Term
| Subdivisions of Nervous System |
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Definition
Two major anatomical subdivisions
Central nervous system (CNS)
brain and spinal cord enclosed in bony coverings
Peripheral nervous system (PNS)
nerve = bundle of axons in connective tissue
ganglion = swelling of cell bodies in a nerve |
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Term
| Functional Divisions of PNS |
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Definition
Sensory (afferent) divisions (receptors to CNS)
visceral sensory and somatic sensory division
Motor (efferent) division (CNS to effectors)
visceral motor division (Autonomic NS)
effectors: cardiac, smooth muscle, glands
sympathetic division (action)
parasympathetic division (digestion)
somatic motor division
effectors: skeletal muscle |
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Term
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Definition
Motor nervous system controls glands, cardiac and smooth muscle
also called visceral motor system
Regulates unconscious processes that maintain homeostasis
BP, body temperature, respiratory airflow
ANS actions are automatic
biofeedback techniques
train people to control hypertension, stress and migraine headaches |
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Term
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Definition
Two divisions innervate same target organs
may have cooperative or contrasting effects
Sympathetic division
prepares body for physical activity
increases heart rate, BP, airflow, blood glucose levels, etc
Parasympathetic division
calms many body functions and assists in bodily maintenance
digestion and waste elimination |
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Term
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Definition
| Carries signals to the skeletal muscles. This output produces muscular contractions under voluntary control, as well as involuntary muscle contractions called somatic reflexes. |
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Term
| Directional Terms and Landmarks |
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Definition
Rostral: toward forehead
Caudal: toward spinal cord
Major parts: cerebrum, cerebellum, brainstem
cerebrum is 83% of brain volume
cerebellum contains 50% of the neurons
brain weighs 3 to 3.5 pounds |
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Term
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Definition
Gyri: folds
Sulci: grooves
Cortex: surface layer of gray matter
Nuclei: deeper masses of gray matter
Tracts: bundles of axons (white matter)
Longitudinal Fissure: separates the right and left hemispheres from each other
Central Sulcus: large deep groove or indentation that separates the parietal and frontal lobes.
Lateral Sulcus: large deep groove or indentation that separates the parietal and temporal lobes.
Transverse Fissure: separates the cerebrum from the cerebellum. |
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Term
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Definition
Dura mater:
outer periosteal layer against bone
where separated from inner meningeal layer forms dural venous sinuses draining blood from brain
Arachnoid mater:
more deep dura mater and superficial to pia mater
Pia mater:
closely envelops the entire surface of the brain |
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Term
| Anatomical Divisions of the Brain |
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Definition
Forebrain
Telencephalon
Cerebrum
Diencephalon
Thalamus, hypothalamus
Midbrain
Mesencephalon
Corpora quadrigemina
Hindbrain
Metencephalon
Pons, Cerebellum
Myelencephalon
Medulla oblongata |
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Term
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Definition
Cerebral cortex - 3mm layer of gray matter
extensive folds increase surface area - divided into lobes |
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Term
| Functions of Cerebral Lobes |
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Definition
Frontal
voluntary motor functions
planning, mood, smell and social judgement
Parietal
receives and integrates sensory information
Occipital
visual center of brain
Temporal
areas for hearing, smell, learning, memory, emotional behavior |
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Term
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Definition
Oval mass of gray matter protrudes into lateral ventricle and 3rd ventricle
23 nuclei receive nearly all sensory information on its way to cerebral cortex
Relays signals from cerebellum to motor cortex
Emotional and memory functions |
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Term
| Diencephalon: Hypothalamus |
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Definition
Walls and floor of 3rd ventricle
Functions
hormone secretion
autonomic NS control
thermoregulation
food and water intake (hunger and satiety)
sleep and circadian rhythms
memory (mammillary bodies)
emotional behavior
Mammillary bodies contain 3 to 4 nuclei that relay signals from limbic system to thalamus |
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Term
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Definition
Important gland of the endocrine system
Attached to the hypothalumus via the infundibulum
There are three divisions however you only need to know the following two:
Anterior pituitary (adenohypophysis)
Hypophyseal portal system
Posterior pituitary (neurohypophysis)
Median eminence |
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Term
| Diencephalon: Epithalamus |
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Definition
| Epithalamus consists of pineal gland (endocrine) and the habenula (connects limbic system to midbrain) |
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Term
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Definition
Corpora quadrigemina
Superior colliculus
Inferior colliculus |
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Term
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Definition
