Term
|
Definition
| Approx 1 inch in diameter |
|
|
Term
| How many sensory receptors are in the eye? |
|
Definition
| 70% of all sensory receptors |
|
|
Term
|
Definition
| A cushion of fat and the bony orbit |
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|
Term
|
Definition
|
|
Term
| Levator palebrae superioris |
|
Definition
| gives the upper eyelid mobility |
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|
Term
|
Definition
|
|
Term
|
Definition
| move the eyebrows downward and medially; wrinkles forehead |
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|
Term
| Extrinsic Eye Muscles: Purpose |
|
Definition
| Enable the eye to follow moving objects. Maintains the shape of the eyeball |
|
|
Term
| Extrinsic Eye Muscles: Origin |
|
Definition
| Four rectus muscles originate from the annular ring. Superior oblique originates from the annular ring |
|
|
Term
| Names of the 4 rectus eye muscles |
|
Definition
| Lateral, Medial, Superior, Inferior |
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|
Term
| Name of the two oblique eye muscles |
|
Definition
|
|
Term
| Action of the Lateral rectus |
|
Definition
|
|
Term
| Action of the medial rectus |
|
Definition
|
|
Term
| Action of the superior rectus |
|
Definition
| Elevates eye and turns it medially |
|
|
Term
| Action of the Inferior rectus |
|
Definition
| Depresses eye and turns it medially |
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|
Term
| Action of the inferior oblique |
|
Definition
| Elevates eye and turns it laterally |
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|
Term
| Action of the superior oblique |
|
Definition
| Depresses eye and turns it laterally |
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|
Term
| Controlling cranial nerve of the Lateral Rectus |
|
Definition
|
|
Term
| Controlling cranial nerve of the Medial rectus |
|
Definition
|
|
Term
| Controlling cranial nerve of the Superior rectus |
|
Definition
|
|
Term
| Controlling cranial nerve of the Inferior rectus |
|
Definition
|
|
Term
| Controlling cranial nerve of the Inferior Oblique |
|
Definition
|
|
Term
| Controlling cranial nerve of the Superior Oblique |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Palpebrae(Eyelids) Function |
|
Definition
| Protect the eye anteriorly. Act as windshield wipers |
|
|
Term
|
Definition
|
|
Term
| How are the eyelids supported internally? |
|
Definition
| By tarsal plates of connective tissue |
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|
Term
|
Definition
| Project from the free margin of each eyelid. Initiate reflex blinking |
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|
Term
| Lubricating glands associated with the eyelids |
|
Definition
| Ciliary glands, Gland of Zeis, Meibomian or Tarsal glands, Lacrimal caruncle |
|
|
Term
|
Definition
| Lie between hair folliciles, protective film keeps tears from overflowing |
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|
Term
|
Definition
|
|
Term
| Meibomian or Tarsal glands |
|
Definition
| secrete an oily substance that lubricates eyelids preventing the lids from sticking together |
|
|
Term
|
Definition
| contains glands that secrete a whitish, oily secretion, (Sandman's eye sand) |
|
|
Term
|
Definition
| Transparent membrane that lines the eylids as the palpebral conjuctiva. Lubricates and protects the eye immunologically |
|
|
Term
| Conjuctiva: What does it cover? |
|
Definition
| the whites of the eyes as the bulbar or ocular conjuctiva |
|
|
Term
| Lacrimal apparatus: What does it consist of? |
|
Definition
| the lacrimal gland and associated ducts |
|
|
Term
| What do the lacrimal glands secrete? |
|
Definition
|
|
Term
|
Definition
| mucus, antibodies, and lysozyme |
|
|
Term
| How do tears enter the eye? |
|
Definition
| Via superolateral excretory ducts |
|
|
Term
| How do tears exit the eye |
|
Definition
| Medially via the lacrimal punctum |
|
|
Term
| Where do the tears drain into? |
|
Definition
| The nasolacrimal duct - collected in the nasal cavity |
|
|
Term
| What is the structure of the eyeball? |
|
Definition
