Transcript neurons - McMurray VMC

Nervous System
Central
Nervous
System
(CNS)
Peripheral
Nervous
System
(PNS)
1
"You have brains in your head.
You have feet in your shoes.
You can steer yourself
Any direction you choose.”
Watch video:
Human brain built for survival
http://videos.howstuffworks.com/discovery/6835-human-body-built-for-survivalvideo.htm
2
Nervous System
The brain is the center of the nervous system. The
spinal cord and nerves are the connections. Nerves
carry electrochemical signals to and from different
areas of the nervous system as well as between the
nervous system and other tissues and organs.
Watch video clip:
Neurons, how they work
http://www.neok12.com/php/watch.php?v=zX784a525472754f71401a45&t=Nervous-System
3
The Nervous System
Nervous System: Consists of all the nerve cells. It
is the body’s speedy, electrochemical
communication system.
Central Nervous System (CNS): the brain and
spinal cord.
Peripheral Nervous System (PNS): the sensory and
motor neurons that connect the central nervous
system (CNS) to the rest of the body.
4
The Nervous System
5
Peripheral Nervous System
Somatic Nervous System: Part of the peripheral
nervous system that controls the body’s skeletal
muscles.
Autonomic Nervous System: Part of the PNS that
controls the glands and other muscles.
The body’s automatic actions (eg. breathing and
heartbeat)
6
Autonomic Nervous System (ANS)
Sympathetic Nervous System: Division of the
ANS that arouses the body, mobilizing its
energy in stressful situations.
Known as: FIGHT or FLIGHT response
Parasympathetic Nervous System: Division of
the ANS that calms the body, conserving its
energy.
Sympathetic vs Parasympathetic
http://www.garyfisk.com/anim/autonomicns.swf
7
Fight or Flight Response
• fight or flight
8
Autonomic Nervous System (ANS)
Sympathetic NS
“Arouses”
(fight-or-flight)
Parasympathetic NS
“Calms”
(rest and digest)
9
Fainting Goats
• fainting goat video
10
Neurons
• The body’s information system is built from
billions of interconnected cells called neurons.
• A neuron is a nerve cell.
• Neurons communicate with each other through
an electrochemical process.
• Neurons are the basic building blocks of the
nervous system.
• animation
11
Neuron
A nerve cell, or a neuron, consists of many
different parts.
12
Neuron Review
• Neuron animation
• http://www.garyfisk.com/anim/neuronparts.swf
• Neural transmission
• http://www.garyfisk.com/anim/neurotransmission.swf
13
Parts of a Neuron
Cell Body: Life support center of the neuron.
Dendrites: Branching extensions at the cell body.
Receive messages from other neurons.
Axon: Long single extension of a neuron, covered with
myelin [MY-uh-lin] sheath to insulate and speed up
messages through neurons.
Terminal Branches of axon: Branched endings of an
axon that transmit messages to other neurons.
14
Action Potential
A neural impulse. A brief
electrical charge that
travels down an axon and
is generated by the
movement of positively
charged atoms in and out
of channels in the axon’s
membrane.
15
Synapse
Synapse [SIN-aps] a junction between the axon
tip of the sending neuron and the dendrite or
cell body of the receiving neuron. This tiny gap
is called the synaptic gap or cleft.
16
Neurotransmitters
Neurotransmitters
(chemicals) released
from the sending
neuron travel across the
synapse and bind to
receptor sites on the
receiving neuron,
thereby influencing it to
generate an action
potential.
17
Neurotransmitters
18
Active psych synaptic transmission and neurotransmitters
The Endocrine System
The Endocrine
System is the body’s
“slow” chemical
communication
system.
Communication is
carried out by
hormones
synthesized by a set
of glands.
19
Hormones
Hormones are chemicals synthesized by the
endocrine glands that are secreted in the
bloodstream. Hormones affect the brain and many
other tissues of the body.
20
Pituitary Gland
• Is called the “master gland.” It releases
hormones that regulate other glands.
• Releases the growth hormone.
21
Thyroid Glands
Regulate metabolic rate. Produces a
hormone called thyroxine.
22
Adrenal Glands and Pancreas
Adrenal glands secrete hormones adrenaline
(epinephrine and norepinephrine) during stressful
and emotional situations.
Pancreas secretes insulin to regulate the level of
sugar in the blood.
23
Gonads
• Sex glands are located in different places in
men and women. They regulate bodily
development and maintain reproductive
organs in adults.
• Testis produce the hormone testosterone.
• The ovaries produce estrogen.
24
Pineal Gland
Pineal gland produces Melatonin. Melatonin
regulates the sleep cycle.
25