Download 3 Medical Terminology - MedicalScienceTwoCCP

Study of the Nerve (Nervous System)
Neurology Objectives:

 To be able to identify different structures of the
brain and nerves.
 To explain the functions of the nervous system.
 To explain how memory, emotions, consciousness,
sleep, communication, and nerves work.
 To relate the functions of the brain to disorders and
items that alter brain function.
What does the brain do?

 It gives the signals that make our bodies move.
 It has our heart beat faster when needed.
 It is our creativity, intelligence, memory, emotions,
personality.
 It interprets what we see, hear, taste, smell and touch.
Brain function

 Linked to nerves and sensors in the nervous system
 Also works with the endocrine system
 Regulate growth
 Regulate reproduction
 Etc.
Reading Assignment

 Read: “Memory and emotions”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Emotions

 Limbic system and hypothalamus play a major role
in our emotions
 Autonomic nervous system
 Releasing hormones into the pituitary gland
 Common Emotions:





Anger
Disappointment
Happiness
Sadness
Excitement
Limbic System (Part 1)

 Controls our pleasure and pain
 Guards against dangerous situations
 Controls sexual instincts
Limbic System (Part 2)

 Parts of the brain:
 Cingulate gyrus
 modifies behavior/emotions
 Fornix
 nerves linking different parts
 Amygdala
 fear of danger/falling/being attacked
 Hippocampus
 memory
Memory

 Sensory Memory
 Keeps memories for seconds
 Sights/sounds
 Short-term Memory
 Keeps memories for minutes to hours
 Long-term Memory
 Consolidation occurs where short-term items are
transferred by the hippocampus to long-term memory
 3 forms (next slide)
Long-Term Memory

 Procedural Memory
 Skill learned through practice
 Semantic Memory
 Words, language, facts, meanings
 Episodic Memory
 Events
Learning

 All of our knowledge is learned
 Memorize facts and figures
 Vocabulary
 Most of our behavior is learned
 Mannerisms
 Tone and inflection of voice
 Table manners
Questions to Answer:

1. How does an infant learn something?
2. How do young adults learn things?
3. What is needed in order for something to enter our
long-term memory?
Reading Assignment

 Read: “Consciousness and Sleep”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Being Alert (versus asleep)

 Reticular Activating System (RAS)
 Located in the brain stem
 Neurons reach deep into the cortex of the brain
 Receive input from eyes/ears/spinal cord
 Neurotransmitters
 Acetylcholine
 Alertness and concentration
 Serotonin
 Sleep and mood
 Dopamine
 Regulates movements
Sleep

 “Regeneration Cycle”
 Allows the body to rest
 Adults need 3-4 hours of sleep a night (most get 7-8)
 Infants and young children need MUCH more (16-20)
 Teens need approximately 8-10 hours a night
 Thought patterns are separated from the world
 Gives the brain time to sort and store information
 Allows for “housekeeping” – efficient memory storage
 Triggered and maintained by neurotransmitters that
are released by the RAS
Brain Waves

 Electroencephalograph
 Record of the electricity of the brain
 Three different types:
 Alpha Waves
 Beta Waves
 Delta Waves
Alpha Waves

 Occur when brain is awake but relaxed
Beta Waves

 Occur during intense activity
Delta Waves

 Occur during deep sleep
Sleep Patterns

 NREM Sleep
 Stands for non-rapid eye movement sleep
 Stages 1 – 4
 Sleeper moves about but brain activity is very low.
 REM Sleep
 Stands for rapid eye movement sleep
 Body does not move (immobile), eyes move a lot
Stages of Sleep

 NREM Sleep:
Stage 1
 EEG
 Alpha waves
 Body is relaxed
 Person easily
roused (wakes
if disturbed)
Stages of Sleep

 NREM Sleep:
Stage 2
 EEG
 Irregular
 Difficult to
rouse sleeper
Stages of Sleep

 NREM Sleep:
Stage 3
 EEG
 Delta waves
begin to appear
 Decrease in
vitals
 Breathing
 Heart rate
 Body
temperature
Stages of Sleep

