Cranial Nerves Flashcards
What nerves link the nervous system to the periphery?
Cranial and spinal nerves
What do both cranial and spinal nerves attach to?
Cranial nerves attach to the forebrain and brain stem.
Spinal nerves attach to spinal cord.
What are the spinal nerves divided into?
Ventral and dorsal.
Ventral part is motor receiving information from cortex and allowing actions.
What nuclei do we have in the brain?
In brain stem we have sensory and motor nuclei. This is a convention of neurone that receive the information in dorsal part (sensory). This information is then received and goes around the body.
Name the 12 cranial nerves and give basic function
- Olifactory - to smell
- Optic - to see
- Oculomotor - to move eye
- Trochlear - to move eye
- Trigeminal - sensation in face
- Abducens - to move eye
- Facial - controls muscles of facial expression
- Vesto-cochlear - allows you to hear
- Glossopharyngeal - for taste
- Vagus - parasympathetic control of the heart, lungs, and digestive tract
- Accessory - connect to neck
- Hypoglossal - move tongue
What comes through foramen magnum?
Brain stem and accessory nerve 11.
Do we have synapses in ganglia?
no! COLLECTION OF CELL BODIES. HAS A CENTRAL BRANCH GOING TOWARDS BRAIN STEM
What is the dorsal root ganglia?
A sensory group of neurons. The peripheral branch allows information to go through doral root ganglia to cell bodies to around the body.
Central branch goes into the ganglia.
What level do the optic nerves switch over?
The optic chiasma.
What is the PONS and what are some of the nerves coming out of it?
PONS is a continuation of fibres that go from spinal cord to thalamus and cortex. On. Side of PONS is trigeminal nerve. Laterally there is 7 and 8 cranial nerve. At side of PONS, is abducens nerve (6).
What cranial nerves come out the medulla oblongata?
9-12
Explain how the cranial nerves emerge in the brain
The olfactory, optic, oculomotor and trochlear cranial nerves are associated with the anterior portion of the brain.
The trigeminal, abducens and facial (5,6,7) arise in PONS.
The vestibulocochlear (8) nerves arise in the pons.
The glossopharyngeal, vagus, accessory and hypoglossal (9-12) nerves are attached to the medulla oblongata.
Divide the cranial nerves into sensory, motor or both
Sensory - 1, 2, 8
Motor - 3, 4, 6, 11, 12
Both - 5, 7, 9, 10
Which particular nerve fibre has synapses?
Pain
What are some functions of the cranial nerves?
Chewing and swallowing Talking Seeing Facial expression Hearing
What sensory supply are we getting from cranial nerves?
Muscles of facial expression Muscles of mastication Extra-ocular muscles Muscles of tongue Muscles of larynx and pharynx Cervical muscles
What are cranial nerves also involved in?
Carrying autonomic supply of glands and smooth muscle in the head and neck.
Several reflexes:
- Visual
- Auditory
- Swallowing
- Gag
- Sneezing, coughing
What cranial nerves supply presynaptic parasympathetic fibres?
Oculomotor nerve
- ciliary ganglion for sphincter pupillae and ciliary muscle
Facial nerve
- glands of oral and nasal cavity
Glossopharyngeal nerves
- for parotid gland
Vagus nerve
What are some special and general cranial nerve targets in the brain?
Special - smell, vision, hearing
General - skin, teeth, eye. tongue, oral and nasal cavity, throat, meninges
What nerves do we find in the anterior fossa?
Cribiform plate with the olfactory neves (cranial nerve 1) and meningeal nerves
What nerves/foramen do we find in the middle fossa?
Optic foramen - optic nerve and ophthalmic artery
Superior orbital fissure
- Cranial nerve 3, 5, 6
Forman rotundeum
- Maxillary V2
Foramen ovale
- Mandibular V3
Foramen spinosum
- Middle meningeal artery
Carotid canal
- Internal carotid artery
Internal Acoustic meatus (IAM)
- Toughest bone to protect inner ear, have emergence of number 7 and 8 cranial nerve.
What do we find in the posterior fossa?
Jugular foramen
- Cranial nerve 9, 10, 11
Hypoglossal foramen
- Cranial nerve 12
Foramen magnum
- medulla oblongata
- pons
- vertebral artereis
- 11 spinal nerves
- meninges
- csf
What nerve comes through the cribriform plate?
Olfactory nerve (1)
Where does the optic nerve (2) exit the cranial cavity?
Optic canal
Where does the vestibule-cochlear nerve (8) exit the cranial cavity?
The internal auditory meatus
Where does the hypoglossal never (12) exit the cranial cavity?
Hypoglossal canal
Nerves 4 and 6 for moving eye come out the PONS, which comes out top and which out Bottom?
4 on top, 6 at bottom
What does the hypoglossal nerve come out from?
The medulla oblongata and though hypoglossal canal
What nerves exit from jugular foramen?
glossopharyngeal, vagus, accessory (9,10,11)
What is the major role of the vagus nerve?
Parasympathetic effect on heart and guts.
What does the facial nerve exit which and where from?
Exits with nerve 8 (for hearing).
Exits from internal auditory meatus.
What are the 5 facial muscles that fan out over face?
- Temporal
- Zygomatic
- Buccal
- Mandibular
- Cervical
What are the 3 exits of the trigeminal nerve?
- V1. Ophthalmic - exits with eye muscle groups, senses to forehead and nasal cavity
- V2. Maxillary - exits foramen rotundum, senses to cheek, upper lip, teeth, nasal cavity
- V3. Mandibular - exits foramen ovale to mandibular foramen, senses to chin and tongue
Where is the trigeminal nerve nucleus?
Trigeminal nerve nucleus is in PONS and exits into 3 branches.
What are the two pathways we have in brain and spinal cord?
Pathways in brain are composed of cortical spinal (motor pathway). It goes from brain to spinal.
Spinal - thalamic means sensory as it goes from spine to thalamus.
Which cranial nerve is largest?
Trigeminal
Which cranial nerve is only one to exit posterior side of brain?
Trochlear
What does abducens refer to?
Abducting eye balls
Which two nerves carry taste information?
Facial nerve for anterior 2/3 and glossopharyngeal for posterior 1/3
Which cranial nerve is longest?
Vagus
Which two cranial nerves carry information about blood pressure to brain?
9 and 10, glossopharyngeal and vagus
Which vagus nerve is responsible for pupillary constriction?
3- oculomotor
