200 overview Flashcards
Action potential
3 Na+ in
2 K+ out
in the resting state the inside of the neuron is_______ and the charge outside the neuron is_______
Negative
Positive
When the neuron is stimulated _______ ions rush into the cell and begin a wave of _____ that travels down the cell.
sodium ions (Na+) depolarization
Benzodiszepines
- diazepam/Valium
- midazolam/Versed
- lorazepam/Ativan
diazepam/Valium
MOA: acts on the GABA type A receptors in the brain.
GABA
-is the main inhibitory neurotransmitter of the CNS.
-benzos have no direct effect on the GABA recoptors, but do potentiate the effects of GABA.
increased GABA = increased sedation
AEIOUTIPS
A-alcohol/acidosis E-epilepsy/electrolytes/encephalopathy I-infection O-overdose U-uremia T-trauma I-insulin P-psychosis/poisoning S-stroke/seizure/syncope
Sensory neurons
related to touch, pain, temp, proprioception, sight, hearing, taste, smell, equilibrium (balance)
Somatic nervous system
-transmits nerve impulses from the PNS to skeletal muscles
5 drugs narcan reverses
- fentanyl
- heroine
- morphine
- oxycodone
- hydrocodone
- demerol
Morphine
pain managment
opiod analgesic
Acetylcholine (ACH)
is a neurotransmitter released by cholinergic neurons
Autonomic nervous system
transmits action potentials from the PNS to smooth muscles, cardiac muscles and certain glands
in the autonomic nervous system (ANS) cholinergic neurons include
- all sympathetic and parasympathetic pre-ganglionic neurons
- sympathetic post-ganglionic neurons that innervate, most sweat glands
- all parasympathetic posy-ganglionic neurons
ACH always binds with
nicotinic or muscarinic receptors
4 types of neuroglia of the CNS
- astrocytes
- oligodendrocytes
- microglial cells
- ependymal cells
astrocytes
- build blood brain barrier
- star shaped, have many processes
- largest and most abundant
2 types of astrocytes
- protoplasmic astrocytes
- short branching processes
- found in gray matter
- fibrous astrocytes
- long unbranched processes
- found in white matter
processes of the astrocytes
make contact with blood capillaries, neurons and pia matter
functions of astrocytes
- support neurons
- help create unique selectively permiability around the endothelial cells
- in the embryo, secrets chemicals that appear to regulate growth, migration and interconnection among the brains neurons
- help maintain proper chemical enviromnt
- aids in learning and memory by influencing the formation of the neural synapses
oligodendrocytes
- resemble astrocytes but smaller and fewer processes
- responsible for forming and maintaining mylein sheath around CNS axons
microglial or microglia cells
- small cells with slender processes that give off spine like projections
- function as phagocytes: remove cellular debris/waste
ependymal cells
cuboidal to columnar cells arranged in a single layer that possess microvilli and cilia
- line the ventricles of the brain and central canal of the spinal cord (anywhere there is CSF)
- produce, monitor and assist in the circulation of CSF
- form blood brain barrier
parts of the brain
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
- brain stem
- cerebellum
- pitutary glad
- wrenickes area
- hypothalamus
- cerebrum
Frontal Lobe functions
- movement
- critical thinking
- problem solving
- concentration
- behavior, personality
- judgement, planning
- mood
parietal lobe
- sensations
- language
- perception
- body awareness
- attention
Broca’s are
speech
occipital lobe
- vision
- perception
temporal lobe
- hearing
- speech
- language
- emotion
- memory
brainstem
- Midbrain:
- Pons:
- Medulla: HR, RR, swallowing, sneezing, vasoconstriction, vomiting ceter
Cerebellum
- posture
- balance
- coordination of movement
- fine motor control
Wernicke’s area
-language comprehension
Hypothalamus
- homeostasis
- hunger
- thirst
- temperature control
Epithalamus
contains pineal gland
secrets melatonin
amygdala
emotional processing
Hipppocampus
- part of limbic system
- involved in learning and memory
cerebrum
- gray and white matter
- corpus callosum joins the hemispheres
reticular function
- helps regulate muscle tone
- alerts the cortex to incoming sensory signals
- maintain consciousness
- awaken from sleep
Brain Lobes and functions
- Frontal lobe: emotion, speech, personality, creativity
- Parietal lobe: processing, nerve impulses relating to the senses
- Temporal lobe: hearing, memory, language
- Occipital lobe: vision
Gray matter
intergration
White matter
tracts
Basal Nuclei (Basal Ganglia)
- helps initiate and terminate movement
- suppress unwanted movement
- regulate muscle tone
Medulla
-controls HR, RR, swallowing, sneezing, vasoconstriction, and is the vomiting center
Pons
- connects different areas of the brain
- helps control breathing
medbrain
- controls eye movement
- sensory impulses to the thalamus
- process visual and auditory information
Cranial nerves
1 Olfactory 2 Optic 3 Oculomotor 4 Trochlear 5 Trigeminal 6 Abducens 7 Facial 8 Acoustic/ Vestibulocochlear 9 Glossopharyngeal 10 Vagus 11 Accessory 12 Hypoglossal
1 olfactory
- sensory nerve
- effects smell
- test: smell alcohol swab
2 Optic
- sensory nerve
- effects vision/ sight
- test: vision chart
3 Occulomotor
- motor nerve
- effects movement of the eye ball, eyelid and pupil constriction
- test: follow finger, light reaction
4 Trochlear
- motor nerve
- movement of the eye up, down, left, right
- test: follow finger
5 Trigeminal
- both sensory and motor nerve
- touch, pain, thermal sense, chewing, middle ear muscle, clenching, innervation of cornea
