Functions f the nervous system
- Take in info (sensory receptors)
- Analysis of info
- sends response to effectors
- higher cognitive fn (thinking)
Structure of NS
Central Nervous System (CNS): Brain and spinal cord
Peripheral Nervous System (PNS): cranial nerves, spinal nerves
Neuroglia def
helper cells for neurons
Functional divisions
- sensory receptors
- Afferent division
- Info processing in CNS
- Somatic nervous system (PNS)-> skeletal muscle (effector)
- Autonomic nervous system (PNS) -> Parasympathetic and sympathetic:: smooth muscle, cardiac muscle, glands (effectors)
List the structures of the neuron (13)
- dendrites
- cell body (aka perikaryon)
- nucleus
- satellite cells (also nissl bodies)
- axon hillock
- axon
- schwann cells
- mitochondria
- myelin sheath
- neurilemma
- nodes of ranvier
- Axon terminal (telodendria)
- synaptic terminal
- endoneureum
What is neurilemma
outer layer of schwann cells, outside the myelin
Schwann cells do…
wrap around the axon and has myelin (lipid based insulating material) which helps protect and keep charges inside, allowing for the action potential to occur
Action potential general flow
- stimuli received at dendrites or cell body
- impulse initiated at axon hillock
- impulse travels down axon and to axon (synaptic) terminals
Na & K directions
Na in
K out
Unipolar neurons
1 connection to cell body
Bipolar neurons
2 connections to cell body
Multipolar neurons
many connections to cell body, “stereotypical drawing of the neuron”
Synapse def and parts
Synapse is where two neurons have a communication center
- presynaptic membrane
- synaptic cleft
- postsynaptic membrane
- postsynaptic receptors
- synaptic vessels
- neurotransmitters
Neuroglia (6)
- Schwann cells: helper cells, insulate for speed
- Satellite cells: surround cell body, maintain NT levels
- Astrocytes: blood brain barrier
- Oligodendrites: myelinate axons
- Microglia: remove debris
- Ependymal cells: CSF production
Bundle of cell bodies in PNS is called
Ganglion
Bundle of axons in PNS is called
Nerve
Fascicle is
cluster of axons, a single nerve has many fascicles
Nerve components (layers) outer in
- epineurium ‘upon’
- perineurium ‘around’
- endoneurium ‘within’
Multiple sclerosis
an autoimmune disease where T cells attack myelin sheath, scarring it, and ultimately slowing down impulses
Progressive, debilitating
Poliomyelitis
virally infectious, virus attacks neurons, specifically cell body
mostly eradicated
Functions of the spinal cord
impulse condition and reflex integration
Reflex arc (kinds and components)
Monosynaptic: afferent and efferent directly connect
Polysynaptc (interneuron involved)
stimuli > receptor> sensory neuron> Association neuron (interneuron)>motor neuron->effector
List spinal cord structure (in terms of nerves)
- Cervical enlargement
- Intercostal nerves (between ribs)
- Lumbar enlargement
- Conus medullaris
- Cauda equina
- filum terminale
Filum terminale fn
connects the spinal cord to the saccrum
Spinal cross section parts (16)
w/o meninges
- central canal
- white matter
- posterior column of white matter
- anterior column of white matter
- lateral column of white matter
- anterior median fissure
- posterior median sulcus
- gray matter
- posterior horn of grey matter
- anterior horn or grey matter
- lateral horn or grey matter
- grey commissure
- dorsal root (of spinal nerve)
- ventral root (of spinal nerve)
- spinal nerve
- dorsal root ganglion
Spinal cord tracts carry
Ascending: sensory
Descending: motor
Spinal cord meninges (inner> outer) w spaces
- Pia mater
- subdural space - Arachnoid mater
- subarachnoid space (filled w CSF) - Dura mater
- epidural space
Cervical plexus nerves (list)
Phrenic: innervates at diaphragm
Falx cerebri is
the meninges in the longitudinal fissure
Sacral plexus nerves (list)
- Sciatic nerve (branches to fibular nerve): hamstrings, flex knee, plantar flexion
- Common peroneal nerve (fibular) branch into superficial and deep peroneal
- Saphenous: sensation to lower leg
- Tibial and sural nerve
Lumbar plexus nerves (list)
- Femoral nerve: anterior, flex hip, extend knee
- Obturator: goes through os coxae, sensation to thigh
Spinal cord injuries (in class)
- Paraplegia: cant send/recieve signals from lower body (damage lower in spinal cord)
- Quadriplegia: can’t send/recieve signals from all 4 limbs (damage higher in spinal cord)
- Spina Bifida: birth defect, verdebral arches don’t develop, bulging of meninges.
