Neuroanatomy Flashcards
Central Nervous System
Brain and spinal cord
Peripheral Nervous System
Part of the nervous system outside of the brain and spinal cord
Meninges
Protective covering of the nervous system composed of three layers: Dura Mater, Arachnoid, Pia Mater
Dura Mater
Tough outer layer of the meninges
Arachnoid
Middle web-like layer of the meninges
Pia Mater
Delicate inner layer of the meninges
Cerebrum Lobes
Frontal Lobe, Parietal Lobe, Temporal Lobe, Occipital Lobe
Frontal Lobe Function
Personality and motor cortex
Temporal Lobe Function
Speech, language, olfactory, auditory
Parietal Lobe Function
Sensory function
Occipital Lobe Function
Vision
Central Sulcus
Separates the motor and sensory cortices
Pre-Central Gyrus
Motor cortex
Post-Central Gyrus
Sensory cortex
Homunculus
Visual representation of the central sulcus devotion to the various parts of the body with feet medial and hands, etc. more lateral.
Grey Matter
Outer layer of the cerebral cortex and inner layer of the spinal cord. Contains unmyelinated neurons.
White Matter
Inner layer of the cerebral cortex and outer layer of the spinal cord. Contains myelinated axons for nerve communication.
Cerebellum
Important part of the hindbrain associated with motor function/coordination
Thalamus
Sits between brainstem and brain, acts as a relay station for processing of incoming and outgoing signals.
Brainstem
Sits between brain and spinal cord. Contains 10 of the 12 cranial nerves as well as autonomic cardiac and respiratory centers.
Parts of the Brainstem with Cranial Nerves
Midbrain (Upper Brainstem): CN III-IV
Pons (Middle Brainstem): CN V-VIII
Medulla (Lower Brainstem): CN IX-XII
Cranial Nerve I
Olfactory Nerve
Modality: Sensory
Function: Smell
Monitored: NA
Cranial Nerve II
Optic Nerve
Modality: Sensory
Function: Vision
Monitored: VEP
Cranial Nerve III
Oculomotor Nerve
Modality: Motor
Function: Eye movement, pupillary constriction
Monitored: EMG from extraocular muscles (inferior rectus)
Cranial Nerve IV
Trochlear Nerve
Modality: Motor
Function: Eye movement
Monitored: EMG from superior oblique
Cranial Nerve V
Trigeminal Nerve
Modality: Both
Function: Facial sensation, mastication
Monitored: EMG from masseter and/or temporalis
Cranial Nerve VI
Abducens Nerve
Modality: Motor
Function: Eye movement
Monitored: EMG from lateral rectus
Cranial Nerve VII
Facial Nerve
Modality: Both
Function: Facial expression, autonomic input to salivary glands, taste to anterior 2/3 of tongue
Monitored: EMG from frontalis, o. oculi, o. oris, mentalis
Cranial Nerve VIII
Vestibulocochlear Nerve
Modality: Sensory
Function: Hearing and balance
Monitored: BAER
Cranial Nerve IX
Glossopharyngeal Nerve
Modality: Both
Function: Motor to stylopharyngeus, sensation to tonsils and pharynx, taste to posterior 2/3 of tongue, input to parotid gland
Monitored: EMG from soft palate
Cranial Nerve X
Vagus Nerve
Modality: Both
Function: Motor to vocal cords, parasympathetic to thoracic and abdominal viscera
Monitored: EMG from vocal cords (RLN)
Cranial Nerve XI
Spinal Accessory Nerve
Modality: Motor
Function: Motor to trapezius and sternocleidomastoid
Monitored: EMG from trapezius and/or sternocleidomastoid
Cranial Nerve XII
Hypoglossal Nerve
Modality: Motor
Function: Motor to tongue
Monitored: EMG from tongue
Circle of Willis
Interconnecting blood vessels that supply blood to the brain. Contains communicating arteries to cover for other arteries if they are blocked.
Arteries for Anterior Brain Perfusion
Internal Carotid Arteries (ICA), composed of two branches:
Middle Cerebral Arteries (MCA)
Anterior Cerebral Arteries (ACA)
Internal Carotid Arteries (ICA)
Supplies blood from the common carotid artery to the anterior portion of the brain via the middle and anterior cerebral arteries
Middle Cerebral Arteries (MCA)
Supplies blood from the Internal Carotid Arteries to the lateral cortex of the brain (includes upper extremity SSEPs)
Anterior Cerebral Arteries (ACA)
Supplies blood from the Internal Carotid Arteries to the medial cortex and frontal lobe (includes lower extremity SSEPs)
Arteries for Posterior Brain Perfusion
Vertebrobasilar System:
Supplied by Vertebral
Arteries (VA), which combine to form the Basilar Artery (BA). BA terminate into the Posterior Cerebral arteries (PCA).
Cerebellar Arteries (CA), Superior Cerebellar Arteries (SCA), Anterior Inferior Cerebellar Arteries (AICA), and Posterior Inferior Cerebellar Arteries (PICA, arise from VA)
Vertebral Arteries (VA)
Travel up the transverse foramina of the cervical vertebrae, enter the foramen magnum, head anteriorly, and join together to form the Basilar Artery (BA)
Basilar Artery (BA)
Formed by the Vertebral Arteries (VA). Travels up the ventral surface of the pons and branches off to the cerebellum, pons, midbrain, and thalamus. Terminates into the Posterior Cerebral Arteries (PCA).
