Overview of Nervous System Functions

Bio 30AP –mechanisms of body control Nervous system- control by electrical impulses. (Ch 37 & 38) Endocrine system- Hormonal control. (Ch 40) 1 Nervous System Biology 30AP 2 Equilibrium/Homeostasis= balance, the main job of the nervous system! 3 Homeostasis video: http://health.howstuffworks.com/adam-200092.htm A system (along with the endocrine system) that controls all of the activities of the body. The nervous system is made of: The brain The spinal cord The nerves The senses 4 Structures & Processes of the Nervous System Sensory Input: Monitor both external and internal environments. Integration: Process the information and often integrate it with stored information. Motor output: If necessary, signal effector organs to make an appropriate response.The brain is composed of over 100 billion nerve cells! 5 Organization of the Nervous System (p367) 2 main divisions: Central nervous system: Brain & spinal cord= coordinate incoming & outgoing info. Peripheral nervous system: carries information between the organs/effectors and the CNS. 6 Peripheral Nervous System all the portions of the NS outside of the brain and spinal cord. • Somatic NS Consists of nerves connected to sensory receptors and skeletal muscles Permits voluntary action (ex. writing your name) • Autonomic NS Consists of the Sympathetic and Parasympathetic systems (on/off switch) Permits the involuntary functioning of blood vessels, glands, and internal organs such as the bladder, stomach and heart 7 Cells of the NS Two types: Glial cells (neuroglial) & neurons. • The Functions of Glial Cells: – Hold neurons in place – Provide neurons with nutrients – Insulate neurons – Remove cellular debris when neurons die -defend against infection 8 Types of Neurons: • Sensory Neurons (afferent neurons): relay info about environment from sensory receptors to the CNS. • Interneurons: link neurons to other neurons (found only in CNS) • Motor Neurons (efferent neurons): carry impulses from the CNS to the effectors (muscles, organs, glands) produce response 9 a. Label the neurons below as a interneuron, motor neuron and a sensory-neuron: b. Where is each neuron found in the body? 10 Anatomy of a Nerve Cell • Neurons: vary in size, and appearance. 3 main jobs (input, integration & output) 11 • Cell body: functional portion, when in groups out side of CNS called: ganglion • Dendrites: short extensions that receive signals from other neurons or environment • Axon: long extension that transmits impulses away to other neurons or effectors. 12 Myelinated Neurons • Myelin sheath: peripheral neurons have white insulation around the axon called which is formed by Schwann cells. – Myelin sheathing acts as an insulator preventing the loss of charged ions from the axon, and allows conduction of faster nerve impulses. • Areas between myelin sheath: Nodes of Ranvier • Neurilemma: membrane surrounding axon, that promotes regeneration 13 Decreased impulses to muscles If MS causes nerve signal loss, how would this effect the muscles, the brain, and other organs? 14 1. 2. 3. 5. 6. 7. STOP & THINK!: what does 1-7 represent? 1. Dendrites 2. Cell body (nucleus) 3. Axon 4. 4. Schwann Cell 5. Myelin Sheath 6. Node of Ranvier 7. Neurilemma 15 Question # 1 16 Reflex Arc Reflex arc: 5 steps 17 REFLEX ARC: automatic response controlled primarily by spinal cord. stimulus → receptor → sensory neuron → interneuron → motor neuron → effector organ → response Reflex videos: http://bcs.whfreeman.com/WebPub/Biology/hillis1e/Animated%20Tutorials/at3404/at_3404_info_proc_spinal_ cord.html 18 2. http://health.howstuffworks.com/adam-200012.htm .htt:www.sumanasinc.comwebcontentanisamlesnonmaorsbioloreflexarcs.html 19 Question # 2 20 Nerve Impulses (pg372) Nerves have two states: 1. Resting potential • “polarized” • Resting nerve • Charge inside is -70mV 2. Action potential • “depolarized” nerve • Charge inside jumps to +40mV 21 Restin membrane: htts://www.outube.com/watch?v=b2ctEsGEe0&t=19s Resting Membrane Potential • The membranes contain sodium-potassium pumps that pump out 3 Na+ and 2 K+ in. • HOW -70mV? – Uses ATP (active transport) to pump 3 sodium ions out and 2 potassium ions in. this unequal distribution of ions leads to a polarized membrane. – Presence of negatively charged plasma proteins and ions – K+leak channels allow K+to leave the inside of the axon. 22 Nerve Impulse - The Action Potential Steps: 1. Depolarization: Nerve becomes more permeable to highly concentrated Na+ than K+. This rapid influx of Na+ causes -70 to jump to +40mV. 2. Repolarization: Na+ channels close, K+ gates open, and K+ diffuses out of cell restoring original polarization. 