6.a&p i nervous system2010
Upcoming SlideShare
Loading in...5
×
 

6.a&p i nervous system2010

on

  • 2,521 views

A and P I Nervous System Power Point

A and P I Nervous System Power Point

Statistics

Views

Total Views
2,521
Views on SlideShare
2,521
Embed Views
0

Actions

Likes
0
Downloads
95
Comments
0

0 Embeds 0

No embeds

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

6.a&p i nervous system2010 6.a&p i nervous system2010 Presentation Transcript

  • Unit III- Nervous System
    • Marieb, 8th Edition
      • Chaps 11-12; skim 14
      • pages 385-483; 491-493, 510- 519 skim; skim 525-539
      • Book and CD-ROM
    • CD-ROMS in SLC Rm 1214
  •  
  •  
    • Nervous System
    • I. A. Introduction
      • 1. Homeostasis - maintain internal life functions within a normal range
      • 2. Communication an important component
        • Detect a problem - sensory system
        • Correct the problem with an adjustment
        • Communication between two components involves the nervous system and its principles
    • I. B. Organization of the Nervous System
      • 1. Central Nervous System (CNS)
        • Brain
        • Spinal cord
      • 2. Peripheral Nervous System (PNS)
        • a) Somatic Nervous System
          • Voluntary system that controls skeletal muscles attached to limbs / bones
        • b) Autonomic Nervous System (ANS)
          • Involuntary system that controls cardiac and smooth muscles (stomach, uterus, blood vessels, etc.) and glands
          • Sympathetic and Parasympathetic Divisions
    • I. C. Cellular Neuroanatomy
      • 1. Nerve Cell = Neuron
        • Cell body = nucleus, Rough ER, neurotubules, Golgi, etc.
        • Dendrites = processes which receive input to cell body
        • Axon = longer process which communicates with other neurons
        • Terminal Branches / End Terminals = end of axon that communicates with next neuron or muscle or gland
      • How can we protect this long axonal process?
    Fig. 11.4
    • I. C. Cellular Neuroanatomy
      • 2. Glial Cells - supportive cells of the CNS
        • Protective, metabolic, phagocytosis, transport nutrients & wastes between neurons & blood vessels
        • Schwann cells in the PNS and a glial cell in the CNS produce myelin sheath - phospholipids membranes of cell wrapped around neuronal axon, function:
          • protection - regeneration
          • Speed up rate of conduction down axon (node to node)
    Fig. 48-5
  • Fig. 11.3
  • Fig. 48-5
  • Fig. 11.5
  • Fig. 13-4
  • Fig. 48-4 and Table 11.1
    • I.C. Cellular Neuroanatomy
      • 3. Types of Neurons
        • a) Sensory / Afferent Neurons - carry information about the environment (internal and external) towards the CNS
        • b) Motor / Efferent Neurons - carry information away from the CNS towards the periphery & effectors (muscle or gland)
        • c) Interneuron / Association Neurons
          • Only within the CNS
          • Connect two other neurons together, any combination
  • Fig. 48-1
    • I. C. 4. Synapse space or gap between a neuron and a neuron or a neuron and an effector
    • I. C. 5. Stimulus Response Mechanism
      • a) Stimulus
        • Change in the environment
      • b) Response
        • Reaction by the organism in response to the original stimulus
      • c) Basis of all functioning of the nervous system, communication directed at stimulus - response mechanisms basis of behavior, learning, etc.
  • II. Impulse conduction
    • A. Introduction
      • 1. 1930s - at Woods Hole Mass., work on the giant squid axon - nonconducting cell
        • Large enough to isolate from animal and remove the cellular/axonal cytoplasm and chemically analyze
  • 1a. Ionic Distribution
    • EXTRACELLULAR INTRACELLULAR
    • SODIUM - Na + Na +
        • HIGH LOW
    • POTASSIUM - K + K +
        • LOW HIGH
    • CHLORIDE - Cl - Cl -
        • HIGH LOW
    • HIGH PROTEINS -
    • SEMI-PERMEABLE MEMBRANE
  • 1b. CHANGES BASED UPON NORMAL NET DIFFUSION
