Chapter 2 Nervous System Flashcards
(28 cards)
The brain consists of 3 main parts and certain subparts:
1) Cerebrum
i) ________
ii) _______
2) Cerebellum
3) Brain Stem
i) ______
ii) ______
iii) _______
Telencephalon
Diencephalon
Mid Brain
Pons
Medulla (Oblongata)
Brain boats 3 poles: _____, _____ and ______ poles
Frontal
Temporal
Occipital
CEREBRUM
TELENCEPHALON
Is the _____, most recently evolved area of the brain
It is shaped like a _____ ____
Divided into the left and right hemispheres by the _____ FISSURE or _____
The horizontal fissure separates the telencephalon from the _____ and has a prominent _____ fissure separating the temporal lobe with the upper part of the cerebrum
It can be divided into 4 lobes
Frontal - above lateral fissure, in front of central ____
Parietal - between central sulcus and _____- ______ sulcus
Occipital - behind parieto-occipital sulcus
Temporal - below _____ fissure
The outer covering of this hemisphere, the ____, is thrown into many folds. The folds are called ____ and ____.
The most prominent of which are named: Central \_\_\_\_\_\_\_ Postcentral \_\_\_\_\_\_-\_\_\_\_\_\_ \_\_\_\_\_ \_\_\_\_\_
________________________________________
DIENCEPHALON
Found in the center of the vase of the ________
Thalamus - a large ____ located on both sides of the _____ _____. It is the main sensory nucleus of the brain handling every sense apart from _____
Hypothalamus - situated below the thalamusas and connected directly to the _____ _____, which hangs from it
Subthalamus - a small nucleus located below the ______
Epithalamus - another small nucleus located behind the thalamus
Largest
Boxing Glove
Sagittal
Sulcus
Cerebellum
Lateral
Sulcus
Parieto-occipital
Lateral
Cortex
Gyri (bumps)
Sulci (valleys)
Central
Parietal-Occipital
Calcarine
Cingulate
___________________
Cerebrum
Nucleus
Third Ventricle
Smell
Pituitary Gland
Thalamus
GREY MATTER
Contains the cell bodiues of the neurons. In the cerebrum these structures are confined to the ____ and the ____ ____
The basal ganglia are deep nuclei and mostly related to ____ function, they are the:
Lentiform Nucleus
i) \_\_\_\_\_
ii) \_\_\_\_\_\_ \_\_\_\_\_\_\_
Caudate Nucleus
\_\_\_\_\_\_\_\_
These are at the same horizontal level as the thalamus and the internal capsule, which is made of ____ ____
Cortex
Basal Ganglia
Motor
Putamen
Globus Pallidus
Amygdala
White Matter
WHITE MATTER
It is made of ____ and is organized in 3 types of fibers
A) Association Fibers are for communication within one ________ and can be long, short or ______
B) Commissural Fibers are for communication _______ the hemispheres
There are 3 sets of these fibers in the brain: the small _______ commissure, the tiny _______ commissure and the huge _____ _____
The corpus callosum communicates between hemispheres, beneath the ______ fissure. It is one once centimeter thick and runs from the frontal lobe to the ______ lobe. It has 3: the bent ____ anteriorly, the long _____ and the large posterior ______
_________________________
C) Projection Fibers
They communicate between different ____ of the ______ _____. These are not confined to the ______
They are defined as fibers that pass from one level to another. For example, the ______ ____ fibers pass from the motor cortex, down through the internal capsule, through the _______ ____, through the Pons and Medulla to the spinal cord and eventually to the spinal level of their target tissue
Axons
Hemisphere
Intermediate
Between
Anterior
Posterior
Corpus Callosum
Sagital Occipital Genu Body Splenium
______________
Levels
Nervous System
Cerebrum
Pyradimal Tract
Cerebral Peduncles
BRAIN STEM
MIDBRAIN (MESENCEPHALON)
The midbrain has 2 large fiber bundles: anteriorly the cerebral peduncles and posteriorly the paired _____ and ______ colliculi
Anteriorly we find the paired ______ _____
At the junction of the midbrain and the pons are the attachments of cranial nerves __ and ___
________________________
PONS
This structure appears to bridge the cerebellar ______
