Flashcards in General Neuroanatomy Deck (184):
The spinal cord extends from the ___ to the __ (in adults, in infants)
in adults: foramen magnum to inner space between L1 and L2 (in infants, L2-L3)
Why is the spinal cord shorter than the vertebral column?
During development, the vertebral bones grow at a faster rate than the spinal cord that grows within it.
What space contains CSF?
How many pairs of spinal nerves are there?
How many pairs of cranial nerves are there?
Where is the cervical enlargement?
From the fourth cervical spinal segment to the first thoracic spinal segment
Why does the cord enlarge at cervical levels?
Spinal nerves come off to form the brachial plexus
Why does the cord enlarge at lumbo-sacral levels?
Spinal nerves come off to form lumbosacral plexus
The cord becomes continuous with the brainstem just as it passes through the ___
What are the components of the brainstem?
Medulla oblongata, pons, midbrain (mesencephalon)
True or False: The spinal cord is continuous with the brainstem.
True or False: The cerebellum is part of the brainstem.
False. Though the cerebellum is attached to the dorsal surface of the brainstem, it is not a part of the stem.
Which four cranial nerves arise from the medulla?
IX (glosspharyngeal), X (Vagal), XI (spinal accessory), XII (hypoglossal)
Which four cranial nerves arise from the pons?
V (trigeminal), VI (abducens), VII (facial), VIII (vestibulo-cochlear/auditory)
How many cranial nerves does it take to move your eyes around?
What is the only cranial nerve that emerges from the posterior surface of the brainstem?
Which cranial nerves arise from the mesencephalon?
III (oculomotor), IV (trochlear)
Where is the lumbosacral enlargement?
Between the second lumbar and third sacral spinal segments
What two arteries provide arterial blood supply to the brain?
Internal carotid arteries, vertebral arteries
What 3 arteries supply arterial blood to the cerebrum?
anterior, middle and posterior cerebral arteries
What 3 arteries supply arterial blood to the cerebellum?
superior, anterior inferior and posterior inferior cerebellar arteries
What 6 arteries contribute to arterial blood supply to the brainstem?
superior cerebellar artery, anterior inferior cerebellar arteries, posterior inferior cerebellar arteries, pontine branches of the basilar artery, posteromedial group of central arteries, posterolateral group of central arteries
What 5 veins comprise the superficial group of cerebral veins that drain cortical and adjacent subcortical regions?
superior cerebral veins, superior middle cerebral veins, superior anastomotic vein (of Trolard), inferior anastomotic vein (of Labbe), inferior cerebral veins
What 3 arteries supply the spinal cord with oxygenated blood?
anterior and two posterior spinal arteries
What 3 veins drain the spinal cord? Where do these drain into?
posterior spinal, posterolateral spinal and anterior spinal vein, drain into anterior and posterior radicular veins
Which bones of the skull comprise the orbit?
Frontal, sphenoid, zygomatic, maxilla, ethmoid, lacrimal
WHich bones comprise the anterior cranial fossa?
Frontal, ethmoid (cribiform plate), sphenoid (body and lesser wing)
Which bones comprise the middle cranial fossa?
sphenoid (greater wing), temporal, parietal
Name 6 important foramina associated with the middle cranial fossa
optic canal, superior orbital fissure, foramen spinosum, foramen ovale, foramen rotundum, carotid canal
Which lobes are housed in the anterior cranial fossa?
Which lobes are house din the middle cranial fossa?
Temporal lobes (approximately)
Which bones comprise the posterior cranial fossa?
Temporal, occipital, parietal
Name 4 important foramina associated with the posterior cranial fossa
foramen magnum, hypoglossal canal, jugular foramen, internal acoustic meatus
Which cranial fossa are cerebellar hemispheres located?
Posterior cranial fossa
Which bones articulate at the atlanto-occipital joint?
occipital condyles of skull articulates with C1
What actions occur at the atlanto-occipital joint?
flexion and extension movement of head and some lateral movement of head
What actions occur at the atlanto-axial joint?
contributes to head rotation
What contributes to the atlanto-axial joint?
skull and atlas move around pivot joint between the odontoid process (dens) of the axis and the ring formed by the transverse ligament of the atlas
Which ligament holds the dense of the axis in place
transverse ligament of the atlas
What type of joint is the atlanto-axial joint?
