Nervous System

Central vs. Peripheral Nervous System 1. Central Nervous System (CNS) : brain and spinal cord

1. Central Nervous System (CNS) : brain and spinal cord

Central vs. Peripheral Nervous System 2. Peripheral Nervous System (PNS) : cranial nerves, spinal nerves and ganglia * ( Ganglion =group of neuron cell bodies located outside CNS)

2. Peripheral Nervous System (PNS) : cranial nerves, spinal nerves and ganglia

* ( Ganglion =group of neuron cell bodies located outside CNS)

Sensory division vs. Motor division 1. Sensory Division : receives information FROM body and transmits it TO the CNS for processing a) Somatic Sensory component – receives sensory information from skin, joints, muscle, special senses b) Visceral Sensory component – receives sensory info from blood vessels and viscera 2. Motor Division : transmits info FROM the CNS TO muscles and glands a. Somatic motor component: innervates skeletal muscle b. Autonomic motor (Autonomic Nervous System) : innervates smooth muscle, cardiac muscle, and glands of viscera (organs)

1. Sensory Division : receives information FROM body and transmits it TO the CNS for processing

a) Somatic Sensory component – receives sensory information from skin, joints, muscle, special senses

b) Visceral Sensory component – receives sensory info from blood vessels and viscera

2. Motor Division : transmits info FROM the CNS TO muscles and glands

a. Somatic motor component: innervates skeletal muscle

b. Autonomic motor (Autonomic Nervous System) : innervates smooth muscle, cardiac muscle, and glands of viscera (organs)

NERVOUS TISSUE CELLS A. Neurons : respond to stimuli and conduct nerve impulses

A. Neurons : respond to stimuli and conduct nerve impulses

NERVOUS TISSUE CELLS B. Glial Cells: support and protect neurons (maintenance)

B. Glial Cells: support and protect neurons (maintenance)

NEURON COMPOSITION (p 104) A. Cell Body : B. Nucleus : C. Dendrites : D. Axon : E. Synapse:

A. Cell Body :

B. Nucleus :

C. Dendrites :

D. Axon :

E. Synapse:

NEURON CLASSIFICATION 1. Sensory (Afferent) Neuron : brings information TO the CNS 2. Motor (Efferent) Neuron : takes information FROM CNS to other parts of the body, cell body located in CNS 3. Interneuron (Association Neurons) : helps coordinate and integrate info between sensory and motor neurons, cell body located in CNS

1. Sensory (Afferent) Neuron : brings information TO the CNS

2. Motor (Efferent) Neuron : takes information FROM CNS to other parts of the body, cell body located in CNS

3. Interneuron (Association Neurons) : helps coordinate and integrate info between sensory and motor neurons, cell body located in CNS

GLIAL CELLS - PNS A. Satellite Cells : surround neuron cell bodies in spinal ganglia * ( Ganglion =group of neuron cell bodies located outside CNS) B. Schwann cells : myelinate axons in PNS

A. Satellite Cells : surround neuron cell bodies in spinal ganglia * ( Ganglion =group of neuron cell bodies located outside CNS)

B. Schwann cells : myelinate axons in PNS

Glial Cells - CNS C. Astrocytes : regulate transfer of materials from blood to the brain - help the workings of "blood -brain barrier" D. Oligodendrocytes : myelinate axons in CNS E. Microglia : phagocytize damaged neurons F. Ependymal Cells : line central canal and ventricles - help circulate cerebrospinal fluid (CSF)

C. Astrocytes : regulate transfer of materials from blood to the brain - help the workings of "blood -brain barrier"

D. Oligodendrocytes : myelinate axons in CNS

E. Microglia : phagocytize damaged neurons

F. Ependymal Cells : line central canal and ventricles - help circulate cerebrospinal fluid (CSF)

MYELINATION OF AXONS wrapping an axon with myelin

wrapping an axon with myelin

The Brain 4 Regions Cerebrum R & L Hemispheres Diencephalon Brain Stem Cerebellum

4 Regions

Cerebrum

R & L Hemispheres

Diencephalon

Brain Stem

Cerebellum

Brain – Cerebrum Largest Region Gyri (twisters) & Sulcus (grooves) Fissures (deep grooves) Longitudinal (hemispheres) Divide Lobes

Largest Region

Gyri (twisters) & Sulcus (grooves)

Fissures (deep grooves)

Longitudinal (hemispheres)

Divide Lobes

Brain – Cerebrum (lobes) Parietal Lobe Somatic sensory area “ homunculus”

Parietal Lobe

Somatic sensory area

“ homunculus”

