ToB: Nervous System Flashcards
Where is CSF found?
What is its function?
Name the disease where there’s too much CSF
In subarachnoid space of the brain, ventricular system of spinal cord and brain and central canal of spinal cord
Nourishes, removes metabolites and exerts hydrostatic pressure (cushioning)
Hydrocephaly
Name the meninges
SDASP:
skull, dura mater, arachnoid mater, subarachnoid space, pia mater
Name two autoimmune diseases (one PNS and one CNS) where myelin is destroyed
What PNS and CNS cells do myelination?
PNS: Guilliam Barré
CNS: Multiple sclerosis
PNS: Schwann cells, CNS: oligodendrocytes
What do ependyma cells do and where are they found?
What do astrocyte cells do and where are they found?
In the CNS:
Ependyma cells secrete CSF
Astrocytes transport nutrients and waste across the BBB
Name the 3 ‘sheaths’ in the nerve structure and what they cover
Epineurium: covers the nerve
Perineurium: covers the fascicle
Endoneurium: covers an axon
Name the 3 structures of nerves and their differences
Multipolar: single axon, many dendrites
Bipolar: single axon and one dendrite
Unipolar: single axon, no dendrites
Contrast temporal and spatial summation
Temporal: waves of neurotransmitter from one pre-synaptic neurone to overcome the threshold
Summation: neurotransmitters from multiple pre-synaptic neurones to overcome the threshold
What are dendritic spines?
What do they provide and what condition lacks them?
Small membranous protrusions from the dendrite
They allow for neural plasticity/ ability for the brain to change over time.
Thus, Down’s syndrome individuals have learning difficulties and fewer dendritic spines
Why do we have dendrites?
What is arborisation?
To increase the surface area for signal reception
‘Arborisation’ is when a neurone integrates signals with other neurones
How many cranial nerves are there and where do they originate from?
How many have parasympathetic components?
12 cranial nerves: 2 from the brain and 10 from the brain stem
4 have parasympathetic components
What kind of glandular secretions are stimulated by parasympathetic and sympathetic systems?
Parasympathetic:
Facial nerve 7: Serous salivary secretions from submandibular and sublingual, lacrimal gland: tears, nasal gland
glossopharyngeal nerve 9: salivary secretions from parotid gland (also leads to tongue and pharynx)
Sympathetic: Stimulates mucous secretion and sweat
What are cranial nerves 3 and 10 called, what do they do?
3: ocular motor parasympathetic nerve: constricts the pupil and controls 4/6 muscles for eye movement
10: VAGUS parasympathetic nerve controls heart rate and GI tract
Describe the differences in the parasympathetic and sympathetic pathways (including neurotransmitter differences)
What is one sympathetic exception?
Parasympathetic: long pre-synaptic and short post-synaptic, uses Ach at both synapses
Sympathetic: Short presynaptic (that often synapses at/around the sympathetic chain) and a long post-synaptic, uses Ach at the presynaptic and Noradrenaline at the effector organ
Exception: sweat glands are sympathetic but use Ach at the effector organ
Name the 3 sacral spinal nerves.
Explain the parasympathetic and sympathetic interactions with sex and urination
S2, S3, S4
Sex:
P: increases blood flow to the genitalia
S: ejaculation
Urination:
P: Pee: contracts the detrusor muscle
S: No pee: Relaxes the detrusor muscle and constricts the internal sphincter
Explain a vasovagal syncope.
When a trigger (fear, pain, phobia, etc) overly stimulates a parasympathetic response of vasodilation: causing a drop in BP and HR.
The brain quickly lacks perfusion and person faints