Bulge in brainstem, rostral to medulla
Ascending sensory tracts
Descending motor tracts
Pathways in and out of cerebellum |
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Term
| Metencephalon: Pons cont. |
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Definition
Nuclei
concerned with posture, sleep, hearing, balance, taste, eye movements, facial expression, facial sensation, respiration, swallowing, and bladder control
cranial nerves V, VI, VII, and VIII |
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Term
| Metencephalon: Cerebellum |
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Definition
Two hemispheres connected by vermis
Cortex: surface folds called folia
Output comes from deep gray nuclei
granule and purkinje cells |
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Term
| Metencephalon: Functions of the Cerebellum |
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Definition
Evaluation of sensory input
coordination and locomotor ability
spatial perception
Timekeeping center
predicting movement of objects
Distinguish pitch and similar sounding words
Planning and scheduling tasks |
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Term
| Myelencephalon: Medulla Oblongata |
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Definition
3 cm extension of spinal cord
Ascending and descending nerve tracts
Nuclei of sensory and motor CNs (IX, X, XI, XII) |
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Term
| Myelencephalon: Medulla Oblongata cont. |
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Definition
Cardiac center
adjusts rate and force of heart
Vasomotor center
adjusts blood vessel diameter
Respiratory centers
control rate and depth of breathing
Reflex centers
for coughing, sneezing, gagging, swallowing, vomiting, salivation, sweating, movements of tongue and head |
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Term
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Definition
12 pair of nerves
arise from brain
exit through foramina leading to muscles, glands and sense organs in head and neck
Input and output ipsilateral except CN II and IV |
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Term
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Definition
Sense of smell
Damage causes impaired sense of smell |
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Term
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Definition
Provides vision
Damage causes blindness in visual field |
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Term
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Definition
Eye movement, opening of eyelid, constriction of pupil, focusing
Damage causes drooping eyelid, dilated pupil, double vision, difficulty focusing and inability to move eye in certain directions |
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Term
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Definition
Eye movement (superior oblique muscle)
Damage causes double vision and inability to rotate eye inferolaterally |
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Term
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Definition
Sensory to face (touch, pain and temperature) and muscles of mastication
Damage produces loss of sensation and impaired chewing |
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Term
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Definition
Provides eye movement (lateral rectus m.)
Damage results in inability to rotate eye laterally and at rest eye rotates medially |
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Term
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Definition
Motor - facial expressions; salivary glands and tear, nasal and palatine glands
Sensory - taste on anterior 2/3’s of tongue
Damage produces sagging facial muscles and disturbed sense of taste (no sweet and salty) |
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Term
| Vestibulocochlear nerve VIII |
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Definition
Provides hearing and sense of balance
Damage produces deafness, dizziness, nausea, loss of balance and nystagmus |
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Term
| Glossopharyngeal nerve IX |
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Definition
Swallowing, salivation, gagging, control of BP and respiration
Sensations from posterior 1/3 of tongue
Damage results in loss of bitter and sour taste and impaired swallowing |
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Term
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Definition
Swallowing, speech, regulation of viscera
Damage causes hoarseness or loss of voice, impaired swallowing and fatal if both are cut |
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Term
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Definition
Swallowing, head, neck and shoulder movement
damage causes impaired head, neck, shoulder movement; head turns towards injured side |
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Term
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Definition
Tongue movements for speech, food manipulation and swallowing
if both are damaged – can’t protrude tongue
if one side is damaged – tongue deviates towards injured side; see ipsilateral atrophy |
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Term
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Definition
| Old Opie Occasionally Tries Trigonometry And Feels Very Gloomy, Vague, And Hypoactive |
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Term
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Definition
| Some Say Marry Money But My Brother Says Big Brains Matter More |
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Term
External Structures
of the eye |
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Definition
Conjunctiva
Transparent mucous membrane lines eyelids and covers anterior surface of eyeball except cornea
Richly innervated and vascular (heals quickly)
Lacrimal apparatus- the system that secretes and drains tears.
