Physiology Flashcards
Lobes of cerebral cortex
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Primary cortex
Basic motor or sensory functions
Association cortex
Complex motor functiom
What does the medulla control
Breathing blood pressure swallowing coughing vomiting
The pons controls
Balance
Posture maintenance
Breathing
Midbrain function
Eye movements
Auditirh and visual system relay
Cerebellum function
Coordination of movements planning execution of movement maintenance of posture coordination of head andeye movements
Thalamus function
Processes all sensory information going to the cerebral cortex
processes all motor information coming from the cerebral cortex to the brain stem
Hypothalamus function
Regulates body temperature
food intake
water balance
hormone secretion of pituitary gland
primary motor cortex
Contains upper motoneurons which project to the spinal cord and activate lower motor neurons to innervate skeletal muscles
Primary sensory cortex
Primary visual cortex primary auditory cortex primary somatosensory cortex
receive information from sensory receptors in Periphery
What are the three deep nuclei of the cerebral hemisphere
Basal ganglia
hippocampus
amygdala
Basal ganglia
Composed of the cadaute nucleus, the putamen, the Globus pallidus.
receives input from lobes of cerebral cortex and have projection to assist in regulating movement
What deep nuclei of the cerebral hemisphere are part of the limbic system
The amygdala and the hippocampus
Hippocampus function
Memory
Amygdala function
Emotions
Relationship between diameter and conduction velocity of nerve
The larger the fiber the highrr the conditions of velicity
What are the different type of sensory and motor nerve fiber
A alpha A beta A gamma A Delta B C
A alpha neurons
Alpha motor neurons
Very large
Very fast
Myelinated
A Beta nerve fiber
Touch ,pressure
medium diameter
medium velocity
myelinated
A gamma
Motoneurons to muscle spindles intrafusal fibers
Medium diameter
Medium velocity
Myelinated
A delta
Touch ,pressure ,temperature ,fast pain
small diameter
medium velocity
myelinated
B fiber neurons
Preganglionic autonomic nerves
small diameter
medium velocity
myelinated
C fiber neuron
Slow pain Postganglionic nerves Olfaction Smallest diameter slowest velocity no myelination
Medulla function
Centers for breathing and blood pressure
Centers for swallowing, coughing, vomiting reflexes
Pons function
Balance
Maintenance of posture
Regulation of breathing
Relay information to cerebellum from cortex
Midbrain function
Eye movements
Relay nuclei of auditory and visual nuclei
Cerebellum function
Coordination of movement
Planning and execution of movement
Maintenance of posture
Coordination of eye and head movements
Thalamus function
Processes sensory information going to cerebral cortex to brainstem and spinal cord
Hypothalamus function
Body temp regulation
Food intake
Water balance
Release hormone
3 deep nuclei of the cerebral hemispheres
Basal ganglia
Hippocampus
Amygdala
Basal ganglia nucleus
Caudate nucleus
Putamen
Globus pallidus
Hipoccampus function
Memory
Phasic receptors
Adapt rapidly to stimulus
Tonic receptors
Adapty slowly to stimulus
\most rapidly adapting mechanoreceptor
Pacinian corpuscle
Types of nocireceptor
Thermal / mechanical
Polymodal
Type of nerve fiber for mechanical nocireceptor
A delta
Type of nerve fiber for polymodal nocireceptor
Unmyelinated c fiber
Inflammatory compound that directly activates nocireceptor
Histamin
2 pathways for transmission of somatosensory information to cns
Dorsal column pathway
Spinothalamic tract pathway
Dorsal colum pathway function
Discriminative touch Pressure Vibration 2 point discrimination Propioception
Where in the body, do second order neuron of dorsal colum pathway decussate
Medulla
Spinothalamic pathway function
Pain
Temperature
Light touch
Fiber rsponsible for fast pain
A delta fiber
Slow pain fiber
C fibers
What is referred pain
Pain of visceral origin perceived as coming from somatic location
Type of nerves that innervantes muscle fibers
Motoneurons
What is the neuromuscular junction
The synapse between a motoneuron and a muscle fiber
What is the action and effect of botulinum toxin
Block release of acetylcholine from presynaptic terminal’s
blockade of neuromuscular transmission
paralysis of skeletal muscle
death from respiratory failure
What is myasthenia gravis
