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Nervous System (NS) Pablo Collazo Period 1 - Coggle Diagram
Nervous System (NS)
Pablo Collazo
Period 1
Major functions
The master controlling and communicating system in the body.
Integration:
Processing and interpretation of sensory input
Sensory Input:
Gathers information by sensory receptors about inside and external changes
Motor Output:
:
Activates effector organs to produce response
Major divisions and subdivisions
Central NS:
Brain and spinal cord
Integrative and control centers
Brain and spinal cord
Interpretation and control center:
Interprets information and sends motor output
Peripheral NS:
Cranial and spinal nerves
Communicates CNS with body
Sensory (afferent) division:
Somatic and visceral sensory nerves fibers
Conducts impulses from receptors to CNS
Motor (efferent) division:
Motor nerve fibers
Conducts impulses from CNS to effectors
Somatic NS:
Voluntary motor nerve fibers
Conducts impulses from CNS to skeletal muscles
Autonomic NS:
Involuntary motor nerve fibers
Conducts impulses from CNS to glands, smooth and cardiac muscle
Sympathetic division:
Mobilizes body systems during activity
Parasympathetic division:
Conserves energy
Tissues
Neuroglia (glial cells):
Surround and wrap delicate neurons
Astrocytes:
Most abundant in CNS,; help neurons and capillaries
Microglial cells:
Have processes that form myelin sheaths around CNS fibers
Ependymal cells:
Defensive cells of CNS
Oligodendrocytes:
Line cerebrospinal fluid-filled CNS cavities, may have cilia
Satellite cells:
Surround cell bodies in PNS, similar to astrocytes
Schwann cells:
Surround peripheral nerve fibers and create myelin sheaths for thicker ones, vital to regeneration of damaged peripheral nerves
Neurons (Nerve cells):
Excitable cells that transmit
electrical signals. Structural units of NS
Cell body, perikaryon or soma
Dendrites
Nucleus
Nucleolus
Axon
Myelin Sheath
Classification of neurons
Structural Classification:
Multipolar:
2 processes (axon + dendrite)
Rare (ex: retina and olfactory mucosa)
Bipolar:
1 T-like process (2 axons)
Also called pseudounipolar
Unipolar:
3+ processes (axon + dentrites)
Most common and major in CNS
Functional Classification:
Sensory:
Sensory receptors to CNS
Most are unipolar
Cell bodies in ganglia in PNS
Motor:
CNS to effectors
Multipolar
Most cell bodies in CNS (except some autonomic neurons)
Interneurons:
AKA association neurons
Lie between motor and sensory
Shuttle signals through CNS pathway
Most are entirely within CNS
99% of all body neurons are interneurons
Connective Tissue Coverings
Endoneurium:
Loose connective that encloses axons and their myelin sheaths (Schwann cells)
Perineurium:
Coarse connective tissue that bundles fiber into fascicles
Epineurium:
Tough fibrous sheath around all fascicles to form a nerve
Major parts and functions of the brain
Cerebral Hemispheres
Surface Markings
Sulci:
shallow grooves
Central
Parieto-Occiptal
Lateral
Fissures:
deep grooves
Longitudal:
Separates right and left hemispheres
Transverse:
Separates cerebrum and cerebellum
Gyri:
ridges
Lobes
Frontal
Parietal
Temporal
Occipital
Insula
Diencephalon
Thalamus:
Relay station for information coming to cortex
Hypothalamus
Visceral control and regulating center; homeostasis
Epithalamus:
Contains pineal body, regulate sleep wake cycle
Brain Stem:
Controls automatic behavior for survival
Midbrain
Corpora quadrigemina:
Paired dorsal protrusions
Superior Colliculi:
Visual reflex centers
Inferior Colliculi:
Auditory relay center
Pons:
Play role in reticular formation and maintain normal breathing
Medulla Oblongata
Respiratory center:
Control rate and depth of breathing
Regulate vomiting, hiccuping,
swallowing, coughing and sneezing
Cardiovascular center:
Regulates blood pressure
Cerebellum:
Processes information to provide precise, coordinated movements of skeletal muscles
Plays role in thinking, language, and emotion
Balance and coordination
Cerebral cortex:
Executive suite of brain
Motor areas:
voluntary movement
Sensory areas:
conscious awareness of sensation
Association areas:
integrate diverse information
Major parts and functions of the spinal cord
Epidural Space:
Cushion of fat and network of veins in space between vertebrae and spinal dura mater
Filum Terminale:
Extends to coccyx and anchors spinal cord