Lacrimal Gland- releases tears
Lacrimal Punctum- holes in medial eye that drain tears into lacrimal canal
Lacrimal Canal- tubes that lead from the lacrimal punctum to lacrimal sac
Lacrimal Sac- collect tears and leads them into nasolacrimal duct.
Nasolacrimal duct- tube that runs from lacrimal sac to the nasal cavity that drains tears. |
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Term
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Definition
Aqueous humor: Produced by the ciliary body, flows to posterior chamber through the pupil to anterior chamber - reabsorbed into canal of Schlemm (also known as the scleral venous sinus)
Vitreous humor (body): Transparent jelly that fills the large space behind the lens. |
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Term
| Fibrous Tunic Outermost layer of the eye, made of dense avascular connective tissue |
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Definition
Sclera- Tough, fibrous, white outer protective covering.
Purpose: Surrounds the eye and gives it shape; gives muscles a surface to anchor to.
Structure: Where pierced by optic nerve, continuous with the dura mater of the brain
Cornea- Crystal clear window of the eye
Purpose: Allows light into the eye; begins the bending process of the light.
Structure: Innervated with nerves |
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Term
| Vascular Tunic Middle coat of the eye. Also called Uvea (grape) |
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Definition
Choroid- Highly vascular membrane
Purpose: provides nutrition to all of the eye tunics
Structure: Full of melanocytes that absorb stray light.
Ciliary body- Thickened, anterior portion of the choroid.
Purpose: controls lens shape
Structure: Contains ciliary muscles
Iris- Visible colored part of the eye
Purpose: controls size of the pupil
Pupil- round central opening
Purpose: allows light into the eye |
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Term
| Sensory Tunic The innermost tunic |
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Definition
Retina- light sensitive tissue lining the inner surface of the eye. Outgrowth of the diencephalon
Pigmented Layer- Single cell thick layer of the retina
Purpose: absorbs light and prevents it from scattering
Neural Layer- Contains millions of photoreceptor cells
Purpose: transduce light energy
Optic Nerve- Carries signals from eye to brain for interpretation |
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Term
| Purpose: Produce finely detailed images |
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Definition
Optic disc- “blind spot” Does not contain Photoreceptors. Located where optic nerve leaves the eye
Fovea Centralis- Spot on the retina most dense with cones. |
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Term
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Definition
Lens- located behind the iris. Lens shape can be adjusted by ciliary bodies to focus light on retina.
Rods- Responsible for peripheral and night vision. Cannot detect colors or fine details. There are approx. 130 million rods per human retina
Cones- Responsible for detecting color and fine detail. There are approx. 6.5 million cones per human retina. (Cones=Color) |
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Term
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Definition
Cornea (allows light in, begins process of bending light)
Aqueous Humor
Iris controls the size of the pupil, which then allows light into the eye
Ciliary body adjusts lens shape, allowing lens to focus light to the retina
Vitreous Humor, then cell layers
Pigmented layer of the retina absorbs light to prevent it from scattering. Photoreceptor cells in the neural layer then convert the light energy
Optic Nerve then carries signals from eye to brain for interpretation |
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Term
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Definition
Conjunctivitis- More commonly known as “pink eye”. Inflammation of the conjunctiva. Can be caused by bacterial infection, allergies, and irritants.
Glaucoma- Blindness due to damage of the optic nerve. Most often caused by pressure on the optic nerve, causing it’s blood supply to diminish and the nerve to atrophy.
