Glucagon

Raises blood sugar by making the liver release glucose

Glycogen

Glucose stored in the liver

Stimulus that raises blood sugar

Eating

Stimulus that lowers blood sugar

Time without eating

Where glucose ends up

Body cells and the liver

Diabetes

Pancreas doesn't make enough insulin

Diabetic with high blood sugar

Takes an insulin shot

Diabetic with low blood sugar

Eats or drinks something sugary

Pancreas and homeostasis

Releases insulin or glucagon to keep blood sugar at the set point

Thermostat

Turns on the heat when it's too cold, turns off when it reaches the set temperature

Blood sugar control

Negative feedback

Memory trick

Insulin puts sugar IN cells. Glucagon means glucose is GONE