Nervous System 1 Flashcards
What are the 2 main functional divisions of the NS?
Visceral or Autonomic (ANS)
Somatic (SNS)
How many spinal cord segments are there?
31
Are the nerves passing through dorsal root afferent or efferent?
Afferent
Are the nerves passing through ventral root afferent or efferent?
Efferent
Define meninges.
layers of connective tissue that envelope the CNS. Important as support the brain and allow the cerebrospinal fluid to flow around the brain and allow thermoregulation.
What are the 3 main meninges of the brain?
Dura mater
Arachnoid
Pia mater
Role of dura mater
tough outermost layer
Role or arachnoid
layer with trabeculae projecting from the underside, creating the subarachnoid space
Role of pia mater
delicate innermost layer adhered to the surface of the brain and cord
How many pairs of cranial nerves are there?
12
Name, component, role I cranial nerve
Olfactory, SVA, smell
Name, component, role II cranial nerve
Optic, SVA, vison
Name, component, role III cranial nerve
Oculomotor, GVE & GSE, pupillary constriction and eye movement
Name, component, role IV cranial nerve
Trochlear, GSE, eye movement
Name, component, role VI cranial nerve
Abducent, GSE, eyemovement
Name, component, role VIII cranial nerve
Vestibulocochlear, SVA, balance and sound
Name, component, role XI cranial nerve
Accessory, GSE, neck muscles
Name, component, role XII cranial nerve
Hypoglossal, GSE, tongue muscles
Explain the components and role of the V Trigeminal nerve.
SVE - branchiomotor fibres supplying the muscles of mastication in the jaw.
GSA - sensory (including pain) input from the head, including the oral cavity.
3 divisions
Ophthalmic (V1)
Maxillary (V2)
Mandibular (V3)
Branches of the V2 and V3 are the main targets for dental nerve blocking (anaesthesia)
Explain the components and role of the VII Facial nerve.
GSA - general sensation from around the external ear
SVA - taste from anterior two-thirds of the tongue (hitches a lift with V part way)
SVE fibres - branchiomotor fibres supplying the muscles of facial expression
GVE - preganglionic parasympathetic fibres hitch a lift with trigeminal fibres to supply:
Lacrimal glands
Submandibular and sublingual salivary glands
Mucous membranes
Explain the components and role of the IX Glossopharyngeal nerve.
GVA - carotid body & sinus (monitors blood pressure)
GVE - innervates parotid gland
GSA - general sensation in back of mouth
SVA - taste from posterior one-third of tongue
SVE - branchiomotor fibres innervating stylopharyngeus muscle (pharynx)
Explain the components and role of the X Vagus nerve.
GSA - parts of the larynx and of the dura mater
GVA - sensation from the viscera
GVE - parasympathetic innervation of the viscera
SVA - taste from epiglottis and pharynx
SVE - branchiomotor fibres innervating remaining muscles of pharynx and larynx