Which bones articulate at the TMJ?
the condylar process of the mandible articulates with the mandibular fossa of the temporal bone
Which muscles contribute to protrusion of the mandible?
lateral pterygoid assisted by medial pterygoid
Which muscles contribute to retraction of the mandible?
temporalis, masseter, geniohyoid and digastric
Which muscles contribute to elevation of the mandible?
temporalis, masseter, medial pterygoid
Which muscles contribute to depression of the mandible?
gravity, digastric, geniohyoid and mylohyoid muscles
Which nerve innervates all the muscles of mastication?
trigeminal nerve (CN V), specifically the mandibular branch (V3)
name four structures that pass through the jugular foramen
internal jugular vein, CN IX, X, XI
triangle: internal carotid arteries
triangle: external carotid arteries
triangle: internal jugular vein
triangle: CN VII
triangle: CN IX
triangle: CN X
triangle: CN XI
anterior (SCM) and posterior (trapezius)
triangle: CN XIII
triangle: external jugular vein
triangle: phrenic nerve
triangle: brachial plexus (proximal part)
Which ventricle is associated with the diencephalon?
What three structures are connected to the cerebellum?
pons, medulla, mesencephalon
Which ventricle is associated with the medulla and pons?
What are the four components of the diencephalon?
thalamus, hypothalamus, epithalamus, subthalamus
What is the function of the thalamus?
processes sensory & motor information UP to cerebral cortex
WHere does the lateral geniculate body receive input? What is this nuclear group involved with?
gets input from optic tract, involved with vision
Fcn: frontal lobe
Fcn: pre-frontal area
judgement, plan of action, memory
Fcn: precentral gyrus
primary motor cortex
fcn: parietal lobe
somatosensation, integration of sensory information
fcn: postcentral gyrus
primary sensory cortex
fcn: occipital lobe
vision & processing visual information
fcn: temporal lobe
receiving and processing auditory information, speech, olfaction, limbic system
What comprises gray matter
collections of neurons and the synapses formed on them
What comprises white matter
True or False: There is a decreasing amount of white matter as one ascends the cord.
False. THere is an increasing amount of white matter as one ascends the cord.
True or False: In the adult, the central canal of the adult spinal cord is continuous with the ventricular system.
False. In the adult spinal cord, the central canal is not continuous with the ventricular system of the brain, as it was during development.
What type of cells line the central canal of the spinal cord?
What does the posterior intermediate sulcus separate?
the gracile and cuneate fascicles
in the white matter, a funiculus consists simply of a group of tracts, ascending, descending, or both ascending & descending
composed of bundles of axons
What is the antero-lateral funiculus?
In some classifications, the lateral and ventral funiculi are considered to be a single structure, the antero-lateral funiculus.
Which tract extends the full length of the spinal cord: gracile or cuneate?
Where is fasciculate cuneatus present (what spinal levels)?
Cervical and upper thoracic spinal cord levels
What is the posterolateral tract?
Intrinsic spinal tract consisting of small fibers traveling short distances cranially or caudally within the spinal cord. These fibers arise from neurons in the spinal ganglia or posterior horn.
What is included in the lateral funiculus?
posterior part: lateral corticospinal and posterior spinocerebellar tracts
anterior part: lateral (medullary) reticulospinal, lateral spinothalamic, spinorecticular and anterior spinocerebellar tracts
In which funiculus (anterior, lateral or posterior) is the posterior fasciculus proprius?
What is included in the anterior funiculus?
ascending: anterior spinothalmic tract
intrinsic: anterior fasciculus proprius
descending: anterior corticospinal, lateral and medial vestibulospinal and medial (ponto-) reticulospinal tracts
What are nuclei? What are they involved with?
Nerve cell bodies and the axon terminals which synapse on them. Involved with information processing.
What three structures are included in the central cord?
Central canal, spinal lamina X, gray and white commissures
Projection interneurons from which laminae are the origin of contralateral spinothalmic and spinoreticular tracts?
Lamina I and V
In the cervical and lumbosacral enlargements, the medial neuron nuclei innervate the muscles of the __ and lateral nuclei innervate ___ muscles.
Where along the spinal cord is the substantia gelatinosa Rolandi found?
Entire spinal cord
What sensations synapse on the substantia gelatinosa?
Pain and temperature
What is the functino of the substantia gelatinosa?
Processes incoming pain sensations, but does not give rise to axons conveying sensory information to higher levels.
True or False: incoming fibers conveying pain and temp can synapse on the dendrites of neurons in the nucleus proprius which extend into the substantia gelatinosa
Where along the spinal cord is the nucleus proprius found?
Entire spinal cord
Neurons comprising the nucleus proprius give rise to axons which cross the cord where? Ascend in what tracts?
in the ventral white commissure; ascend in spinothalmic tracts
Where along the spinal cord is the nucleus dorsalis (Clarke's column) found?
Thoracic and upper lumbar regions (C8 to L3)
Neurons in the nucleus dorsalis ascend the cord ipsi/contralaterally in the ____ tract.
ipsilaterally, dorsal spinocerebellar tract
The spinocerebellar tract conveys ____ information from the _____ to the ____ (in the case of nucleus dorsalis)
proprioceptive; lower limb and trunk, cerebellum
Where is the interomedial cell column (lateral horn) found?
