Final Study guide

Anterior Chamber

- part of the anterior cavity
- Between the cornea and the iris
- holds aqueous humor

Aqueous Humor

Clear watery liquid

Choroid

- posterior part of vascular tunic
- Lines the interior of the sclera

Ciliary Body

- posterior to the iris at the junction of the cornea and scelera amd extends to the ora serrata

Ciliary Process

-Folds that protrude from th eciliary body towards the lens
- Contain capilaries that secrete aqueous humor, the fluid in the anterior chamber of the eye

Cornea

- Transparent atnterior portion that covers the iris, pupil, and sclera.

Inferior oblique

Moves eyes superiorly and laterally

Inferior rectus

Moves eyes inferiorly

Lateral Rectus

Moves eyes laterally

Medial Rectus

Moves eyes medially

Superior Oblique

Moves eyes inferiorly and laterally

Superior Rectus

Moves eyes superiorly

Fovea Centralis

- Middle of the macula lutea
- Highest density of cones
- not covered by ganglion and bipolar cell layers
- has the sharpest vision of any area of the eye

Iris

- anterior portion of of the vascular tunic
- contains pigmented cells
- controlls the pupil size

Lacriminal Gland

- Produces and secretes tears onto the eye surface

Lens

- Divides interior of eyeball into an anterior cavity and viterous chamber

Macula lutea

- center of neural portiomn of the retina

Optic Disc

- blind spot of the eye
- does not contain photoreceptors
- conatins centralis centralis

Optic Nerve

- II
- Sensory
- vision
- Axons form the ganglion cells extend through the optic disc and leave the eybal as the optic nerve

Posterior Cavity (vitreous chamber)

- larger
- Posterior cavity located between lens and the retina
- filled with viterous humor

Posterior chamber

-part of the anterior cavity
-Between iris and lens
- contains aqueous humor

Pupil

- The opening in th emiddle of the iris
- allowslight to enter the eyeball and change size in response to intensity of light

Retina

- (inner tunnic)
- begins at the ora serrata and continues posteriorly
- lining the interior of the choroid

Sclera

The tough white part of the eyes
majority of it

Vitreous Humor

- Gel like substance that holds the retina flat against the choroid

Auditory Ossicles

- small bones within the middle ear that are connected by synovial joints.
- They transfer vibrations from the tympanic membrane to the oval window

Malleus

- the outter most bone and is attatched to the tympanic membrane

Incus

- Middle bone and connects to the stapes

Stapes

- Innermost bone which connects to the incus and oval window

Auditory (Eustanchian) Tube

- connects the middle ear to the nasophyrnx and equalizes the air pressure of the middle ear with atmospheric air

Basilar Membrane

vibration patterns have the effect of separating incoming sound into its component frequencies that activate different cochlear regions.
- seperates the scala tympani from the cochlear duct

Cochlea

- the spiral are of the bony labyrinth anterior to the vestibule,
- plays a key role in the sense of hearing and participates in the process of auditory transduction

Cochlear Duct

- the section of membraneous labyrinth within the cochlea
- contains hearing receptors and is conected to the saccule

Endolymph

- The fluid within the membraneous labyryth.
- allows for our perception of balance and equilibrium

External Auditory Canal (Meatus)

conducts sound waves from the auricle to the tympanic membrane

Hair cells

located in the maculae
- convert, or transduce, mechanical stimuli evoked by sound and head movements into electrical signals which are transmitted to the brain.

Oval Window

- the membranecovered opening that seperates the middle and and inner ear.
- Transfers vibrations to the inner ear

Perilymph

- fluid that surrounds the membraneous labyrinth

Pinna (Auricle)

- flexible structure called the ear,
- collects soundwaves a directs them toward the external canal

Round window

- membrane covered openening that seperates between the middle ear and cochlea of the inner ear

Scala Tympani

- part of the cochleaand is posterior to the cohlear duct
- provides a pressure relief for movement of the cochlear fluid.

Scala Vestibuli

- part of the cochlea and is superiour to the cochlear duct.

Semicircular Canals

- 3 bony canals posterior to the vestibule that project posteriorly, laterally, and superiorly from vestibule

Spiral Organ (of corti)

- sits on the basilar membrane.
- It contains hair cells and supporting.

