Nervous System: Functions

SensorySenses internal and external changes

IntegrativeAnalyzes sensory

informationStores information

Decides what to do with information

MotorResponds to Stimuli

Involuntary Control Voluntary

ControlComposed of two divisions

1. Sympathetic

2. Parasympathetic

Controls

Heart, GI Tract, Glands,

Hormones, Respiration

Controls

Skeletal MusclesPeripheral Nervous System

Autonomic vs. Somatic

Two (2) – Neuron Pathway

One (1) – Neuron Pathway

Neuron extends from CNS Neuron extends to effector organs

Antagonists

“Fight or Flight” “Rest and Digest”

•Exercise

•Emergency

•Excitement

•Embarrassment

Digestion

Defecation

Diuresis (Urination)

The effects produced upon stimulation of the sympathetic

division of the autonomic nervous system

Facilitated by the release of large amounts of catecholamine

(epinephrine) from the adrenal medullae (superior portion of

kidney) Fight or Flight

SCARED??????

Noticeable Effects

Hidden Effects

Pupils Dilate

Sweating

Oxygen Debt = Muscles demand for more oxygen

Mouth Goes Dry

Brain Stimulates Action Potential

Neck & Shoulder Muscles Tense

Heart Beat Increases

Muscles acquire action potential

Respiratory Rates Increase

Possible Hyperventilation

Blood Pressure Increases

Adrenaline released by

Adrenal GlandsGlycogen broken down

to glucose and released into blood for

immediate energy source

Digestion Ceases

Sphincters Tighten

Cortisol released depresses the

immune system

Blood Vessels Dilate

Everyday Responses• Music

– Jazz = Parasympathetic– Rap & Rock = Sympathetic

• Television– Anger = Sympathetic– Sports & Excitement = Sympathetic

• Screaming/Arguing = Sympathetic• Excitement

– Bell Rings for end of school = Sympathetic• Colors

– Light Colors = Parasympathetic– Dark Colors = Sympathetic

Can You Think of Any Other Responses?

Males• Stress response

– Social Withdrawal– Substance Abuse– Aggression

• Mortality– Believed responses to

stress contribute to early mortality when compared to women

Women“Tend and Befriend”

– Social Support• Emotions• Sympathy

– Aggression• Protective responses

towards offspring and affiliate with together for shared emotional responses to threat

•Disruption of Sexual Response

•Digestive System Disorders

~ Diarrhea

~ Constipation

~ Vomiting

•Chronic Stress = Suppression of Immune System

Mental Disorders ~ Post-Traumatic Stress ~ Anorexia & Bulimia

Cardiac Arrest

Aneurysm

Migraine Headaches

Neurons

• Functional Properties– Irritability

• Respond to stimulus and convert to a nerve impulse

– Conductivity• Transmits nerve impulse

to other neuron, muscle, or gland

• Occurs at synapses where neurotransmitters diffuse and bind chemoreceptors

• Ability to be Altered, Controlled, or Destroyed– Nerve impulses can be

blocked and cause membrane to become impermeable to diffusing sodium ions

• Cold• Pressure• Sedatives & Anesthetics• Limbs falling “asleep”

then influx of “pins and needles feeling”

Neuron Neuron StructureStructure

3 main parts

1. Dendrites

2. Cell Body

3. Axon

Axons - Neurological messenger

Dendrites - Neurological Receiver

Progressive Develop from Infancy to Adulthood

Helps 1.Protect2.Insulate

3. Increase Speed of Impulse

Neurolemmocytes – PNSOligodendrocytes-CNS

Pipe Cleaner Neuron

• 1. Take one pipe cleaner and roll it into a ball. This is will be the cell body. • 2.Take another pipe cleaner and attach it to the new "cell body" by

pushing it through the ball so there are two halves sticking out. Take the two halves and twist them together into a single extension. This will be the axon.

• 3.Take other pipe cleaners and push them through the "cell body" on the side opposite the axon. These are dendrites. These can be shorter than your axon and you can twist more pipe cleaners to make more dendrites.

• 4.Wrap small individual pipe cleaners along the length of the axon. These will represent the myelin sheath.

