NS Flashcards
A group of tissues composed of highly
specialized cells possessing the
characteristics of excitability and
conductivity.
NERVOUS SYSTEM
Morphological divisions of nervous system:
- Central nervous system
- Peripheral nervous system
a. Brain
b. Spinal cord
Central nervous system
- Innervating visceral or involuntary structures like smooth muscles, cardiac muscles and glands.
- This is autonomic nervous system.
Visceral efferent
a. Cranial nerves (12 pairs)
b. Spinal nerves (31 pairs)
c. Autonomic nervous system
Peripheral nervous system
Functional divisions of PNS:
- Somatic efferent
- Visceral efferent
- Produce myelin sheath in the central nervous system.
Oligodendrocyte
- involve in the blood brain barrier (BBB)
Astrocyte
Types of cell in the nervous system:
- Neurons
- Neuroglia
- Innervating somatic structures like skeletal muscles and skin.
- Pertaining to the body
Somatic efferent
Two types of processes: Neuron
- Dendrites
- Axons
- The active conducting elements
- This is the Parenchymal – functional cells
Neurons
- the supporting element
- supporting cells of the CNS and PNS means do not conduct action
Neuroglia
types of neuroglia
a. Astrocyte
b. Oligodendrocyte
c. Microglia
d. Ependymal cells
- Phagocytic cells (protecting)
- Nangangain ng Microorganisms
- immune cells of the CNS
Microglia
- Basic unit of the nervous system which
conducts electrical impulses from one part of the body to another.
Neuron
- Transmit impulses toward the cell body.
- Afferent process
Dendrites
- point of connection between neurons.
Synapse
- that will allow the conduction of impulse to pass through from one neuron to another.
neurotransmitters
- lining the ventricles at the brain and central canal of spinal cord.
- Flow of your CSF, fluid of your brain
Ependymal cells
Main neurotransmitters:
- Epinephrine (Adrenalin)
- Norepinephrine (Nor Adrenaline)
- Acetylcholine
- Conducting impulses away from the cell
body. - Efferent process
Axons
- Insulating material covering axons in central and peripheral nervous system.
- The electrical impulse jumps from node to node in myeline sheath instead of traveling continuously along the nerve fiber. (Saltatory Conduction of Impulses)
Myelin Sheath
- periodic gap in the insulating myelin sheath on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses.
Node of Ranvier
- Includes the brain and spinal cord.
- It is divided grossly into gray and white
matter:
CENTRAL NERVOUS SYSTEM
- So, called because of its appearance and preponderance of nerve cell bodies and true dendrites.
- Outer part in brain; inner part in spinal cord
Gray matter
- Composed chiefly of myelinated nerve
fibers - Inner part in brain; outer part in spinal cord
White matter
- Group or aggregates of nerve cell bodies outside the CNS
Ganglion/ganglia cells
Embryological Divisions of the Brain:
- Forebrain (Prosencephalon)
- Midbrain (Mesencephalon)
- Hindbrain (Rhombencephalon)
- Part of the central nervous system contained within the skull
- Most complex and largest mass of nervous tissue in the body and contains literally billions of nerve cells.
- The average weight of the human brain in the adult is approximately 1380 grams in the male and 1250 grams in the female
Brain
a. Telencephalon (Cerebrum)
b. Diencephalon (thalamus, hypothalamus, epithalamus, subthalamus)
- Forebrain (Prosencephalon)
a. Corpora quadrigemina (tectum)
- 2 superior colliculi – visual reflexes
- 2 inferior colliculi – auditory reflexes
b. Cerebral peduncles
c. Vertebral Aqueduct of Sylvius (iter)
- Midbrain (Mesencephalon)
a. Metencephalon (cerebellum, pons)
b. Myelencephalon (medulla oblongata)
Hindbrain (Rhombencephalon)
- 7/8 of weight of brain
- discriminatory identification; integration of sensory information; memory; reasoning; for use of language; for emotional behavior; for initiation of movement
Cerebrum (Telencephalon)
Fissures of Cerebrum:
- Longitudinal Fissure
- Lateral Sylvian Fissure
- Central Sulcus (Rolandic Fissure)
- Transverse Fissure
- Parieto – occipital Fissure
- Calcarine Fissure
- Separating 2 cerebral hemisphere
Longitudinal Fissure
- Separate your frontal lobe and parietal lobe above from the temporal lobe.
