-
What is the nervous system?
Body's principal control system, regulates all bodily functions via electrical impulses transmitted thru nerves
-
Nervous system is broken down into '2' divisions
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
-
What is the central nervous system?
Consists of the brain and the spinal cord
-
Peripheral Nervous System breakdown
-
What is the Peripheral Nervous System?
Composed of the cranial nerves from the brain and peripheral nerves from the spinal cord
Subdivision are: somatic nervous system (aka. voluntary) & automatic nervous system (aka involuntary)
-
What are the '4' categories of peripheral nerves?
- Somatic sensory
- Somatic motor
- Visceral (automatic) sensory
- Visceral (automatic) motor
-
What is the somatic sensory nerve?
Afferent nerves that transmit sensations such as touch, pressure, pain, temperature, & position
-
What is the somatic motor nerve?
Efferent fibers that carry impulses to the skeletal (voluntary) muscles
-
What is the visceral (automatic) sensory nerve?
Afferent tracts that transmit sensations from the visceral organs.
Sensation such as need to pee & take a crap
-
What is the visceral (automatic) motor nerve?
Efferent fibers that exit the CNS & branch to supply nerves to the cardic muscle & smooth muscle of the viscera (organs) & glands
-
What is the Somatic (Voluntary) Nervous System?
Governs voluntary functions (those we consciously control)
ie. control of movement & skeletal muscles
Subdivision of the peripheral nervous system
-
What is the Automatic (Involuntary) Nervous System?
Controls involuntary bodily functions (ie. smooth muscle, cardiac muscle, glands)
Subdivision of the peripheral nervous system
Divided into: sympathetic nervous system & parasympathetic nervous system
-
What is autonomic ganglia?
Groups of autonomic nerve cells located outside the CNS
-
What are the preganglionic nerves?
Nerve fibers that extend from the CNS to tht autonomic ganglia
-
What is the postganglionic nerves?
Nerve fibers that extend from the autonomic ganglia to the target tissues
-
What is the Sympathetic Nervous System?
Division of the automatic nervous system
Prepares the body for 'fight or flight'
- Body reacts by:
- * ^ HR
- * Bronchioles dilate
- * Pupils dilate
- * Decrease organ & digestion activity
- * Vasocontriction
Nerves: thoracic & lumbar regions
Adrenal medulla gland is responsible for the release of the hormones
- Neurotransmitters: epinephrine (80%)
- norepinephrine (20%)
-
What are the '2' types of sympathetic ganglia?
- Sympathetic chain ganglia
- Collateral ganglia
-
What are the effects when the sympathtic chain ganglia is stimulated?
- ^ BP
- Stimulation of secretion by sweat glands
- Constriction of blood vessels in the skin
- ^ in blood flow to skeletal muscles
- ^ HR
- ^ force of cardiac contraction
- Bronchodilation
- Stimulation of energy production
-
What are the effects when the collateral ganglia is stimulated?
- Reduction in blood flow to abdominal organs
- Decreased digestive activity
- Relaxation of smooth muscle in the wall of the urinary bladder
- Release of glucose stores from the liver
-
What are the '2' types of sympathetic receptors?
- Adrenergic receptors
- Dompaminergic receptors
-
What are the '4' types of adrenergic receptors?
-
What are the effects of the apha1 receptors?
- Peripheral vasoconstriction
- Mild bronchoconstriction
- Stimulation of metabolism
-
What are the effects of the alpha2 receptors?
Prevent overrelease of norepinephrine
-
What are the effects of beta1 receptors?
- ^ HR
- ^ cardiac contractile force
- Cardiac automaticity & conduction
-
What are the effects of beta2 receptors?
- Vasodilation
- Bronchodilation
-
What are the effects of dopaminergic receptors?
Dilation of renal, coronary & cerebral arteries
-
What is the parasympathetic nervous system?
Division of the automatic nervous system
Controls the 'feed or breed' or rest & regenerative
Arises from the brainstem & sacral segments of the spinal cord
- Body actions:
- * decreased HR & cardiac contractile force
- * bronchioles constrict
- * Pupils constrict
- * sexual stimulation
- * ^ digestive activity
Nerves: sacral region & cranial nerves (vagus nerve)
Neurotransmitters: Acetylcholine
-
What are the '4' cranial nerves that carry parasympathetic fibers?