    • EXTRACELLULAR INTRACELLULAR
    • SODIUM - Na + Na +
        • HIGH LOW
    • POTASSIUM - K + K +
        • LOW HIGH
    • CHLORIDE - Cl - Cl -
        • HIGH LOW
    • HIGH PROTEINS -
    • SEMI-PERMEABLE MEMBRANE
  • 1c. CHANGES BASED UPON NORMAL NET DIFFUSION OPPOSED BY ACTIVE TRANSPORT AND ELECTROSTATIC CHARGES
    • EXTRACELLULAR INTRACELLULAR
    • SODIUM - Na + Na +
        • HIGH LOW
        • PASSIVE
        • ACTIVE
    • POTASSIUM - K + K +
        • LOW HIGH
        • PASSIVE
        • ACTIVE
    • CHLORIDE - Cl - Cl -
        • HIGH LOW
        • ELECTROSTATIC
    • NEGATIVE
    • HIGH PROTEINS -
    • SEMI-PERMEABLE MEMBRANE
    • 2. Summary of Above Ionic Behaviors
    • 2a. Against maintaining the neuronal ionic gradient
      • Passive diffusion (high to low)
    • 2b. Favors maintaining the neuronal ionic gradient
      • Active transport of the Na + - K + pump
      • Electrostatic forces due to intracellular protein negative charge
        • Keeps chloride out
        • Binds to positive K + to keep intracellular
  • Figure 48.6 Negative Intracellular Electrical Charge
  • Fig. 48-7
  •  
  • II. A. 3.Terms:
    • a) potential difference - difference in electrical charge
    • b) polarized membrane - potential difference across membrane due to combination of membrane permeability and ionic concentrations
    • c) resting potential - non-conducting neuron with a potential difference across the membrane equal to -70 to -90 millivolts (mV) inside compared to outside
    • d) action potential or nerve impulse or spike a brief transient change in resting potential
  • Fig. 48.6 & 11.7 II.B. Action Potential 1. Stimulating and recording setup stimulator
    • ACTION POTENTIAL
    • +
    • -
    • -50
    • -70
    • TIME msec
    2 3 4 5 6 7 8 9 10 0 mV
    • B. Action Potential
      • 2. Electrode enters the axon
      • 3. Excitatory stimulus - below threshold
      • 4. Threshold stimulus - (outside) sodium gates suddenly open and the Na-K pump OFF
      • 5. Depolarization - sodium continues to enter past 0mV (loss of polarization)
      • 6. Sodium inactivation around -35mV as (inside) gate closes - too much positive charge inside
      • 7. Repolarization - potassium out since Na + gates closed & K + no longer attracted to positive protein
      • 8. Hyperpolarization - pump actively back on as K + exit overshoots resting potential
      • 9. Equilibrium or normal resting potential
      • 10. Inhibitory stimulus - a hyperpolarizing stimulus, harder to excite neuron during this time period
  •  
  • Fig. 11.8
  • FIG. 48.8, 11.9
  • FIG. 48.9
  • FIG. 48.9
  • FIG. 48.9
  • FIG. 48.9
  • FIG. 48.9 or 11.12
    • 11. All - or - Nothing Phenomenon
      • Once threshold is reached, no variation in strength of response
      • How does stronger stimulus manifest itself?
      • Increase in frequency - not change in magnitude or height of action potential
    • 12. a) Absolute Refractory Period - impossible to stimulate a neuron a second time while the Na - K pump turned off, from threshold to repolarization (while K + moving inwards)
      • b) Relative Refractory Period - can stimulate a neuron with a stronger stimulus, to reach threshold, while neuron in hyperpolarization
  • Fig. 11.13
    • 13. Propagation
      • Signal does not die out before reaching the end of the axon, nor does it have to boosted
      • Each area act as stimulus for the next portion of the membrane
      • Depolarizing region with its positive charge moves into the adjacent negatively charges “sink”
      • Why doesn’t action potential go BOTH ways in the axon??
    Fig. 48-10 & 11.12
  • Fig. 11.14
    • 14. Factors influencing conduction velocity
      • Size of axon - larger diameter means faster conducting velocity
      • Temperature - higher temperature means faster conduction velocity
        • Cold block on axon stops conduction
      • Myelin sheath faster conduction than non-myelinated axon
      • Fig. 11.16