 NREM Sleep:
Stage 4
 EEG
 Delta waves
prominent
 Vital Signs are
at their lowest
 Difficult to
arouse sleeper
Stages of Sleep

 REM Sleep
 EEG
 Alpha Waves
appear
 Vital signs
increase
 Skeletal
muscles
inhibited (do
not move)
 Dreaming
Occurs
Dreams

 Almost everyone dreams (however, we may forget
them)
 Possible reasons why we dream
 Results of nerve cells firing at random
 Plays a part in memory storage
 Old being removed, new ones being filed
 Reveal hidden anxieties
 Be a window into human subconscious
 Austrian doctor Sigmund Freud (1856-1939)
Questions to Answer:

1. What is the purpose of sleep?
2. What triggers our brain to sleep?
3. How many hours a night does a teen NEED to
sleep?
4. Describe a typical sleep pattern.
5. When do we dream?
6. Describe the three explanations for why we dream.
Which one do you think is the most plausible and
why?
Reading Assignment

 Read: “Nervous System”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Nervous System

 Most complex system in our body
Communication Network

 Controls everything along with the endocrine
system
Nervous System Functions

 Sensory
 Notices changes inside and outside of the body
 Eyes, ears, pressure/pain receptors, chemicals
 Integrative
 Analyzes sensory information
 Modifies or begins a response
 Motor
 Stimulate or inhibit muscles and glands
Central Nervous System

 Abbreviation: CNS
 Command center of the nervous system
 Consists of: Brain and spinal cord
 Coordinates all activities
 Analyzes signals and based on past experiences,
sends out instructions
Peripheral Nervous System

 Abbreviation: PNS
 Relay’s messages between the CNS and body
 Made up of bundles of nerves
 Has 3 divisions:
 Sensory
 Somatic
 Autonomic
Sensory Division

 Gathers information from sensors to update the CNS
Somatic Division

 Conscious control of skeletal muscles
Autonomic Division

 Internal organs controlled
Neuron Basics

 Neurons are also called Nerve Cells
 Carry electrical impulses to other nerves
 Electricity “jumps” from one neuron to another at a
chemical junction called a synapse.
Rapid Response

 Nerves
communicate
fast!
 330 feet per
second
 Millions of
signals occur
at one time.
Questions to Answer:

1. What are the two divisions of the Nervous system?
And what are they composed of?
2. Why is the autonomic division of the nervous
system important? Give an example
3. Using a soccer player as an example, give an
example of 8 different things that the nervous
system does to help the player perform.
Reading Assignment

Read: “The Brain”
Highlight/underline a
minimum of 3 items
Make comments in the
margin about the items you
picked
The Brain

 Weighs approximately 1.4 kilograms (3 pounds)
 Control center of the body
 100 billion neurons
 1 trillion synapses
 Energy demanding
 Uses 1/5 of the body’s oxygen and yet is only 2 % of the
total body weight
 Brain gets energy/oxygen 1st when there is a high
demand
Cerebrum - Forebrain
Part 1

 Largest part of the brain –
85% of brain’s weight
 Made up of White and Gray
matter
Cerebrum - Forebrain
Part 2

 Thalamus
 Relays sensory nerve impulses to the cerebral cortex
 Hypothalamus
 Controls endocrine system and regulates sleep
 Corpus Callosum
 Bundle of axons (part of the nerve) and connects the
right and left hemispheres
Cerebrum - Forebrain
Part 3

 Frontal Lobe
 Thought, emotion, speech, skilled movements
 Located in front of the central sulcus
 Parietal Lobe
 Perceives sensations (touch, pain)
 Located between the frontal and occipital lobe and above
the Sylvian fissure
 Occipital Lobe
 Detects and interprets visual images
 Located behind the parietal lobe (back of the head)
 Temporal Lobe
 Recognizes sounds, memory storage
 Located on the sides of the head, near the temples, below
the Sylvian fissure
White and Gray Matter
  White Matter
 Made up of Nerve
Fibers (Cells)
 Gray Matter
 Controls higher
brain functions
(thought)
 Cerebral Cortex
Brain Stem

