key words: left hemisphere; right hemisphere; visual infomation; touch information
Example : You read a geometry problem in a textbook. The words are seen and the visual forms translated into meaning by the language center in the left hemisphere. To solve the problem you have to imagine a cone shaped object. This is accomplished by centers in the right hemisphere. The solution is written down using language generated by the left hemisphere. What would happen in cases like this if the callosum was damaged ?
key words: left hemisphere; right hemisphere; corpus callosum; epilepsy One method used to treat severely epileptic patients involves cutting the corpus callosum to prevent the spread of seizures acorss the entire brain. The video clip on this slide shows a man who has had such a surgery. Double click on video to start video clip. This clip discusses the types of information processing deficits associated with cutting the corpus callosum and shows a task often used to assess corpus callosum damage. This task is also represented in drawing form on the following slide as well.
keywords: sympathetic nervous system; fighlt or flight response
key words: parasympathetic nervous system; rest and digest system
key words: sympathetic nervous system; parasympathetic nervous system
I control everything…
Functions of the Nervous System1. Communication and coordination Adapt and respond to changes from both inside and outside the body2. Site of reasoning- your brain3. Two main divisions Central nervous system (CNS): brain and spinal cord Peripheral nervous system- the nerves
Neuron- basic structuralunit of the nervoussystemDendrites- carryimpulses towards thecellAxon-carry impulsesaway from the cellMyelin sheathSynaptic terminal Epinephrine Norepinephrine Acetylcholine
NervesNerves are made of many nerve cells Afferent-sensory nerves carry message to brain Efferent-motor neurons carry message from brain to muscle Associate- do both Heads up
The Nervous System Major division - Central vs. Peripheral Central or CNS- brain and spinal cord Peripheral- nerves connecting CNS to muscles and organs Central Nervous System Peripheral Nervous System
Central Nervous System Brain Spinal Cord Brain and Spinal Cord
Cerebrum Cerebrum-largest part of brain. Responsible for reasoning, thought, memory, speech, sensation, etc. Divided into two halves. Further divided into lobes; occipital, parietal, temporal and frontal
Cerebellum and Brain Stem Cerebellum- responsible for muscle coordination Brain stem- most basic functions; respiration, swallowing, blood pressure. Lower part (medulla oblongata) is continuous with spinal cord
Spinal cord Spinal cord- begins at foramen magnum and ends at second lumbar vertebrae Contains both afferent (to the brain) and efferent (motor neurons- away from the brain)
Both the brain and spinal cord are covered bya membrane system called the meningesIn addition, the brain has four hollow areascalled ventricles. Cerebrospinal fluid isproduced in the ventricles and bathes thebrain and spinal column
Brain has 2 Hemispheres Left & Right sides are Corpus Callosum separate Right Corpus Callosum : Hemisphere major pathway between hemispheres Some functions are ‘lateralized’ language on left math, music on right Lateralization is never Left 100% Hemisphere
Each hemisphere isdivided into 4 lobes Frontal Parietal Occipital Temporal
Sensory Information sentto opposite hemisphere Left visual Right visual Principle is Contralateral field field Organization Sensory data crosses over in pathways leading to the cortex Optic Visual Crossover nerves left visual field to right hemisphere right field to left Other senses similar Left Visual Corpus Right Visual Cortex Callosum Cortex
Contralateral MotorControl Movements controled by motor Motor Cortex Somatosensory Cortex area Right hemisphere controls left side of body Left hemisphere controls right side Motor nerves cross sides in spinal cord
Corpus Callosum Major ( but not only) Medial surface of right hemisphere pathway between sides Connects comparable structures on each side Permits data received on one side to be processed in both hemispheres Aids motor coordination of left and right side Corpus Callosum
Corpus Callosum What happens when the corpus callosum is cut? Sensory inputs are still crossed Motor outputs are still crossed Hemispheres can’t exchange data
The ‘Split Brain’ studies “What did “Using“Whatleft hand, your did Picture to right brain you see?” Pick up what you saw.” you see?” can’t name the object left hand can identify by touch Picture to left brain can name the object left hand cannot ?? identify by touch I saw an Verbal Verbal apple. Nonverbal left left right hemisphere hemisphere hemisphere
Localization of function Frontal Parietal Occipital Temporal