  •  
  • III. Synaptic Transmission
    • 1. Synapse = space or gap between two neurons or a neuron and an effectors (muscle or gland)
      • Electrical synapse - smaller gap where electrical charge (action potential) of a neuron jumps the gap to stimulate second neuron (electric eel)
      • Chemical synapse - larger space or gap where a chemical diffuses across synapse
      • Large number of synapses on a neuron’s cell body and dendrites
  • Fig. 48-13
  •  
  • Fig. 11.16
    • 2. Anatomy of a synapse
      • Pre-synaptic unit - end terminals of axon that comes before the synapse, has action potential invading the end terminal where synaptic vesicles are located
      • Synaptic vesicles contain neurotransmitters which will be released into the (chemical) synapse
      • Post-synaptic unit - dendrites or the cell body (possibly the axon) of the next neuron in the sequence, after the synapse, or could be an effectors
  • Signal travels from pre-synaptic, across synapse, to post-synaptic unit
    • 3. Neurotransmitter chemicals
      • a) Synaptic vesicle of the pre-synaptic side are membrane bound vesicles that contain specific chemicals = neurotransmitters
      • b) There are dozens of different types of neurotransmitters
      • c) Norepinephrine (norepi/NE)
        • Found in the CNS and the Autonomic NS
        • Stimulates different parts of the CNS
        • Can stimulate OR inhibit the ANS (see VI)
        • Often similar action to Epinephrine
    • 3. Neurotransmitters (continued)
      • d) Acetylcholine (Ach)
        • Found in the CNS and the Peripheral NS
        • Stimulates in the Somatic NS - skeletal muscles
        • Can stimulate OR inhibit the ANS (see VI) - involuntary muscle and glands
      • e) Serotonin
        • Found only in the CNS
        • Inhibits a variety of neurons
        • Anti-depressants (Prozac) work on serotonin
      • f) GABA - inhibitory in the CNS
    • 3. Neurotransmitters (continued)
      • g) Dopamine
        • Found primarily in the CNS
        • Can stimulate or inhibit different areas
      • h) Nitric Oxide (NO)
        • Gas molecule released as a local regulator peripherally
        • NO causes smooth muscle to relax
        • Work on blood vessels, smooth muscle of penis, etc.
  • A&P - Table 11.3
    • 4. Actions at the synapse
      • a) pre-synaptic unit fires / depolarizes / is active as an electrical charge is propagated down the axon (remember Na + /K + changes of part II)
      • b) the electrical signal invades the pre-synaptic area of the terminal branch and the electrical signal dies - Why might signal die in this area?
      • c) Calcium channels open and Ca ++ enters the pre-synaptic area from the extracellular environment
      • d) Ca ++ causes the synaptic vesicles to migrate towards the pre-synaptic membrane and fuse with the membrane = exocytosis
      • e) the vesicle contents - neurotransmitter - is released into the synaptic space and starts to diffuse across to the post-synaptic side
  • Fig. 48-12 A&P Flix
  •  
    • 4. Actions at synapse (continued)
      • f) as chemical reaches post-synaptic membrane, it reacts with specific receptors on this side to trigger a response by the post-synaptic unit due to a change in post-synaptic membrane permeability
      • g) if the post-synaptic membrane is now more permeable to Na + by opening sodium channels,
        • this neuron becomes excited and depolarizes
      • h) if the post-synaptic membrane is now more permeable to K + or Cl -
        • this neuron becomes inhibited and hyperpolarizes - WHY?
      • A single post-synaptic neuron will have different types of receptors on its membrane - like a door with several locks - each receptor can be activated by a different chemical
  • Fig. 48-14 or (11-19) EPSP = excitatory postsynaptic potential (depolarizing) IPSP = inhibitory postsynaptic potential (hyperpolarizing)
  • Fig. 11-6
    • 5. Summary
      • a) Excitation or Depolarization