 Connects the Cerebrum (Forebrain) to the spinal
cord
 Relays nerve impulses between the brain and spinal
cord
 Controls heart rate and breathing
 Made up of three parts:
 Midbrain – upper portion
 Pons - middle
 Medulla – connects to spinal cord
Cerebellum

 Means “little brain”
 Located under the Cerebrum and behind the brain
stem
 Controls muscle movement and balance
Brain Protection
Part 1

 Skull
 Bone
Brain Protection
Part 2

 3 meninges
(membranes)
 Pia Mater –
surface of
the brain
 Arachnoid
- middle
 Dura
Mater –
surface of
the skull
Brain Protection
Part 3

 Cerebrospinal Fluid
 Found in the subarachnoid space (Between the Pia
Mater and Arachnoid)
 Nourishes the brain
 Protects the brain (cushion)
Brain Features

 Hills and Valleys
 Ridges (humps) and grooves that increase the surface
area
 Gyri (singular: gyrus)
 Ridge of the brain
 Sulci (singular: Sulcus)
 Groove of the brain
 Fissure
 Deep groove of the brain
Brain Assignment #1:

1. Label the following structures on the picture of a
brain:
1.
2.
3.
4.
5.
6.
The 4 different lobes
Cerebellum
Brain stem
Cerebrum (forebrain)
Sulcus
Gyrus
2. Fill in the names of each part of the brain on the
back of the sheet. Use your handout and notes as a
guide
Reading Assignment

 Read: “Cerebral Activities”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Cerebral Activity

 The brain’s purpose: To process and store
information
 Different regions of the brain have their own
function, and many work together to complete
complex functions
White and Gray Matter
  White Matter
 Made up of Neuron
Axons
 “Wiring” of the brain
 Gray Matter
 Made up of
Neuron cell bodies
 Surface of the brain
Broca’s Area

 Produces speech
Wernicke’s Area

 Interprets spoken and written language
Prefrontal Cortex

 Abstract thought (problem solving, planning)
Visual Association Cortex

 Analyzes patterns in visual information.
 Compares to items previously seen
 Forms images
Premotor Cortex

 Coordinates complex movements
 Driving, using a keyboard
Corpus Callosum

 Bridge of nerve fibers that connect the left and
right hemispheres of the brain
 Right side of brain controls left side of the body
 Left-handed people tend to have a greater
appreciation for the arts, music, recognizing faces
 They are Right Brain dominant
 Left side of brain controls right side of the body
 Right-handed people tend to be better with problem
solving, numbers and language
 They are Left Brain dominant
Reaction Times

 Do you always think before your body reacts?
 Sports – not enough time to make conscious
decisions
 Tennis – eyes, arms, legs
 Baseball – eyes, arms, body
 Do we think about how we are going to pick up a
small object?
 Often our body reacts by reflexes.
Questions to Answer:

Reaction times are faster than our brain can think.
1. How do our brains know how to react?
2. What do we need to do to increase our reaction
times?
3. How is having a fast reaction time beneficial to us?
Complete Lobes of the Brain Dominoes and attach to
the above questions. (Directions on next slide)
Lobes of the Brain Dominoes

 Cut out the dominoes
 Match each word with its correct description.
 The dots will line up and you will create a rectangle
if you do it correctly.
 Glue to a piece of paper, put your name on it, turn it
in.
Reading Assignment

 Read: “Neurons”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Neurons

 Neurons are only found in the Nervous System
 Highly specialized cells
 Carry electrical signals
 Act like wires
 Act like batteries
 Neurons “charge” themselves then “fire” by reversing
their charge to send electrical impulses along their
“wires”
 Can not divide once matured
 Can not be replaced when damaged.
Types of Neurons

 Sensory
 Triggered by stimuli (light/touch/etc)
 Strength of stimulus affects the rate of neuron
response
 Association (Intermediate or Relay)
 Process information, issue commands
 Motor
 Body response (muscles)
Neuron Structure