Emerging from the anterior surface are the paired _______ _______ (CN V)
Behind the pons is the _______ ______ and the cerebellum
___________________
MEDULLA OBLONGATA
The medulla is continuous with the spinal cord. On the anterior surface are the paired ________ medially and ______ laterally
CEREBELLUM
It is appended to the back of the brain stem. It is responsible for ________. Its main connection to the brain stem is via the large ____ cerebellar peduncles
Superior
Inferior
Mammilary Bones
III
IV
_________________
Hemispheres
Trigeminal Nerves
Fourth Ventricle
____________________
Pyramids
Olives
Coordination
Middle
SPINAL CORD
GROSS ANATOMY
It extends in the vertebral canal from the foramen magnum down to ___
32 sets of spinal nerves emerge from the spinal cord and leave through the ________ foramina
The spinal cord tapers to a point, the _______ ______, which attaches to the sacrum by a thread known as the ____ ____
Since the cord ends at L1/2, the nerves exiting the foramina below L2 form a structure, the _____ ____
The spinal cord is thicker where the nerves to the upper and lower limbs exit. These thickenings are called the ____ and _____ _____
_________________________
GROSS SECTION
In a cross section of the spine the grey matter is located deep in the cord in the shape of an ___
The anterior projections or _____ _____ are responsible for _____ _____
The posterior limbs or ______ _____ are responsible for ______ function
The posterior and anterior horns of the spinal nerves attach to their respective horns
Between T1 and L2 the cord has a small _______ horn for the sympathetic nervous system
The spinal cord features a narrow ______ _____ and a wide _____ ____
The white matter is arranged in 3 columns: the _____, ______ and _____ FUNICULI
L1/2
Intervertebral
Conus Medullaris
Filum Terminale
Cauda Equina
Cervical
Lumbar Enlargements
_____________________
“H”
Anterior Horns
Motor Function
Posterior Horns
Sensory
Intermediate
Posterior Groove
Anterior Sulcus
Posterior
Lateral
Anterior
VENTRICULAR SYSTEM
The CNS is essentially hollow, it contains a fluid-filled system of chambers known as ______ and ducts
The ventricles are continuous with the narrow central canal of the spinal cord they may be listed:
LATERAL VENTRICLES
These are strange wing-like objects; numerically they are ventricles 1 and 2. They consist of: Anterior Horn - in the \_\_\_\_ lobe Posterior Horn - in the \_\_\_\_\_ lobe inferior Horn - in the \_\_\_\_\_ lobe Body - in the \_\_\_\_\_ lobe
The wide posterior part of the body joining the posterior and inferior horns is called the _____
They contain the ____ ____ and are filled with Cerebrospinal Fluid (CSF). They connect to the third ventricle via the paired _____ of ____
____________________
THIRD VENTRICLE
It is a thin, sagittally oriented space located between the 2 halves of the thalamus. It is joined to the 4th ventricle by the ______ of _____ which passes through the midbrain
___________________
FOURTH VENTRICLE
A roughly diamond-shaped space between the pons and medulla in front and the _______ behind
In the lateral recesses of the ventricle are the 2 Foramina of _______ and at the inferior angle is the Foramen of ______
It is through these foramina that the CSF travels from the ventricles into the _______ Space
The fourth ventricle is continuous with the central canal of the spinal cord
Ventricles
Frontal
Occipital
Temporal
Parietal
Atrium
Choroid Plexuses
Foramina
Munro
_____________________
Aqueduct of Sylvius
___________________
Cerebellum
Luschka
Magendie
Subarachnoid
MENINGES
The CNS is is encased in 3 layers of specialized connective tissue. From outermost to innermost, they are: Dura Mater, ______ Mater and ___ Mater
DURA MATER
It means “____ ____”
Multilayered envelope of dense connective tissue and is therefore the closest to the surrounding bones
It invaginates into the _______ fissure to form the ______ ____and into the horizontal fissure as the ______ _____