Cerebrospinal Fluid fn
-shock absorption
-buoyancy
-chemical & waste removal
-made in the ventricles of the brain (hollow spaces filled with CSF)
constantly flowing
Ventricles of the brain
- Lateral ventricles (c-shaped)
- Foramen Monro (interventricular) connects lateral to third ventricle
- Third ventricle (connected to lateral vent.)
- Aqueduct of sylvius (between 3rd and 4th ventricle, csf)
- Fourth ventricle (where CSF goes to spinal cord)
Ventricles of the brain
- Lateral ventricles (c-shaped)
- Foramen of Monro (interventricular) connects lateral to third ventricle
- Third ventricle (connected to lateral vent.)
- Aqueduct of sylvius (between 3rd and 4th ventricle, csf)
- Fourth ventricle (where CSF goes to spinal cord)
Embryonic brain regions (5; bulgy)
- Telencephalon->cerebrum
- Dienchephalon->thal, hypothal, epithal, pit gland
- Mesencephalon->midbrain
- Metencephalon->cerebellum
- Myelincephalon->medulla oblongata
Adult brain subdivisions (4)
- Cerebrum
- cerebral cortex(gray mattter)
- inner white matter - Diencephalon
- Epithalamus
- Thalamus- intermediate mass of thalamus
- Hypothalamus
- pinneal gland
- pituitary gland
- mamillary bodies
- intermediate mass of thalamus
- Brain Stem
- Midbrain
- Pons
- Medulla oblongata - Cerebellum
- Arbor vitae
- Folia
Corpus callosum
c-shape, made up of myelinated axons, helps join the hemispheres
Cerebral Cortex
Grey matter & cell bodies, outer layer of the brain (visible in slices)
The convolutions in brain are called:
Gyri (gyrus): raises in brain
Sulci (sulcus): depths in the brain
The convolutions in brain are called:
Gyri (gyrus): raises in brain Sulci (sulcus): depths in the brain precentral gyrus (motor) central sulcus postcentral gyrus (sensory)
List the Lobes of cerebrum
- Fontral lobe: memory, reasoling, planning, motor output
- Parietal lobe: touch, pain, taste
- Temporal lobe: auditory, olfactory, face recog
- Occipital lobe: visual perception
List the Lobes of cerebrum
- Frontal lobe: memory, reasoning, planning, motor output
- Parietal lobe: touch, pain, taste
- Temporal lobe: auditory, olfactory, face recog
- Occipital lobe: visual perception
Thalamus fn and structures
transfers sensory info to cerebrum, motion awareness
interthalamic adhesion(rod connecting sides of thal)
Hypothalamus fn
major organ fn, emotions, hormone secretions
*mamillary bodies:fn: chewing and licking)
Pineal gland does what and where is it
secretes melatonin, in hypothalamus
Pituitary gland structure to know
infundibulum: stalk-like part that holds the pituitary gland
List the midbrain regions
- corpora quadrigemina
- Superior colliculi: visual processing
- Inferior colliculi: auditory processing
- Cerebral peduncles: carry messages to and from thalamus and cerebrum
Pons fn
nuclei for cranial nerves, respiratory control (subconscious things)
Corpora Quadrigemina
- superior colliculi
- inferior colliculi
Cerebellum Structures
-arbor vitae
-folia
-transverse fissure
- cerebellar peduncles
coordination of skeletal muscle contraction; Superior, middle and inferior peduncles
Medulla oblongata fn
controls heart rate, respiratory rate, reflexes like coughing, sneezing, swallowing
12 Cranial Nerves
I: Olfactory tract: s, smell
II:Optic: s, vision
III: Oculomotor: m, eye and eyelid movement
IV: Trochlear: m, eye muscle movement
V: Trigeminal: m,s, chewing, face and mouth sensation and pain
VI: Abducens: m, lateral eye movement
VII: Facial: m,s, facial express and taste
VIII: Vestibulocochlear: s, hearing and equilibrium
IX: Glossopharyngeal: m,s, taste, sense blood pressure
X: Vagus: m, s, sense blood pressure, slow heart rate, peristalsis
XI: Accessory: m, swallowing, movement
XII: Hypoglossal: m, tongue movement
Parkinson’s Disease
Substantia Nigra (area that produces dopamine) is diminished so decreased production leads to inability to inhibit muscle activity