| A slightly irregular hollow sphere with anterior and posterior poles |
|
|
Term
| What is the wall of the eye composed of? |
|
Definition
|
|
Term
| What are the three tunics of the eye? |
|
Definition
| Fibrous, vascular, and sensory |
|
|
Term
| The internal cavity of the eye is filled with what? |
|
Definition
|
|
Term
| How is the internal cavity separated? |
|
Definition
| By the lens into anterior and posterior segments |
|
|
Term
| Where is the fibrous tunic located? |
|
Definition
| The outermost coat of the eye |
|
|
Term
| What is the fibrous tunic composed of? |
|
Definition
| Opaque sclera, Clear Cornea |
|
|
Term
| Is the opaque sclera posterior or anterior? |
|
Definition
|
|
Term
| Is the clear cornea anterior or posterior? |
|
Definition
|
|
Term
| What is the function of the sclera? |
|
Definition
| Protects the eye and anchors extrinsic muscles |
|
|
Term
| What is the function of the cornea? |
|
Definition
|
|
Term
| Vascular tunic: Other name |
|
Definition
|
|
Term
| Regions of the Vascular Tunic |
|
Definition
| Choroid, Ciliary body, Iris |
|
|
Term
|
Definition
| A dark brown membrane that forms the posterior portion of the uvea |
|
|
Term
|
Definition
| supplies blood to all eye tunics |
|
|
Term
|
Definition
| Thickened ring of tissue surrounding the lens |
|
|
Term
|
Definition
| non-neuronal area of the retina |
|
|
Term
| Ciliary body: composition |
|
Definition
| Smooth muscle bundles (ciliary muscles) |
|
|
Term
|
Definition
| anchors the suspensory ligament that holds the lens in place |
|
|
Term
|
Definition
|
|
Term
|
Definition
| central opening of the iris |
|
|
Term
|
Definition
| regulates the amount of light entering the eye |
|
|
Term
| When do pupils constrict? |
|
Definition
| Close vision and bright light |
|
|
Term
|
Definition
| Distant vision and dim light. Changes in emotional state. When subject matter is appealing or requires problem-solving skills |
|
|
Term
| How is the Parasympathetic system related to the pupil? |
|
Definition
| Constricts the pupil via the sphincter pupillae muscle |
|
|
Term
| How is the sympathetic system involved with the pupil? |
|
Definition
| Dilates the pupil via the dilator pupillae muscle |
|
|
Term
| Sensory Tunic: Retina - how many layers? |
|
Definition
|
|
Term
|
Definition
| the outer layer that absorbs light and prevents its scattering |
|
|
Term
| Neural layer contains what? |
|
Definition
| Photoreceptors that transduce light energy. Bipolar cells and ganglion cells. Amacrine and horizontal cells. |
|
|
Term
| What are the two layers of the Retina? |
|
Definition
| Pigmented and neural layer |
|
|
Term
| What are the two layers of the Retina? |
|
Definition
| Pigmented and neural layer |
|
|
Term
| What are the two types of photoreceptors? |
|
Definition
|
|
Term
|
Definition
| Respond to dim light. Used for peripheral vision |
|
|
Term
|
Definition
| Respond to bright light, have high-acuity color vision, found in the macula lutea, concentrated in the fovea centralis |
|
|
Term
|
Definition
| Run along the inner surface of the retina. Leave the eye as the optic nerve |
|
|
Term
|
Definition
| Where the optic nerve leaves the eye. Lacks photoreceptors (the blind spot) |
|
|
Term
| Blood supply to the retina: Neural retina |
|
Definition
| Outer third receives from the choroid. Inner 2/3 served by the central artery and vein |
|
|
Term
| Posterior segment: Filled with what? |
|
Definition
| Clear gel called vitreous humor |
|
|
Term
|
Definition
| Transmits light, supports the posterior surface of the lens, Holds the neural retina firmly against the pigmented layer, contributes to intraocular pressure |
|
|
Term
| Anterior Segment - What are the two chambers called? |
|
Definition
|
|
Term
| How are the two anterior chambers divided? |
|
Definition
Anterior - cornea and iris
Posterior - iris and lens |
|
|
Term
|
Definition
| Plasmalike fluid that fills the anterior segment |
|
|
Term
| How does the Aqueous humor drain? |
|
Definition
|
|
Term
| What is the role of Aqueous humor? |
|
Definition
| Supports, nourishes and removes wastes |
|
|
Term
|
Definition