The dura mater also contains channels - the Dural _____ ____
The dura mater covers the brain and extends down the vertebral canal as far as the ___
It is firmly attached to the skull but has a fat-filled space between it and the vertebral column known as the _____ Space
_________________
ARACHNOID MATER
Is a much thinner, filmy layer that contains the ____ ____
It invaginates into the fissures and extends a short way into the ____
When it is in the cranial vault it is attached to the third layer, the pia mater, by thin connective tissue threads, leaving a space, the ________ Space, in which the CSF circulates
In the vertebral column the arachnoid is firmly attached to the dura but is only conencted to the pia by a series of coronal ‘ligaments’, the _________ Ligaments
________________
PIA MATER
This layer is attached firmly to the superficial cortex and to the outer surface of the spinal cord. It is therefore, practically speaking, the ____ ____ of the CNS
Arachnoid
Pia
Tough Mother
Sagittal
Falx Cerebri
Tentorium Cerebelli
Venous Sinuses
Sacrum
Epidural
__________________
Blood Vessels
Sulci
Subarachnoid
Denticulate
______________
Outer layer
CSF CIRCULATION
Produced in the ventricles by the ______ ____ from filtered arterial blood
Its functions are both metabolic and protective. It passes from the lateral ventricles, through the foramina of _____ to the third ventricle and through the aqueduct to the fourth ventricle and central canal
It passes into the subarachnoid space via the foramina of ______ and ______
It then circulates all around the CNS in the subarachnoid space, providing a shock absorptive function. It eventually passes from the subarachnoid space in the region of the ____ of the ____
In this region, the arachnoid mater penetrates through the dura into the _____ _____ _____. These arachnoid ‘pockets’ are called _____ ___
The CSF can thus filter through the villi into the sinus, which is also filled with venous ____. The sinuses eventually empty into the ____ ____ Vein
There are large openings of the subarachnoid space known as _____, The largest of these is the ______ Cistern created when the spinal cord terminates at L1/2 and the dura and arachnoid mater extend into the ___
The cistern is the most common place for the physicians to sample CSF; the so-called spinal tap or lumbar puncture
Choroid Plexuses
Munro
Luschka
Magendie
Root
Falx
Superior Sagittal Sinus
Arachnoid Villi
Blood
Internal Jugular
Cisterns
Lumbar
Sacrum
BLOOD SUPPLY TO THE BRAIN
Brain receives blood from 2 sources, the ____ _____ arteries and the _____ arteries, which reach the inside of the skull via the ____ ____ and the ____ ____, respectively
Vertebral arteries anastomose to form the ______ Artery which runs up the pons, It then bifurcates to from the 2 _______ _____ Arteries
The internal carotid artery reaches the ____ ____ and splits into the Middle and Anterior Cerebral Arteries
A single Anterior Communicating Artery joins the 2 anterior cerebral arteries, while the paired Posterior Communicating Arteries join the middle and posterior _____ arteries. These arteries finally form the ____ of _____ around the pituitary gland
The anterior and posterior cerebral arteries supply the sagittal surface of the brain. They also supply the _____ of the ____ Cortex
The Middle Cerebral Artery comes through the lateral fissure and supplies the ____ of the brain
Cerebellum is supplied by the _____ and _____ cerebellar arteries and the spinal cord gets blood from the vertebral arteries at the _____ end and from the ____ lower down
Veins of the brain essentially empty into the ____ venous sinuses, which drain into the _____ ____ vein
Internal Carotid
Vertebral
Carotid Canal
Foramen Magnum
Basilar
Posterior Cerebral
Sella Turica
Cerebral
Circle of Willis
Periphery
Outer
Center
Superior
Inferior
Superior
Aorta
Dural
Internal Jugular
PERIPHERAL NERVOUS SYSTEM
SOMATIC SYSTEM