3. Refractory Period: recovery time (1-10ms) required before a neuron can return to resting potential. pumping time required to produce another action potential Hyperpolarization: K+ gates close slowly , so more K+ ions move out than normal = more negative charge inside. 23 • Impulse video: https://www.youtube.com/watch?v=bfokof2YMVU&t=148s Nerve Impulse - The Action Potential Threshold potential will trigger an action potential or nerve impulse -The action potential is an all-or-none response, moves like a wave from cell body down the axon to next neuron. -Positively charged ions that rush into the neuron are attracted to adjacent negative ions. -Hyperpolarization in previous area (in refractory period) stops impulse from traveling backwards (re-pump Na+ back out before another impulse can be sent) 24 25 Saltatory Conduction in Myelinated Axons Myelin sheathing has bare patches called nodes of Ranvier •Action potentials seem to jump from node to node (saltatory conduction) •Faster conduction than unmyelinated action potential 26 Myelination: 27 Nerve impulse: https://www.youtube.com/watch?v=fHRC8SlLcH0&t=3s1. Identify and explain the three factors that contribute to the resting membrane potential. 2. Explain the difference between depolarization and the repolarization of a neuron? 28 Threshold: All-or-none Threshold level: minimum level of stimulus required to produce a response (> 2mV) All-or-none response: nerves or muscles respond completely or not at all. • Charge greater than minimum required will not produce a increased response Message priority determined by: 1. More frequency of impulses (spinal gate theory) 2. Some neurons have higher threshold levels, they only fire with an increased stimulus Therefore: The greater the number of impulses reaching the brain the greater the 29 intensity of the response. The Synapse – The space between! • A synaptic cleft divides at least 2 (usually more) neurons by ~20nm. • Presynaptic Neurons: carry impulses to the synapse • Postsynaptic Neurons: carry impulses away from synapse 30 How does a signal move from one neuron to another? • The action potential will not move across the synapse • More synapses= slower transmission. (reflex arc has little synapses) Neuro-transmitters (chemicals) brave the gap: •Released by the end plate of presynaptic neuron to the receptor sites of postsynaptic neuron. 31 •Move by diffusion Mechanism of Neurotransmission 1. Action potential reaches end plate 2. Ca2+ gates open influx of + ions 3. Build-up of Ca2+ causes release of acetylcholine 4. Acetylcholine released 5. Acetylcholine binds with Na+ channels opening them (postsynaptic receptor sites) 6. Na+ ions rush in causing depolariazation. 7. Action potential continues through dendrite of post synaptic neuron. 8. Presynaptic endplate membrane releases cholinsterase (enzyme) which destroys acetylcholine 9. Na+ gates close, recovery phase begins Chemical synapse videos: 32 http://bcs.whfreeman.com/WebPub/Biology/hillis1e/Animated%2520Tutorials/at3403 /at_3403_synaptic_trans.html Neurotransmitter Jobs • Excitatory: triggers receptor proteins in post synaptic cleft to allow positive ions in (ex. sodium) → Depolarization! & lowered threshold level! • Inhibitory: triggers potassium channels to open→ hyperpolarization! (increased threshold level) Common Neurotransmitters: Dopamine Function: Sensation of pleasure + body mov’t Serotonin Regulates temp. + perception + mood control Endorphins Natural painkiller + emotions Norepinepherine Works with epinephrine (fight-flight response) GABA Inhibitory (natural tranquilizer) 33 What would happen if the neurotransmitter on the post synaptic neuron was not broken by cholinesterase? 34 Synaptic wonders Summation: Quit messing with my synapses! -effect produced by the accumulation of transmitter chemical from two or more neurons. -can be inhibitory or excitatory threshold 35 Neurotransmitter disorders Parkinson's Disease: -inadequate dopamine (inhibitory) causes involuntary muscle contraction -Michael j fox Alzheimer’s Disease: -inadequate acetylcholine (excitatory) deterioration of memory & mental capacity. 36 37 How does the drug cocaine affect synaptic transmission? 38 Question # 3 39 Question # 4 40 Question # 5 41 Question # 6 42 Question # 7 43 Question # 8 44 Question # 9 45 46 * The Central Nervous System controls all of the body’s activities. * The Central Nervous System is made of two main organs. 