• 5. Wrap another pipe cleaner on the end of the axon. This will be the synaptic terminal.

~Propagation along unmyelinated fibers

Functional Classification of Neurons

• Sensory (Afferent) neurons– Carry impulses from the sensory receptors

• Cutaneous sense organs• Proprioceptors – detect stretch or tension

• Motor (Efferent) neurons– Carry impulses from the CNS to the

effectors

• Interneurons (Association Neurons)– Found in neural pathways in the central

nervous system– Connect sensory and motor neurons

~~ Rapid, predicted, involuntary response to a stimuli

Autonomic vs. SomaticAutonomic vs. Somatic

Autonomic – Regulate activity of Smooth & Cardiac Muscle, and Glands

Somatic – Stimulate Skeletal Muscle

Receptor Sensory Neuron Interneuron Motor Neuron Effector

ReflexesSomatic vs. Autonomic

• Pupillary Autonomic• Salivary Autonomic• Patellar Somatic• Hand on hot stove Somatic• Sudoriferous Glands Autonomic• Peristalsis Autonomic

1. Faster Communication2. Synchronize (Heart)

3. Two-Way Transmission

Synapses

Neurotransmitters

• Endorphins – Inhibit pain impulse

• Acetylcholine– Muscular Contraction, R.E.M Sleep

• Dopamine– Emotional responses

• Serotonin– Muscle Relaxor, Induces sleep– Hyposecretion = Depression (Prozac)

• Melatonin– Regulates Circadian Rhythm

• Epinephrine– Vasodilator

• Norepinephrine– Arousal, Dreaming, Mood

Nervous Tissue : Supporting Cells

“Neuroglia”• Astrocytes– Maintains K+ Balance for Nerve Impulse Propagation– Brain Development– Helps Form Blood-Brain Barrier

• Microglia– Phagocytes of the brain

• Ependymal Cells– Forms Cerebrospinal Fluid– Helps circulate cerebrospinal fluid and forms

protective cushion around CNS• Oligodendrocytes (CNS)

– Form Myelin sheaths

Protective Coverings

Meninges “P.A.D.” the Brain

Cerebrospinal Fluid• Produced by the Choroid Plexus• Circulates Through Subarachnoid Space• Clear, Colorless – Contains Glucose, Lactic Acid,

Proteins, Urea, Anions(- ions), Cations (+ ions), WBC

• Major Function– Mechanical Protection

•Shock Absorber•Allows Brain to “Float”

– Chemical Protection•Regulates ionic balance responsible for

neuron signaling– Circulation

•Nutrient/Waste Exchange Between Cardiovascular and Nervous Systems

Choroid PlexusArachnoid Villus

Circulation

Brain Blood Supply

Less PermeableEasy Passage – Glucose, O2, CO2, Water, Caffeine,

Nicotine, Narcotics, and Anasthetics

• Frontal– Primary Motor Area– Concerned with reasoning, planning, parts of speech (Broca’s Area),

movement (motor cortex), emotions, language comprehension and problem-solving , learned skills

• Parietal– Contains Somatic Sensory Area– Concerned with perception of stimuli related to touch, pressure, temperature ,

and pain. • Occipital

– Concerned with many aspects of vision • Temporal

– Concerned with perception and recognition of auditory stimuli (hearing), Olfactory (Smell), and memory (hippocampus).

Which Fissures/Sulci Separate Lobes of the Brain?

White Matter

Myelinated fibers, Carry impulses to and from Cerebral Cortex

110,000 Miles

Corpus Callosum

Cerebral Separations

Longitudinal Fissure___________________

Central Sulcus ___________________Lateral Cerebral Sulcus ___________________Parieto-Occipital Sulcus ___________________Transverse Fissure ___________________

Broca’s Area(Motor Speech)

Wernicke’s Area(Sensory Speech)

Past vs. Present

Interpret/Store Sensations

Learned , sequential Movements

Postcentral Gyrus

Postcentral

Precentral

Paleomammalian Brain – Primitive– Regulates Survival Emotions

•Fear / Anger•Sex•Pain/Pleasure•Memory•Hunger Memory Video

Thalamus“Relay Center”

Limbic StructuresAmygdala - almond shaped mass of nuclei involved in emotional responses, hormonal

secretions, and memory. Responsible for determining what memories are stored and where the memories are stored in the brain. It is thought that this determination is based on how huge an emotional response an event invokes

Cingulate Gyrus - a fold in the brain involved with sensory input concerning emotions and the regulation of aggressive behavior.