Provides _____ motor control and general sensation information. It consists of 31 or 32 pairs of spinal nerves and 12 pairs of cranial nerves
Spinal Nerves exit the spinal cord and the vertebral column through the _______ foramina. Each nerve has a ____ ____ which receives sensory information and a _____ ____ which sends motor information
The spinal nerves exit their intervertebral foramina and split into a small ______ _____ and a large _____ _____
The Sacral Nerves are unique in that they split into rami before _____ the foramina
The cell bodies of the sensory nerves are found in the _____ ____ _____
The spinal nerves are classified alphanumerically according to their spinal levels:
C1-C8 - cervical nerves (exit above their corresponding vertebrae)
T1-T12 - thoracic nerves (exit below their corresponding vertebrae)
L1-L5 - lumbar nerves (exit below their corresponding vertebrae)
S1-S5 - sacral nerves (exit below their corresponding vertebrae)
Voluntary
Intervertebral
Dorsal Root
Ventral Root
Dorsal Ramus
Ventral Ramus
Exiting
Dorsal Root Ganglia
AUTONOMIC SYSTEM
Provides _______ motor control and visceral _____ _____
Involuntary
Sensory Perception
MAJOR PATHWAYS OF THE SOMATIC NERVOUS SYSTEM
i) SENSORY PATHWAYS - ASCENDING
Sensations experienced on the body surface and on the deep structures are carried to the cortex of the brain via the _____ _____, brain stem, thalamus and the ______ _____
Sensory modalities may be listed:
TOUCH - discriminatory (fine) TOUCH - non-discriminatory (crude) PAIN \_\_\_\_\_\_\_\_\_\_\_ JOINT \_\_\_\_\_\_\_ - \_\_\_\_\_\_\_\_\_ VIBRATION
________________
Generally these modalities are carried by the spinal and cranial nerves. These tracts run up the spinal cord and brain stem to eventually synapse in the thalamus. The 2 most important tracts are:
i) DORSAL COLUMNS
They carry discriminatory touch, ______ _____ and vibration
The fibers run from below T6 and travel in the medial part of the dorsal column called the ______ _____
Those fibers above T6 travel in the more lateral Fasciculus _______
This pathway ascends to the brain stem in a structure called the _____ _____ and synapses again in the thalamus. The pathway then goes through the internal capsule and ends on the postcentral gyrus in the _____ ____
__________________
ii) ANTEROLATERAL COLUMNS
This system carries crude touch, pain and ______ _____. The sensory nerves enter the spinal cord, but unlike the dorsal column axons they synapse in the _____ ____
The second axon of this system crosses over almost immediately and ascends in the _____ _____
These pathways go into the brain stem and attach to the medial lemniscus to synapse for the second time in the thalamus, and then travel through the internal capsule to the sensory cortex, again specifically to the ______ ____
Spinal Cord
Internal Capsule
Temperature
Position
Proprioception
____________
Joint Position
Fasciculus Gracilis
Cuneatus
Medial Lemniscus
Sensory Cortex
__________________
Temperature Sensations
Dorsal Horn
Anterolateral Tracts
Postcentral Gyrus
MAJOR PATHWAYS OF THE SOMATIC NERVOUS SYSTEM
b) MOTOR PATHWAYS - DESCENDING
These pathways initiate ______ in the muscles:
i) CORTICOSPINAL TRACT
This is the most ______ motor pathway. Motor activity is initiated in the motor cortex and the premotor cortex.
The fibers travel down through the ______ _____, the cerebral peduncles, the pons and then through the pyramids of the medulla
In the lower medulla most fibers then ______ (crossover) and form the _____ ______ Tract
The rest of the fibers run ipsilateral to form the Anterior Corticospinal tract. All corticospinal fibers terminate in the anterior horn of the spinal cord where they synapse with large anterior horn neurons whose axons leave the spinal cord in the ventral root and subsequently form the spinal nerve along with the dorsal root sensory axons
________________
ii) OTHER MOTOR TRACTS
The remaining motor tracts are the Rubrospinal, Vestibular and Reticulospinal tracts, they are known collectively as the ______ ____ System.