1. The brain 2. The spinal cord 47 Protecting the CNS Control center consisting of brain & spinal cord • Skull/vertebrae: bone covering • Brain surrounded by protective membranes: Meninges – Outer layer: dura mater – Middle layer: arachnoid – Inner layer: pia mater • Cerebrospinal fluid: transport medium & shock absorber that circulates between inner & middle meninges and the central canal of the spinal cord. 48 • Carries sensory nerve messages from receptors to the brain and relays messages from the brain to effectors (muscles, organs & glands). • Foramen magnum: opening in skull for spinal cord • Spinal cord travels within the vertebral backbone Gray vs white: • Gray: unmyelinated neurons/axons • White: myelinated neurons that connect spinal cord to brain Dorsal vs ventral: • Dorsal nerve: brings sensory info in • Ventral nerve: carries motor info out to effectors (muscles/glands) 49 50 Dorsal root ganglion 51 3 regions: Forebrain (reason, intellect, memory, language, personality) Midbrain (relay center for eye & ear) Hindbrain (balance, muscle control, autonomic control) 52 Gray matter White matter Ventricles 54 Forebrain Contains: • Cerebrum: largest portion of brain, surface is the cerebral cortex (gray matter). – coordinating center for: • Motor actions, speech, reasoning, memory, personality – 2 distinct hemi-spheres (left: verbal skills, right: visual/spatial awareness) linked by the corpus callosum (communication bridge) – Each hemi-sphere has 4 lobes: • Frontal, temporal, parietal, and occipital • Thalamus: interprets sensory information (relay station) • Hypothalamus & Pituitary: unites nervous and endocrine systems (autonomic functions) • Olfactory bulbs: detect smell 55 Cerebrum lobes: Frontal: -voluntary muscles (walking, speech) -personality -memory Temporal: -interpret sensory info (hearing, smell) Parietal: -touch, pain, taste (temperature) -emotions -Interpreting speech Occipital: - vision 56 57 Midbrain • 4 spheres of gray matter • Relay center for eye & ear reflexes 58 Hindbrain Contains: • Cerebellum: controls limb mov’t, balance, muscle tone • Pons: (bridge) relay station between two regions of cerebellum and the medulla • Medulla Oblongata: joins spinal cord to cerebellum, site of autonomic nerve control (breathing mov’ts, diameter of blood vessels…) 59 Interpreting Speech • In Cerebrum: • Broca’s Area: coordinates speech muscles & translates thoughts into speech (Frontal lobe) • Wernicke’s Area: language comprehension & storage. (left Temporal lobe) Silk & Milk Out loud get your partner to spell S-I-L-K. Repeat. Repeat. 60 Now get your partner to say "silk" three times fast. Now ask them what do cows drink... Brain mapping • Different areas have specific functions • Other areas can substitute for Damaged areas. 61 Lips Jaw Tongue Frontal lobe Parietal lobe Toes Pharynx Genitalia Primary motor cortex Abdominal organs Primary somatosensory cortex 63 Brain imaging technology PET (positron emission tomography)- radioactive glucose is consumed in certain areas of the brain. MRI (magnetic resonance imaging)- giant magnet detects changes in H+ that emit radio signals. MRI game: https://educationalgames.nobelprize.org/educational/me dicine/mri/game/index.html 64 Hearing words Speaking words Seeing words Generating words Max Min LABEL The Brain Cerebrum Corpus Callosum Hypothalamus Pituitary Gland Pons Cerebellum Medulla Oblongata Question # 10 67 Question # 11 68 Question # 12 69 Question # 13 70 Question # 14 71 Peripheral Nervous System PNS 2 parts: Both contain sensory and effector nerves 1. Autonomic system: nerves designed to maintain internal homeostasis (not under conscious control) 2. Somatic system: designed to adjust to external stimuli by controlling skeletal muscle (under conscious control), exception - reflexes 72 Composed of: A. 12 paired cranial nerves – Control vision, hearing, balance, taste, smell, facial, tongue, neck & head mov’t B. 31 paired spinal nerves – Control skeletal muscles 73 Sensory Somatic System Divisions A. Cranial nerves B. Spinal nerves 74 Involuntary internal homeostatic control. Ex. Controls smooth muscle, internal organs, glands controls 2 types of ANS nerves: 1st group: preganglionic (CNS→ ganglion) 2nd group: postganglionic (ganglion → target organ/gland/muscle) 75 Comparison of Somatic and Autonomic Systems76 Autonomic Nervous System halves Sympathetic (on) • Prepares body for stress (fight or flight) • Short preganglionic nerve • Preganglionic nerves release acetylcholine. Postganglionic release norepinepherine. • Come from the thoracic (ribs) & lumbar (small of back) vertebrae Parasympathetic (off) • Restores balance (rest & digest) • Long preganglionic nerve • Preganglionic & postganglionic release acetylcholine. • Come from the brain, cervical (neck) or the caudal (tail bone) area. • Master “off” nerve: Vagus Nerve controls: – Heart, Bronchi, Liver, Pancreas, Digestive tract 77 78 Chapter 13 Nervous System 79 Fill in the missing actions of the parasympathetic and Sympathetic ANS: (letters a-f) a. b. c. d. e. f. 80

