12 Cranial Nerves
Olfactory – sense of smell
Optic – visual information from the eye to the brain
Occulomoter – external eye muscles
Trochlear – superior oblique muscles of eye
Trigeminal – 3 large branches a. ophthalmic b.maxillary c. mandibular
6. Abducens – lateral rectus muscles of the eye
7. Facial – taste and facial muscles
8. Vestibulocochlear – a. vestibular b. cochlear * hearing
9. Glossopharyngeal – tongue and throat, corotid sinus which controls
blood pressure
10.Vagus – (wonderer) has many widely distributed branches: pharynx,
larynx, trachea, heart, lungs, esophagus, stomach, small intestine, and
gall bladder.
11.Accessory – “accessory” to the vagus nerve
12. Hypoglossal – “under the tongue” – controls the tongue
Nervous System
Central Nervous System (CNS) - brain and spinal
Peripheral Nervous System (PNS) - Nerves
connecting the brain and spinal cord to other parts of
the body
- structural and functional center of the entire
nervous system
- consists of the brain and spinal cord
- integrates incoming pieces of sensory
information, evaluates the information, and
initiates an outgoing response
- Nerve tissue that lies on the “outer regions” or
- Nerves that originate in the brain are called
cranial nerves
- Nerves that originate in the spinal cord are called
spinal nerves
Afferent (carry toward)
* all incoming sensory pathways
Efferent (carry away)
*all the outgoing motor pathways
Somatic – Carry information to skeletal muscles
Autonomic – Carry information to smooth muscle,
cardiac muscles, and glands
Neuron – excitable cells that conduct the impulses
that make possible all nervous system functions
* Human brain contains about 100 billion neurons
10% of the nervous system cells
Cell body contains nucleus, cytoplasm
Dendrite “tree” – distal ends are called receptors that
receive stimuli that initiate nerve signals
- receive signal and conduct electrical signals toward
the cell body
Axons – conduct impulses away from the cell body
* mylenation increases impulse speed