| A biconvex, flexible, avascular structure |
|
|
Term
|
Definition
| Allows precise focusing of light onto the retina |
|
|
Term
| What is the lens composed of? |
|
Definition
| Epithelium and lens fibers |
|
|
Term
|
Definition
| anterior cells that differentiate into lens fibers |
|
|
Term
|
Definition
| Cells filled with the transparent protein crystallin |
|
|
Term
| What happens to the lens with age? |
|
Definition
| Becomes more compact and dense and loses its elasticity |
|
|
Term
|
Definition
| process by which the eye detects light energy |
|
|
Term
| What do rods and cones contain? |
|
Definition
| Visual pigments (photopigments) |
|
|
Term
| How are the visual pigments arranged? |
|
Definition
| In a stack of disklike infoldings of the plasma membrane that change shape as they absorb light |
|
|
Term
| Functional characteristics of Rods |
|
Definition
| Sensitive to dim light and best suited for night vision. Absorb all wavelengths of visible light. Perceived input is in gray tones only. Sum of visual input from many rods feeds into a single ganglion cell. Results in fuzzy and indistinct images |
|
|
Term
| Functional characteristics of Cones |
|
Definition
| Need bright light for activation (have low sensitivity), have pigments that furnish a vividly colored view, each cone synapses with a single ganglion cell, vision is detailed and has high resolution |
|
|
Term
| Electromagnetic radiation |
|
Definition
| all energy waves from short gamma rays to long radio waves |
|
|
Term
|
Definition
| A light-absorbing molecule |
|
|
Term
| What do retinal and opsin combine to form? |
|
Definition
|
|
Term
| What is retinal synthesized from? |
|
Definition
|
|
Term
| What are the two isomers of Retinal? |
|
Definition
|
|
Term
| What does isomeriziaton of retinal initate? |
|
Definition
| Electrical impulses in the optic nerve |
|
|
Term
| What is the visual pigment of rods? |
|
Definition
| Rhodopsin (opsin + 11 cis retinal) |
|
|
Term
| Excitation of rods: Light phase |
|
Definition
| Rhodopsin breaks down into all trans retinal + opsin (bleaching of the pigment) |
|
|
Term
| Excitation of Rods: Dark phase |
|
Definition
| All-trans retinal converts to 11-cis form. |
|
|
Term
| How is rhodopsin regenerated? |
|
Definition
|
|
Term
| Excitation of cones: Similarities to rods |
|
Definition
| Visual pigments are similar (retinal + opsin). Excitation is similar |
|
|
Term
|
Definition
|
|
Term
| How are intermediate colors perceived? |
|
Definition
| Activation of more than one type of cone |
|
|
Term
| Signal Transmission: Step 0 |
|
Definition
| Photoreceptors and bipolar cells only generate graded potentials |
|
|
Term
| Signal Transmission: Step 1 |
|
Definition
| Light hyperpolarizes photoreceptor cells |
|
|
Term
| Signal Transmission: Step 2 |
|
Definition
| Hyperpolarization ceases release of inhibitory neurotransmitter glutamate |
|
|
Term
| Signal Transmission: Step 3 |
|
Definition
| Bipolar cells (no longer inhibited) are then allowed to depolarize and release neurotransmitter onto ganglion cells |
|
|
Term
| Signal Transmission: Step 4 |
|
Definition
| Ganglion cells generate APs that are transmitted in the optic nerve |
|
|
Term
| Phototransduction: Step 1 |
|
Definition
| Light energy splits rhodopsin into all-trans retinal, releasing activated opsin. |
|
|
Term
| Phototransduction: Step 2 |
|
Definition
| Freed opsin activates the G protein transducin |
|
|
Term
| Phototransduction: Step 3 |
|
Definition
| Transducin catalyzes activation of phophodiesterase (PDE) |
|
|
Term
| Phototransduction: Step 4 |
|
Definition
| PDE hydrolyzes cGMP to GMP and releases it from sodium channels |
|
|
Term
| Phototransduction: Step 5 |
|
Definition
| Without bound CGMP, sodium channels close, the membrane hyperpolarizes, and neurotransmitter cannot be released. |
|
|
Term
| Visual Pathways: What do the axons of retinal ganglion cells form? |
|
Definition
|
|
Term
| Where do the medial fibers of the optic nerve decussat? |
|
Definition
|
|
Term
| Where do most fibers of the optic tracts continue to? |
|
Definition
| The lateral geniculate body of the thalamus |