Alzheimer’s disease
thought to have genetic, enviromental and age facotors
Cerebrovascular accident aka
stroke: blockage or burs in blood vessels
Synesthesia
association of colors to letters and numbers
Autonomic nervous system consist of
- the somatic nervous system
- the autonomic nervous system: symp and parasymp
Somatic nervous system is
voluntary, one motor neuron
Autonomic nervous system
involuntary, two motor neurons
divides into sympathetic and parasympathetic
Effectors of the nervous sytem
- Cardiac muscle
- Skeletal muscle
- Glands
ganglions of the autonomic NS
- preganglionic neurons are not myelinated
- ganglions are far from effectors
- postganglionic neurons are typically very small
Sympathetic NS
- prepares body for fight/flight response
- activates as a whole
Parasympathetic NS
- conserves body energy (opposite to sympathetic)
- Generally activated by parts, what is necessary
examples of sympathetic ns, functions
- inhibits digestive processes
- relaxes bronchi of lungs (meaning bigger diameter=more oxygen)
- accelerates hearth rate (inc blood flow)
- inhibition of bladder release
List some of the common neurotransmitters
- Acetylcholine
- Norepinephrine
- Epinephrine
Acetylcholine fn and location
-stimulates effectors, triggers body activities when body at rest
found in preganglanglionic neurons of ANS, all parasymp postganglionic neurons and some sympathe postgangl
Norepinephrine fn and location
-stimulates effectors, triggers fight or flight
found in most sympathetic postganglionic neurons
Epinephrine fn
-triggers fight or flight responses.
found in the ANS (out f the medulla)
Olfactory sense
smell molecules go into nose>adhere to nasal cavity>olfactory receptor cells> olfactory nerve> trigger action potential>cribriform plate of ethmoid bone>olfactory bulb>bundles of axons>olfactory tract
Gustatory sense
‘Bumps’ are called Papilla(3 kinds) which have taste buds located deep inside
Taste buds have: taste pore, transitional/supportive cells and gustatory cells
3 kinds of papilla
- Circumvallate papilla (bigger, in back of tongue)
- Fungiform papilla
- Filiform papilla
Primary taste sensations
- bitter
- sour
- sweet
- salty
- unami
- water
List Vision accessory structures
- eyebrows, eyelashes
- Palpebrae
- Tarsal gland
- Med and lat Canthus
- Conjuctiva
Palpebrae are
eyelids, keep stuff out and eye lubricated and protected
Tarsal gland
produces oil to help lubricate the eye
Medial and Lateral CAnthus
spot where the eyelids meet
Conjuctiva
the clear tissue covering the sclera and inside of eyelids, has blood vessels to supply eye
Lacrimal apparatus components
- lacrimal gland
- lacrimal ducts
- superior and inferior canaliculi
- lacrimal sac
- nasolacrimal duct
Lacrimal gland fn
produces tears
lacrimal duct fn
transport way of tears
Superior and inferior canaliculi fn
drain tears into the lacrimal sac
nasolacrimal duct
dispose of excess tears through nose
Light intake pathway
light goes thru cornea> iris opens/contracts>hits lense>light rays land on back of eye> hits retina w/ its receptor cells> choroid
White part of the eye called
Sclera
Fibrous tunic includes
the sclera and the cornea
vascular tunic include the
choroid, ciliary body, iris
neural tunic includes
retina
ciliary body surrounds the
lens
List cavities and chambers of the eye
-anterior cavity: in front of the lens, filled w/ aqueous humor
anterior chamber: iris to cornea
Posterior chamber: lens to iris
-Posterior cavity: behind lens, filled w/ vitreous humor
Suspensory ligaments are
what attach to lens, pulling/pushing of lens allowing for focusing
Aqueous humor def
water-like clear fluid between the cornea and lens
Vitreous humor def
transparent, jelly-like tissue behind the lens
fovea is
the indentation, cup-shaped area where light rays fall (at back of eye)
