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Name all CRANIAL NERVES

• CN I: Olfactory nerve: Sense of smell 

• CN II: Optic nerve: Vision 

• CN III: Oculomotor nerve: Controls most eye movements, including pupil constriction 

• CN IV: Trochlear nerve: Controls downward and inward eye movements 

• CN V: Trigeminal nerve: Sensation of the face and controls chewing muscles 

• CN VI: Abducens nerve: Controls outward eye movement 

• CN VII: Facial nerve: Controls facial expressions, taste from the front of the tongue, and salivary glands 

• CN VIII: Vestibulocochlear nerve: Hearing and balance 

• CN IX: Glossopharyngeal nerve: Taste from the back of the tongue, gag reflex, and swallowing 

• CN X: Vagus nerve: Sensations and movements of organs in the chest and abdomen, as well as the gag reflex 

• CN XI: Accessory nerve: Controls muscles in the neck and shoulders 

• CN XII: Hypoglossal nerve: Controls tongue movements

Arrange the following to reflect the correct sequence an action potential would follow to reach the lateral olfacory area of the brain
1. olfactory bulb
2. olfactory cortex
3. olfactory epithelium
4. olfactory tract

3,1,4,2

Why does inhaling deeply and slowly through the nose help to identify an odor?

more air containing the odor is brought into contact with the olfactory epithelium

In order for a molecule to be detected by the olfactory neurons, it must

be dissolved in fluid covering the olfactory epithelium

the lateral olfactory area

is the site of conscious perception of odors

What are the special senses?

vision, hearing, taste, smell and equlibrium

Sensory structures that detect taste are

taste buds

Which type of papilli are not associated with the taste buds?

filiform

Which are the most sensitive taste buds found in the tongue?

foliate

Damage to which cranial nerves would impair the sense of taste?

facial

What are gustatory cells?

taste receptor cell: convert chemical compounds from food into electrical signals to the brain

If you taste a cake frosting with the tip of your tongue, the sensations are carried by which cranial nerve?

facial nerve

What are palpebrae?

eyelids

What is the purpose of the blink reflex?

hydrate and take out debris

What do you call inflammation of the ciliary glands of the eyelashes?

blepharitis

Pink eye is the inflammation of what structure?

conjunctiva

What do we call the transparent mucous membrane that covers the anterior surface of the eye?

bulbar conjunctiva

When are tears produced and what do they do?

irritation and emotion and they lubricate, wash out dust and release stress

Why does someone’s nose run when they cry?

tears drain into the tear ducts into the nasal cavity and mix with mucus

What are the nerves that innervate the eye muscles?

oculomotor (3), trochlear (4), abducens (6)

What is the outermost tunic of the eyeball?

fibrous tunic or the sclera

What do we call the transparent anterior portion of the sclera?

cornea

What would increase fluid accumulation in the cornea result in?

corneal edema: cloudy or blurry vision, halos, light sensitivity, vision loss

Why is the cornea relatively easy to transplant?

avascular

What part of the eye is the vascular tube?

uvea

What is the ciliary body attached to?

lens via zonular fibers and to sclera

If you have bright sunlight entering your eye, what structures control the amount of light?

iris

What is the contractile structure that surrounds the pupil?

iris

What do we call the area of greatest visual acuity?

fovea centralis

What is optic disc?

where the optic nerve connects to the retina

What is fovea centralis?

provides high acuity vision

What is blindspot?

area of vision that is unseen, optic nerve entry

What is macula lutea?

provide detailed, color vision for tasks like reading and driving

• yellow spot in center of the retina

Where do we find the Canal of Schlemm? What does it prevent?

junction of cornea and sclera. it collects aqueous humor to prevent a buildup of fluid that increases IOP (prevents galucoma)

What separates the anterior and posterior compartments of the eye?

iris

What functions are carried out by both aqueous and vitreous humor?

keep eyeballs shape, nutrients, remove waste and provide a clear path for light to retina

What is the function of the vitreous humor?

maintain eyes transparent gel like structure, keep retina in place

What is glaucoma?

vision loss and blindness if untreated. group of eye conditions damaging the optic nerve like IOP pressure

What should happen to the lens to focus on objects further than 20 feet?

ciliary muscles relax, lens flattens and becoms thinnger

What happens to the lens if you try to focus on the tip of your nose?

thicker and more curved or spherical

What factor affects depth of focus?

pupil size, visual acuity, age, target contrast and accomodation

What is the pigmented layer of the retina?

retinal pigment epithelium

What could cause night blindness?

vitamin A deficiency

What does light and dark adaptation involve?

process by which eyes adjust to different light conditions by changing their sensitivity

What cells are responsible for color vision?

cone cells

Why are humans able to distinguish several million shades of color?

red green and blue cones

where are photo receptors located

retina

Damage to the left side of the brain near the visual cortex would result in which changes?

loss of vision in right side

If all vision in left eye is lost, what was damaged?

optic nerve

What is myopia?

distant objects are blurry

What is hyperopia?

close objects are blurry

What is Presbyopia?

loss of focus on close objects

What is Astigmatism?

cornea or lens is football shaped so light is focused on multiple points in the retina

Which portion of the ear contains sense portions for hearing and balance?

vestibulocochlear nerve

Where does the external ear end at?

tympanic membrane

What is the function of the auditory tube and what is the other name for it?

eustachian tube

What structures transmit vibrations from the eardrum to the oval window?

ossicles (MIS)

Where do we find the organ of corti?

cochlea

Where are the sensory cells for hearing located?

in the organ of corti

Which nerve carries auditory impulses to the vestibulocochlear nerve?