- III: oculomotor nerve
- VII: facial nerve
- IX: glossopharyngeal nerve
- X: vagus nerve
-
What are the '2' types of acetylcholinesterase (ACh)?
-
What are the '2' nicotinic receptors called?
NicotinicN (neuron): found in autonomic ganglia; parasympathetic & sympathetic systems
NicotinicM (muscle): found at the neuromuscular junction, initiate muscular contraction; somatic nervous system
-
What are the muscarinic receptors responsible for?
promoting the parasympathetic response
-
What is a neuron?
- * nerve cell
- * fundamental component of nervous system
-
-
Parts of the Neuron & their functions?
- * Soma: cell body, contains the nucleus, mitochondria & ribosomes
- * Dendrites: transmit electrical impulses to cell body
- * Axons: transmit electrical impulses away from the cell body
- * Synaptic terminals: affect another neuron or effector
-
Neuron in resting state....
- '+' charged on outside
- '-' charged on the inside
-
Neuron electrically stimulated....
- NA rapidly surges into the cell
- K rapidly leaves the cell
- thus depolarization of the neuron
-
What is a neurotransmitter?
substance released from axon terminal of neuron on excitation travels across the synpatic cleft to either excite or inhibit the target cell
examples: acetylcholine, norepinephrine, dopamine
-
Where does the brain lie?
Within the cranium vault protected by the skull
-
What bones make up the cranium?
- frontal bone
- occipital bone
- parietal bones
- temporal bones
- sphenoid bones
- ethmoid bones
-
-
What are the meninges?
protective membranes that cover the entire CNS
-
There are '3' layers of meninges...
- Dura Mater: durable outermost layer
- Arachnoid Membrane: weblike structure middle layer
- Pia Mater: innermost layer
-
What is the subarachoid space?
space b/t the pia mater & anachnoid membrane
-
What is the subdural space?
space b/t the dura mater & arachnoid membrane
-
What is the space outside the dura mater called?
Epidural space
-
What is cerebrospinal fluid (CSF)? Where is it found?
- Its a watery clear fluid
- brain & spinal cord are bathed in it
-
What are the '6' parts of the brain?
- Cerebrum
- Diencephalon (thalmus & hypothalmus)
- Mesencephalon (midbrain)
- Pons
- Medulla Oblongata
- Cerebellum
-
What '2' areas of the brain make up the forebrain?
-
What is Cerebrum?
- Located in the anterior & middle are of the cranium
- Contains '2' hemispheres which are joined together by the corpus callosum
- Responsible for: sensory & motor actions, intelligence, learning, analysis, memory, language
-
What functions do the frontal areas of the Cerebrum control?
-
What is the temporal lobe of the cerebrum responsible for?
Speech
-
What is the occipital cortex of the cerebrum responsible for?
Vision
-
What are the parietal lobes of the cerebrum responsible for?
Sensory
-
What is the Diencephalon?
- covered by the cerebrum
- aka. interbrain
- thalamus, hypothalamus & limbic system
- Responsible for: involuntary actions, temperature regulation, sleep, water balance, stress response & emotions
- Major role: regulating autonomatic nervous system
-
What areas of the brain make up the brainstem?
- Mesencephalon (midbrain)
- Pons
- Medulla Oblongata
-
What areas of the brain make up the hindbrain?
-
What is the mesencephalon?
- aka. midbrain
- Located b/t the diencephalon & the pons
- Responsible for: motor coordination & eye movement
-
What is the pons?
- Located b/t midbrain & medulla oblongata
- Contains connections b/t the brain & spinal cord
-
What is the medulla oblongata?
- Located b/t the pons & the spinal cord
- Marks the division b/t the spinal cord & brain
- Responsible for: controlling respirations, cardiac activity, vasomotor activity
-
What is the cerebellum?
- Located in the posterior fossa
- Consists of '2' hemispheres
- Responsible for: fine motor movement, posture, equilibrium, muscle tone, balance & coordination
-
What is the Reticular Activating System (RAS)?
- Operates in the lateral portion of the medulla, pons & midbrain
- Sends impulses to & receives impulses from cerebral cortex
- Responsible for: maintaining consciousness & ability to respond to stimuli
-
What '2' systems supply blood to the brain?