Peripheral Nervous System 3 kinds of neurons Brain Spinal connect CNS to the body Cord sensory motor interneurons Nerves Motor - CNS to muscles and organs Sensory - sensory receptors to CNS Interneurons: Connections Within CNS
Peripheral Nervous System Peripheral Nervous System Skeletal Autonomic (Somatic) Sympathetic Parasympathetic
Somatic System Nerves to/from Brain spinal cord control muscle movements Sensory Neuron somatosensory inputs Both Voluntary and reflex movements Motor Skin receptors Neuron Skeletal Reflexes Interneuron simplest is spinal reflex arc Muscle
Autonomic System Two divisions: sympathetic Parasympatheitic Control involuntary functions heartbeat blood pressure respiration perspiration digestion Can be influenced by thought and emotion
Sympathetic CENTRAL NERVOUS SYSTEM SYMPATHETIC Brain“ Fight or flight” Dilates pupilresponse Stimulates salivation SalivaryRelease adrenaline and Relaxes bronchi glandsnoradrenaline Spinal Lungs cordIncreases heart rate andblood pressure Accelerates heartbeat HeartIncreases blood flow to Inhibits activity Stomachskeletal muscles PancreasInhibits digestive Stimulates glucose Liverfunctions Secretion of adrenaline, Adrenal nonadrenaline gland Kidney Relaxes bladder Sympathetic Stimulates ejaculation ganglia in male
Parasympathetic CENTRAL NERVOUS SYSTEM PARASYMPATHETIC Brain “ Rest and digest ” Contracts pupil Stimulates salivation system Constricts bronchi Spinal Calms body to cord conserve and Slows heartbeat maintain energy Lowers heartbeat, Stimulates activity breathing rate, blood pressure Stimulates gallbladder Gallbladder Contracts bladder Stimulates erection of sex organs
Disorders of the nervous system Meningitis- inflammation of the linings of the brain and spinal cord Encephalitis- inflammation of the brain Epilepsy-seizure disorder. Excessive discharge from neurons. 1 in 200 suffer. Grand mal or petit mal seizures Cerebral palsy- disturbance in voluntary muscular action Parkinson’s –decreased neurotransmitter MS multiple sclerosis- autoimmune
The Nervous System:Summary Major structures of the nervous CNS, Somatic, Autonomic Two hemispheres & 4 lobes Organization contralateral input & output primary sensory areas motor areas Commissure Localization of functions Central Nervous System Peripheral Nervous System
Sense organs carry messages about the environment to thecentral nervous system.
The eyes, ears, nose, tongue, and skin are examples of sense organs. The sense organs gather information (light, sound, heat, and pressure) from the environment.
The environment is everything outside the body.The sense organs gather information from outside the body, then send the messages to the brain.
Vision is your ability to see.Vision involves the eye and the brain.
The eye is one of your sense organs. The eye is made of the iris and the pupil. The eye gathers pictures and sends them to the brain.
The colored part of the eye is the iris. The black part of the eye is the pupil. The pupil becomes larger and Pupil Iris smaller as it controls the light coming into the eye.
When a sound is made, the air around the sound vibrates.Hearing starts when some of the sound waves go into the ear.
There are nine main parts of the ear. 1. Pinna 5. Anvil 2. Ear canal 6. Stirrup 3. Ear drum 7. Cochlea 4. Hammer 8. Eustachian tube 9. Auditory nerve
The pinna is the part of the ear that you can see.The ear canal is the tube between the outside of the ear and the ear drum.The ear drum is in the middle ear. It vibrates when sound waves hit it.
The three smallest bones in the body, the hammer, the anvil, and the stirrup, are in the middle ear. The hammer gets the vibrations from the eardrum, then sends them to the anvil.The anvil passes the vibrations to the stirrup. The stirrup passes the vibrations to the inner ear.
The Eustachian tube controls the amount of pressure in the ear. The inner ear is made of the cochlea and liquid.The cochlea is in the inner ear. The cochlea looks like a shell. The auditory nerve carries the hearinginformation to the brain and the brain tells us what we heard.
The ear works with the brain to control your balance. All of your movements are controlled by balance and muscles. The liquid in your inner ear is responsible for your balance.The liquid in your ear moves when we move.The liquid movement sends information to the brain to tell it how we are moving.
The sense of touch is located in the skin. The nerves in the skin allow us to feel texture, pressure, heat, cold, and pain. Texture is how something feels.
The nose controls your sense of smell. The nose is able to smell 80 different kinds of smells.
Your sense of taste comes from the taste buds in the tongue.Taste buds are the parts on the tongue that allow us to taste. The four kinds of taste buds are sweet, sour, bitter, and salty.
Tastes and smells work together to make flavors. Flavors are the tastes of food and drinks.