What determines the position of the head with respect to gravity?

vestibular system and utricle and saccule

What helps a person detect movement in all directions?

vestibular system

If you have damage to the vestibular branch of your vestibulocochlear nerve, what problem will that cause?

balance

What is the function of the nervous system?

receive sensory input, send motor output

What part of the nervous system is responsible for problem solving skills?

CNS- cerebrum

What is the central nervous system comprised of?

brain and spinal cord

What does the peripheral nervous system include?

cranial, spinal nerves and their branches

How many pairs of cranial nerves and spinal nerves do we have?

12 cranial; 31 spinal

Where are the cell bodies of the peripheral nervous system located?

ganglia, neuron

Where does the sensory or afferent division of the peripheral nervous system convey action potentials to?

axon: generate and conduct action potentials

Where does the motor division transmit impulses to?

CNS to peripheral organs

What regulates digestion of food?

parasympathetic division of ANS

Where does protein synthesis in neurons occur in?

Cell bodies or soma

What are dendrites?

Are the input part of the neuron

What is the function of axons?

-Help with the cable transmission between neurons.
-Have a distal portion that branches to form the presynaptic terminals

What do synaptic vesicles contain? Which terminal are they found in?

Contain neurotransmitters and are present in the presynaptic terminals

What neuron carries action potentials from one neuron to another?

Interneuron

What are unipolar neurons? Bipolar? Multipolar? Pseudopolar?

Unipolar: One axon which extends into dendrites
Bipolar: one axon and one dendrite (sensory afferent neurons)
Multipolar: One axon with two or more dendrites
Pseudounipolar: Single short process that splits into two axons (no dendrites)

What are neuroglia? Which cells are part of this group?

• Major support tissue in CNS
  -Part of the blood-brain barrier (Astrocyte)
  -Neuroglia form myelin sheaths arounds some axons
  -Produce cerebrospinal fluid

What is the blood brain barrier? How does it function?

Protects neurons from toxic substances in the blood

What kind of substances pass through the blood brain barrier?

water, small ions, lipophilic molecules, essential polar molecules

What are the phagocytic cells in the CNS called?

microglia- small & scarce cells; activated by injury into wandering phagocytic cells within CNS; ingest disease-causing microorganisms, dead neurons, and cellular debris.

What is the condition in which neuroglia cells damage the myelin sheath?

Demyelination is damage or loss of the myelin sheath around axons.

• multiple sclerosis

Define the following cells: microglia, astrocytes, oligodendrocytes, ependymal cells, Schwann cells.

• Microglia: activated by injury/ phagocytic cells/ ingest disease causing microorganisms

• Astrocytes: blood-brain barrier/ transports nutrients & gases between blood vessels and neurons.

• Oligodendrocytes: Form Myelin

• Ependymal Cells: Manufacture and circulate cerebrospinal fluid.

• Schwann Cells: encircle axons found in PNS to provide them with myelination.

What is saltatory conduction?

leaping along myelinated axon with nodes of Ranvier

What are the nodes of Ranvier?

gap between adjacent neuroglia; where myelin sheath is absent

What is white matter? Gray matter?

• White matter: composed of myelinated axons that appear white

• Gray matter: composed of neuron cell bodies, un-myelinated dendrites and axons that appear gray

If you cut bundles of axons and their myelin sheaths in the PNS, what have you cut?

nerves

If the flu virus increases membrane permeability to potassium, what would the cell undergo in terms of its charge? Permeability to sodium?

If increase of permeability to potassium the cell will become more negative. Permeability to sodium, cell becomes more positive.

What is a local potential?

• small local changes in potential of a neuron's plasma membrane; serve as vital triggers for long-distance action potentials
  - graded potential

What is depolarization? Hyperpolarization?

• Depolarization - more positive

• Hyperpolarization - more negative

Voltage gated sodium channels are sensitive to change in the extracellular concentration of which ions?

Sodium and potassium

What factor increases or decreases in direct proportion to the stimulus strength?

Action potential

When you have a rapid influx of sodium ions into a nerve cell membrane, what follows?

depolarization

When does an action potential occur?

AP reaches treshold

What do we mean by an "all or none" response?

one threshold is reached a AP will or will not be conducted

When repolarization of a neuron is complete, what happens to that neuron?

cell goes back to resting membrane potential, ions are at equilibrium

Burn patients are more likely to suffer from what condition due to destruction of cells and release of their contents?

Infection contraction

What happens during an absolute refractory period?

no additional stimulus (no matter how strong) is able to produce an additional action potential

As the strength of a stimulus is increased, what happens to the frequency of action potentials?

frequency rate increases