Central nervous  system: Brain &  
spinal cord=  
coordinate incoming &  outgoing info. 
Peripheral nervous  system: carries  
information between  the organs/effectors  and the CNS.
6 
Peripheral Nervous System   all the portions of the NS outside of the brain and spinal cord. 
• Somatic NS 
Consists of nerves  connected to sensory  receptors and skeletal  muscles 
Permits voluntary action (ex. writing your name)   
• Autonomic NS 
Consists of the Sympathetic  and Parasympathetic 
systems (on/off switch) Permits the involuntary  functioning of blood  
vessels, glands, and  
internal organs such as  the bladder, stomach and  heart 
7 
Cells of the NS  
Two types: Glial cells (neuroglial) & neurons. 
• The Functions of Glial Cells: 
– Hold neurons in place 
– Provide neurons  
with nutrients 
– Insulate neurons 
– Remove cellular  
debris when neurons die 
-defend against infection
8 
Types of Neurons: 
• Sensory Neurons (afferent neurons):  relay info about environment from sensory  receptors to the CNS.     
• Interneurons: link neurons to other neurons  (found only in CNS) 
• Motor Neurons (efferent neurons):  carry impulses from the CNS to the  effectors (muscles, organs, glands)  produce response
9 
a. Label the neurons below as a interneuron, motor neuron and a  sensory-neuron:    
b. Where is each neuron found in the body? 
  
