protected by bone: skull and vertebrae *not protected by bone

•Protected by bone:

skull and vertebrae

*not protected by bone

Controls VOLUNTARY body movements, through the action of skeletal muscles. Interacts with surroundings using senses

Maintains INVOLUNTARY actions such as heart rate, digestion, sweating, sexual arousal

Vigorous activity.

Ex: “Fight or Flight” response

Non-emergency activity. Ex: “Rest and Digest”

Sympathetic Structure Parasympathetic

Rate increased Heart

Force increased Heart

Bronchial muscle relaxed Lungs

Pupil dilation Eye

Food motility reduced Intestine

Sphincter closed Bladder

Decreased urine secretion

Kidneys

Examples:

Rate decreased

Force decreased

Bronchial muscle contracted

Pupil constricted

Digestion increased

Sphincter relaxed

Increase urine secretion

Sympathetic Responses

Dominance by the sympathetic system is caused by physical or emotional stress

-- “E situations”– emergency- embarrassment- excitement- exercise

• Alarm reaction = flight or fight response

– dilation of pupils – increase of heart rate, force of

contraction & BP – decrease in blood flow to

nonessential organs – increase in blood flow to skeletal

& cardiac muscle – airways dilate & respiratory rate

increases – blood glucose level increase

Parasympathetic Responses

• Enhance “rest-and-digest” activities • Mechanisms that help conserve and restore body energy during times of rest • Normally dominate over sympathetic impulses • SLUDD type responses = salivation, lacrimation, urination, digestion & defecation and 3 “decreases”--- decreased HR, diameter of airways and diameter of pupil

• Paradoxical fear when there is no escape route or no way to win– causes massive activation of parasympathetic division – loss of control over urination and defecation

Neuron: nerve cell

Cell body (soma)

dendrites

axon

Myelin sheath (yellow padding)

axon

Node of Ranvier (gap)

Axon terminals

Multiple Sclerosis

Dendrite

Axon

Soma

Sensory neuron receives information from the senses (environment) and sends it to the CNS

A motor neuron receives information from the CNS and sends it to a muscle or gland.

“Afferent” : Ascending “Efferent”: Descending

Sensory impulse

Mot

or im

puls

e

Sensory neurons

Mot

or n

euro

ns

Optic: eye

Auditory: ear

Olfactory: smell

Taste: taste buds

Touch: skin receptors

Muscle

gland

Stimulus (fire)

Response (pull away)

2 Additional neurons

1. Interneuron– Found in the CNS only. – They associate or “connect” sensory neurons

and motor neurons.

2. Mirror Neurons

• allow humans to “mimic” each other

• possibly allow us to learn speech, signal meaning to one another, and to feel empathy

•New field of study (1990s)

Mirror neurons are found all over the brain and they look just like other neurons.

What makes them special is the web of connections that link these neurons in the motor and sensory systemsmotor and sensory systems to the limbic limbic centerscenters that process visceral and visceral and emotional reactions.emotional reactions.

While they may be in place at birth, they are vastly expanded through experience. A baby smiles…her mother smiles back…the brain sets up a circuit.

Evidence for mirror neurons:

When a researcher would pick up raisins or sunflower seeds, neurons that a macaque would use when engaged in the same task would fire.

In humans, the same neurons fired when subjects felt a glove brush their leg and when they watched a video of an actor’s leg being brushed by a glove.

The thought of a loved one’s hand receiving an electric shock lights up many of the same brain areas as shocks that are directly experienced.

Can even indicate strength of emotion…The same mirror neurons fired when the subjects saw a hand reaching for both of these, BUT…

Neurons fired strongly neurons fired more weakly

http://www.ted.com/talks/vs_ramachandran_the_neurons_that_shaped_civilization.html

The Neurons that Shaped CivilizationLecture on Mirror Neurons (7min)

PBS; Mirror Neurons (15 min)

Synapse• Point of communication between two nerve cells.

• Three parts:

• A __________________is the chemical that is exchanged at the synapse. This allows the chemical message to be______________________________

• presynaptic membrane• synaptic cleft (gap)• postsynaptic membrane

neurotransmitter

Passed from one neuron to the next

Click for animation

Action Potential

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html

Synapse

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__chemical_synapse__quiz_2_.html

http://www.youtube.com/watch?v=90cj4NX87Yk&feature=related

Questions• The brain and spinal cord make up the _______________________• Which of the following do not belong in this grouping

– Autonomic – sympathetic – parasympathetic – central nervous system

• Stimuli from the environment are received by _______________• The insulating sheath of the axon is composed of ________________• Impulses that go to the brain are? Ascending or Descending• The gaps between the myelin in a neuron are called? ________________• The gaps that exist between two neurons are called _____________________• The part of the neuron where the nucleus is found is the __________________• What is “fight or flight”?

• What part of the nervous system would be responsible for flight or flight?

• Explain what else happens to your body during this response.

• Why might yawning be contagious?

Nervous System

Central Nervous System

Peripheral NervousSystem

Somatic Autonomic

Sympathetic

Parasympathetic

Brain Plasticity (video clip)

Nerve Proliferation and Pruning: “use it or lose it” in the brain.