        • due to increase in positive charges intracellular which brings membrane potential towards threshold which allows sodium gates to open and neuron fires
      • b) Inhibition or Hyperpolarization
        • Due to an increase in negative charges intracellular or positive charges leaving (K + ) which brings the membrane potential away from threshold, making it HARDER to fire this neuron
      • c) How do we turn off the neurotransmitter?
    • 5d) As long as neurotransmitter is present in the synapse, it will keep reacting with post-synaptic receptors and keep the gates/channels open or closed and the reaction continues.
      • 1. Norepinephrine and Epinephrine are transported AWAY from synapse or transported back into the pre-synaptic unit to be recycles
      • 2. Acetylcholine has specific enzyme in the synapse - Acetylcholinesterase - which cleaves the Ach into Acetyl plus Choline to be recycled
    • 6. Summation and Integration
      • Number of excitatory vs. inhibitory synaptic inputs determine post-synaptic response
      • Time course of inputs
      • Examples
        • Car - brake and gas pedal
        • Preying Mantis
    • 7. Effect of Drugs on Synaptic Activity
      • a) Insecticide or nerve gas
        • What is behavior of animal exposed to this poison?
        • Block the action the enzyme which destroys Ach
        • Acetylcholinesterase = rigidity of muscles
      • b) Curare
        • Derived from plants
        • Blocks receptors on skeletal muscle
        • Prevents Ach from working - muscle flaccid/relaxed
      • c) Stimulants / Amphetamines
        • Mimic action of Norepi in brain
        • Stimulate release of Norepi in brain
        • Dependency
        • What over counter pill a stimulant, but not used to keep you awake?
    • 7. Drugs (continued)
      • d) Depressants / Anesthetics
        • Inhibit many centers in the brain
        • Base of brain and higher up
        • Overdose = depresses respiratory centers
        • Alcohol?
      • e) LSD / Hallucinogenic Drugs
        • Normally - there is inhibition between the different sensory inputs
        • Smell goes to one place, sight another region
        • These drugs cause overspill of one input to different areas of the brain, so you see a sound, taste a light
        • Yellow Submarine experiment
  •  
  • IV. Spinal cord A. Definitions
    • 1. Grey Matter - collection of neuron cell bodies and dendrites within the CNS
    • 2. White Matter - collection of myleinated axons within the CNS
    • 3. Nucleus - a cluster or collection of related neurons within the CNS
    • 4. Ganglion - a collection of related neuron cell bodies outside the CNS, in the periphery
    • 5. Interneuron or Association neuron - connecting neuron within the CNS
  • Fig. 12.31/33
    • 6. Ascending tracts - related sensory axons within the white matter of the CNS
    • 7. Descending tracts - related motor axons within the white matter of the CNS
    • 8. Meninges - three membranes that cover the entire CNS (brain and spinal cord)
      • Dura Mata - tough , fibrous outer membrane that protects
      • Arachnoid membrane - middle layer that supports the blood vessels in a sub-arachnoid space (web like appearance)
      • Pia Mata - inner most membrane, (gentle) tissue paper thin but helps shape CNS, which normally has a jell-like consistency
  • Fig. 12.24
    • 9. Cerebral Spinal Fluid - CSF
      • a) Formed in ventricles of brain as a filtrate of blood, CSF circulates through ventricles and central canal
        • Stabilize extracellular environment
        • Tight junctions between capillary cells plus glial cells
        • Selective, not absolute permeability - varies in different parts of the brain (hypothalamus, vomit center)
      • b) Ventricles - fluid-filled spaces of brain (large lateral, 3rd, 4th ventricles)
      • c) CSF carries nutrients, hormones, white blood cells and acts as shock absorber