Fornix - an arching, fibrous band of nerve fibers that connect the hippocampus to the hypothalamus.

Hippocampus - a tiny nub that acts as a memory indexer -- sending memories out to the appropriate part of the cerebral hemisphere for long-term storage and retrieving them when necessary.

Hypothalamus - about the size of a pearl, this structure directs a multitude of important functions. It wakes you up in the morning, and gets the adrenaline flowing. The hypothalamus is also an important emotional center, controlling the molecules that make you feel exhilarated, angry, or unhappy.

Electroencephalogram (EEG)

Relaxed, Calm, Meditation

Awake, Normal Consciousness

Emotional Stress, Disorders

Sleep

Why get an EEG?Assess Brain Function due to

- Trauma- Infection- Coma

Cerebellum

“Little Brain”

• Receives impulses from proprioreceptors and eyes

• Coordination of complex voluntary muscular movement

• Posture and balance

Diencephalon

– Thalamus• Relay station for nerve

impulses to Sensory Cortex

• Recognition of impulse and (Good vs. Bad)

– Hypothalamus• Overall Autonomic NS• Regulates body

homeostasis; metabolism, body temperature, water balance

• Limbic System – Emotions• Regulates the Pituitary

Gland– Pituitary Gland

• Hormone Production – Epithalamus

• Pineal Body – Hormone Production

• Choroid Plexus – Formation of Cerebrospinal Fluid

Brain Stem

Midbrain- nerve pathway of the

cerebral hemispheres and contains auditory and visual reflex centers

Pons- Involved in BreathingMedulla Oblangata- Controls heart rate,

blood pressure, breathing, swallowing

DiseasesDiseases• Multiple SclerosisMultiple Sclerosis– Myelin sheath broken down, person loses ability to control body’s muscles

• MeningitisMeningitis– Virus or bacteria infection passes into the blood stream and then into the

cerebrospinal fluid that surrounds the brain and spinal cord causes bleeding in the brain

• Cerebral PalsyCerebral Palsy– Neuromuscular disability in which voluntary muscles are poorly controlled and

become spastic– Most likely due to lack of oxygen during delivery

• Cerebrovascular Accident (A.K.A Stroke)Cerebrovascular Accident (A.K.A Stroke)– Blood circulation to the brain is blocked or a blood vessel ruptures causing

necrotic brain tissue• Parkinson’s DiseaseParkinson’s Disease

– Persistent tremors in muscle fibers; due to deficiencies in dopamine – Not controlled by Basal Ganglia– Hard to initiate skeletal muscle movement

• Alzheimer’s DiseaseAlzheimer’s Disease– Dementia is a brain disorder that seriously affects a person’s ability to carry out

daily activities. The most common form of dementia among older people is Alzheimer’s disease (AD), which initially involves the parts of the brain that control thought, memory, and language

• Huntington’s DiseaseHuntington’s Disease– Degeneration basal nuclei– Hard to control involuntary skeletal muscle movements– Constant movements

Alzheimer's Eye Test

Count Every “F” in the following text:

Finished Files are The Result of Years of Scientific Study

Combined with the Experience of Years.

How Many?

Letter from Mr. Jfreefry,I lvoe Cmarbrigde so mcuh. It is fllied wtih ltos of srmat poelpe. I Cnanot blveiee that yuo cna aulaclty uesdnatnrd waht I am wirtnig. The phaonmneal pweor of the Braes mnid is fscatninag, it deosn’t mttaer in what order the ltteers in a wrod are, the olny iprmoatnt tihng is taht the first and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseaea the huamnn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? Yaeh and I awlyas tghuhot slpeling was ipmorantt?

Go Bares!

Alzheimer's Eye Test

Count Every “F” in the following text:

Finished Files are The Result of Years of Scientific Study

Combined with the Experience of Years.

How Many?