Download Unit: Regulation Notes

Unit 13:
How the body helps keep our
body’s condition constant.
1
What is Regulation?
• Definition
- life process that helps keep conditions
inside the body constant (homeostasis)
• Regulation is accomplished using the
Nervous System and the Endocrine
System
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Regulation Using The
Nervous System
NERVOUS
SYSTEM
Uses nerves to detect changes in
the environment so the body can
respond
Composed of the Central Nervous
System (CNS) and the Peripheral
Nervous System (PNS)
Uses neurons (nerve cells)
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The Nervous System
Central Nervous
System
Peripheral Nervous
System
• Consists of the brain
and the spinal cord
• Contains all other
nerves that run
through the legs and
arms, which
eventually connect
to the spinal cord
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The Nervous System - CNS
The brain is divided
into three main
sections:
- Cerebrum
- Cerebellum
- Medulla
* Meningitis: When the membranes of
the brain become inflamed
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Brain Part Functions
Cerebrum
Cerebellum
Medulla
• Part of the brain
responsible for thinking,
reasoning, memory, etc.
• Part of the brain that
controls balance and
coordination
• Part of the brain that
controls automatic
functions such as
breathing and your
heart beat
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The Brain
Medulla
Cerebrum
Cerebellum
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The CNS - The Brain and
Spinal Cord
• Attached at the base of the brain is the
spinal cord
• The spinal cord carries messages from
the nerves in the body to the brain
• Damage to the spinal cord can result in
paralysis (loss of muscle control)
Ex. Paraplegic (cannot walk)
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Stimulus/Response
• Stimulus: a change in the external
environment that triggers an impulse
– Detected by receptors of the five senses
(touch, taste, hearing, sight, smell)
• Response: the body’s reaction to a
stimulus
– Activated when the brain sends a message to
the motor neuron which then activates the
effector (muscle or gland)
Ex. Bee sting (stimulus); swatting the bee away (response)
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Reflexes
• How we respond to a
stimulus is our behaviors
• Some behaviors are
learned but others are
reflexes (born with these
behaviors)
• The reflex arc is the path
a reflex takes through
the body.
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Reflexes cont…
• A reflex starts with the 1)
receptor (recognizes the
stimulus), goes to the 2)
sensory neuron (sends signal to
brain), to the 3) interneuron
(routes the impulse to the
correct part of the brain), to the
4) motor neuron (alerts the
muscle), and then to the 5)
effector (the muscle or gland)
Ex. Touching hot stove
11
The PNS - Nerves of the Body
• The Peripheral Nervous System is the
network of branching nerves from the
spinal cord into other parts of the body
(Nerves outside the brain and spinal cord)
• The peripheral nerves pick up stimuli from
the environment and send it to the spinal
cord and vice versa
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PNS cont…
3 Types of neurons (nerve cells)
sensory
neurons
interneurons
- found in
receptors;
carry
messages to
spinal cord
- relay signals
in the
brain/spinal
cord from the
sensory
neuron to the
motor neuron
motor neurons
- carry
messages from
inside the
brain/spinal
cord back to
parts of the
body
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The Neuron - scientific for
“nerve cell”
Dendrite
Terminal
branch
Cyton
Nucleus
Axon
Neurotransmitter
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Parts of a Neuron
Impulse
Dendrite
• An electrical or
chemical message that
is carried by a nerve
cell
• Receive impulses from
other neurons
Cyton
• Contains nucleus
Terminal branch
• End of cell; sends
impulses to next cell
15
Parts of a Neuron
Synapse
Neurotransmitter
• Gap between
neurons
• Allow impulses to
transfer between
nerve cells
Axon
• Long fiber that
carries impulse from
cell body
16
Drugs of the Nervous System
How do drugs impact our Nervous
System?
- slow us down; called depressants
ex. Alcohol,Valium, morphine
- speed us up; called stimulants
ex. Caffeine, cocaine, nicotine
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The Endocrine System
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Regulation Using The
Endocrine System
Uses glands and the
hormones they produce
to regulate
ENDOCRINE
SYSTEM
The glands release the
hormones into the
blood; called chemical
regulation
Slower responses than
responses of the
Nervous System
19
Endocrine Glands
Gland/Location
Hormone
Function
Pituitary (brain)
Human Growth
Hormone
Controls growth and other
glands; Master gland
Thyroid (neck)
*Parathyroid (also neck)
Thyroxine
*Parathyroid hormone
Controls metabolic rate
*Ca and Phosphorus use
Adrenal (top of kidney)
Adrenalin
Increases heart and
breathing rate; fight or flight
Islet of Langerhans
(Pancreas)
Insulin
Regulates sugar levels in
blood
Testes (male)
Testosterone
Controls sperm production
and secondary sex
characteristics
Ovaries (female)
Estrogen
Controls egg production
and secondary sex
characteristics
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Disruptions in Homeostasis
GOITER
- enlarged thyroid due
to lack of iodine in
diet
- Iodine is found in
fish and table salt
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Disruptions in Homeostasis
DIABETES
- too little insulin
released by the
pancreas causing
an increase in blood
sugar
- Can be regulated
through diet and/or
injections of insulin
22
Disruptions in Homeostasis
GIANTISM
- too much growth
hormone
- Andre the Giant
suffered from
giantism
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Disruptions in Homeostasis
DWARFISM
- too little growth
hormone produced
- “Mini Me” in Austin
Powers
24
Disruptions in Homeostasis
Meningitis
- inflammation of
membranes
(meninges)
surrounding brain
and spinal cord
- bacterial or viral
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RECAP: Regulation Review
Regulation occurs using
The Nervous
System
Uses electrical
firings and
neurons to
regulate
Fast
The Endocrine
System
Uses hormones
and glands to
regulate
Slower
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