Download Chapter 24 Regulatio..

Chapter 24 Regulation
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Look around you.
What do you see?
What sounds can you hear?
Do you smell any odors?
– Information about your environment is detected
1st by your sense organs.
The 5 Sense organs
1.
2.
3.
4.
5.
Eyes
Ears
Skin
Tongue
Nose
How do sense organs work?
• Each sense organ has special cells called
receptor cells that detect information.
• The receptor cells send nerve impulses to
sensory neurons, which carry impulses to the
brain.
• The brain interprets the impulse (Ex: taste or
vision).
Vision
• Eyes are very sensitive to light
• How light travels through the eye?
– Light  Cornea  Iris/Pupil  Lens  Retina (rods &
cones)  Optic Nerve  Brain
• Cornea = curved part of the eye
• Iris = smooth muscle behind the cornea (color
part of the eye)
• Pupil = controls the amount of light that enters
the eye
• Lens = focuses the incoming light
Vision cont.
• Retina = thin tissue @ the back of the eye
contains rods and cones
• Rod = detect black and white colors
• Cones = detect color
Hearing
• Ear has 3 main parts:
1. Auricle (ear flap) = outer ear
2. Eardrum, incus, stapes, malleus = middle ear
3. Cochlea, auditory nerve = inner ear
Have you ever felt dizzy after spinning
around in a circle?
• Your ear also helps maintain balance.
• Dizziness is a sensation produced by 3 looped
tubes (semicircular canals) in your inner ear.
• These are fluid filled tubes that have hairlike
receptors.
• Every time you move your head, the fluid
inside these tube move.
• The hairlike receptors also move based on
orientation.
Touch
• Your skin is the largest sense organ in your body.
• Skin can detect touch, pressure, pain, heat, and
cold.
• Touch receptors are found near the surface of the
skin
• Pressure and pain receptors are found deep
within the skin.
• Receptors on the skin are not evenly distributed
over your body.
Taste & Smell
• The organs of taste and smell are stimulated by
chemicals.
• Receptors for taste are located on taste buds
found on your tongue.
• Taste buds can only detect 4 tastes: sweet, sour,
salty, and bitter.
Taste & Smell cont.
• The flavor of food is also detected by odor
receptor of the nose.
• When your nose is blocked, your odor receptors
don’t function as well.
• This is why food often taste bland when you have
a cold.
• Odor receptors = olfactory cells respond to gas
molecules
Why do people grow rapidly during
adolescence? Have you ever heard of
someone having “superhuman”
strength during an emergency?
• These responses result from the action of the
endocrine system
The Endocrine System
• This system is made up
of glands that secrete
hormones into the
bloodstream.
• Hormones are
chemical messages
that regulate many of
your bodily functions.
Endocrine Glands
Endocrine Gland
Pituitary
Thyroid
Hormone
Growth hormone /
other hormones
Thyroxine
Parathyroid
Adrenals
Parathyroid hormone
Cortisone
Adrenaline
Pancreas
Insulin
Ovaries
Testes
Estrogen
Testosterone
Function
Controls growth;
regulates other glands
Regulates growth and
metabolism
Regulates calcium use
Maintains salt/water
balance
Regulates body
response to stress
Regulates blood-sugar
levels
Female characteristics
Male characteristics
What regulates the endocrine
glands?
• Most endocrine glands are regulated by a
feedback mechanism.
– Ex: Thermostat of an heater or AC unit
Behavior
• 2 main types of behavior:
– Innate: unlearned that you are born with
• Ex: coughing, swallowing, sneezing, blinking
– Learned behavior
• Things that you practice and get better at over time.