- Carotid system is anterior
- Vertebrobasilar system is posterior
Venous drainage thru venous sinuses & internal jugular veins
-
-
-
What is the spinal cord?
Central nervous system pathway responsible for transmitting sensory input from the body to the brain & for conducting motor impulses from the brain to the body muscles & organs.
Acts as a reflex center
-
What is the anterior medial fissure?
Deep crease along the ventral surface of the spinal cord that divides the cord into right & left halves
-
What is Posterior Medial Sulcus?
Shallow longitudinal groove along the dorsal surface of the spinal cord
-
What is Gray Matter of the spinal cord?
Areas in the CNS dominated by nerve cell bodies; the central portion of the spinal cord
-
What is the white matter of the spinal cord?
Material that surrounds gray matter in the spinal cord
Made up largely of axons
-
What are Ascending Tracts?
Bundles of axons along the spinal cord that transmit signals from the body to the brain
-
What are the '3' Ascending Tracts?
- Fasciculus Gracilis
- Fasciculus Cutaneous
- Spinothalamic Tracts
-
What are the Fasciculus Gracilis & Fasciculus Cutaneous responsible for?
- * Carry sensory impulses of light touch
- * Vibration
- * Positional sense from the skin, muscles, tendons & joints
**Injury results in deficits on same side of body
-
What is the Spinothalamic Tracts responsible for?
- * Conducts pain & temperature (anterior)
- * Conducts touch & pressure (lateral)
** Injury results in opposite side deficits
-
What are Descending Tracts?
Bundles of axons along the spinal cord that transmit signals from the brain to the body
-
What are the '3' Descending Tracts?
- Corticospinal Tract
- Reticulospinal Tract
- Rubrospinal Tract
-
What is the Corticospinal Tract?
Responsible for voluntary & fine muscle movement
-
What is the Reticulospinal Tract responsible for?
Consists of '3' subtracts: one lateral, one medial, one anterior
Responsible for: sweating & muscular activity associated w/ posturing
-
What are the rubrospinal tracts responsible for?
Control the fine motor functions of the hands & feet
-
What are Spinal Nerves?
- Peripheral nerve roots that branch in pairs from the spinal cord
- Have both sensory & motor components
- Provide largest part of innervation to skin, muscles & internal organs
- There are '31' pairs of spinal nerve roots
-
What is a dermatome?
Topographical region of the body surface innervated by one nerve root
-
What are some of the 'key' locations to recognize for assessment for dermatomes?
- C3: collar region
- C7: little finger
- T4: nipple line
- T10: umbilicus
- S1: small toe
-
What is a myotome?
muscle & tissue of the body innervate by a spinal nerve root
-
What are some of the 'key' locations to recognize for assessment for myotomes?
- C5: arm extension
- C7: elbow extension
- T1: knee extension
- S1: ankle flexion
-
What are the 12 pairs of spinal nerve roots?
- C1-C8: Cervical
- T1-T12: Thoracic
- L1-L5: Lumbar
- S1-S5: Sacral
- Co: Coccygeal
-
Each pair has '2' dorsal & '2' ventral roots. What do each of these do?
- Ventral Roots: carry motor impulses from the cord to the body
- Dorsal Roots: carry sensory impulses from the body to the cord
-
What is a Plexus?
Nerve roots converging in a cluster of nerves to form as a group
-
What are reflexes?
- Those primary processing functions that the spinal cord performs
- Maintaining balance & muscle tone
-
What are interneurons?
Special neurons in the cord that intercept sensory signals from our 'reflex response'
-
Definition of cranial nerves?
12 pairs of nerves that originate in the brain & supply nervous control to the head, neck & certain thoracic & abdominal organs
-
What are the 12 cranial nerves?
- I: Olfactory nerve - smell
- II: Optic nerve - vision
- III: Oculomotor nerve - eye movement, pupil constriction
- IV: Trochlear nerve: ocular movement
- V: Trigeminal nerve: sensitivity of face
- VI: Abducens nerve: Ocular movement
- VII: Facial nerve: facial expression
- VIII: Acoustic nerve: hearing
- IX: Glossopharyngeal nerve: viseral sensibility
- X: Vagus nerve: involuntary muscle control
- XI: Spinal accessory muscle: speech
- XII: Hypoglossal nerve: movement of tongue
|
|