10
Anatomy of a Nerve Cell  • Neurons: vary in size, and appearance.  3 main jobs (input, integration & output)
  
11 
• Cell body: functional portion, when in groups out side of CNS  called: ganglion 
• Dendrites: short extensions that receive signals from other  neurons or environment 
• Axon: long extension that transmits impulses away to other  neurons or effectors.
  
12 
Myelinated Neurons
  
• Myelin sheath: peripheral neurons have white insulation around the  axon called which is formed by Schwann cells. 
– Myelin sheathing acts as an insulator preventing the loss of charged ions from  the axon, and allows conduction of faster nerve impulses. 
• Areas between myelin sheath: Nodes of Ranvier 
• Neurilemma: membrane surrounding axon, that promotes  
regeneration 
13

Decreased impulses  
to muscles 
If MS causes nerve signal loss, how would this effect the  muscles, the brain, and other organs?
14 
1. 
2. 
3. 
5. 
6.
7. 
STOP & THINK!:  
what does 1-7 represent? 
1. Dendrites  
2. Cell body (nucleus) 
3. Axon 
4. 
4. Schwann Cell 
5. Myelin Sheath 
6. Node of Ranvier 
7. Neurilemma 
15 
Question # 1

16
Reflex Arc

Reflex arc: 5 steps
17 
REFLEX ARC: automatic response controlled primarily by spinal cord. stimulus → receptor → sensory neuron → interneuron → motor neuron → effector organ → response

Reflex videos:  
http://bcs.whfreeman.com/WebPub/Biology/hillis1e/Animated%20Tutorials/at3404/at_3404_info_proc_spinal_ 
cord.html 
18 
2. http://health.howstuffworks.com/adam-200012.htm 
.htt:www.sumanasinc.comwebcontentanisamlesnonmaorsbioloreflexarcs.html
19
Question # 2 
20
Nerve Impulses (pg372) 
Nerves have two states: 
1. Resting potential 
• “polarized” 
• Resting nerve 
• Charge inside is -70mV 
2. Action potential 
• “depolarized” nerve 
• Charge inside jumps to +40mV 
21 Restin membrane: htts://www.outube.com/watch?v=b2ctEsGEe0&t=19s
Resting Membrane Potential • The membranes contain  
sodium-potassium pumps 
that pump out 3 Na+ and 2  
K+ in.  
• HOW -70mV? 
– Uses ATP (active transport) to  
pump 3 sodium ions out and 2  
potassium ions in. this unequal  
distribution of ions leads to a  
polarized membrane. 
– Presence of negatively charged  
plasma proteins and ions 
– K+leak channels allow K+to leave  
the inside of the axon.
22 
Nerve Impulse - The Action Potential
Steps: 
1. Depolarization: Nerve becomes more permeable to highly concentrated  Na+ than K+. This rapid influx of Na+ causes -70 to jump to +40mV. 
2. Repolarization: Na+ channels close, K+ gates open, and K+ diffuses out of  cell restoring original polarization.  
3. Refractory Period: recovery time (1-10ms) required before a neuron can  return to resting potential. pumping time required to produce another action  potential 
Hyperpolarization: K+ gates close slowly , so more K+ ions move out  than normal = more negative charge inside. 
23 
• Impulse video: https://www.youtube.com/watch?v=bfokof2YMVU&t=148s 
Nerve Impulse - The Action Potential Threshold potential will trigger an  
action potential or nerve impulse 
-The action potential is an all-or-none 
response, moves like a wave from cell  
body down the axon to next neuron.  
-Positively charged ions that rush into the  
neuron are attracted to adjacent negative  
ions.  
-Hyperpolarization in previous area (in  
refractory period) stops impulse from  
traveling backwards (re-pump Na+ back  
out before another impulse can be sent)
24 
25
Saltatory Conduction in Myelinated  
Axons 
Myelin sheathing has bare patches called nodes  
of Ranvier 
•Action potentials seem to jump from node to  
node (saltatory conduction) 
•Faster conduction than unmyelinated action potential

Myelination: 
27
Nerve impulse: https://www.youtube.com/watch?v=fHRC8SlLcH0&t=3s1. Identify and explain the three factors that contribute to the resting membrane potential. 2. Explain the difference between depolarization and the repolarization of a neuron? 
28 
Threshold: All-or-none Threshold level: minimum level of stimulus  
required to produce a response (> 2mV) 
All-or-none response: nerves or muscles  
respond completely or not at all. 
• Charge greater than minimum required  
will not produce a increased response 
Message priority determined by: 
1. More frequency of impulses (spinal gate  
theory) 
2. Some neurons have higher threshold  
levels, they only fire with an increased  
stimulus  
Therefore: The greater the number of  
impulses reaching the brain the greater the  
29 
intensity of the response. 
The Synapse – The space between!  
• A synaptic cleft divides  
at least 2 (usually more)  
neurons by ~20nm. 
• Presynaptic Neurons:  
carry impulses to the  
synapse 
• Postsynaptic Neurons:  
carry impulses away 
from synapse
30 
How does a signal move  
from one neuron to another? 
• The action potential will not move  
across the synapse 
• More synapses= slower transmission. (reflex arc has little  synapses) 
Neuro-transmitters (chemicals)  
brave the gap: 
•Released by the end plate of  
presynaptic neuron to the  
receptor sites of  
postsynaptic neuron. 
31 
•Move by diffusion 
Mechanism of Neurotransmission 
1. Action potential reaches end plate 
2. Ca2+ gates open influx of + ions 
3. Build-up of Ca2+ causes release of  
acetylcholine 
4. Acetylcholine released 
5. Acetylcholine binds with Na+ channels  
opening them (postsynaptic receptor sites) 
6. Na+ ions rush in causing depolariazation. 
7. Action potential continues through dendrite  
of post synaptic neuron. 
8. Presynaptic endplate membrane releases  
cholinsterase (enzyme) which destroys  
acetylcholine 
9. Na+ gates close, recovery phase begins 
Chemical synapse videos: 
32 
http://bcs.whfreeman.com/WebPub/Biology/hillis1e/Animated%2520Tutorials/at3403 
/at_3403_synaptic_trans.html
Neurotransmitter Jobs 
• Excitatory: triggers receptor proteins in post synaptic  cleft to allow positive ions in (ex. sodium) → 
Depolarization! & lowered threshold level! 
• Inhibitory: triggers potassium channels to open→ hyperpolarization! (increased threshold level)
Common Neurotransmitters: Dopamine 
	Function: 
Sensation of pleasure + body mov’t
	Serotonin 
	Regulates temp. + perception + mood control
	Endorphins 
	Natural painkiller + emotions
	Norepinepherine 
	Works with epinephrine (fight-flight response)
	GABA 
	Inhibitory (natural tranquilizer)
33