Lateral Sylvian Fissure
– don’t interchange the fissure and sulcus because anteriorly ang spinal mo hinahati sya ng deep groove
Antero median fissure
called in the End of lateral Sylvian Fissure is
Supramarginal Gyrus
– shallow groove, Lumalabas un Middle cerebral artery
Dorso median fissure
Depression that separating the frontal lobe and the parietal lobe.
Central Sulcus (Rolandic Fissure)
- Between the cerebellum and the cerebrum.
- Cerebellum – big brain; cerebrum – little brain.
Transverse Fissure
- Between the occipital and parietal lobes.
- Middle surface of the brain
Parieto – occipital Fissure
- Found in the occipital lobe
- Visual center (calcarine area)
- 2 parts of visual area: Cuneus and Lingual gyrus
Calcarine Fissure
Lobes of the Cerebral cortex:
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
- calcarine lobe
- Temporal lobe
- yun dulo nya, Angular gyrus
Superior Temporal Sulcus
- Includes all the cortex lying anterior to the central sulcus of Rolando and above the lateral sulcus sylvius.
- Center for motor functions and personality.
Frontal lobe
- Lies posterior to central sulcus of Rolando and above lateral Sylvian fissure.
- Center for sensory functions
Parietal lobe
- Lies beneath the lateral sulcus of Sylvian
- Center for hearing and olfaction.
Temporal lobe
3 part of inferior frontal gyrus:
Pars opercularis
Pars triangularis
Pars orbitalis- (not part of Broca’s area)
- Exposed when the lips of lateral Sylvian
fissure are separated. - Icucut ng coronal and makikita yun lateral sulcus, un nasa gilid tapos nandoon sa loob yun Insula.
Insula (Island of Reil)
- Above lateral sulcus into the deep layers of the sensory area
- Taste area or gustatory area
- Opercular part of the post central gyrus
(Brodmann’s area 43)
Taste Area
- Lies in the frontal lobe immediately anterior to the central sulcus
- Controls voluntary movements in the
opposite side of body. - Brodmann’s area 4
Primary Motor area or Pre-central gyrus
- Occupies the posterior extremity of the
cerebral hemisphere behind parieto-occipital fissure. - Visual center
Occipital lobe
Functional areas of the cerebrum:
- Primary Motor area or Pre-central gyrus
- Pre-motor Area
- Pre-frontal area
- Primary sensory/ somesthetic area or Post-central gyrus
- Motor speech area
- Sensory speech area
- Auditory or Hearing Area (transverse gyri of Heschl)
- Visual Area
- Olfactory or smell Area
- Taste Area
Frontal lobe is divided to 3 gyri:
Superior frontal gyrus
middle frontal gyrus
inferior frontal gyrus
- Lies in inferior frontal gyrus of dominant hemisphere
- Will control the muscles that you used for talking.
Motor speech area
– Brodmann’s 44
Pars opercularis
- (Brodmann’s area 45, 44)
Broca’s area (
- In front of the motor area
- Exerts a controlling influence over the motor area, ensuring an orderly series of movements.
Pre-motor Area
- Concerned with behavior, character and emotional state of the individual.
- Concerned with foresight, good judgement, abstract thinking.
Pre-frontal area
- Within the temporal lobe
- Uncus (Brodmann’s area 34)
Olfactory or smell Area
- Lies behind the central sulcus of Rolando in parietal lobe
- Sensations of pain, temperature, pressure, and touch, position and movement sensation from opposite side of body are received and interpreted.
