The HUMAN BODY
Chapters 31 and 34
Nervous and Endocrine Systems
Chapter 31.1 The Neuron
• Objectives
– Identify the functions of the
nervous system
– Describe the function of
neurons
– Describe how a nerve impulse
is transmitted
NERVOUS SYSTEM
• Function:
– Send and receive
messages within the
body
– Respond to stimuli
Systems:
-Central Nervous System
-Peripheral Nervous System
Nerve Cells AKA Neurons
• Neuron- basic unit of
structure and function
of the nervous system
• Bundles of neurons
form nerves
Parts of a
Neuron:
-Dendrite
-Cell Body
-Axon
-Myelin sheath
(speeds up impulses)
-Axon Terminals
Types of Neurons
• Sensory Neurons:
Impulse from sense
organ to spinal cord/brain
• Motor Neurons:
Impulse from
brain/spinal cord to
muscles and glands
• Interneurons:
Connect sensory and
motor neurons
Nerve Transmission
• Messages are electrical and chemical signals
• An electric charge is conducted down a neuron
(Dendrite to axon)
– Axon is covered in an insulating layer called a myelin
sheath to speed up impulses
• As it reaches the end of the axon, chemicals
(neurotransmitters) are released across the synapse
(gap between neurons) to the next neuron
• The message continues neuron to neuron
Nerve Impulse Videos
Neurons: Nerve Cells
Describe the path of nerve transmission
that allows the batter to hit a ball.
Reflexes
How is a reflex different from the
example of the batter hitting a ball in the
previous video clip?
Check-in
• What is the function of the nervous system?
– Send and receive messages and respond to
stimuli
• Basic unit of structure and function of
nervous system
– Neuron (nerve cell)
• Part of neuron that receives the impulse
– Dendrite
Check-in
• Type of neuron that sends message from
sense organ to spinal cord/brain
– Sensory neuron
• Type of neuron that connects sensory and
motor neurons
– Interneuron
Chapter 31.2 Central Nervous
System
• Objectives
– Discuss the functions of the
brain and spinal cord
– Discuss the effects of drugs on
the brain
Central Nervous System
• Brain- control center;
transmits and receives
messages
– Cerebrum
– Cerebellum
– Brain Stem (midbrain, pons,
medulla oblongata.)
• Spinal Cord- connects
brain with rest of the
nervous system
Brain function fun!
• The Brain
Addiction and the Brain
• Dopamine – neurotransmitter released with
pleasurable activities
• Addictive drugs cause large release of
dopamine (resulting in “high”)
• Brain reacts by reducing number of
receptors for dopamine  normal
activities no longer produce the pleasure
they once did
Check-in
• Part of brain that controls balance
– Cerebellum
• Part of brain that controls heart rate
– Brain stem (medulla oblongata)
• Part of brain that controls thinking
– Cerebrum (frontal lobe)
• Part of brain that controls body temperature
– Hypothalamus
Check-in
• Neurotransmitter associated with pleasure
– Dopamine
• Why do addictive drugs create a cycle in
which more and more is needed to get the
“high”?
– Because brain responds to excess dopamine
released when they are taken by decreasing the
number of dopamine receptors
Chapters 31.3 and 31.4 Peripheral
Nervous System & Senses
• Objectives
– Discuss the functions of the sensory
division of the peripheral nervous system
– Identify the five sense organs and the
sensory receptors associated with each
– Discuss the functions of the motor
division of the peripheral nervous system
Peripheral Nervous System
• Link between the central
nervous system and the rest
of the body
– Network of nerves
throughout the body
*Made of many neurons
Sensory Division
• Transmits impulses from sense organs to
central nervous system
• Uses sensory receptors
–
–
–
–
–
Chemoreceptors
Photoreceptors
Mechanoreceptors
Thermoreceptors
Pain receptors
SENSES
• Vision- eyes
• Hearing and Balanceears
• Smell and taste- nose
and mouth
• Touch- skin
Motor Division
• Transmits impulses from central nervous
system to muscles or glands
Somatic nervous system:
Autonomic nervous system:
regulates activities under
regulates activities that are
conscious control
automatic or involuntary
Check-in
Peripheral Nervous System
Sensory Division
Motor Division
Impulses from sense
organs to CNS
Impulses from CNS
to muscles/glands
Somatic
Autonomic
Conscious control
Involuntary control
Check-in
• Hearing/balance
• Chemoreceptor
• Smell
• Mechanoreceptor
• Taste
• Pain receptor
• Touch
• Photoreceptor
• Vision
• Thermoreceptor
Chapter 34.1 and 34.2
Endocrine System
• Objectives
– Describe the structure and
function of the endocrine
system
– Identify the functions of the
major endocrine glands
ENDOCRINE SYSTEM
• Function- produce chemical
messengers (hormones) from
glands to regulate certain
body activities
What are hormones? Glands?
• Hormone: chemical messenger
• Gland: organ that produces and releases a
substance
Exocrine: release
substances out of
body or into digestive
tract
Endocrine: release
hormones directly into
blood
Glands of Endocrine System
Head Region:
-Pituitary: controls other glands
-Pineal Gland: regulates sleep and
wake cycle, along with other
basic functions
-Hypothalamus: controls
secretions of the pituitary gland
(link between endocrine and
nervous system)
Glands of the Endocrine System
Neck Region:
-Thyroid: regulates
metabolism (rate at
which food is turned into
energy)
-Parathyroids: maintains
homeostasis in blood
calcium levels
Glands of the Endocrine System
Abdominal Region:
-Adrenals: helps body
prepare for and deal with
stress (fight or flight)
-Pancreas: Releases insulin
and glucagon to regulate
level of glucose in blood
Glands of the Endocrine System
Reproductive Region:
-Ovaries (females): produce
eggs and estrogen to create
female characteristics
-Testes (males): produce
sperm and testosterone to
create male characteristics
Check-in
• Controls the pituitary gland
– Hypothalamus
• Regulates metabolism
– Thyroid
• Regulates sleep/wake cycle
– Pineal
• Controls other glands
– Pituitary
Check-in
• Produces eggs and estrogen
– Ovary
• Helps deal with stress (fight or flight)
– Adrenal
• Maintain blood calcium levels
– Parathyroid
• Regulates blood glucose/sugar levels
– Pancreas