Xeropthamalia –Corneal degeneration and progressive, irreversible blindness of the eye
Cataracts- Clouding of the lens. Occurs as we age. Leading cause of blindness.
Color blindness- inability to perceive difference between certain colors (most common is red/green color blindness). Most often genetic, but can be caused by environmental factors.
Myopia- “near sightedness”- can see close up but not far away objects.
Hyperopia- “far sightedness”- can see far away objects but not close up. |
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Term
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Definition
Fleshy auricle (pinna) directs air vibrations down external auditory meatus
cartilagenous and bony, S-shaped tunnel ending at eardrum
glandular secretions and dead cells form cerumen (earwax) |
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Term
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Definition
Air-filled tympanic cavity in temporal bone between tympanic membrane and oval window
continuous with mastoid air cells
Contains
auditory tube (eustachian tube) connects to nasopharynx
equalizes air pressure on tympanic membrane
ear ossicles
malleus
incus
stapes
stapedius and tensor tympani muscles attach to stapes and malleus |
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Term
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Definition
Bony labyrinth - passageways in temporal bone
Membranous labyrinth - fleshy tubes lining bony tunnels
filled with endolymph (similar to intracellular fluid)
floating in perilymph (similar to cerebrospinal fluid) |
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Term
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Definition
Control of coordination and balance
Receptors in vestibular apparatus
semicircular ducts contain crista
saccule and utricle contain macula
Static equilibrium
perceived by macula
perception of head orientation
Dynamic equilibrium
perception of motion or acceleration
linear acceleration perceived by macula
angular acceleration perceived by crista |
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Term
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Definition
Contain macula
hair cells with stereocilia and one kinocilium buried in a gelatinous otolithic membrane
otoliths add to the density and inertia and enhance the sense of gravity and motion |
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Term
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Definition
Static equilibrium - when head is tilted, weight of membrane bends the stereocilia
Dynamic equilibrium – in car, linear acceleration detected as otoliths lag behind |
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Term
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Definition
Scala media (cochlear duct)
separated from
scala vestibuli by vestibular membrane
scala tympani by basilar membrane
Spiral organ
(Organ of Corti) |
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Term
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Definition
Stereocilia of hair cells attach to gelatinous tectorial membrane
Inner hair cells
hearing
Outer hair cells
adjust cochlear responses to different frequencies
increase precision |
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Term
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Definition
Tectorial Membrane: gelatinous substance that rests on top of the stereocilia (not to be confused with true cilia).
Basilar Membrane: thick substance that separates the cochlear duct from the scala tympani below. |
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Term
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Definition
Muscle belly
Made up of multiple fasicles
Fascicle
Made up of multiple muscle fibers
Muscle fiber
Myofiber = muscle cell |
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Term
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Definition
Organized in a precise way in skeletal and cardiac muscle
A band – dark – A stands for anisotropic
Part of A band where thick and thin filaments overlap is especially dark
H band in the middle of A band – just thick filaments
M line is in the middle of the H band
I band – alternating lighter band – I stands for isotropic
The way the bands reflect polarized light
Z disc – provides anchorage for thin filaments and elastic filaments
Bisects I band
Sarcomere – the segment of the myofibril from one z disc to the next |
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Term
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Definition
Motor unit – one nerve fiber and all the muscle fibers innervated by it
Muscle fibers of one motor unit
Dispersed throughout the muscle
Contract in unison
Produce weak contraction over wide area
Provides ability to sustain long-term contraction as motor units take turns contracting (postural control)
Effective contraction usually requires the contraction of several motor units at once
Small motor units - fine degree of control
Large motor units – more strength than control |
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Term
| Muscle Contraction & Relaxation |
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Definition
Four major phases of contraction and relaxation
Excitation
The process in which nerve action potentials lead to muscle action potentials
Excitation-contraction coupling
Events that link the action potentials on the sarcolemma to activation of the myofilaments, thereby preparing them to contract
Contraction
Step in which the muscle fiber develops tension and may shorten
Relaxation
When its work is done, a muscle fiber relaxes and returns to its resting length