- Brodmann’s area 3, 1, 2
Primary sensory/ somesthetic area or Post-central gyrus
dito lumalabas sa lateral sylvian fissure; sinusupply nya yun mga primary motor, primary sensory, motor speech area.
Middle cerebral artery
- Brodmann’s 45
Pars triangularis
- Lies below lateral sulcus within the temporal
lobe - Center for hearing
- Brodmann’s area 41 & 42
Auditory or Hearing Area (transverse gyri of Heschl)
- Masses of gray matter embedded in the white matter of the cerebral hemispheres
- Include the caudate nucleus (medial portion) and the putamen and globus pallidus called lentiform nucleus.
- Constitute the corpus striatum
- Play a role in the control of motor function and injury manifest as uncontrolled aimless movements.
Basal Ganglia
- Lies in temporal lobes posterior to auditory area of dominant hemisphere.
- Wernicke’s area (Brodmann’s area 22)
- Nagoorganize ng thoughts na sasabihin mo
- Pag eto naapektuhan, nagkakaroon ng change un mga letters ng word, hindi mona naoorganize un sasabihin mo (instead na Fork, kork un nasasabi mo) parang napapalitan lng un letters.
Sensory speech area
types of Diencephalon
- Thalamus
- Hypothalamus
- Around the calcarine fissure, including
greater part of the occipital lobe - Brodmann’s area 17
Visual Area
- Relay center for sensory impulses (except olfactory) from peripheral receptors to cerebral cortex.
Thalamus
- Involved in the regulation of body
temperature, feeding activities, biorhythm, emotion, etc.
Hypothalamus
- Largest commissural fibers
Corpus Callosum
- Above the corpus callosum and callosal
sulcus.
Cingulate Gyrus
- Depression above the corpus callosum
Callosal Sulcus
Cerebellum divided into lobes by deep and distinct fissures, these lobes include the:
a. Anterior Lobe
b. Posterior Lobe
c. Flocculonodular lobe
Concerned with the function of equilibrium, posture and balance
Flocculonodular lobe
- Depression above the cingulate gyrus
Cingulate Sulcus
- Coordination of voluntary motor activity
Posterior Lobe
- Oval in shape with a central constriction and lateral expanded portions.
- The constricted centra; portion is called the Vermis
- 2lobes: Vermis and Corpus Callosum
Cerebellum
- Lies anterior to the cerebellum and between the midbrain and medulla.
- Bridge-like structure, consisting almost
entirely of white matter linking the various parts of the brain.
Pons
- Regulation of muscle tone
Anterior Lobe
– as a connection (Latin of worm)
and the lateral expanded portions the
hemisphere.
Vermis
- found anteriorly in midbrain
- pair of cylindrical bodies made up of nerve fiber tracts which connect the forebrain with the hindbrain.
Cerebral peduncles
upper 2; for visual reflexes
Superior colliculi
types of Midbrain
a. Cerebral peduncles
b. Corpora quadrigemina
- Connects the forebrain and hindbrain
- Concerned with motor coordination
- Also called mesencephalon
Midbrain
lower 2; for auditory reflexes
Inferior colliculi
- Found posteriorly in midbrain
Corpora quadrigemina
- Continuous with the spinal cord inferiorly with the spinal cord inferiorly and with the pons superiorly.
- Lies ventral to the cerebellum
- Has a number of vital regulatory and reflex centers, including those controlling the circulatory system, breathing, swallowing, vomiting, coughing, sneezing.
Medulla Oblongata
- Circulating within the ventricles, the central canal of the spinal cord and also within the subarachnoid space.
- Production will be by the choroid plexus, which are present in all of the ventricles of the brain
- Nagbibigay ng nutrition and immune
function - Colorless, with a composition similar to that of lymph.