In auto immune disorder in which antibodies are produced to bind to acetylcholine receptors creating competition
Acetylcholine cannot bind therefore creating muscle weakness and fatigability
Treatment of myasthenia gravis
Pyridostigmine
What are excitatory postsynaptic potential
Synaptic input that depolarize the postsynaptic cell by bringing membrane potential closer to threshold for firing an action potential
They are produced by opening of Na + and K+ channels
What are some excitatory neurotransmitters
Acetylcholine norepinephrine epinephrine dopamine glutamate serotonin
What are inhibitory postsynaptic potential
Synaptic input that’s hyperpolarized bassinets excel by taking membrane potential away from threshold
Produced by opening of Cl- Channels
What are some inhibitory neurotransmitter
GABA
Glazing
What is spatial summation
2 excitatory potential will add up
What excitatory and one inhibitory potential will cancel each other out
Onl’y neurotransmitter used at the neuromuscular junction
Acetylcholine
Neurotransmitter released from all preganglionic neurons
Acetylcholine
Two parts of what the Autonomic nervous system
Parasympathetic and sympathetic
Type of neuron in somatic innervation
Motoneuron
Type of receptor at skeletal muscle in somatic innervation
N1 with acetylcholine
Sympathetic innervation preganglionic receptor
N2 with acetylcholine
Sympathetic innervation post ganglionic receptors at smooth muscles and glands
NE receptors ( a1,a2,b1,b2)
Sympathetic postganglionic receptors at sweat glands ( no preganglionic )
Muscarinic
Acetylcholine
Parasympathetic preganglionic receptor
N2
Acetylcholine
Parasympathetic postganglionic receptor At smooth muscle endurance
Muscarinic
Acetylcholine
Where do the pre-ganglionic neurons of sympathetic come from
Thoracolumbar spinal cord
Where do the parasympathetic neurons come from
Brainstem and sacral spinal court
Location of autonomic ganglia of sympathetic division
Paravertebral and prevertebral
Location of autonomic ganglia in parasympathetic division
Near or in effector organs
Length of preganglionic and postganglionic sympathetic division
Short preganglionic
long post ganglionic
Cranial nerves with nuclei from which preganglionic neurons of parasympathetic division arise
III
VII
IX
X
Spinal cord segments with nuclei from which preganglionic neurons of parasympathetic division arise
S2-S4
Types of ganglion found in the parasympathetic division
Ciliary ganglion (CNIII) Submandibular ganglion (CNVII) Otic ganglion (CNIX) Pterygopalatine ganglion(CNVII)
Effect of parasympathetic on heart rate
Decrease heart rate
Effects of sympathetic on heart rat e
Increase heart rate
Action of sympathetic on the bladder
Relaxation of bladder wall
contraction of sphincter
Action of parasympathetic on the bladder
Contract bladder wall
relax internal sphincter
The sympathetic constricts or dilates pupil
Constricts
Which division of autonomic system is responsible for near vision ? Far vision ?
Near vision => parasympathetic by contraction of ciliary muscle
Far vision => sympathetic by relaxation of ciliary muscle
What is the location of the centers that regulates and coordinate autonomic regulation of organ system functions
Centers in the hypothalamus and brainstem
3 things that impact intensity of signal
Number of receptors activated
Firing rates of sensory neuron
Different types of receptors activated
What are phasic receptors
Adapt rapidly to stimulus
What are tonic receptors
Adapt slowly
Two qualities of light detected by the eyes
Light Brightness
Light wavelength
Outer fibrous layer of the eye is composed of
Cornea
Corneal epithelium
Conjunctiva
Sclera
Middle layer of eye composed of
Iris
Choroid
Inner layer of eyes composed of
Retina
Part of the retina with highest visual acuity
Macula
Depression in macula where light focuses
Fovea
2 liquids in eye
Aqueous humor - anterior chamber
Vitreous humor - posterior chamber
Photoreceptors in retina
Rods
Cones
Rods characteristics
Low threshold Low intensity light Good in darkness Low acuity Not involved in color vision
Cones characteristics
Higher threshold
Good in daylight
Higher visual acuity
Color vision
Pathway of vision
Information to eyes (retina) -> axons of retinal ganglion cells -> optics nerves -> optic chiasm ( only temporal field cross , nasal field uncrossed )-> optic tract -> synapse in latera geniculate body of thalamus -> ascend to visua cortex in genicuocalcarine tract