      • d) After circulating in the CNS, CSF returns to veins on the surface of the brain, carrying wastes
  • Fig. 12.26
  • Fig. 12.26b
    • 9. CSF (continued)
      • e) Meningitis - inflammation of the meninges, bacterial or viral, can spread to the nervous tissue of the CNS
      • f) Encephalitis - brain inflammation
      • g) Hydrocephalus - water on the brain - CSF forms normally, but there is an obstruction to flow and it accumulates in ventricles
        • New born - enlarged head since skull bones not fused
        • Adult - compresses blood vessels and crushes soft nervous tissue
        • Remove obstruction or insert shunt to drain CSF
    • 10. Spinal Puncture
      • Removal of CSF below L 1 where spinal cord has ended
      • Nerves exiting at this point drift away from needle
      • Fluid removed from subarachnoid space and analyzed
      • Look for infection, excessive white blood cells, proteins, removal of hydrostatic pressure on the CNS
  • IV. B. Spinal cord anatomy
    • 1. Spinal cord runs from base of brain to L 1 segment with enlargements in cervical and lumbar areas for serving arms and legs and 31 pairs of mixed spinal nerves
    • 2. Dermatome - area of skin that has sensory innervations from a specific spinal nerve, there is some overlap
    • 3. Spinal cord cross-section: Identify
      • Deeper anterior/ventral median fissure
      • Shallow posterior/dorsal median sulcus
      • Central canal in middle of grey matter
      • Surrounding white matter
      • Dorsal and ventral horns connecting to a spinal nerve
  • Fig. 48-16
  • Fig. 13.12
  • IV. B. Spinal Cord anatomy (continued)
    • 4. Trace the following pathway: (use diagram in notes)
      • Sensory receptor or dendrites (stimulus)
      • Myelinated dendrite passes through spinal nerve
      • Travels up dorsal root
      • Dendrite finds its own sensory cell body in dorsal root ganglion
      • Central process/axon exits ganglion and travels in dorsal root to spinal cord
      • Enters dorsal horn proper of grey matter and synapses with an interneuron
      • Interneuron sends branch to brain AND branch to ventral area of grey matter and
      • Synapses with motor cell body in ventral horn
      • Motor axon exits spinal cord via ventral root and enters same spinal nerve (mixed)
      • Motor axon innervates an effector and a response occurs
    • 5. There are synapses -
      • One between incoming sensory axon and dendrite/cell body of interneuron
      • Second between the terminal branch of the interneuron and the dendrite/cell body of the motor neuron
      • Third between the motor terminal branch and the effector (neuromuscular junction)
      • Why is there not a synapse in the dorsal root ganglion?
    • 6. Injections:
      • Epidural - outside the dura mater and outside the spinal cord (more sensory in effect)
      • Subdural - into the CSF area of the middle arachnoid membrane and penetrates the spinal cord (both sensory and motor in its effects)
  • IV. C. Spinal Cord Reflexes
    • 1. Reflex - innate, automatic response to a given stimulus
    • 2. Reflex arc - functional unit of the stimulus-response mechanism, highly specific neural pathway involving above (B.4.)
    • 3. Two types of reflexes
      • Inborn / inherited
      • Learned / acquired / conditioned
  •  
  • Fig. 48-3& A&P Flix
  • Fig.13.18
    • 4. Inborn or inherited or 2 neuron reflex
      • Pupillary eye reflex to light, heart rate
      • Patellar knee reflex, respiration
      • 2 neuron reflex - sensory synapses directly with motor output, monosynaptic
      • No interneuron - no involvement of brain
      • No conscious control over response
    • 5. Learned or conditioned or polysynaptic or 3 neuron reflex
      • Finger on hot stove
      • 3 neurons - sensory, interneuron, motor, multisynaptic
      • Interneuron involves the brain which adds a conscious control over the motor response
      • Can you leave your finger on a hot stove for 30 seconds?
    • 6. Crossed Reflex