Cerebrospinal Fluid (CSF)
Ventricles of the brain:
- Lateral ventricle
- Third ventricle
- Fourth ventricle
- absorption will be by the Arachnoid villi or Arachnoid granulate
Ventricles of the brain
- Found inside the cerebral hemispheres
- Interventricular foramen (foramen of
Monroe)
Lateral ventricle
- Between the 2 thalamic nuclei, continuous with the cerebral aqueduct of Sylvius
Third ventricle
- Communicates with subarachnoid space through foramen of Luschka and Magendie
- Iter
Fourth ventricle
cerebral aqueduct of sylvius (this is the
communication between third ventricle and fourth ventricle)
Iter
- Three membranes collectively known as the meninges provide protection to the brain and spinal cord.
Meninges
– outermost (below of dura
mater, there have Subdural space)
Dura Mater
Meninges from outside in, there are the:
a. Dura Mater
b. Arachnoid mater
c. Pia mater
– middle (below this,
there have subarachnoid space)
Arachnoid mater
– innermost (closely adherent
to the brain)
Pia mater
2 enlargements Spinal Cord:
- Cervical enlargement
- Lumbar enlargement
- Continuous with the medulla oblongata
above - Extends from the level of foramen magnum to the lower border of 1st lumbar vertebra in adult and level of L3 vertebra in children.
- Average length: 45 cm
Spinal Cord
- Where nerve supply of arms arises from
- Upper extremities
- C4 to T2
Cervical enlargement
The lumbar and sacral spinal nerves descend along the filum terminale in a bundle known as the
cauda equina
- Where nerve supply of legs arises from
- Lower extremities
- Level of 10th thoracic vertebra; widest at the 12th thoracic vertebra
- It narrows down was conus medullaris, where it gives rise to the thread-like filum terminale.
– that will be attached to your coccygeal
vertebral - The lumbar and sacral spinal nerves descend along the filum terminale in a bundle known as the cauda equina. (horse tail like)
Lumbar enlargement
- (M) Arise in between your cerebral peduncle; Found in brainstem.
- Innervate the extraocular muscles of the eye
- Exception: LR6 – Lateral rectus muscles of the eye that innovated by abducens; SO4 –superior oblique innovated by trochlear.
- (PS) – innervates the iris.
Oculomotor (III)
- (S) nerve for smell.
- Located in the axons of superior concha of nose.
- Tutusok sya sa cribriform plate of ethmoid para tumusok doon sa olfactory bulb at dadaloy sa olfactory tract.
- Anosmia
Olfactory (I)
- 12 pairs of symmetrically arranged nerves attached to the brain
3, 4 – midbrain
5, 6, 7, 8 – pons
9, 10, 11, 12 – medulla oblongata
(S) – Purely sensory nerve;
(M) – Purely motor function;
(Mx) – Mixed Nerve;
(PS) – Parasympathetic
Cranial Nerves
PERIPHERAL NERVOUS SYSTEM
I. Cranial Nerves
II. Spinal Nerves
III. Autonomic Nervous system
loss of the sense of smell
Anosmia
- (S) Nerve arising from the eye; for vision
- Magcocross sya sa optic chiasm
- Anopsia
Optic (II)
blindness
Anopsia
- (M) only cranial nerve that will arise from posterior surface of the brainstem.
- Thinnest nerve
- Innovating your superior oblique muscle
Trochlear (IV)
- (M) – LR6 innovating by abducens
Abducens (VI)
- (S) hearing
Vestibulocochlear (acoustic) (VIII)
- (Mx) Largest of the cranial nerves
- Has 3 branches: ophthalmic, mandibular and maxillary
- Sensory – general sensation on the anterior 2/3 of the tongue, special sensation - tastesensation innovated by the facial nerve; motor – yun mandibular division ay nag susuply sa muscles of mastication = Mixed Nerve (Mx)
Trigeminal (V)
- (Mx) Sensory – special sensation of taste anterior 2/3 of the tongue; Motor –
nagsususply sa mga muscles of facial
expression = Mixed Nerve (Mx) - (PS) – glands; innovation of the lacrimal
glands and salivary glands except parotid gland.