 Cell Body
 Swelling
 Nucleus found here (as well as mitochondria and other organelles)
 Axon
 Long fiber up to 1 yard (1 meter) long
 Sends signals away from cell body
 Terminals produce neurotransmitters
 Dendrites
 Short filaments
 Receives signals from neighboring axons
 Node of Ranvier
 Gap between Schwann cells on the axon
 Schwann Cell
 Glial cell that wraps itself around an axon
 Creates a myelin sheath
 Synapse
 Chemical junction “connecting” neurons.
Supporting Cells

 9/10 of nervous system are supporting cells (1/9 are
neurons)
 Glial cells
 Can replace themselves if damaged
 Different types:
 Astrocytes
 Supply neurons with nutrients
 Schwann cells
 Provide protection and insulation for the neurons
 Others (bacteria eaters, etc)
Schwann Cells

 Can replace themselves if damaged
 Cells that wrap themselves around neurons
 Myelin
 Fatty substance
 Insulates the axon of the neuron
 Keeps electrical charge from “leaking” or diminishing.
 Separated from adjoining Schwann cells by small
gaps called Nodes of Ranvier (nodes for short)
High Speed Impulse

 Neurons CAN fire up to 2,500 times per second
 Impulses CAN travel at 218 mph (350 kmh)
 When a neuron is at rest, it pumps electrically
charged ions across its cell membrane and waits.
 When triggered, the neuron allows the ions to rush
back across the membrane, reversing the charge
Questions to Answer:

1. Why is a frame attached to a person’s head with
screws important while doing brain surgery?
2. How does a neuron work?
3. How fast is a neuron?
4. Draw a nerve cell and label its parts.
Reading Assignment

 Read: “Synapses”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Synapses

 Most found between neurons (some are between a
neuron and another cell)
 Synaptic bulb
 Swelling and the end
 Produce neurotransmitters
 Chemicals that “communicate” with adjoining cells
 Work like a one-way switch (they only work in one
direction)
 Trillions of these in the nervous system
 Extra synapses form where “circuits” are used
frequently
 Playing an instrument gets easier with practice
How do synapses work?

 Neurotransmitters are stored in vesicles
 Released at the edge of the synaptic bulb
 Travel the small gap (cleft)
 Enter receptor sites
 Broken down by enzymes
Drugs

 Stimulants
 Caffeine
 Reduce the amount of neurotransmitter needed to
have a neuron fire
 Neurons fire more often
 Depressants
 Alcohol
 Increase the amount of neurotransmitter needed to
have a neuron fire
 Neurons fire less
Neurotoxins

 Switch synapses on or off permanently.
 Paralysis
 Synapse turned on permanently
 Unable to breathe
 Synapse turned off permanently
 Fatal dose one-millionth of a gram
 Found in nature:
 Bacteria
 Black widow
 Poison dart frogs
 Bug spray
Questions to Answer:

Reading Assignment

 Read: “Nerves”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Nerves

 Contain millions of individual neurons
 Nerves Carry two-way traffic
 Sensory Neurons – impulse travels towards the CNS
 Motor Neurons– impulse travels to the muscles (away
from CNS)
 Buried deep in the muscles
 Except: Ulnar nerve
 Elbow (humerous)
 Tingling sensation
Sciatic nerve

 Longest and thickest nerve in the body
 Controls the thigh muscles that bend the leg
 Sciatica
 Pain can radiate down the leg and up the back
 Pregnant women have a big issue
Inside the Nerve
 Fascicles

 Axons grouped together
 Wrapped in perineurium
 Several fascicles grouped together
 Wrapped in an epineurium
 Blood vessels and fat-containing cells also found in
here
 Flexible
 Cell bodies found in swellings called ganglia
Major Nerves

Part 1
 12 pairs of cranial nerves
 All control the head and neck region except one
 Vagus nerve
 Controls muscles and glands such as the heart, lungs, and
stomach
Major Nerves

Major Nerves

 31 pairs of spinal nerves
 Sciatic
 Controls thigh muscle
 Ulnar
 Controls muscles that bend the wrist
and fingers
 Phrenic
 Controls diaphragm
 Intercostal
 Control the muscles between the
ribs
Part 2
Reading Assignment

 Read: “Spinal Cord”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
Reading Assignment

 Read: “Reflexes”
 Highlight/underline a minimum of 3 items
 Make comments in the margin about the items you
picked
