Transcript Regents Biology - Baldwinsville Central School District

Why do animals need a nervous system?
 Because the world
is always coming
at you!
 Take in
information
 Regulation
Remember…
Poor
thinkbunny
about!
the bunny…
Regents Biology
2003-2004
Nervous System
 Central nervous system
cerebrum
cerebellum
spinal cord
CNS
 brain & spinal chord

 Peripheral nervous system

nerves from senses
 Take in info from environment

nerves to muscles
cervical
nerves
thoracic
nerves
lumbar
nerves
femoral
nerve
sciatic
nerve
 Allow for response
tibial
nerve
Regents Biology
2003-2004
Nervous cells
 Neuron
signal

direction
a nerve cell
dendrites
cell body
nucleus
axon
Regents Biology
signal direction
ONE WAY
terminal branches
synapse
(space)
2003-2004
Fun facts about neurons
 Most specialized cell in
animals
 Longest cell

blue whale neuron
 10-30 meters

giraffe axon
 5 meters

human neuron
 1-2 meters
Nervous system allows for
1Regents
millisecond
Biologyresponse time
2003-2004
Myelin coating - lipid
signal
direction
 Axon coated with insulation
made of myelin cells

speeds signal
 signal hops from node to node

330 mph vs. 11 mph
Multiple Sclerosis
 immune system (T cells) attacks myelin coating
 loss of signal
Regents Biology
2003-2004
Synapse
Junction between nerve cells

1st cell releases chemical to trigger
next cell – neurotransmitters
 proteins – remember 3-D shape??

where drugs affect nervous system
synapse
Drugs –
1. block receptor sites on
receiving neuron
2. Bind with neurotransmitter to
change shape
3. Prevent release of neurotransmitter
Regents Biology
2003-2004
axon
vessicle
synapse
dendrite
channel
protein
Regents Biology
myelin
terminal branch
protein
exocytosis
(active
transport)
Mitochondia – R
– provide ATP
2003-2004
3 Types of neurons
sensory neuron
(from senses)
receive stimulus
interneuron
(CNS -brain & spinal chord)
Regents Biology
motor neuron
(to effector – muscle/gland)
produces response
2003-2004
Human brain
Regents Biology
2003-2004
Primitive brain
 The “lower brain”

medulla oblongata
 basic body functions
 breathing, heart, digestion,
swallowing, vomiting
 homeostasis

cerebellum
 coordination of movement
and balance
Regents Biology
2003-2004
Higher brain
 Cerebrum
2 hemispheres
 left = right side of
body
 right = left side of
body

 Corpus callosum

connection
between 2 hemispheres
Regents Biology
2003-2004
Division of Brain Function
 Left hemisphere



“logic side”
language, math, logic operations, vision &
hearing details
fine motor control
 Right hemisphere


“creative side”
pattern recognition, spatial
relationships, non-verbal
ideas, emotions, multi-tasking
Regents Biology
2003-2004
Simplest Nerve Circuit – Reflex Arc
 Reflex, or automatic response
signal only goes to spinal cord - FASTER
 advantage
 essential actions
 don’t need to think or make decisions about
(automated)
 blinking
 balance
 pupil dilation
 startle – “fight or flight”

Regents Biology
2003-2004
Reflex ARC
AP Biology
2003-2004