- test: (touch test) touch patients face, clench jaw
6 abducens
- motor nerve
- movement of eyeballs
- test: follow finger
7 facial
- both sensory and motor
- sensory signals form tongue, facial expression
- test: stick out tongue, smile
8 Acoustic
- sensory nerve
- hearing, equilibrium
- test: balance on one leg, hearing from different distances
9 Glossopharyngeal
- both sensory and motor
- digestion, resting body, swallowing, BP, O2/CO2 retention, saliva
10 Vagus
- both sensory and motor
- parasympathetic response, swallowing, thoracic/abdominal sensation
- test: swallow/ bare down
11 Accessory
- motor nerve
- movement of head, pectoral girdle
- test: shoulder shrug
12 Hypoglossal
- motor nerve
- speech, chewing, swallowing
- test: speech, stick out tongue
Cranial nerves in the Medulla
- acoustic
- glossopharyngeal
- vagus
- accessory
- hypoglossal
cranial nerves in the Midbrain
- occulomotor
- trochlear
cranial nerves in the pons
- trigeminal
- abducens
- facial
- acoustic
nerve plexuses
- cervical
- brachial
- lumbar
- sacral & coccygeal
Cervical Plexus
- formed by the anterior rami (roots) of the first four cervical nerves: C1-C4 with some contributions from C5
- supplies the skin and muscles of the head, neck and upper portion of the shoulders
- the phrenic nerve arises from the cervical plexus
Phrenic nerve
- arises form cervical plexus
- C3, C4, C5
- supplies motor function of the diaphragm
Brachial plexus
- anterior rami (roots) of spinal nerves
- C5-C8 and T1
- extends inferiorly and laterally
- passes above the first rib posterior to the clavicle
- provides nerve supply to the shoulders and upper limbs
- has 5 main branches
Branches of Brachial plexus
-axillary
-musculocutaneous
-radial
median
-ulnar
Lumbar plexus
anterior rami of L1-L4
-supplies abdo wall, external genitals and lower limbs
Sacral & coccygeal plexuses
-anterior rami of L4-L5 and S1-S4
Reflex arc
1) sensory receptor
2) sensory neuron
3) integration center
4) motor neuron
5) effector
damage to C1-C3
- no function maintained from the neck down
- require a vent for breathing
damage to C4-C5
-loss of control of diaphragm
damage to C6-C7
-maintain some arm and chest muscles
damage to T1-T3
intact arm function
damage to T4-T9
maintain control of trunck above navel
Damage to T10-L1
use of upper leg muscles
Damage to L1-L2
use of some lower leg muscles
Saltatory conduction
- special mode of action potential propagation that occurs along myelinated axons.
- nodes of ranvier
- jumping from node to node: faster
continuous conduction
- step by step depolarization and repolarization
- unmyelinated
neurotransmitters
- ACH: acetylcholine
- glutamate
- GABA
- norepi
- epi
- dopamine
- serotonin
ACH
- excitatory at the neuromuscular
- inhibitory at other synapses
Glutamate
-main excitatory neurotransmitter of the brain
GABA
-main inhibatory neurotransmitter of the brain
Dopamine
- active during emotional responses
- addictive
serotonin
- involved with sensory perception
- regulating mood, appetite and sleep
CPP= MAP-ICP
MAP=DBP + 1/3 PP
CPP
MAP
ICP
CPP 60-80 mmHg
MAP 70-95 mmHg
ICP 10-15 mmHg
anisocoria
unequal pupils
coma patients pupil response
normal pupil respones = toxic or metabolic cause
asymmetrical or unresponsive = tramatic or stuctural cause
stimulation of the parasympathetic nervous system
- decreased cardiac strength
- decreased HR
- decreased electrical excitability
- accelerated digestive function
classifications of neurons
structural or functional
structural neurons are classified by number of processes extending from the cell body
- multipolar: several dendrites, one axon. all motor neurons and most neurons in the brain
- Bipolar: one main dentrite and one main axon, found in retina and inner ear as well as olfactory area of the brain
- unipolar: dendrites and axon are fused together
functional neuron classifactions
-based on the direction in which they convey impulse in regaurds to CNS
1) Sensory neuron: Afferent
- unipolar
- convey impulses toward CNS
2) Motor neuron: Efferent
- multiolar
- convey action potentials away from CNS
3) interneurons: Association
- located within the CNS between sensory and motor neurons
- process incoming information and elicit a motor response
- most are multipolar
Ion channels
- leak
- ligand-gated
- mechanical
- voltage-gated
leak channels
- gated channels that randomly open and close
- found in nearly all cells, this includes dendrites, cell bodies and axons
ligand-gated channels
- open in response to binding of ligand(chemical stimulation)
- found in dendrites and some sensory neurons such as pain recptors
- found in dendrites and cell bodies of interneurons and motor neurons
mechanically gated channels
- open in response to mechanical stimulation (touch, pressure, vibration)
- found in dendrites of sensory neurons
voltage-gated channels
- open in response to voltage stimulation
- found in axons of all neurons
Dermatones
- sensory information only
- C1 doesn’t a dermatone
- trigeminal nerve has a dermatone
removal of neurotransmitter
removed by
- diffusion
- ezymatic degradation
- uptake into the cell
Sympathetic
- stems from Thoracolumbar region
- Distributed to wide regions of body
- skin
- sweat glands
- arrector muscles of the hair
- adipose tissue
- smooth muscle of blood vessels.
Parasympathetic
-stems from Craniosacral regions
Limited mainly to head and to viscera of thorax, abdomen, and pelvis; some blood vessels.
sypathetic
-anterior rammi of the thoracolumbar T1-L2
parasympathetic
cranialscaral
-Nuclei of cranial nerves III, VII, IX, and X
-lateral gray matter of S2–S4.