      • Interneuron crosses to opposite side of the spinal cord as well
      • Reflex excites extensor on one side and flexor on the other side
      • Think of balancing on see-saw or stepping on a sharp tack
    Fig. 13.19
  • Figs. 12.1/2 V. BRAIN
  • V. Brain
    • A. Cerebrum or Cerebral Hemispheres
      • 1. Mammals - grows over other, older parts of the brain, assumed functions or control over older portions
        • Furrows and convolutions of surface to increase surface area of gray matter
        • White matter of cortex = ascending and descending tracts plus interneurons within cortex
        • Left - Right Hemispheres connected via the Corpus Callosum - band of connecting interneuron axons
        • Ventricles and CSF
        • Function of the left brain?? Anatomical control??
        • Function of the right brain?? Anatomical control??
        • Lobes = frontal, parietal, occipital, temporal
  • Fig. 12.5
  • Fig. 12.4
  • Fig. 12.10
    • Figs. 12.6
  • Fig. 48-24
  • Fig. 28-25 or 12.9
    • A. Cerebrum (continued)
      • 2. Function and locations
        • Controls learned behavior
        • Highest reflection of sensory input (parietal)
          • Vision - occipital
          • Hearing - temporal
          • Olfaction - temporal
        • Highest origin of motor output (frontal)
        • Integrative functions for both
        • Intelligence
        • Memory
        • Language and speech (frontal & temporal)
        • Emotions (see limbic system)
  • Fig. 12.8
  • Fig. 12.8
  • Fig. 28-20
  • Fig. 28-27 or 12.18
    • A. Cerebrum (continued)
      • 3. Cut corpus callosum = split brain
      • 4. Limbic System
        • Emotion due to interactions with sensory input and association centers
        • Memory - Hippocampus
        • Frontal lobotomy
      • 5. Basal Ganglia
        • Conscious and unconscious movements
        • Movement sequencing
        • Parkinson’s and Huntington’s diseases
        • Dopamine involvement ( Awakenings )
  • Fig. 12.11b Basal Ganglia
  • Fig. 12.17
    • B. Cerebellum
      • 1. Under cortex, above medulla
      • 2. Convoluted surface with internal axons
      • 3. Communicates with many other areas (F 4 .)
        • Sensory and motor areas
      • 4. Monitors and corrects motor activities
        • Posture
        • Muscle coordination
        • Error control compares intention with performance
  • Fig. 12.12
  • Fig. 12.13
    • C. Thalamus
      • 1. Collection of nuclei bordering the third ventricle
      • 2. Communicates with other areas (see F 4 below)
      • 3. Relay for sensory input to the cerebrum
      • 4. Conscious recognition
    • D. Hypothalamus
      • 1. Below the thalamus, above the pituitary gland
      • 2. Communicates with other areas (see F 4 below)
      • 3. Psychosomatic disorders ??
        • Endocrine functions - produces different hormones that control the pituitary and other body organs and functions
      • 4. Nuclei controlling Autonomic Functions
        • Food intake Fluid balance
        • Temperature regulation Sex Drive
        • Pleasure - Pain
    • E. Pons
      • 1. Posterior to the hypothalamus, part of the Brain Stem
      • 2. Communicates with other areas (F.)
      • 3. Influences other breathing centers of brain
    • F. Medulla (oblongata)
      • 1. Part of the Brain Stem, connects the brain to the spinal cord
      • 2. Conduction pathway for incoming sensory axons and outgoing motor axons
      • 3. Nuclei that control Vital Reflexes
        • Cardiac Respiratory centers
        • Swallow Cough Vomit centers
      • 4. Origin of the Reticular formation
  • Fig. 12.16a/b
  • Fig. 12.16c
  • Fig. 28-21 or 12.19
  • F. Medulla 4. Reticular formation (continued)
      • Ability to facilitate or inhibit incoming sensory and outgoing motor activities
        • Aids in ignoring certain stimuli as brain processes other inputs
      • Responsible for normal arousal of the higher centers of brain
      • Patient in coma