Thoracic and upper lumbar regions. (T1-L3)
What arises from the lateral horn?
sympathetic preganglionic motor neurons; axons enter the ventral root and then enter the sympathetic chain of ganglia via the white ramus communicans
What type of neurons are located in the lateral horn? What are they called? What do they innervate?
intermediolateral nucleis; visceral motor neurons of the sympathetic nervous system; innervate sympathetic ganglia and adrenal medulla
Where are ventral horn motor neurons located along the spinal cord?
IN the thoracic cord, only a medial/lateral nuclear group of ventral horn motor neurons is found.
The nuclei in the lateral part of the intermediate zone of the sacral spinal cord (S2-S4) contains
visceral motor neurons of the parasympathetic nervous system; innervate pelvic parasympathetic ganglia
Does the fasciculus gracilis extend the entire length of the spinal cord? The fasciculus cuneatus?
FG - yes
FC - mid-thoracic level of the cord upward
Where are the cells of origin located for the dorsal spinocerebellar tract?
ipsilaterally at the nucleus dorsalis
The dorsal spinocerebellar tract is uncrossed/crossed while the ventral spinocerebellar tract is uncrossed/crossed.
dorsal - uncrossed
ventral - crossed
Where are the cells of origin located for the ventral spinocerebellar tract?
contralaterally at the base of the dorsal horn of the spinal grey
The dorsal and ventral spinocerebellar tracts convey what type of information?
proprioceptive information from lower limb to the cerebellum
The dorsal spinocerebellar tract enters the cerebellum via the
inferior cerebellar peduncle
The ventral spinocerebellar tract enters the cerebellum via the
superior cerebellar peduncle
What is the difference between the region of input to lateral spinothalamic tract vs ventral spinothalamic tract?
input to neurons whose axons form the lateral tract is derived from dorsal root ganglion cells within a segement or two away; input to neurons whose axons form the ventral tract may receive input from dorsal root ganglion cells many segments removed
What type of sensory information is carried by the lateral spinothalamic tract?
pain and temperature
What type of sensory information is carried by the ventral spinothalamic tract?
The lateral and ventral spinothalamic tracts are crossed/uncrossed
How far does the ventral corticospinal tract extend?
only as far as the upper thoracic cord
Where do the pyramidal tract fibers of the lateral corticospinal tract cross?
pyramidal decussation in the medulla
Where does the ventral corticospinal tract cross?
uncrossed in the cord, ultimately cross at cord level in ventral white commissure
Most of the arterial blood flowing through the anterior and posterior spinal arteries is derived from the
anterior and posterior radicular arteries, segmental arteries
Arterial blood from the vertebral arteries flowing through the spinal arteries supplies only what area of the SC?
upper cervical cord
Describe the venous drainage of the spinal cord
The spinal veins drain into the anterior and psoterior radicular veins
True or False: the anterior spinal artery extends the entire length of the spinal cord
Where does the anterior spinal artery receive its blood supply?
from the vertebral arteries and spinal branches of segmental arteries (from the descending aorta)
What syndrome is caused by occlusion of the anterior spinal artery?
anterior cord syndrome
What are the functions of the cervical spinal column?
support the head, allow movement of the head, protect spinal cord
The body of a cervical vertebrae is small/large relative to other typical vertebrae.
the vertebral arch of a cervical vertebra is small/large relative to other typical vertebrae.
what passes through the foramen transversarium of cervical vertebrae?
True or False: cervical spinous processes are often bifid.
What part of the vertebrae contains the spinal cord?
The superior articular facet of the atlas articulates with the
What does the atlas possess in place of a spinous process?
The posterior articular facet of the dens of the axis contains a groove for the
transverse atlantal ligament
What major movements occur at cervical vertebral joints?
flexion and lateral flexion
What movements occur at the atlanto-occipital joint?
flexion and extension of neck; nodding of head
What type of joint is the atlanto-occipital joint?
What movements occur at the atlanto-axial joint?
rotation of the neck; "no"
What type of joint is the median atlanto-axial joint?
What are the articulating surfaces at the median atlanto-axial joint?
facet for dens of anterior arch of atlas & anterior articular facet of dens axis
What extracapsular ligaments are part of the atlanto-occipital joint?
anterior atlanto-occipital membrane, posterior atlanto-occipital membrane
True or False: The atlanto-occipital joint has two synovial joint capsules.
What extracapsular ligaments are part of the median atlanto-axial joint?
transverse atlantal ligament; ligaments connecting axis and occipital bone
What are the articulating surfaces at the lateral atlanto-axial joints?
inferior articular facet of atlas; superior articular facet of axis
What ligament is part of the lateral atlanto-axial joints?
