Anatomy of the Nervous System Flashcards
What separates the two hemispheres of the brain?
Longitudinal fissure
What makes up the surface of the brain?
The surface is made up of grooves/fissures called a sulcus and ridges called a gyrus.
What is a sulcus?
A groove/fissure on the surface of the brain.
What is gyrus?
A ridge on the surface of the brain.
What connects the two hemispheres of the brain?
Hemispheres are connected mainly by the bundle of nerve fibres called the corpus callosum.
What is the corpus callosum?
A bundle of nerve fibres that connects the two hemispheres of the brain.
What does the hypothalamus do?
Hypothalamus links nervous system to endocrine system via pituitary.
What does the brainstem include?
The midbrain, the pons and the medulla oblongata.
What makes up the midbrain?
Tectum and cerebral peduncle
What makes up the pons?
Basilar and pontine tegmentum
Why are there enlargements at the cervical and lumbosacral regions of the spinal cord?
Due to the increased nervous tissue to the upper and lower limbs.
Where does the spinal cord taper off?
Conus medullaris
What does the filum terminale do?
Inferior to the conus medullaris the spinal cord is anchored to the coccyx by a fibrous strand of tissue the filum terminale.
What types of matter make up the spinal cord?
White and grey matter
What does grey matter contain and form?
Grey matter contains numerous cell bodies which form longitudinal columns along the cord.
What does white matter contain?
White matter contains myelinated axon tract that ascends and descends along the spinal cord.
What are the two roots of each spinal nerve?
Posterior and anterior.
What does the posterior root of a spinal nerve do?
Posterior root is the afferent sensory root and carries signals towards the CNS.
What does the anterior root of a spinal nerve do?
The anterior root is the efferent motor root and carries signals away from the CNS.
What is the cerebellums main role?
Motor control - language - fear
What causes the enlargements at the cervical and lumbosacral regions of the spinal cord?
Due to the increased nervous tissue of the arms and legs.
What does the autonomic nervous system control?
Detects changes and controls the activity of the organs
What are the ventral spinal roots axons of?
Motor control
What are the dorsal spinal roots axons of?
Sensory axons
Where does the spinal cord end?
Cauda equina at L1-L2
Where does motor neurons reside in the spinal cord?
In the grey matter in the ventral root.
Where do sensory neurons reside?
Dorsal root ganglia
What is the cauda equina?
A collection of nerve roots inferior to the spinal cord.
Where in the skull does the spinal cord travel through?
Foramen magnum
What is CN1?
Olfactory nerve
What is CN2?
Optic nerve
What is CN3?
Oculomotor nerve
What is CN4?
Trochlear nerve
What is CN5?
Trigeminal nerve
What is CN6?
Abducens nerve
What is CN7?
Facial nerve
What is CN8?
Vestibulocochlear nerve
What is CN9?
Glossopharyngeal nerve
What is CN10?
Vagus nerve
What is CN11?
Accessory nerve
What is CN12?
Hypoglossal nerve
What does the oculomotor nerve innervate?
Ciliary muscle
Sphincter of the pupil
What does the trochlear nerve innervate?
Superior oblique muscle
What does the trigeminal nerve innervate?
Sensory to face, and teeth
Muscles of mastication
What does the abducens nerve innervate?
Muscle of the eye
What does the facial nerve innervate?
Sense of taste to the anterior tongue
Motor to the salivary, nasal and lacrimal glands
Motor to facial muscles
What does the vestibulocochlear nerve do?
Special sense of hearing and balance
What does the glossopharyngeal nerve innervate?
Sensory to pharynx and middle ear
Motor to parotid gland
Motor to one stylopharyngeas muscle.
What does the vagus nerve innervate?
Special sense of taste - epiglottis
Sensory and motor to pharynx, larynx, thoracic and abdominal muscles.
What does the accessory nerve innervate?
Sternocleidomastoid muscle
Trapezius muscle
For movement of the head
What does the hypoglossal nerve innervate.
Motor to tongue muscles
Where do spinal nerves leave the vertebral column?
Through intervertebral foramen
What does the central sulcus separate?
Pre-central gyrus (motor region)
Post-central gyrus (sensory region)
What is the pre-central gyrus?
Motor region of the brain
What is the post-central gyrus?
Sensory region of the brain
Where is the thalamus located?
Diencephalon
What does the thalamus do?
Relays sensory and motor signals to the cerebral cortex.
Regulates consciousness, sleep and alertness.
How does the cerebellum attach to the brainstem?
With a superior, middle and inferior peduncle
What makes up the brainstem?
Midbrain
Pons
Medulla Oblongata
What does the filum terminale do?
Attaches the spinal cord to the coccyx.
What are the meninges?
The meninges refer to the membranous coverings of the brain and spinal cord.
What are the three layers of the meninges (in order)?
Dura mater
Arachnoid
Pia mater
Where is CSF produced?
Choroid plexus in the 4 ventricles of the brain
How much CSF do you have in ventricular spaces and subarachnoid space?
150ml
What do arachnoid granulations do?
Absorb the CSF being produced into dural sinuses
Explain the venous drainage of the confluence of sinuses in the brain.
The confluence of sinuses drain into a sigmoid sinus and then into the internal jugular vein.
What is the ascending pathway of the spinal cord?
A nerve pathway that goes upward from the spinal cord toward the brain carrying sensory information from the body to the brain.
What is the descending pathway of the spinal cord?
Descending pathways are nerve pathways that go down the spinal cord and allow the brain to control movement of the body below the head.
What is the blood brain barrier?
A semipermeable membrane separating the blood from the cerebrospinal fluid, and constituting a barrier to the passage of cells, particles, and large molecules. Exist due to tight junctions.
How are astrocytes involved in the blood brain barrier?
Astrocytes have astrocytic end feet which surround the blood vessels in the brain. They signal the endothelial cells in the brain to form the tight junctions that make the blood brain barrier.
Where in the brain is there not the blood brain barrier, why?
Posterior pituitary gland, pineal gland, part of the hypothalamus and the area postrema.
These areas require access to the bloodstream to carry out their functions.
What do the tectum and cerebral peduncle make up?
The midbrain
Where is the area postrema and what does it control?
The area postrema is a structure in the medulla oblongata in the brainstem that controls vomiting.
What innervates the trapezius and sternocleidomastoid muscles?
Accessory nerve
What does the somatic nervous system control?
Skeletal muscle contractions.
What does the autonomic nervous system control?
Smooth muscle
Cardiac muscle
Glands
Adipose tissue
What do somatic sensory receptors do?
Detect position, touch, pressure, pain and temperature sensations.
What do pelvic splanchnic nerves innervate?
Parasympathetic innervation to the hindgut.
What is the perineurium?
The sheath of connective tissue surrounding a bundle (fascicle) of nerve fibres within a nerve.
What nerves pass through the superior orbital fissure of the skull?
Oculomotor
Opthalmic (CV1)
Trochlear
Abducens
What nerve passes through the foramen rotundum?
Maxillary nerve V2
What nerve passes through the foramen ovale?
Mandibular nerve V3
What nerves pass through the Jugular foramen?
Glossopharyngeal
Vagus
Accessory
What nerves pass through the internal acoustic meatus?
Facial nerve
Vestibulocochlear nerve