What would happen if the neurotransmitter on the post synaptic neuron was not broken  by cholinesterase? 
34 
Synaptic wonders Summation: 
Quit messing with my  synapses! 
-effect produced by the accumulation of transmitter  chemical from two or more neurons.  
-can be inhibitory or excitatory

threshold
35 
Neurotransmitter disorders 
Parkinson's Disease: 
-inadequate dopamine (inhibitory)  
causes involuntary muscle contraction -Michael j fox 
Alzheimer’s Disease: 
-inadequate acetylcholine (excitatory)  deterioration of memory & mental  
capacity.
36 
37

How does the  drug cocaine  affect synaptic  transmission?
38 
Question  
# 3

39
Question # 4

Question # 5

41
Question # 6

42
Question # 7

43
Question # 8

44
Question # 9

45
46
* The Central Nervous System controls  all of the body’s activities. 
* The Central Nervous System is  made of two main organs. 
1. The brain 
2. The spinal cord
47 
Protecting the CNS 
Control center consisting of brain & spinal cord • Skull/vertebrae: bone covering 
• Brain surrounded by protective  
membranes: Meninges 
– Outer layer: dura mater 
– Middle layer: arachnoid 
– Inner layer: pia mater 
• Cerebrospinal fluid: transport  
medium & shock absorber that  
circulates between inner &  
middle meninges and the central  
canal of the spinal cord.
48 
• Carries sensory nerve messages from receptors to the  brain and relays messages from the brain to effectors  (muscles, organs & glands). 
• Foramen magnum: opening in skull for spinal cord • Spinal cord travels within the vertebral backbone 
Gray vs white: 
• Gray: unmyelinated neurons/axons 
• White: myelinated neurons that connect spinal cord to brain Dorsal vs ventral: 
• Dorsal nerve: brings sensory info in 
• Ventral nerve: carries motor info out to effectors (muscles/glands)
49 
50
Dorsal root ganglion
51 
3 regions:  
Forebrain  
(reason, intellect, memory,  language, personality) 
Midbrain 
(relay center for eye & ear) 
Hindbrain 
(balance, muscle control,  autonomic control)
52 
Gray matter 
White 
matter 
Ventricles
54
Forebrain 
Contains: 
• Cerebrum: largest portion of brain, surface is the cerebral  cortex (gray matter). 
– coordinating center for: 
• Motor actions, speech, reasoning, memory, personality 
– 2 distinct hemi-spheres (left: verbal skills, right: visual/spatial awareness)  linked by the corpus callosum (communication bridge) 
– Each hemi-sphere has 4 lobes: 
• Frontal, temporal, parietal, and occipital 
• Thalamus: interprets sensory information (relay station) 
• Hypothalamus & Pituitary: unites nervous and endocrine  systems (autonomic functions) 
• Olfactory bulbs: detect smell
55 
Cerebrum lobes: 
Frontal: 
-voluntary muscles  
(walking, speech) 
-personality 
-memory 
Temporal: 
-interpret sensory info  
(hearing, smell) 
Parietal: 
-touch, pain, taste  
(temperature) 
-emotions 
-Interpreting speech 
Occipital: 
- vision
56 
57
Midbrain
• 4 spheres of gray  matter 
• Relay center for eye  & ear reflexes 
58 
Hindbrain 
Contains: 
• Cerebellum: controls limb mov’t, balance,  muscle tone 
• Pons: (bridge) relay station between two  regions of cerebellum and the medulla 
