Nervous System 2 Flashcards
What is the PNS and what are its divisions?
It is everything outside of the CNS and is broken into sensory and motor (then somatic NS and autonomic NS(broken down into sympathetic and parasympathetic))
What are cutaneous sensory organs?
Sensory receptors in the skin
What are proprioceptors?
Sensory receptors in muscles and tendons
What are the characteristics of cranial nerves?
12 pairs that arise symmetrically from base of brain, distribute to head and neck, numbered in order from front to back in which they arise, some are motor, sensory or both
What is the cranial nerve functions?
Convey sensory impulses (smell, vision, hearing, pain, touch, temperature, deep muscle sense, pressure, vibration). Voluntary muscles control or somatic motor impulses. Involuntary control or visceral effector messages to glands and involuntary muscles
What does somatic mean?
Voluntary
What are the 12 cranial nerves?
Olfactory Nerve, Optic Nerve, Occulomotor nerve, Trochlear Nerve, Trigeminal Nerve, Abducens nerve, Facial nerve, Vestibulocochlear Nerve, Glossopharyngeal nerve, vagus nerve, accessory nerve and Hypoglossal nerve
What is the function of the olfactory nerve?
Carries smell impulses from receptors in nasal mucosa to brain
What is the function of the Optic nerve?
Carries visual impulses from retina to brain
What is the function of the Occulomotor nerve?
Concerned with contraction of eye muscles
What is the function of the Trochlear nerve?
Supplies one eyeball muscle on each side
What is the function of the Trigeminal Nerve?
Great sensory nerve of face and head. 3 branches- ophthalmic, maxillary and mandibular. Carries general sense impulses (pain/touch/temp)
What is the function of the Abducens nerve?
Controlling impulses to eyeball muscles
What is the function of the Facial nerve?
Largely motor nerve, muscles of facial expression all supplied by branches from facial nerve. Includes special sensory fibres for taste contains secretory fibres to salivary glands and lacrimal glands
What is the function of the Vestibulocochlear nerve?
Special sensory fibres for hearing aswell as for balance
What is the function of the Glossopharyngeal nerve?
General sensory fibres from back of tongue and pharynx. Motor nerve fibres to control the swallowing muscles in pharynx
What is the function of the Vagus nerve?
Longest cranial nerve, supplies most organs in thoracic and abdominal cavities. Contains secretory fibres to glands that produce digestive fluids and other secretions
What is the function of the Accessory Nerve?
Motor nerve fibres controlling 2 muscles of neck (trapezius and sternocleidomastoid)
What is the function of the Hypoglossal Nerve?
Carries impulses controlling the muscles of the tongue
What do the brachial and lumbar plexus refer to?
The arm and leg
What are dermatomes and what does this mean in terms of infection?
Skin is innervated by a single spinal nerve. Body is broken down into segments and if virus enters, can only spread in that section but wont leave it.
What is the prime nuerotransmitter?
Acetylcholine (Ach)
What characteristic does the motor nueron have on the autonomic nervous system?
Motor nueron goes from spine or brains but axon is shorter and synapses with second motor nueron at a junction outside CNS (ganglion) which then goes to organ to make it work
What characteristic does the motor nueron have on the somatic nervous system?
Motor nueron goes straight to muscles from spin. It is myelinated so signal is quick
What is a preganglion nueron and what are the differences between sympathetic and parasympathetic ganglia?
It is lightly myelinated and the post unmyelinated signal is slower. Sympathetic ganglia is close to spinal cord where as parasympathetic is close to muscles
What are the two main divisions of the autonomic nervous system and what do they do?
Sympathetic which is the fight or flight reaction and parasympathetic which is the metabolic phase and returns body back to normal. They have opposite effects by releasing antagonistic nuerotransmitters
What is the role of the autonomic nervous system?
Supplies impulses to heart, muscles , smoot muscles and glands to maintain homeostasis, controls functions of glands: respiratory, circulatory, digestive, urogenital systems. Controls involuntary muscles in theses systems and skin and effects internal secretions (interaction with hormone)
What is the development of the autonomic nervous system?
Comes from nueral tubes but relies on CNS releasing nueral growth factor to develop. With age it decreases; constipation and orthostatic hypotension in elderly
When is the sympathetic part activated and what does it do?
It acts as an acceleration under stress. When there is excitement, emergency, embarrassment or exercise, it stimulates adrenal gland which releases hormones including adrenelin preparing for action
What are the effects of the sympathetic part?
Dilation of pupils, increase in heart rate and forcefulness, increase in blood pressure, dilation of bronchial tubes allowing more air in, digestion is slowed, liver releases glucose, kidneys decrease urine output, blood vessels constrict, hair stands and sweat pores open
When is the parasympathetic part activated?
Opposite of sympathetic and serves to balance it out. Activated in ‘SLUDD’
Salivation, Lacrimation, Urination, Digestion and Defecation
What are the effects of the parasympathetic part?
Pupils constrict, nasal glands produce mucous, salivary glands produce thin, copious secretions, trachea and bronchiol constrict, heart rate and force decrease, liver stores glucose, stomach secretes more digestive enzymes, movement of food accelerated, bladder muscles relax and sexual organs stimulated