|
|
Term
| Where do Opticr adiations travel from? |
|
Definition
| The thalamus to the visual cortex |
|
|
Term
| Cortical Processing: Primary visual cortex |
|
Definition
| Basic dark/bright and contrast information |
|
|
Term
| Cortical processing: Prestriate cortices (visual associations areas) |
|
Definition
| Form, color, and movement |
|
|
Term
| What are the two streams the visual information proceeds to anteriorly? |
|
Definition
| Ventral and Dorsal stream |
|
|
Term
|
Definition
| Temporal lobe - processes identification of objects |
|
|
Term
|
Definition
| Parietal cortex and post central gyrus - processes spatial location |
|
|
Term
|
Definition
| gustation (taste) and olfaction (smell) |
|
|
Term
|
Definition
| Proteins found on the outside of cells that bind to chemical or other proteins |
|
|
Term
| What happens during binding with chemoreceptors? |
|
Definition
| Sets off a chain of intracellular events that result in signal being sent to the brain |
|
|
Term
| How do chemoreceptors respond to chemicals in regards to taste? |
|
Definition
| Via substances dissolved in saliva |
|
|
Term
| How do chemoreceptors responds to chemicals in regards to smell? |
|
Definition
| Substances dissolved in fluids of the nasal membranes |
|
|
Term
| What is the organ of smell? |
|
Definition
|
|
Term
| What does the olfactory epithelium cover? |
|
Definition
| The superior nasal concha |
|
|
Term
| What are olfactory receptor cells? |
|
Definition
| Bipolar neurons with radiating olfactory cilia |
|
|
Term
| What are olfactory receptors surrounded and cushioned by? |
|
Definition
|
|
Term
| Where do basal cells lie? |
|
Definition
| At the base of the epithelium |
|
|
Term
| What do olfactory cells synapse with? |
|
Definition
|
|
Term
| What processes odor signals? |
|
Definition
|
|
Term
| What do mitral cells send impulses to? |
|
Definition
| The olfactory cortex, the hypothalamus, amygdala, and limbic system |
|
|
Term
| Physiology of smell: Step 1 |
|
Definition
| Odorant bind to its receptor |
|
|
Term
| Physiology of smell: Step 2 |
|
Definition
| Receptor activates Gprotein |
|
|
Term
| Physiology of smell: Step 3 |
|
Definition
| G protein activates adenylate cyclase |
|
|
Term
| Physiology of smell: Step 4 |
|
Definition
| Adenylate cyclase converts ATP to cAMP |
|
|
Term
| Physiology of smell: Step 5 |
|
Definition
| cAMP opens a cation channel allowing Na+ and Ca+ influx and causing depolarization which triggers an AP |
|
|
Term
| Where are many of the taste buds found? |
|
Definition
| Of the 10,000 most are found on the tongue |
|
|
Term
| Where are taste buds found? |
|
Definition
| In papillae of the tongue mucosa |
|
|
Term
| What are the three types of papillae? |
|
Definition
| Filiform, fungiform, and circumvallate |
|
|
Term
| Which papillae contain taste buds? |
|
Definition
| Fungiform and circumvallate |
|
|
Term
| Structure of a taste bud: What three major cell types make up a taste bud? |
|
Definition
| Supporting cells, Basal cells, Gustatory cells |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| What must occur for a chemical to be tasted? |
|
Definition
| Must be dissolved in saliva, must contact gustatory hairs |
|
|
Term
| What occurs with the binding of the food chemical? |
|
Definition
| Depolarizes the taste cell membrane, releasing neurotransmitter which initiates a generator potential that elicits an action potential |
|
|
Term
| Which nerves carry impulses from the taste buds to the solitary nucleus of the medulla? |
|
Definition
| Cranial Nerves VII (facial) and IX (glossopharygneal) |
|
|
Term
| Where do the impulses travel after reaching the solitary nucleus of the medulla? |
|
Definition
| Branch to the gustatory cortex, hypothalamus and limbic system |
|
|
Term
|
Definition
|
|
Term
| Hypothalamus and limbic system |
|
Definition
|
|
Term
| How much does smell influence taste? |
|
Definition
|
|
Term
| Which receptors influence taste? |
|
Definition
| Heat (thermo-), touch (mechano-), and pain (noci-) |
|
|
Term
| What other variables affect taste? |
|
Definition
|
|
