How can we help?

You can also find more resources in our Help Center.

Science Ch. 21-Control and Sensing

STUDY
PLAY
4 Functions of the nervous system
~Communication and control system- made up of the brain, spinal cord, and nerves ~Receives information from your environment and from inside your body ~Controls reactions that involve emotion ~Most important system in the body
2 Parts of the nervous system
CNS and PNS
What is CNS?
Central Nervous System; made up of the brain and spinal cord.
What is PNS?
Peripheral Nervous System; connects the CNS to the rest of the body.
Brain
Control center of the body. Directs and coordinates all body processes.
Spinal Cord
Bundle of nerves extending from your brain down to your back.
Nerves
Are controlled automatically by your brain. Cause some muscles to contract.
Neurons
Basic functioning units of the nervous system
Dendrites
Relay electrical messages to the neurons.
Axons
Carries nerve impulses away from the cell body.
Nerve Impulses
Neurons use electrical and chemical energy to send nerve impulses
Synapse
The space between neurons.
3 main parts of the brain
Cerebrum, Cerebellum, Medulla
Cerebrum
Largest part of your brain that controls functions including all conscious body movement like running. (When you are awake)
Cerebrum is divided into two halves
Left Half and Right Half
Left Half
controls your ability to speak, use mouth, and think logically.
Right Half
Center for music ability, the creation of art, and expression of emotions
Cerebellum
Second largest [art of the brain that adjusts impulses of motor neurons so motion is not robot-like or jerky.Fine-tunes motion.
Medulla
Smallest portion of brain
Name 3 areas that make up the brain stem
Mid-brain, pons, medulla
Spinal Cord
connects the brain to the PNS
Nerves made up of 2 kinds of nerve fibers
Motor neurons and sensory neurons
Motor Neurons
lead from the spinal cord to the muscles and cause them to contract
Sensory Neurons
Nerves carry sensory information to the spinal cord, which sends it to the brain.
Function of Sensory receptor
functions of a sensory receptor is to take in a stimulus and convert it into a nerve impulse (Ex: Camera flash)
Sound waves
all sound comes from vibration. When an object vibrates it creates pressure waves in the air surrounding it.The pressure waves in the are sound waves.
eardrum
sound waves pass through the ear canal and strike a thin, round, tightly stretched membrane.
Cochlea
fluid-like structure that makes up the inner ear.
Semicircular canals are filled with what?
fluid and motion receptors
Smell
receptors change odor stimuli into nerve impulses, these nerve impulses are carried by the olfactory nerves to the brain.
Taste buds
your tongues sensory receptors
4 different taste sensations
salty, sweet, bitter, sour
4 different sensations you can feel with your skin
detect cold and heat, pressure, pain
Touch and pressure receptors are concentrated where?
On the hands and fingertips
endocrine glands
a ductless gland that releases hormones directly into the blood stream
Hormones
the chemicals made by endocrine glands
Hormones can cause changes in?
other organs and regulate many body activities
How many endocrine glands are in the human body?
9
Where is the pituitary gland located?
at the base of the cerebrum
What has two lobes?
the pituitary gland
What is produced by the pituitary gland?
HGH(human growth hormone)
HGH controls?
how fast your muscles, bones and organs grow.
HGH stores hormones by what part of the brain?
Hypothalamus
what does hypothalamus regulate?
blood pressure
What controls the thyroid gland?
the pituitary gland
what do the thyroid glands produce?
thyroxine
What does thyroxine regulate
body's metabolism
Where is the thyroid located?
at the base of the neck, beneath the larynx next to the trachea
The pancreas is part of what?
endocrine gland
what does the pancreas release?
a hormone called insulin
what does insulin do?
helps transport sugar from the blood into the body's cell.
The pancreas produces what?
glucagon but it's function is opposite of insulin
feedback and control of hormone levels
tightly controlled by a feedback system that automatically turns the endocrine gland on or off.