Figures 11.8 to 11.11 in textbook; APR animations (Muscular systems> Animations) |
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Term
| Phases of a Twitch Contraction |
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Definition
Latent period - 2 msec delay between the onset of stimulus and onset of twitch response
Time required for excitation, excitation-contraction coupling and tensing of elastic components of the muscle
Internal tension – force generated during latent period and no shortening of the muscle occurs
Contraction phase – phase in which filaments slide and the muscle shortens
Once elastic components are taut, muscle begins to produce external tension – in muscle that moves a load
Short-lived phase
Relaxation phase - SR quickly reabsorbs Ca+2, myosin releases the thin filaments and tension declines
Muscle returns to resting length
Entire twitch lasts from 7 to 100 msec |
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Term
| Recruitment and Stimulus Intensity |
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Definition
Stimulating the nerve with higher and higher voltages produces stronger contractions
Higher voltages excite more and more nerve fibers in the motor nerve which stimulates more and more motor units to contract
Recruitment or multiple motor unit (MMU) summation – the process of bringing more motor units into play |
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Term
| Twitch Strength & Stimulus Frequency |
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Definition
When stimulus intensity (voltage) remains constant twitch strength can vary with the stimulus frequency
Up to 10 stimuli per second
Identical twitches
Full recovery
10-20 stimuli per second produces treppe (staircase) phenomenon
Muscle still recovers fully between twitches, but each twitch develops more tension than the one before
Stimuli arrive so rapidly that the SR does not have time between stimuli to completely reabsorb all of the Ca+2 it released |
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Term
| Incomplete and Complete Tetanus |
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Definition
20-40 stimuli per second produces incomplete tetanus
temporal summation – results from two stimuli arriving close together
wave summation – results from one wave of contraction added to another
each twitch reaches a higher level of tension than the one before
muscle relaxes only partially between stimuli
produces a state of sustained fluttering contraction called incomplete tetanus |
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Term
| Isometric and Isotonic Contractions |
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Definition
Isometric muscle contraction
Muscle is producing internal tension while an external resistance causes it to stay the same length or become longer
Can be a prelude to movement when tension is absorbed by elastic component of muscle
Important in postural muscle function and antagonistic muscle joint stabilization
Isotonic muscle contraction
Muscle changes in length with no change in tension
Concentric contraction – muscle shortens while maintains tension
Eccentric contraction – muscle lengthens as it maintains tension |
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Term
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Definition
Active force - force produced when a muscle is stimulated to contract
Passive force - muscles are elastic (like a rubber band), due to the protein titin
When stretched, they will rebound to regain shape |
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Term
| Overview of neurophysiology |
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Definition
Structure of neuron:
Large cells with long cell processes
Dendrites - branched
Axons – unbranched
Surrounded by smaller glial cells lacking processes
Glial cells protect neurons and help them function
Function: pathway for signals between brain and the rest of the body
Location: brain, spinal cord, nerves and ganglia |
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Term
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Definition
Dendrites
Highly branched sensory processes that extend out from the cell body
Non-myelinated
Receives information, typically from other neurons
Cell Body
Body or soma of a neuron that contains the nucleus and other organelles |
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Term
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Definition
Axons - myelinated extension of a neuron that propagates an action potential
Myelin – insulation or sheath around an axon, which increases the speed of an action potential
provided by 2 different glial cells
Gaps in the sheath are known as Nodes of Ranvier |
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Term
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Definition
Myelin helps to propagate the electrical signal along the length of the axon
Starts new Action Potential at each Node |
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Term
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Definition
Oligodendrocytes
Insulate neurons from the extracellular fluid in the central nervous system
This speeds up signal conduction.
Schwann cells
Sheath peripheral neurons
Similar function as Oligo’s but also assist in regeneration of damaged fibers |
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Term
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Definition
Gray matter
Neuron cell bodies
Dendrites
Synapses
White matter
Axons
Myelin is white |
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