These other pathways come from the lower parts of the brain and the _____ ___ and are involved in muscle tone and control as well as some extensor function
It is possible to train the extra pyramidal pathways to take over, in a very limited way, from a compromised pyramidal system
Movement
Direct
Internal Capsule
Decussate
Lateral Corticospinal
____________
Extra Pyramidal
Brain Stem
CRANIAL NERVES
I - Olfactory - ______ - _____ Cribriform Plate
II - Optic - ______ - ____ - Optic Canal
III - Oculomotor - ______ - ___ _____ - Superior Orbital Fissure
IV - Trochlear - _____ - ___ ____ - Superior Orbital Fissure
V - Trigeminal - _____ - _______ ____ and _____ of ________ - Superior Orbital Fissure
V2 - Foramen Rotundum
V3 - Foramen Ovale
VI - Abducens - _____ - ____ ______ - Superior Orbital Fissure
VII - Facial - ____ - _____ ____ and ____ - Stylomastoid Foramen
VIII - Vesibulococlear - ____ - _____ and ____ - Internal Acoustic Meatus
IX - Glossopharyngeal - _____ - ____ and _____ _____ - Jugular Foramen
X - Vagus - ____ - ____ ____ and _____ - Jugular Foramen
XI - Spinal Accessory - ____ - ____ ___ ____ - Jugular Foramen
XII - Hypoglossal - ____ - ______ _____ - Hypoglossal Canal
(I) Sensory
Smell
(II) Sensory
Sight
(III) Motor
Eye Movement
(IV) Motor
Eye Movement
(V) Both
Face Sensation
Muscles of Mastication
(VI) Motor
Eye Movement
(VII) Both
Facial Expression
Taste
(VIII) Sensory
Hearing
Balance
(IX) Both
Taste
General Sensation
(X) Both
Larynx Sense and Movement
(XI) Motor
Upper Limb Movement
(XII) Motor
Tongue Movement
OLFACTORY NERVE (CN I)
Small group of neurons originates in the Olfactory Mucosa in the ____ nose, penetrate the holes in the Cribriform Plate and enter the Olfactory Bulb which rests on the ____ ____
These short nerves synapse in the ____
Upper
Cribriform Plate
Bulb
OPTIC NERVE (CN II)
Nerve fibers leave the _____ and form the paired Optic Nerves which pass back through the Optic Canal. The 2 nerves coalesce in the Optic Chasm from which emerge the left and right Optic Tracts.
These past posteriorly to synapse in the Lateral Geniculate Bodies of the _____
Retina
Thalamus
OCULOMOTOR, TROCHLEAR AND ABDUCENS NERVES (CN III, IV AND VI)
These emerge from the brain stem, specifically III and IV at the junction of the midbrain and the pons an VI at the junction of the pons and medulla. These nerves supply the _____ ____ Muscles
CN III \_\_\_\_\_\_\_ Rectus \_\_\_\_\_ Rectus \_\_\_\_\_\_ \_\_\_\_\_ Inferior \_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_ \_\_\_\_\_ \_\_\_\_
CN IV _____ ______
CN VI _____ _____
Extra Ocular
Superior Inferior Medial Oblique Levator Palpebrae Superioris
Superior Oblique
Lateral Rectus
TRIGEMINAL NERVE (CN V)
Only nerve that directly arises from the pons and it has 3 components
Ophthalmic component exits the superior orbital fissure - _____
Maxillary component exits the foramen rotundum - _____
Mandibular component exits the foramen ovale - _____
Motor component is carried by the Mandibular Nerve
Forehead
Cheek
Jaw
FACIAL NERVE (CN VII)
Exits teh brain stem lateral to CN VI and passes through the Internal Acoustic Meatus
Travels into the middle ear and exits the skill via the _______ Foramen
Fans out in 5 branches to innervate the Muscles of Facial Expression
Has a special ____ function to the anterior 2/3 of the tongue and provides parasympathetic supply to the submandibular, sublingual and lacrimal glands
Stylomastoid
Sensory
GLOSSOPHARYNGEAL NERVE (CN IX)
Attached to the medulla below the exit of CN VIII
Provides ________ innervation to the parotid glands, motor innervation to the stylopharyngeus muscle and sensory innervation to the posterior 1/3 of the tongue and ____
Exits the skull via the Jugular Foramen
Sensory
Pharynx
GLOSSOPHARYNGEAL NERVE (CN IX)
Attached to the medulla below the exit of CN VIII
Provides ________ innervation to the parotid glands, motor innervation to the stylopharyngeus muscle and sensory innervation to the posterior 1/3 of the tongue and ____
Exits the skull via the Jugular Foramen
Sensory
Pharynx
SYMPATHETIC NERVOUS SYSTEM
Sympathetic preganglionic neurons originate in the intermediate horn of the grey matter of the spinal cord (between T1 - L2) and exit through the anterior root to join the spinal nerve
Axons traveling to the superior parts of the body - head, neck and upper limbs - originate in the superior most portion of the ______ horn, while those destined for the thorax exit inferioroly and so on until L1-2
Intermediate