Babies have about 15,000 connections per neuron while adults have about a third less (10,000).

The brain undergoes two major developmental phases, one in the womb and the second during the childhood/teen years. Links that are used are reinforced and strengthened while the ones that aren’t used are “pruned” or die off.

Spinal Nerves:

31 pairs of nerves leave the spinal cord and carry impulses to and from the rest of the body (except for the head which is served by the cranial nerves).

•8 pairs of cervical•12 pairs of thoracic•5 pairs of lumbar•5 pairs of sacral•1 pair of coccygeal

Spinal Cord Injuries

Nervous System Animations

CranialNerves

Number Name Function

I Olfactory Nerve Smell

II Optic Nerve Vision

III Oculomotor Nerve Eye movement; Pupil dilation

IV Trochlear Nerve Eye movement

V Trigeminal Nerve Somatosensory information (touch, pain) from the face and head; muscles for chewing.

VI Abducens Nerve Eye Movement

VII Facial Nerve Taste (anterior 2/3 of tongue);Somatosensory information from ear;Controls muscles used in facial expression.

VIII Vestibulocochlear Nerve Hearing; Balance

IX Glossopharyngeal Nerve Taste (posterior 1/3 of tongue);Somatosensory information from tongue, tonsil, pharynx; Controls somemuscles used in swallowing.

X Vagus Nerve Sensory, motor and autonomic functions ofviscera (glands, digestion, heart rate)

XI Spinal Accessory Nerve Controls muscles used in headmovement.

XII Hypoglossal Nerve Controls muscles of tongue

* Largest part of the brain

• Cerebrum (cerebral cortex)

• Thalamus

• Pituitary

Also:

• Limbic System

• Hypothalamus (regulates homeostasis…hunger, thirst, temp, sexual behavior, fighting, activity level)

• Hippocampus (build new memories)

• Amygdala (emotional responses)

• fear, anger, aggression, sexual desire

Limbic System

Consists of:

•Cerebellum

• Pons

• Medulla oblongata

Parietal LobeFrontal Lobe

Temporal Lobe

Occipital Lobe

CerebellumBrainstem

* There are two hemispheres in the brain: Left and Right.

Which one is shown in this diagram? __________________RIGHT

Left Hemisphere controls RIGHT side of the body

Right Hemisphere controls LEFT side of the body

Frontal Lobe:

Functions:• How we know what we are doing within our environment (Consciousness).• How we initiate activity in response to our environment = reasoning / thinking • Controls our impulsive responses. • Controls our expressive language. • Controls motor functions. • Involves word associations. • Memory for habits and motor activities.

Observed Problems:

• Loss of simple movement of various body parts (Paralysis). • Inability to plan a sequence of complex movements. • Loss of spontaneity in interacting with others. • Loss of flexibility in thinking. • Persistence of a single thought (Perseveration). • Inability to focus on task (Attending). • Mood changes (Emotionally Labile). • Changes in social behavior. • Changes in personality. • Difficulty with problem solving. • Inability to express language (Broca's Aphasia).

Frontal Lobe

Parietal Lobe

Function•Location for visual attention. •Location for touch perception. •Goal directed voluntary movements. Manipulation of objects. •Integration of different senses that allows for understanding a single concept.

Observed Problems:•Inability to attend to more than one object at a time.•Inability to name an object. •Inability to locate the words for writing. •Problems with reading (Alexia). •Difficulty with drawing objects. Difficulty in distinguishing left from right. •Difficulty with doing mathematics (Dyscalculia). •Lack of awareness of certain body parts and/or surrounding space (Apraxia) that leads to difficulties in self-care. •Inability to focus visual attention. .

Parietal Lobe

Occipital Lobe:

Location: Most posterior lobe, at the back of the head.

Functions:• Vision• Color recognition

Observed Problems:• Defects in vision (Visual Field Cuts). • Difficulty with locating objects in environment. • Difficulty with identifying colors (Color Agnosia). • Visual illusions - inaccurately seeing objects. • Word blindness - inability to recognize words. • Difficulty in recognizing drawn objects.• Inability to recognize the movement of an object

(Movement Agnosia). • Difficulties with reading and writing

Occipital Lobe

Temporal Lobe:

Location: Side of head above ears.

Functions:•Hearing ability •Memory acquisition •Some visual perceptions •Categorization of objects.

Observed Problems:•Difficulty in recognizing faces•Difficulty in understanding spoken words (Wernicke's Aphasia). •Disturbance with selective attention to what we see and hear.•Difficulty with identification of, and verbalization about objects. •Short-term memory loss. •Interference with long-term memory •Increased or decreased interest in sexual behavior. •Inability to categorize objects.•Right lobe damage can cause persistent talking. •Increased aggressive behavior

Temporal lobe

Motor functions

Problem solving

Planning

Reasoning

Judgment

Impulse

memory

Cognition

Information processing

Pain/touch sensation

Spatial orientation

Speech

Visual perception

Vision

Color recognition

Emotional response

Hearing

Memory

Speech

Broca’s areaWernicke’s Area

“Language output”. Responsible for spoken language. People with damage to this area have trouble creating words and sentences.