Tectorial Membrane

- Superior to and in contact with the streocilia
- provides for a second line of defense, preventing the odontoid process from compressing the spinal cord and by doing so, secondarily limits movement of the craniocervical juncture.

Tympanic Membrane

- eardrum converts sound waves to vibrations that are transfered to middle ear structures

Vestibular Membrane

- helps to transmit vibrations from fluid in the vestibular duct to the cochlear duct.
- Together with the basilar membrane, the vestibular membrane creates a compartment in the cochlea filled with endolymph

Vestibule

- The middle area of the bony labyrinth that contains 2 sections of membraneous labyrinth, labyrinth, the utricle and saccule

Vestibulocher Nerve

- VIII
- Sensory
- Hearing and equilibrium

General Senses

somatic (tactile, thermal, proprioceptive)
visceral (pressure, chemicals, stretch, nausea, hunger, temperature)

Senses senses

Smell, Taste, Tatse, Vision, Hearing, and Equilibrium

---Sensation---

Sensory Modalities

- Each type of sensation is called sensory modality
- Are either GENERAL or SPECIAL sences

Process of Sensation

1. Stim. of sensory recptor
2. Transduction of the stimulus
3. Generation of nerve impulse
4. Integration of sensory input in the CNS

Sensory Receptors

Gustatory receptor cells (taste buds)
Photoreceptors (retina)
Hair cells (in the inner ear)

-Free nerve endings

are used to detect pain, temperature, tickle, itch and some touch

Encapsulated nerve endings

are used to detect pressure, vibration and some touch

---Somatic Sensations---

Somatic/Tactile Sensations

S- Tactile thermal, pain, proprioceptive
T- Touch, pressure, vibration, itch, and tickle

Tactile Sensations

Tactile Corpuscles [swhann cells, dermal papillae] (touch and low frequency)
Hair root plexus [hairfollicle of skin] (movement on skin surface)
Nonencapsulated sensor corpuscles [epithelial cells in epidermis] (Continous touch and pressure)
Bulnous corpuscles [schwann cells in ligaments and tendons] (Skin stretching and pressure)
Lamellar corpuscles [tissue and joints] (High frequency vibration)
Itsch and tickle [skin and mucous membrane] (Itching and tickling)

Thermal Sensations

Warm/Cold recptors [Skin, mouth, vagina, anus] (Warm and cold)

Pain sensations

Nociceptors [every body tissue NOT in brain] (pain)

Proprioceptor sensation

Muscle spindles [
Tendon Organs
Joint Kinestethic recptors

---Maps in cerebral cortex--

---Somatic Motor Pathways---

Low motor neurons (LMNs)

- Nerves that extend out of the brain stem and spinal cord
- LMNs innervate skeletal muscles of the face and head through cranial nerves, and skeletal muscles of the limb and trunk through spinal nerves

4 distinct circuits of Somatic Motor pathways

* Local circuit neurons: located close to LMNs in the brain stem and spinal cord
* Upper motor neurons (UMNs): input to both lower circuit neurons and LMNs
* Basal nuclei neurons: assist movement by providing input to UMNs
* Cerebellar neurons: assist movement via control of activity of UMNs

Direct Motor Pathways

- Deliver signals to LMNs from the cerebral cortex, used for voluntary movement
1. Corticospinal pathways (the lateral corticospinal tract and the anterior corticospinal tract)
2. Corticobulbar pathway

Indirect Motor Pathways

- deliver signals to LMNs from motor centers in the basal nuclei, cerebellum and cerebral cortex
- Indirect motor pathways (extrapyramidal pathways): rubrospinal, tectospinal, vestibulospinal, lateral reticulospinal, and medial reticulospinal tracts

---Somatic Sensory Pathways---

Somatic Sensory Pathways

- carry information from somatic sensory receptors to the primary somatosensory area in the cerebral cortex and to the cerebellum

Order of somatic sensory pathways

- First-order neurons: impulses from somatic receptors to the brain stem or spinal cord
- Second-order neurons: impulses from the brain stem and spinal cord to the thalamus
- Third-order neurons: impulses from the thalamus to the primary somatosensory area of the cortex on the same side