Photo reception steps
Light strikes retina
11-cis retinal -> all trans retinal
Transducin G protein activated
Transducin stimulates phosphodiesterase
Phosphodiesterase catalyzes cGMP -> 5’-GMP
Closure of Na+ => hyperpolarization
Decreased release of glutamate
Consequence of optic nerve lesion
What composed the right optic tract
Left nasal Hemiretina fibers
Right temporal hemiretina fibers
Optic nerve lesion consequence
Blindness in same side
All sensory information lost
Optic chiasm lesion consequence
Heteronymous / both eyes bitempora/ both temporal visual fields hemianopia
All information lost from crossing fibers
Optic tract lesion consequence
Homonymous contralateral hemianopia
So if left side cut -> temporal field loss from right side, nasal field loss from left side
Units of sound pressure
Decibes
Measure of sound frequency
Hertz
External ear structure
Pinna
External auditory meatus
Function external ear
Direct sound waves into auditory cana
Medium filling external ear
Air
Structure of middle ear
Tympanic membrane
Malleus
Incus
Stapes
Middle ear medium filling it
Air
Inner ear structure s
Semicircular canals (bony labyrinths )
Membranous labyrinths -> Scala vestibule, scala tympani, scala media
Cochlea with organ of corti
Medium in inner ear
Fluid
Fluid in scala vestibuli and tympani
Perilymph
Fluid in scala media
Endolymph
Structure responsible for sensory transduction of sound
Organ of corti in cochlea
Receptor cells in organ of corti
Inner hair cells
Outer hair cells
Auditory transduction steps
Sound waves -> organ of corti vibration -> bending of cilia on hair cells -> change in K+ conductance -> cochlear microphonic potential -> intermittent glutamate release -> intermittent action potential
Auditory pathway
Information -> hair cells -> afferent cochlear nerves -> synapse on dorsal and ventral cochlear nuclei in medulla -> ascend in CNS -> some cross and ascend in lateral leminscus -> go to inferior colliculi ->ascend to medial geniculate nucleus of thalamus -> ascend to auditory cortex ->
Structure which function is to detect angular and rotational acceleration of head
Semicircular canals perpendicular to each other
Structure that detect linear acceleration
Otolith organ
Utricle
Saccule
Vestibular pathway
Afferent nerves from vestibular hair cells -> vestibular nuclei of medulla (superior, medial, lateral)
input from semicircular canals -> Medial and superior -> medial longitudinal fasciculus -> project to nerves in extraocular muscles
Utricle, saccules , semicircular canals -> Inferior vestibular nucleus ->medial longitudinal fasciculus -> brainstem , cerebellum
What is nystagmus
Response to rotational and angular acceleration in which the eyes go the opposite direction to maintain constant direction (slow component ) then go to the same direction to fix new position in space (rapid component )
Anosmia
Absence of smell
Hyposmia
Impaired sense of smell
Dysomia
Distorted sense of smell
Olfactory sense pathway
Odorant molecules -> cilia -> olfactory nerve -> cribiform plate -> olfactory bulb -> lateral and medial olfactory tract->
Ageusia
Absence of taste
Hypogeusia
Decreases taste sensitivity
Taste pathway
Chemical signal in taste buds -> CN IX (posterior 2/3) , CN VII (anterior 1/3), CN X (epiglottis , throat back ) -> brain stem -> solitary tract -> solitary nucleus of medulla -> thalamus -> taste cortex
Types of motoneurons
Alpha motoneurons
Gamma motoneurons
Alpha motoneurons innervate …
Extrafusal skeletal muscle fibers
Gamma motoneurons innervates…
Specialized intrafusal muscle fibers in muscle spindle ( adjust sensitivity )
Function of muscle spindle
Sense muscle length
Function of extrafusal fibers
Generate force , found in skeletal muscle
2 types of intrafusal fibers
Nuclear bag fibers Nuclear chains (more numerous )
Two types of gamma motoneurons
Static In chain fibers
Dynamic in in bag fibers
Group Ia innervates
Central region of nuclear bag and chain fibers
Function of group Ia afferent fibers
Detect velocity of length change
Send signal to alpha motoneurons to contract
Group II afferent innervates
Nuclear chain fibers
Group II afferent function
Detect length of muscle fiber
Golgi tendon organ function
Stretch receptor in tendons which senses contraction ( shortening ) and activate group Ib afferent -> inhibitory interneurons activated -> inhibit firing of a motoneurons -> relaxation of muscle