•Motor speech.

“Language input”. Responsible for language comprehension. People with damage to this area can speak, but it is incoherent.

•Sensory speech

* These parts are found in the left hemisphere only!!

Motor Speech

Sensory speech

Cerebellum:

Location: at the base of the skull

Functions:•Coordination of voluntary movement •Balance and equilibrium •Some memory for reflex motor acts.

Observed Problems:•Loss of ability to coordinate fine movements.•Loss of ability to walk. •Inability to reach out and grab objects.• Tremors. •Dizziness (Vertigo). •Slurred Speech (Scanning Speech). •Inability to make rapid movements

cerebellum

Brain Stem:

Location: Deep in Brain, leads to spinal cord.

Functions: •Breathing •Heart Rate •Swallowing •Reflexes to seeing and hearing (Startle Response). •Controls sweating, blood pressure, digestion, temperature

Observed Problems:•Decreased vital capacity in breathing, •important for speech. •Swallowing food and water (Dysphagia). •Difficulty with organization/perception of the environment.• reflex control

Brain Stem

Major Parts:MidbrainPonsMedulla Oblongata

midbrain

pons

Medulla oblongata

Brain Parts

Brain Glands

Thalamus Hypothalamus Pituitary

Cerebral Cortex CerebellumBrainstem

Thalamus:

Location: found in the center of the brain

Function:

•Translates sensory information and relays it to the cerebral cortex.

•Responsible for levels of awareness, such as sleep.

•Maintains consciousness

Observable Problems:

•Damage can lead to permanent coma

•If sensory information is not transported to the cerebral cortex, you will not respond to the external stimuli.

thalamus

Hypothalamus:

Function:•The hypothalamus is like your brain's inner thermostat •The hypothalamus knows what temperature your body should be (about 98.6° Fahrenheit or 37° Celsius). •If your body is too hot, the hypothalamus tells it to sweat. •If you're too cold, the hypothalamus gets you shivering. •Both shivering and sweating are attempts to get your body's temperature back where it needs to be.

Hypothalamus

PITUITARY GLAND: (“master gland”)

•The pituitary gland is very small — only about the size of a pea! •Its job is to produce and release hormones into your body. (Growth Hormone). •This gland is a big player in puberty, ultimately producing sperm in males and eggs in females• This little gland also plays a role with lots of other hormones, like ones that control the amount of sugars and water in your body. And it helps keep your metabolism going. Maintains homeostasis.• The pituitary controls other glands…therfore called the “Master Gland”.

Pituitary Gland

With each heartbeat, arteries carry about 20 to 25 percent of your blood to your brain, where billions of cells use about 20 percent of the oxygen and fuel your blood carries.

When you are thinking hard, your brain may use up to 50 percent of the fuel and oxygen.

Carotid artery

Skull bone

Meninges

Cause: Inflammation of the meninges. Can be caused by a virus or bacteria and can be extremely harmful and contagious.

Symptoms: stiff neck, sore back, light irritation, nausea, body aches, sleepy, confused, fever

brain

sensations

sight

sound

smell

Generate thoughts, problem solve, make plans

Form and store memories

Motor movement

The positron emission tomography (PET) scan on the left shows typical patterns of brain activity associated with: Reading Hearing

thinking speaking

Kluver-Bucy Syndrome

• Caused by damage to the temporal lobe and amygdala.• Inability to recognize familiar objects. • Lack of fear of objects such as snakes, spiders, fire, and other

commonly feared objects• Inappropriate or unnatural oral fixations • Inappropriate sexual behavior, such as public masturbation

Deterioration of brain cells. Observable shrinkage, shriveling, cell death and tissue loss.

Hippocampus is destroyed. Responsible for new memories

Cerebral cortex shrivels up. Affects thinking, planning, and memory

Early Alzheimer’s

Late Alzheimer’s

Learning and memory

Thinking and planning

•Deterioration of cell in a portion of the brain called Substantia Nigra (“black substance).

•No longer release the neurotransmitter Dopamine.

•Responsible for control of movement and balance and is essential to the proper functioning of the central nervous system

•Leads to slowed and/or uncontrolled movements, tremors, and rigidity.

The convolutions of the brain are made up of “ridges and grooves”

Grey matter: dark areas around the outside of the cerebral cortex. The dark color is the soma of the neurons found here.

White matter is the “lighter” inner layer of the brain section. This is composed of the axon part of the neuron and it is responsible for connecting to the billions of other neurons in the brain.

Cross section of the cerebral cortex

What’s it’s function? _________________________________

Longitudinal fissure:

Long groove that separates the left and right hemispheres in the brain

Sulcus: “Grooves” in the brain

Gyrus: “Ridges” that lie between the grooves in the brain

Together the gyrus and sulcus make up the “folded” pattern you see in the brain. This patterns are called convolutions of the brain.

1. _________________ 5. _______________ 9. _______________

2. _________________ 6. _____________ (lobe) 10. ______________

3. _________________ 7. _____________ (lobe) 11. ______________

4. _________________ 8. _____________ (lobe) 12. ______________

Cross section