Examples of Sensory pathways

- The posterior column-medial lemniscus pathway
• impulses from the limbs, trunk, neck and posterior head

- The anterolateral (spinothalamic) pathway
• impulses for pain, temperature, itch, tickle and posterior head

- The trigeminothalamic pathway
• impulses for most somatic sensations—tactile, thermal and pain—from the face, nasal cavity, oral cavity and teeth

---Funcrions of Cerebrum---

Wakefulness and sleep

- Relies on the reticular activating system (R A S)
- R E M sleep
- N R E M sleep

Coma

- A state of unconsciousness in which an individual has little to no response to stimuli

Learning and Memory

- Immediate
- Short-term
- Long-term memory

Language

-Wernicke’s association area
- Broca’s motor area

---Disorders---

Parkinson's Disease

- Mostly affects people around age 60
- Too little dopamine is produced
- Tremor
- Bradykinesia
- Hypokinesia

What are the general senses

1.pain
2. temperature
3. touch
4. pressure
5. vibration
6. proprioception.

What are the special sensces

1. Olfaction
2. Gustation
3. Vision
4. Hearing/Equilibrium

What Part of the brain deal with speciel sense

Frontal = Smell
Temporal = hearing
Occipital = sight
Parietal = sight
Insula = equilibrium

Olfaction

Sense of smell

Olfactory Receptors

- Receptors in the nasal mucosa send impulses along branches of olfactory (I) nerve
- Through the cribriform plate
- Synapse with the olfactory bulb
- Impulses travel along the olfactory tract
- Interpretation in the primary olfactory area in the cerebral cortex (temporal lobe)

Olfactory Hairs

- (columnar epithelium)
- Located in the mucous membrane lining the nose
- Used for physical support, nourishment and electrical insulation for olfactory receptor cells

Olfactory Glands/Bowmans glands

- produce mucus that is used to dissolve odor molecules so that transduction may occur

Odor Thresholds

- the lowest concentration of that chemical in air that people can smell

Olfactory Pathway

1. Odorant molecules dissolve in the mucous layer of the olfactory epithelium.
2. The chemicals bind to G-protein receptors on the cilia, causing a cascade of events to open ion gates to open. This makes the cell depolarize.
3. If the stimulus is strong enough, an AP will fire in the sensory neurons (sensory neurons are located in the olfactory epithelium). The sensory neuron will synapse onto the olfactory bulb.
4. The olfactory bulb will conduct AP's down the olfactory nerve/tract to the limbic system and olfactory cortex on the temporal lob
5. Smells are then sorted, identified, and discriminated from each other.

Gustation

Sense of taste

What are the 5 primary tatse

- Sour
- Sweet
- Bitter
- Salt
- Umami

Tatse Buds

- Contain recptors for the sensation of tatse
- Over 10,000 Found on soft palate, pharynx, and epiglottis
- Conatin 3 kinds of epithelial cells
~ Supporting cells
~ Gustatory Receptor cells
~ Basal stem cells
- Located in elevations on tounge called papillae

Vallate Papillae

- about 12 that contain 100–300 taste buds

Fungiform Papillae

- scattered over the tongue with about 5 taste buds each

Foliate Papillae

- located in lateral trenches of the tongue (most of their taste buds degenerate in early childhood)

Filiform Papillae

- Contain tactile receptors but no taste buds
- Increase friction to make it easier for the tongue to move food within the mouth

Tatse Threshold

the higher the stimulus concentration, the greater the perceived intensity of taste.
The front of tounge has the lowest thresehold

Gustatory Pathway

1. molecule to taste dissolves in saliva, reaching taste pore
2. molecule to taste, binds to receptor on gustatory hair
3. sends signal to dendrite of sensory neuron of cranial nerve 7,9,10
4. signal travels along nerve to the thalamus
5. thalamus relays signal to cerebral cortex
6. Taste detected at the gustatory cortex in the insula

3 craniel nerves with tatse

- Facial Nerve (VII): carries taste information from the anterior 2/3 of the tongue
- Glossopharyngeal ]nerve (IX): carries taste information from the posterior 1/3 of the tongue
- Vagus nerve (X): carries taste information from taste buds on the epiglottis and in the throat

Vision

To see