Posterior Cerebral Arteries (PCA)
Arise from the terminal tip of the Basilar Artery (BA). Perfuse the posterior cortex (occipital lobe)
Cerebellar Arteries (CA)
Perfuse the cerebellum and parts of the brainstem
Superior Cerebellar Arteries (SCA)
Arise from the superior portion of the Basilar Artery (BA). Perfuse the superior portion of the cerebellum.
Anterior Inferior Cerebellar Arteries (AICA)
Arise from the lower part of the Basilar Artery (BA). Perfuse the inferior portion of the cerebellum and feeds into the internal auditory artery of the inner ear.
Posterior Inferior Cerebellar Arteries (PICA)
Arise from the Vertebral Arteries (VA) near the vertebrobasilar junction. Perfuses inferior portion of the cerebellum and parts of the medulla oblongata
Communicating Arteries
Serve to connect the vasculature of the Circle of Willis. Provide a means of collateral circulation.
Anterior Communicating Artery (Acomm)
Posterior Communicating Arteries (Pcomm)
Spinal Cord
Extends from the skull down to L2. Carries all information from the body to the brain (afferent, sensory) and from the brain to the body (efferent, motor). Terminates into the Cauda Equina.
Conus Medullaris
The tapering of the spinal cord at the base, usually occurring from T11 through L2
Cauda Equina
The nerve roots of the lumbar and sacral spine. Since the nerve roots of this region begin in the conus medullaris, they must travel down for a distance before exiting at their vertebral levels, thus forming the free standing nerve roots of the “horse’s tail”
White Matter of the Spinal Cord
Surround the spinal cord. Myelinated axons that carry ascending or descending signals to or from the brain.
Grey Matter of the Spinal Cord
Form the grey butterfly shape when viewing a cross-section of the spinal cord. Unmyelinated interneurons. Spinal cord processes incoming/outgoing signals from the grey matter. Anterior and posterior protrusions of the butterfly pattern are called the anterior and posterior horns.
Dorsal Root
Mediates all incoming sensory impulses into the spinal cord. The dorsal root ganglion (the “bulge”) contains the sensory cell bodies.
Ventral Root
Mediates the outgoing motor impulses from the spinal cord. Cell bodies contained in the ventral horn of the grey matter in the spinal cord.
Anterior Spinal Artery
Runs the entire length of the midline of the spinal cord. Perfuses the anterior 2/3 of the spinal column.
Posterior Spinal Arteries
Runs the entire length of the spinal cord. Located immediately lateral to the posterior columns. Perfuses the posterior 1/3 of the spinal column.
Radicular (Segmental) Arteries
Located at the each segment of the spinal cord, supplying blood to the anterior and posterior spinal arteries. Most are underdeveloped and don’t contribute much to perfusion. A few are exceptions, the most important being the Artery of Adamkiewicz, which is usually located around T10
Brachial Plexus
C5-T1
A network of nerves in the shoulder supplying the upper extremities
Median Nerve
C5-T1
Innervates the abductor pollicis brevis and several muscles of the forearm.
Ulnar Nerve
C8-T1
Innervates the abductor digiti minimi as well as other hand and forearm muscles.
Radial Nerve
Innervates the triceps, brachioradialis, and other wrist flexors in the forearm
Axillary Nerve
Innervates the deltoid
Musculocutaneous Nerve
Innervates the biceps
Lumbosacral Plexus
Branching of nerves from the lumbar and sacral spine
Sciatic Nerve
Large nerve in the upper leg, formed by the joining of the peroneal and posterior tibial nerves.
Posterior Tibial Nerve
L4-S3
Branch of the sciatic nerve. Descends through the midline of the popliteal fossa and wraps around the medial malleolus. Innervates the gastrocnemius and foot flexors.
Peroneal Nerve
L4-S2
Branch of the sciatic nerve. Descends lateral to the fibular head. Innervates the tibialis anterior among other foot dorsiflexors.
Femoral Nerve
L2-L4
Innervates the quadriceps and femoris muscles
Saphenous Nerve
Sensory branch of the femoral nerve. Transmits sensory information from the medial portion of the leg and foot.
Vertebrae
Individual segments making up the spinal column. The human body usually contains 33 vertebrae Cervical: 7 Thoracic: 12 Lumbar: 5 Sacral: 5 (fused) Coccygeal: 4 (fused)
Vertebral Body
Main cylinder of bone that stacks on top of other vertebral bodies.
Pedicles
Two columns of bone on either side of the vertebral body, connecting it to the lamina
Lamina
The posterior wall of bone that covers and protects the spinal cord
Transverse Process
Protrusions of bone that stick out laterally from the pedicles
Spinous Process
The protrusions of bone that stick out from the posterior portion of each vertebrae
Foramen
A hole between the anterior and posterior portions of the vertebra through which nerve roots exit the spinal cord