Chapter 9 Nervous Tissue-Chapter 10 Brain Note-taking and study guide

Vocabulary Words• Autonomic nervous

system• Enteric nervous

system• Ganglia• Neuron• Cell body• Dendrites• Axon• Nodes of Ranvier• Myelin Sheath• Central Nervous

System

• White matter• Gray matter• Neuroglia• Astrocytes• microglia• Oligodendrocytes• Schwann Cells• Satellite cells• Ependymal cells• Membrane

potential• Peripheral Nervous

System• Somatic Nervous

System

• Depolarizing phase• Repolarizing phase• conduction• Synapse• Neurotransmitter• Leakage channels• Gated channels• Resting membrane

potential• Action potential

Structure and Organization

• Central Nervous System (CNS)

• Peripheral Nervous System (PNS)

• Subdivided: Somatic (SNS) & Autonomic (ANS) nervous systems, (ENS) enteric

nervous system

• INPUT-Afferent or Sensory division

• OUTPUT- Efferent or Motor division

• Brain-

• Spinal cord–

• Nerves-

– Cranial emerge from _____________________________; spinal nerves-

emerge from __________________________________

• Ganglia-

• Enteric plexuses-

• Sensory receptors-

• Functions

• Sensory Receptors & afferent nerves

– ___________________________________________________________

_

• Integration- information processing

– Perception = ______________________________________________

– Carry by ___________________________________

• Motor activity- efferent nerves

– _________________________________________________________

Nervous System

• Neuron= __________________________________________

– Specialized for __________________________ &

_________________________________

• Neuroglia cells-

______________________________________________________

– Neuroglia critical for ________________________________ of

interstitial fluid around neurons

Neuronal Structure

• Cell body- _____________________________________________________

• Dendrites________________________________________________________

• Axon____________________________________________________________

– Emerges at cone-shaped axon hillock

• Axon terminals -_________________________________________________

Myelination

• Axons covered with a ____________________________________

– Many layered ________________________________________ creating

___________________________________________

– Increases speed of ___________________________________________.

• Nodes of Ranvier= _______________________________________________

– Nodes are important for ______________________________________

• Some diseases destroy ______________________________ E.g. multiple

sclerosis & Tay-Sachs

Gray and White Matter

• White matter- ________________________________________

• Gray matter- __________________________________________

• spinal cord gray matter is centrally located

• Gray matter in brain covers ___________________________________________

– cortex

• deep cluster of neuronal cell bodies =

__________________________________

• Bundle of white matter in CNS= __________________________

•

Neuroglia

• ~ half the volume of CNS

• Cells ____________________________________

• _________________________________________________ and fill in brain

areas

• Do not ______________________________________________

• Astrocytes- _____________________________________________________

• Oligodendrocytes- _____________________________________________

• microglia - ________________________________

• Ependymal cells- __________________________________________________

• Schwann-

___________________________________________________________

• Satellite cells- __________________________________________________

Action Potentials

• Action potentials = ________________________________

• Require a __________________________________

– electrical charge difference across cell membrane – like a Battery

Ion Channels

• Ion Channels-

_______________________________________________________________

• Two types: leakage channels and gated channels

• Leakage channels-_______________________________________________

• Gated channels-___________________________________________________

• If no action potential then resting cell has

_______________________________________________

• Allow ____________________________________________ to diffuse across

membrane

• Move from _________________________________________________

• or toward area of ____________________________________________

• Voltage-

______________________________________________________________

Resting Membrane Potential

• Leakage channels

• Cytosol __________________________________ & interstitial fluid high in

________________________ (sodium –potassium pumps)

• Leakage lets ___________________ through easily and

______________________ poorly

• Starts ______________________________________ and

_________________________________, slowly changes to the opposite as ions

diffuse.

• Actual value depends on the relative

_______________________________________

•

Action Potential (AP)

• Series of active events

• Channels _______________________________________________

• Some ______________________________________ is required to reach a

voltage threshold (~ = - 55 mv)

• Stimulus = any event bringing membrane to ____________________________

• Then

• Depolarizing phase-

• _________________________________________________________________

_

• Repolarizing phase-

• _________________________________________________________________

_

• May overshoot =____________________________________________________

• Then recovery to rest.

• ______________________________ to reach threshold

• Na+ channel opens=> Na+ ions enter=> positive potential=>Causes K+ channel

opening =>repolarization

All or None

• This sequence is always the same

• If ________________________________ is met, then the same size of changes

occur, __________________________________________________________

• Stimulus must reach threshold to start, if it’s

_____________________________________, NO AP!

• After one AP there is a

_________________________________________________________________

_________________________________________________________________

__

•

Conduction of Nerve Impulses

• Each section ___________________________________________________

• __________________________________________________ keeps it going the

right direction

• unmyelinated fiber- ______________________________________

• With myelin- ___________________________________________

– Can only be triggered at

___________________________________________

• Myelinated fibers __________________________________________________

•

Synaptic Transmission

• Sequence of events at synapse

• Triggered by ____________________________________________ of the

Action Potential

• Sending neuron =_______________________________

• Receiving neuron = ____________________________________

• Space between = _________________________________________

• Neurotransmitter

_____________________________________________________

• AP arrives at ____________________________=>

• Opens ______________________________ channels=>

• _______________________ into cell

• increased ______________________________ =>

• exocytosis of ____________________________=>

• Neurotransmitter released into _____________________

• Diffuse across and bind to _____________________ in postsynaptic cell

membrane

• Binding at __________________________

• Chemical trigger of ______________________________________

• May _________________________ or ____________________________

postsynaptic cell membrane

• If ______________________________reached at axon hillock then postsynaptic

cell ________________________________-- results

• Finally the _________________________________________________ must be

removed from the cleft-

• Diffusion away

• Destroyed by enzymes in cleft

• Transport back into _____________________________________

• _________________________________ destruction

•

Neurotransmitters

• AcetylCholine (Ach)- common in PNS

– ___________________________________________________

• Amino Acids-

– Glutamate, Aspartate, gamma aminobutyric acid (GABA), glycine

• Modified amino acids-

– ___________________________________________________________

___________________________________________________________

__

• Neuropeptides – _________________________________

• Nitric oxide (NO)

