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