Cranial nerves, sympathetic trunk Flashcards
(84 cards)
Motor fibres are efferent and travel out of the CNS, whereas, sensory fibres are afferent and travel into the CNS. True or False?
True
All cranial nerves carry fibres with multiple functions. True or False.
False. Optic nerve carries only sensory function
Motor fibres can be either somatic efferent to voluntary muscles or autonomic to smooth muscle and glands. True or False.
True
What does the autonomic nervous system consist of?
Sympathetic and parasympathetic divisions
Where does the sensory information that sensory nerves carry from peripheral structures ultimately go?
Into the CNS
What are the two classifications of sensations?
- Special
2. General
What are some examples of special sensations? (5)
- Smell
- Taste
- Vision
- Hearing
- Balance
What are some examples of general sensations? (4)
- Temperature
- Pain
- Touch
- Proprioception (position)
Where do somatic motor axons/fibres arise?
From neurons in either the brain or spinal cord
Where do somatic motor axons pass into?
They pass into peripheral nerves and via these nerves directly to the skeletal muscle that they innervate.
Is there a second cell body for somatic motor axons?
No.
What divisions does the ANS have? (2)
- Sympathetic
2. Parasympathetic
What are autonomic nerves involved in? (2)
- Secretion from glands (secretomotor)
2. Smooth muscle contraction in blood vessels (vasomotor) , internal organs, erector pili muscles
All organs havea dual sympathetic and parasympathetic supply with oppositie effects. (e.g. one stimulating and the other inhibiting) True or False?
False. Many but not all organs.
How many neurons does the autonomic pathway involve? What are they?
Two.
- The neuron of origin in the brain or spinal cord
- In peripheral ganglion
What is the definition of a ganglion?
A collection of nerve cell bodies outside the CNS.
What are preganglionic fibres?
Myelinated axons of autonomic nerves that have not undergone a second synapse.
Post-ganglionic fibres are usually myelinated. True or False.
False. They are usually unmyelinated.
Where do the parasympathetic nerves leave the brainstem? (5)
- Occulomotor
- Facial
- Glossopharyngeal
- Vagus
- Via 2nd - 4th sacral spinal nerves
Where do pre-ganglionic fibres from the parasympathetic nerves synapse in?
- Ciliary ganglion in orbit = occulomotor
- Pterygopalatine ganglion in pterygopalatine fossa = facial nerve
- Submandibular ganglion adjacent to submandibular salivary gland = facial nerve
- Otic ganglia just below foramen ovale = glossopharangeal nerve
- Thoracic and abdominal ganglia = vagus
What is different about other classes of fibres (i.e. not pre-ganglionic fibres) that pass through the parasympathetic ganglia?
They do not synapse in these ganglia
What is the sympathetic trunk? Where is it situated?
Chain of axons and ganglia
Along the sides of the vertebral bodies.
Where does the sympathetic trunk extend?
Cranial base to coccyx.
Where is the sympathetic trunk in the neck?
Posterior to carotid sheath and anterior to vertebral transverse processes.