Facial (VII)
- (Mx) Night cranial nerve
- Sensory – will innovate the general and
special sensation on the posterior 1/3 of the tongue, (taste and touch); - Motor – innovate the muscles of the tongue, Palatoglossus and muscles of pharynx, stylopharyngeus = Mixed Nerve (Mx)
- (PS) – innovation of Parotid gland
Glossopharyngeal (IX)
- (Mx) Longest nerve
- Sensory – internal organs; Motor – laryngeal muscles that you use for talking and pharyngeal muscles use for swallowing. = Mixed Nerve (Mx)
- (PS) - smooth muscle of the visceral/ internal organs
Vagus (X)
- (M) Spinal accessory or accessory spinal
- Innovation of sternocleidomastoid and
trapezius
Accessory (XI)
- (M) innervates the tongue muscles except the palatoglossus
Hypoglossal (XII)
Classification of Cranial Nerves
A. Sensory Nerves
B. Motor Nerves
C. Mixed Nerves
- Carry impulses towards brain
- Also called afferent fibers
- Cranial nerves: I, II, VIII
Sensory Nerves
- Carry impulses away from the brain.
- Also called efferent fibers
- Cranial nerves: III, IV and VI which supply the eye muscles; XI and XII
Motor Nerves
- Carry both sensory and motor nerve fibers
- Cranial nerves: V, VII, IX, X
Mixed Nerves
- Containing fibers of motor neurons
- These 2 roots join together to form spinal nerve
Ventral root
- A bundle of nerve fibers attached to spinal cord
- 31 pairs of nerves called spinal nerves arise from the spinal cord along almost its entire length and emerge from the vertebral canal through the intervertebral foramina
- There are eight pairs of cervical spinal
nerves: 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. - Always mixed nerves
- Union of dorsal root and ventral root
Spinal Nerves
- Containing fibers of sensory neurons
Dorsal root
- Group of nerve fibers from ventral rami of cervical, lumbar and sacral spinal nerves.
- Posterior rami never from plexuses.
Plexuses
- Formed by the first 4 cervical nerves (C1, C2, C3, C4)
- This supplies the back and sides of the head and the front of the neck
- Gives off the phrenic nerve to the diaphragm
Cervical plexus
- Lower 4 cervical (C5, C6, C7, C8) nerves and 1st thoracic (T1) supplies the skin and muscles of the upper limb/extremities.
- Gives off large nerves: circumflex, radial, median, ulnar and musculocutaneous nerves.
Brachial plexus
- From L1-L4 spinal nerves
- Anterior portion and medial portion
a. Obturator nerve
b. Femoral nerve
- Arising from anterior division of L2, L3,
L4 spinal nerves - Supplies the muscles and skin on medial aspect of thigh
Obturator nerve
- Arising from the posterior divisions of
L2, L3, L4 spinal nerves - Supplies muscles and skin on anterior
aspect of the thigh
Femoral nerve
- Do not form plexuses
- Independent nerves
- T1 – T11 spinal nerves = Intercostal nerves
- T12 spinal nerves = Subcostal nerve
Thoracic Spinal Nerves
- From L4, L5, S1, S2, S3 spinal nerves
- The largest branch which is the sciatic nerve (the largest nerve in the body)
- Posterior aspect of lower extremities
- Sciatic nerve divides into:
a. Tibial nerve
b. Common peroneal nerve
Sacral plexus
types of Autonomic System
- Sympathetic/ Thoracolumbar Divisions
- Parasympathetic/ Craniosacral Divisions
- Arises from all the thoracic and the first three
lumbar segments of the spinal cord
Sympathetic/ Thoracolumbar Divisions
- Arises from the third, seventh, ninth, and tenth cranial nerves and from the second, third and fourth sacral segments of the spinal cord.
- Repost and repair
Parasympathetic/ Craniosacral Divisions