Brain – Cerebrum (lobes) Occipital Lobe Visual area

Occipital Lobe

Visual area

Brain – Cerebrum (lobes) Temporal Lobe Olfactory Deep inside

Temporal Lobe

Olfactory

Deep inside

Brain – Cerebrum (lobes) Frontal Lobe Primary Motor Area Speech Language

Frontal Lobe

Primary Motor Area

Speech

Language

Cerebrum Cerebral Gray Matter (Cortex) superficial Cerebral White Matter deeper Corpus Callosum connects hemispheres

Cerebral Gray Matter (Cortex)

superficial

Cerebral White Matter

deeper

Corpus Callosum

connects hemispheres

Diencephalon (interbrain) Sits atop brain stem Enclosed by cerebrum Structures Thalamus Hypothalamus Epithalamus

Sits atop brain stem

Enclosed by cerebrum

Structures

Thalamus

Hypothalamus

Epithalamus

Diencephalon Thalamus Relay station from spinal cord Crude impulse Pleasant vs. Unpleasant

Thalamus

Relay station from spinal cord

Crude impulse

Pleasant vs. Unpleasant

Diencephalon Hypothalmus (“under the thalmus”) ANS (Emotional Visceral Brain) Body Temp, H 2 O balance, Metabolism Appetites (thirst, hunger) Pleasure & Pain

Hypothalmus (“under the thalmus”)

ANS (Emotional Visceral Brain)

Body Temp, H 2 O balance, Metabolism

Appetites (thirst, hunger)

Pleasure & Pain

Diencephalon Epithalamus Pineal body (endocrine system) Choroid plexus (cerebrospinal fluid)

Epithalamus

Pineal body (endocrine system)

Choroid plexus (cerebrospinal fluid)

Brain Stem About size of thumb Areas Midbrain Convey impulses Pons Controls breathing Medulla Oblongata Heart rate, BP, Swallowing, Vomiting, etc.

About size of thumb

Areas

Midbrain

Convey impulses

Pons

Controls breathing

Medulla Oblongata

Heart rate, BP, Swallowing, Vomiting, etc.

Cerebellum Convoluted surface Precise timing of Skeletal muscles Balance “ Auto-Pilot”

Convoluted surface

Precise timing of Skeletal muscles

Balance

“ Auto-Pilot”

Protection of Brain Meninges dura mater (tough mother) arachnoid mater pia mater (gentle mother) Cerebrospinal Fluid Eliminate waste Blood-Brain Barrier Least-permeable membrane in body

Meninges

dura mater (tough mother)

arachnoid mater

pia mater (gentle mother)

Cerebrospinal Fluid

Eliminate waste

Blood-Brain Barrier

Least-permeable membrane in body

Spinal Cord Aprox. 17 in long Continuation of Brain Stem Ends Below ribs

Aprox. 17 in long

Continuation of Brain Stem

Ends Below ribs

Spinal Cord Gray Matter Posterior Horns (dorsal) Anterior Horns (ventral) CSF Central Canal Protection Vertebrae Dura mater Arachnoid Pia mater

Gray Matter

Posterior Horns (dorsal)

Anterior Horns (ventral)

CSF

Central Canal

Protection

Vertebrae

Dura mater

Arachnoid

Pia mater

Spinal Cord Cervical Thoracic Lumbar Sacral Coccygeal

Cervical

Thoracic

Lumbar

Sacral

Coccygeal

Spinal Cord - Cervical 8 Cervical Nerves C1-C8 Diaphragm, Shoulders, Neck Damage may result in: Respiratory Paralysis

8 Cervical Nerves C1-C8

Diaphragm, Shoulders, Neck

Damage may result in:

Respiratory Paralysis

Spinal Cord - Thoracic T1-T12 Intercostal

T1-T12

Intercostal

Spinal Cord - Lumbar L1-L5 Lower abdomen, buttocks, anterior & medial thigh, hip muscles, skin of thigh Damage: Inability to flex hip Loss of cutaneous sensation Inability to adduct thigh

L1-L5

Lower abdomen, buttocks, anterior & medial thigh, hip muscles, skin of thigh

Damage:

Inability to flex hip

Loss of cutaneous sensation

Inability to adduct thigh

Spinal Cord – Sacral & Coccygeal S1-S5 + Coccygeal Nerve Lateral & posterior leg/foot, gluteus, lower trunk Damage: Inability to extend hip Inability to flex knee

S1-S5 + Coccygeal Nerve

Lateral & posterior leg/foot, gluteus, lower trunk

Damage:

Inability to extend hip

Inability to flex knee