      • Muscle jerk as one falls asleep
        • Response???
    • G. EEG or Brain Waves
      • External detection of depolarizations and hyperpolarizations over brain
      • Alpha = quiet rest Beta = active
      • Theta = stress Delta = sleep
  • Fig. 48-22 Fig. 12.20
  • Fig. 13.5
    • H. Cranial Nerves
      • 1. 12 pairs exiting/entering from the brainstem
      • 2. Olfactory (#1) - sensory
      • 3. Optic (#2) - sensory to optic chiasm
      • 4. Trigeminal (#5) - mixed - chewing and facial sensations
      • 5. Vagus (#10) - mixed from.to all over body including cardiac, visceral and skeletal
    • I. Neural Disorders
      • 1. Polio - viral degeneration of ventral horn motor cell bodies of spinal cord
      • 2. Cerebral palsy - voluntary muscles are poorly controlled due to brain damage during fetal development or birth (oxygen deprivation)
    • I. Disorders (continued)
      • 3. Parkinson’s Disease - degeneration of dopamine producing cells of the substantia nigra, which target Basal Ganglia cells of the inner cerebrum
        • Tremors
        • Slow in initiating and executing voluntary motion
        • L-dopa compounds, fetal tissue, genetically engineered adult cells
      • 4. Multiple Sclerosis - autoimmune loss of myelin from motor and sensory neurons causes short-circuiting of signals
        • Since axon healthy, variable remissions occur
    • 5. Alzheimer’s Disease - progressive degeneration of the brain resulting in dementia (genetic factors)
      • Ach problems
      • Structural changes in cerebrum and hippocampus
      • Protein bound to beta amyloid protein plus neurofibrillar tangles in cell body
    • 6. Stroke or CVA - blockage of blood circulation to brain and brain tissue dies
      • Caused by clot, compression by hemorrhaging or edema
      • Atherosclerosis - narrowing of blood vessel by deposits
  • VI. Autonomic Nervous System
    • 1. Peripheral Nervous system
      • Somatic NS -
      • Autonomic NS - involuntary motor system that connects to cardiac and smooth muscles and glands
    • 2. Two divisions of the ANS
      • Parasympathetic NS
      • Sympathetic NS
    • 3. Dual Innervations - both parasympathetic and sympathetic systems connect to the same effectors
      • Heart Intestine Salivary glands etc.
      • Why have two systems to same organs?
  • Fig. 14.2
  • Fig. 14.3
    • 4. Antagonist Functions of the 2 ANS divisions
      • One system excites and the other system inhibits
    • Organ Parasympathetic Sympathetic
    • Heart
    • Smooth
    • muscle
    • Of
    • Digestive
    • System
  • Organ Parasympathetic Sympathetic Inhibits Heart Rate & Strength of beat Heart (cardiac muscle) Increases HR & Strength of beat Stimulates Peristalsis - smooth rhythmic contraction of gut Smooth Muscle of Digestive System Inhibits Peristalsis
    • 5. Properties of Parasympathetic NS
      • a) 80% of all parasympathetic activity from brain is associated with the Vagus Nerve (10th cranial nerve), all parasympathetic nerves originate from the top or bottom of the spinal cord
      • b) main neurotransmitter released is Acetylcholine
      • c) main functions: conserve or restore energy levels in the body
        • Appetite related
        • Digestion
        • excretion
  • Figs. 14.4/6
    • 6. Properties of Sympathetic NS
      • a) no one single nerve, but nerves originate from the middle of the spinal cord
      • b) main neurotransmitter released is Norepinephrine plus these nerves also release hormones of the adrenal gland to prolong the actions of the sympathetics
      • c) main function: utilize energy
        • Fight or Flight Syndrome
        • Stress Related - opposite of homeostasis
      • d) too much stress causes imbalance between these two systems resulting in changes in blood pressure, ulcers, heart arrhythmias, etc.
      • e) reduce stress in your life - don’t let Biology get to you!
  • Fig. 14.9 Levels of ANS Control
  • THANKS FOR A GREAT SEMESTER