Photoreceptors include
- rods: perceive black and white images, blurry
- cones: perceive color and sharp images
Rods fn and location
-black and white image
-blurry
-in low light
in the peripheral: to macula and fovea
Rods fn and location
-black and white image
-blurry
-in low light
in the peripheral: to macula and fovea
These are the cell layers that light goes thru before optic nerve
photoreceptors-> bipolar cells-> ganglion cells-> optic nerve
optic chiasma is
the crossover of optic nerves, in the brain
Auditory sense includes parts
- Outer ear
- Middle ear
- Inner ear
Outer Ear components
- helix: top of the ear
- auricle: captures sound waves
- earlobe
- external auditory canal (meatus)
- tympanic membrane (eardrum, vibrates)
Middle ear components
- Auditory Ossicles: Malleus, Incus and Stapes
- oval window (where stapes connects)
- round window (also on the cochlea)
- auditory tube (air filled; connects nose mouth and ear [pressure])
Inner ear components
- Bony labyrinth
- Membranous labyrinth
- Semicircular ducts (anterior, lateral, posterior)
- Cochlea
- cochlear duct
- organ of corti:
- Basilar membrane
- Tectorial membrane
- Hair cells
- vestibular membrane
- Scala vestibuli
- Scala Tympani
Membranous labyrinth is composed of
-soft tissue
-Perilymph is the membrane around and it is fluid
endolymph is inner layer
Equilibrium definition
Position in space, important for homeostasis: up vs down, front vs, back, and rotation. Mostly using our head position to determine this
membranous membrane ‘bags’
- Utricle (horizontal accel) bigger
- Saccule (vertical accel) smaller
filled with endolymph
utricle and saccule are what and where
bulb looking chambers within the vestibule (triangle shaped), which is what moves with respect to gravity
Maculae
has utricle and sacculae within, also crystals (Statoconia)
Otoliths are…
collection of crystals suspended in endolymph within the maculae in the ear (also suspended in maculae are hair cells)
Ampullae is
the bulgy part of the semicircular ducts that has gelatinous structure called Cupula, which is very flexible
Cupula is
flexible gelatinous material within the ampullae (of semicircular ducts), in which the hairs and support cells are suspended
cupula shifts> since hairs are embedded, they too shift
Cerebellum has white matter called ___ and grey matter called ___
- arbor vitae (inner white matter “tree”
2. folia (outer grey matter “leaves outside”
Static vs dynamic equilibrium
static: body’s sense of up vs down
dynamic: body’s sense of movement
what is an otoscope?
aka: auriscope
device used to look inside the ear. gives a view of the ear canal and tympanic membrane
What are statocytes?
specialized cells in plants that help them sense gravity, located in endodermis of their shoot, they use statoliths (free-floating starch granules) to sense
Auditory tube aka
eustachian tube, connects middle ear to the nasopharynx, equalizes pressure in env.
Common place for ear infections in children
list the auditory ossicles
-malleus
-incus
-stapes
from outer to inner
basilar membrane is
within the organ of corti (triagle shape in the cochlea cross section. contains the hair cells that move with sound
organ of corti def (in relation to cochlea) and what makes it up
the organ of corti is the sensory apparatus within the cochlear duct (between vestibular and basilar membranes)
cochlear nerve fn
sends the auditory information from the cochlea to the brain
crista ampullae def
are the cluster of hair cess and support cells within the ampulla (within semicircular ducts)
perilymph vs endolymph
perilymph: inside the scala vestibuli and tympani
endolymph: inside the cochlear duct
what is a labyrinth
inner ear structures that are filled with fluids, to hold the inner ear components
what is a pinna(e)?