• Medulla Oblongata: joins spinal cord to  cerebellum, site of autonomic nerve control  (breathing mov’ts, diameter of blood vessels…)
59 
Interpreting Speech 
• In Cerebrum: 
• Broca’s Area: coordinates speech  
muscles & translates thoughts into  
speech (Frontal lobe) 
• Wernicke’s Area: language  
comprehension & storage. (left  
Temporal lobe) 
Silk & Milk 
Out loud get your partner to spell S-I-L-K. Repeat. Repeat. 
60 
Now get your partner to say "silk" three times fast. 
Now ask them what do cows drink...
Brain mapping 
• Different areas have  
specific functions 
• Other areas can  
substitute for  
Damaged areas. 
61 
Lips 
Jaw 
Tongue 
Frontal lobe Parietal lobe 
Toes 
Pharynx
Genitalia 
Primary 
motor cortex 
Abdominal organs 
Primary 
somatosensory cortex 
63
Brain imaging technology 
PET (positron emission tomography)- radioactive  glucose is consumed in certain areas of the  brain.  
MRI (magnetic resonance imaging)- giant magnet  detects changes in H+ that emit radio signals. 
MRI game:  
https://educationalgames.nobelprize.org/educational/me dicine/mri/game/index.html
64 
Hearing words 
Speaking words 
Seeing 
words 
Generating words
Max Min 
LABEL The Brain Cerebrum 
Corpus Callosum
Hypothalamus 
Pituitary Gland 
Pons 
Cerebellum 
Medulla Oblongata 
Question # 10

67
Question # 11

68
Question # 12 
69
Question # 13 
70
Question # 14

71
Peripheral Nervous System 
PNS 2 parts: 
Both contain sensory  
and effector nerves 
1. Autonomic system: 
nerves designed to  
maintain internal 
homeostasis (not under  
conscious control) 
2. Somatic system: 
designed to adjust to  
external stimuli by  
controlling skeletal muscle  
(under conscious control),  
exception - reflexes
72 
Composed of:  
A. 12 paired cranial nerves 
– Control vision, hearing, balance, taste,  smell, facial, tongue, neck & head mov’t  B. 31 paired spinal nerves  
– Control skeletal muscles
73

Sensory Somatic System Divisions 
A. Cranial nerves 
B. Spinal nerves
74 
Involuntary internal homeostatic control. 
Ex. Controls smooth muscle, internal  
organs, glands 
controls
2 types of ANS nerves: 
1st group: preganglionic (CNS→ ganglion) 
2nd group: postganglionic (ganglion → target organ/gland/muscle) 
75 
Comparison of Somatic and Autonomic Systems76 
Autonomic Nervous System halves 
Sympathetic (on) • Prepares body for stress  (fight or flight) 
• Short preganglionic nerve 
• Preganglionic nerves release  acetylcholine. Postganglionic  release norepinepherine. 
• Come from the thoracic (ribs) &  lumbar (small of back) vertebrae
Parasympathetic (off) • Restores balance (rest & digest) 
• Long preganglionic nerve 
• Preganglionic & postganglionic  release acetylcholine.  
• Come from the brain, cervical  (neck) or the caudal (tail bone)  area. 
• Master “off” nerve: Vagus Nerve controls: 
– Heart, Bronchi, Liver, Pancreas,  Digestive tract 
77 
78
Chapter 13 Nervous System 79

Fill in the missing  actions of the  parasympathetic  and Sympathetic  ANS: 
(letters a-f) 
a. 
b. 
c. 
d. 
e. 
f.
80

Transcript for:Overview of Nervous System Functions

Transcript for:
Overview of Nervous System Functions