Capsular accessory ligament
What type of joint is the lateral atlanto-axial joint?
synovial, plane ("sliding") joints
What are the four lateral vertebral muscles?
anterior scalene, middle scalene, posterior scalene, levator scapulae
What are the anterior vertebral muscles?
Flexors of the neck acting on atlanto-occipital joint (C1-C3 anterior rami): Rectus capitis anterior, Rectus capitis lateralis and Longus capitis
Longus cervicis - flexor and rotator of cervical spine (C2-C6 anterior rami)
Platysma: attachments, action, innervation
skin & subQ tissue of lower face, and mandible
skin & subQ tissue of upper thorax
Sternocleidomastoid: attachments, action, innervation
mastoid process of temporal bone
sternal head - manubrium; clavicular head - sternal end
unilateral contraction turns head to opposite side
bilateral contraction extends superior neck and flexes inferior neck
Trapezius, descending (Superior) part: attachments, action, innervation
occipital bone and ligamentum nuchae
clavicle (acromial end)
tilts head to same side, or elevates and laterally rotates scapula
What are the actions of the lateral vertebral muscles?
lateral flexors of the neck (or elevators of ribs and scapula)
How are the lateral vertebral muscles of the cervical spine innervated?
anterior rami of C3-C8 spinal nerves
What are the attachments of the anterior scalene muscle?
transverse process of C3-C6 and first rib
What are the attachments of the middle scalene muscle?
transverse processes of C1-C7 and first rib
Where is the ligamentum nuchae?
spans from occipital bone to spinous process of C7 vertebrae
What are the major actions of suboccipital muscles?
extensors acting on atlanto-occipital joint
rotators acting on atlanto-axial joint
What is the innervation of suboccipital muscles?
C1 posterior ramus
What are the four suboccipital muscles?
rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, obliquus capitis inferior
What are the boundaries of the anterior triangle of the neck?
anterior border of SCM, inferior border of mandible, anterior midline of the neck
What are the boundaries of the posterior triangle of the neck?
SCM, superior fibres of trapezius muscle, medial half of clavicle
What three elements are contained within the carotid sheath?
carotid arteries, internal jugular vein, vagus nerve
What are the boundaries of the carotid triangle?
Superior belly of omohyoid (inferior)
Posterior belly of digastric (superior)
name three branches of the external carotid artery in the carotid triangle of the neck
facial artery, superior thyroid artery, lingual artery
Which cranial nerve is the motor nerve for the tongue muscles?
Hypoglossal nerve (CNXII)
What does the internal laryngeal nerve do
provides sensory and parasympathetic fibres to the mucous membrane of the larynx above the level of the vocal cords
What are the boundaries of the muscular triangle of the anterior triangle of the neck?
superior belly of omohyoid, lower fibres of SCM, hyoid, sternum
What triangle(s) are the thyroid and parathyroid glands
both carotid and muscular
What are the three strap (infrahyoid) muscles
sternohyoid, sternothyroid, thyrohyoid
The inferior thyroid artery is a major branch of the
thyrocervical trunk, a branch of the subclavian artery
What does the recurrent laryngeal nerve do
motor fibres to most of the intrinsic muscles of the larynx and sensory and parasymapthetic fibres to the laryngeal mucous membrane from the level of the vocal cords downwards
What nerves must be protected to avoid paralysis of the vocal cords?
recurrent layrngeal nerves
Describe the course of the recurrent laryngeal nerve.
branches from vagus nerve, wraps around arch of aorta (left)/subclavian artery (right)
What muscle forms the roof of the submandibular triangle?
The internal carotid artery enters the cranium via what canal?
Name three branches of the internal carotid artery in the head/neck
ophthalmic artery (to orbit via optic canal)
middle and anterior cerebral arteries
What are five branches of the external carotid artery in the carotid triangle in the neck
superior thryoid artery, ascending pharyngeal artery, lingual artery, facial artery, occipital artery
Name three branches of the external carotid artery in the parotid region of the neck
posterior auricular artery, superficial temporal artery, maxillary artery (inferior alveolar & middle meningeal arteries)
A fracture near the pterion can cause what type of hemorrhage? What artery is involved?
epidural, middle meningeal artery
Name four branches of the subclavian artery in the neck
vertebral artery, internal thoracic (mammary) artery, thyrocervical trunk, costocervical trunk
Name three areas supplied by the vertebral arteries
brainstem, cerebellum, cervical spinal cord
Name two tributaries to the internal jugular vein
dural venous sinuses (drain the brain), common facial vein (facial vein drains the anterior face, anterior division of Retromandibular vein)
Name three tributaries to the external jugular vein?
posterior division of Retromandibular vein, posterior auricular vein, anterior jugular vein