Download Unit XIV: Regulation

Unit XVI: Regulation
Control and Coordination of
the organism using nervous
and endocrine systems
Control and Coordination of responses to stimuli
Response is a reaction
Stimulus is any change in the environment that
causes a response
A. Nervous Regulation
Impulse Animation
1. Neuron
a) Specialized cell used to carry impulses
b) Impulse = electrochemical message travels
from cell body to terminal branches
c) Parts of the Neuron:
- Cell body – contains all the normal cell parts
nucleus, mitochondria, golgi, ER, cytoplasm, etc.
- Dendrites – receptors on the cell body, receive
impulses, used to pick up stimuli
- Axon – long fiber that extends from the cell body,
carries the impulse
- Schwann’s Cells
produce a Myelin sheath
– layers of a white fatty
substance  acts as
insulation and helps the
impulse travel faster
- Terminal branches and
Synaptic Knobs – carry
impulse to the next
neuron or effector
d) Synapse – space between two neurons
- electrical impulse travels down the neuron from
the cell body, axon, terminal branch, and the
synaptic knob.
- At the synaptic knob neurotransmitters are
released.
- Neurotransmitters are chemicals that travel
across the
synapse to
the next
neuron
e) Types of Neurons
- nerves are bundles of neurons
1 – Sensory Neurons – located in sense organs –
receptors
carry impulses to the
spinal cord and brain
2 – Interneurons
– located in the central
nervous system interpret
impulses
3 – Motor Neurons – located
at effectors carry impulses
from the CNS to muscles
and glands
What kind of neuron is this?
3. Adaptations for Regulation
a) Regulation in Protists
- Special proteins in membrane – receptors
- receptors receive stimuli
- Allow the single cell to respond to stimulus
b) Regulation in Hydra
- Nerve Net
- no organized nervous
center  full body response
c) Regulation in the Earthworm
- Central Nervous System – brain and ventral nerve
cord
- ventral nerve cord has ganglia – bundles of
interneurons
- Peripheral Nervous System – nerve branches from
the ventral nerve cord
controls muscles, skin
receptors
d) Regulation in the Grasshopper
- Central and Peripheral Nervous Systems
- Ganglia
- Highly developed sense organs
Antenna, eye, hairs, taste buds
4. Human Nervous System
a) Central Nervous System
1) Brain – interneurons
- Cerebrum – larger in humans than other
organisms
- many convolutions –
increase surface area
- senses, motor,
associative functions
(memory thought,
reasoning)
- voluntary movement
- Cerebellum
- 2nd largest part of the brain
- Balance, equilibrium, muscle
tone
- Smooth muscle movements
- Medulla
- connects to the spinal cord
- controls involuntary actions –
breathing, heartbeat, blood
flow, coughing
2) Spinal Cord
- connects the central and peripheral nervous
systems
- responsible for certain reflexes
reflex = involuntary automatic response to a
stimulus
skips the brain
b) Peripheral Nervous System
nerves that extend from the spinal cord
1) Somatic Nervous System – voluntary control of
certain muscles,
sense organs, and skin
2) Autonomic Nervous System – usually deals with
the involuntary control of the body
1 - Parasympathetic Nervous System
2 - Sympathetic Nervous System
Opposite Functions
3) Sense Receptors
1 – Eye
2 – Ear
3 – Skin – heat, pressure, touch, pain, cold
4 – Taste – sour, bitter, sweet, salty
5 - Smell
c) Diseases and Disorders of the Nervous System
1) The Effects of Drugs
- can permanently alter brain chemistry
- Stimulants – speeds up the functions of the
nervous system  convulsions, heart attack,
death
ex: cocaine, amphetamines, crystal meth,
caffeine, nicotine, ritalin
- Depressants
- slows down the functions of the nervous system 
depress breathing rate
ex: alcohol, heroin, morphine, barbiturates
- Hallucinogens
- disrupt the function of the nervous system causing
hallucinations  see and feel things that are not
there
ex: marijuana, ecstasy, PCP, LSD, mesculine
2) Meningitis
- inflammation of the membranes surrounding the
brain and spinal cord
- severe head ache and stiff neck
3) Cerebral Palsy
- birth disorder that
effects the motor
neurons
4) Polio
- virus that destroys
nerve tissue causing
paralysis