same as the auricle, the outer part of the ear that catches soundwaves
list the components of cochlear cross section
- basilar membrane
- cochlear duct
- hair cells
- organ of corti
- scala vestibuli
- scala tympani
- tectorial membrane
vestibular nerve vs cochlear nerve vs vestibulocochlear
vestibular: originates from the vestibules (balance/equilibrium)
cochlear: originates from cochlea (most of hearing)
vestibulocochlear: carries info into the auditory cortex (vestibular and cochlear are subdivisions)
afferent fibers of the cochlea
are the fibers taking the information from the movement of hair cells and supporting cells to the cochlear nerve. Innervate the basilar membrane
Afferent vs efferent
afferent is sensory (in)
efferent is motor (out)
Afferent vs efferent
afferent is sensory (in)
efferent is motor (out)
Interneurons, what are they and where
neurons found in the CNS, send information between motor and sensory, meaning they are only in brain and spinal cord, not in periphery
Glial cells
diff types:
astrocytes, oligodendrites, microglia, satellite cells, and Schwann cells
Satellite Cells: provide support for neurons, and increase its speed
Neurofibrils are what
structures that carry the signal (AP) through the body of the neuron, toward axon hillock
Neuromuscular junction
where the motor neuron (efferent) meets the muscle- junction
List the reflex tests (8)
- Patellar: L2-L4
- Biceps: 5th cervical
- Triceps: 7th cervical
- Achilles: sacral nerves
- Plantar: white column spinal cord
- Corneal: brainstem (blinking)
- Gag: brainstem
- Pupillary: brain damage
Mammillary bodies are wehre
two small structures behind the pituitary, relay info from the lymbic system to fornix
Mammillary bodies are wehre
two small structures behind the pituitary, relay info from the lymbic system to fornix (thin under corpus callosum)
all motor neurons are ___polar
multipolar
all sensory neurons are ___polar
unipolar
all sensory neurons are ___polar
unipolar
Terms for vision: normal, nearsightedness, farsightedness
emmetropic
Myopia
Hyperopia
when the lens looses elasticity its called
presbyopia
how is colorblindness a sex-linked trait?
genes for red and green cones are on the x chromosomes, males tend to be colorblind more often
List abnormal conditions of the eye: (5)
- Myopia: elongated eye “nearsightedness”
- hyperopia: narrow eye “farsightedness”
- presbyopia: special hyperopia, lens looses elasticity
- astigmatism: multiple focal points, due to imperfections in cornea
- legally blind: visural acuity below 20/200
blind spot caused by…
the optic nerve (where it enters)
instrument to look at eye called
opthamaloscope
brief def of glaucoma
damage to optic nerve, increased pressure in the humor of the eye
Vision tests (2)
Snellen (letter chart)
Astigmatism chart: numbers around sun-like shape
accomodation and acuity meaning
acommodation: keeping the focal length constant
acuity: ability of lens to get the focal point on the macula lutea
Sheep eye (12)
- aqueous humor
- choroid
- ciliary body
- cornea
- fovea centralis
- iris
- lens
- optic disk
- pupil
- retina
- sclera
- vitreous humor
cross-section of eye parts (5)
lens cornea retina choroid sclera
Major eye components (14)
- cornea
- iris
- pupil
- ciliary bodies
- lens
- suspensory ligaments (holding lens)
- vitreous humor
- fovea centralis
- Macula lutea
- retina
- choroid
- sclera
- optic disk (blind spot)
- optic nerve
anterior vs posterior cavity of the eye
anterior is from the lens forward (aqueous humor)
posterior behind the lens (vitreous humor)
List the eye muscles (7)
- superior levator palpebrae
- superior rectus muscle
- superior oblique muscle
- lateral rectus muscle
- medial rectus muscle
- inferior rectus muscle
- inferior oblique muscle
whats lacrimal punctae?
the tiny hole on the eyelid, collect tears
Lacrimal parts (4)
lacrimal gland lacrimal ducts lacrimal punctae lacrimal sac (nasolacrimal duct)