Chapter 10 Central Nervous System

Vocabulary Words• Dura mater• Arachnoid mater• Pia mater• Blood-Brain Barrier (BBB)• Cerebrospinal Fluid (CSF)• Brain stem-medulla, pons, midbrain• Diencephalon- thalamus, hypothalamus, pineal gland• Limbic system• Cerebrum• cerebellum

• The CNS includes ___________________________.

• The ________________________ are three layers of connective tissue that

extend around the spinal chord and brain.

3 Layers

• Dura mater-

• Arachnoid mater-

• Pia mater-

Spinal Chord

• The interior of the spinal chord

_________________________________________________________________.

• The outer of the spinal chord is ___________________________.

• The spinal chord is protected by the _____________________ in the spine

although the chord doesn’t extend fully throughout the back.

Reflex Arc

A _________________ is a fast, ___________________________ sequence of actions

that occurs in response to a particular stimulus.

Some reflexes are __________________ such as withdrawal reflex (take your hand from

a hot surface.)

• Reflexes that take place in the spinal chord gray matter are called a

_________________________. These bypass the brain.

• If the _________________________ occurs in the brain, it’s called a

_______________________________.

Blood-Brain Barrier

• The ________________________________ protects brain cells from harmful

substances and pathogens by

_______________________________________________ of many substances

from the blood to brain tissue.

• However, the BBB doesn’t prevent all substances from getting through.

– Examples:

___________________________________________________________

___________________________________________________________

__

Cerebrospinal Fluid

• The _________________________________ are further protected against

chemical and physical injury by CSF.

• This is a _________________________________________________________

that carries oxygen, glucose and other nutrients from the blood to neurons and

neuroglia.

• The CSF also removes ___________________________________________.

• CSF circulates in the _____________________________________ in the spinal

chord.

The Brain

• The brain is one of largest organs in the body with _________________________

and 10-50 trillion neuroglia cells.

• The four major parts of the brain are:

1.

2.

3.

4.

The Brain Stem

• The brain stem consists of three regions:

– 1.

– 2.

– 3.

Medulla Oblongata

• Contain all ____________________________ ascending and descending between

the brain and spinal chord.

• Contain _____________________________ which controls heart rate, force of

beat and diameter of blood vessels.

• Contain _________________________________ area which adjusts the rhythm

of breathing.

• Control reflexes for

_________________________________________________________________

_________________________________________________________________

__

• Receive sensory input from or provides motor output to

__________________________.

Pons

• This is a _________________________ that connects parts of the brain with one

another.

• _______________________________ are relayed to the cerebellum.

• Contain sensory and motor tracts.

• Help control ____________________.

Midbrain

• The midbrain connects the

_____________________________________________________________.

• Contains neurons that conduct ____________________ from the cerebrum to the

spinal chord. Medulla, and pons.

• Loss of these neurons is associated with

____________________________________.

• Contain several reflex arcs including:

• ______________________________________________

• ___________________________________ (pupil size)

• _______________________________________ (shape of lens)

• _________________________________

• Also contains an area called the _________________________________ (RAS)

• When RAS is stimulated, the result is _________________________.

• The RAS maintains wakefulness.

• Inactivation of RAS produces _________________________.

• RAS also maintains __________________________.

Diencephalon

• The major regions include:

– 1.

– 2.

– 3.

Thalamus

• They are a paired oval shaped area.

• Important relay station for ____________________________ for all parts of the

brain.

• Plays an essential role in

__________________________________________________ of knowledge,

which is called __________________________.

• Maintains _____________________________ and regulation of involuntary

activities.

Hypothalamus

1. Control of ANS-

2. Control the pituitary gland-

3. Regulation of emotional and behavioral patterns-

4. Regulation of eating and drinking- thirst center-

5. Control of body temperature-

6. Regulation of circadian rhythms and states of consciousness-

Pineal Gland

• Size of a small pea.

• Secretes ___________________________ that promotes sleepiness and setting

the body’s internal clock.

Cerebellum

• Consists of two _________________________.

• Surface consists of _____________________________.

• The cerebellum compares

_____________________________________________________________.

• Regulates ___________________________________________ and coordinate

muscle contractions.

Cerebrum

• Consists of ___________________________________________.

• Consists of two hemispheres connected by the ___________________________.

• Provides us with the ability for higher cognitive functions such as

_________________________________________________________________

_________________________________________________________________

__

• Contains many folds called _________________________ to increase surface

area.

Limbic System

• Sometimes called the _____________________________.

• Produces a variety of emotions including:

_________________________________________________________________

_________________________________________________________________

__

• Control patterns of behavior and may be linked to animal instinct for survival.

• Together with parts of the cerebrum, it functions in _______________________.