This Makes Sense
I can detect changes outside or inside the body and am the basis for responses.
Sensation
What is the pathway for your sense of smell?
Olfactory nerves to olfactory bulbs to olfactory areas in the temporal lobe.
What is the point of eyelids and eyelashes?
What is the point of lacrimal glands?
Protection, keep dust/dirt out
Produce tears to wash the eye and prohibit growth of bacteria
The eyeball has cavities, anterior and posterior.
Where is the vitreous humor located and what is it's purpose?
Where is the aqueous humor located and what is it's purpose? Where is it reabsorbed into the blood?
Posterior cavity which is between the lens and the retina and it keeps the retina in place (semisolid)
Anterior cavity between the cornea and the lens and it nourishes the lens and cornea (liquid)
Canal of Schlemm
1. The ear has three major areas, what are they? outer, middle, and inner
2. The inner ear contains the receptors for two senses: hearing and equilibrium
Which cranial nerve is this?
1. Inner, middle, outer
2. Hearing and equilibrium
3. 8th cranial nerve (Vestibulocochlear/Acoustic)
Receptors – detect a change.
Sensory neurons – transmit impulses.
Sensory tracts – white matter in the CNS.
Sensory area – in the CNS; feels and interprets the sensation.
What does this describe?
Sensory Pathway
Taste buds on the tongue contain what?
Chemoreceptors
The eyeball is within the orbit of the skull.
Six extrinsic muscles move the eyeball.
Movement of these muscles work in tandem with which Cranial nerves?
3rd, 4th, and 6th
Table 9.1 pg. 215
Rods contain rhodopsin, which do what?
Breaks down to scotopsin and retinal, at which point an electrical impulse is generated.
1. What are the main parts of the outer ear?
2. What are the three auditory bones in the middle ear, what do they do?
3. From the middle ear cavity to the nasopharynx it helps stabilizes air pressure and allows ear drum to vibrate
4. A cavity called Bony labyrinth which is lined with the membranous labyrinth, within the temporal bone.
1. Auricle/Pinna (Cartilage covered by skin) and Ear canal (curves down and forward into temporal bone)
2. malleus (Hammer), incus (Anvil), stapes (Stirrup)-All transmit vibrations to inner ear at oval window.
3. Eustachian tube
4. Inner ear
What are the five characteristics of sensations?
Give an example of at least three.
1. Projection – the sensation seems to come from the area where receptors were stimulated.
Example: touching your book
2. Intensity – the degree to which a sensation is felt.
Example: dim light vs. bright sunlight
3. Contrast – the effect of a previous or simultaneous sensation on a current sensation.
Example: jumping into pool on a hot day
4. Adaptation – becoming unaware of a continuing stimulus.
Example: wearing a watch
5. After-image – remaining aware of a sensation after the stimulus has stopped.
Example: flash on a camera
Knowing where our muscles are without looking at them is muscle sense.
Detect stretching of muscles?
Sensory areas for conscious muscle sense?
Coordinates voluntary movements?
Stretch receptors
Parietal lobes
Role of the cerebellum
What are the three layers of the wall of the eyeball?
The sclera(outer most layer), the choroid(middle layer), and the retina(Inner most layer).
Within the retina are the rods and cones, how do cones work?
Specific wavelengths of light are absorbed (red, blue, green) chemical reactions generate nerve impulses.
1. Perilymph?
2. Endolymph?
3. Name the membranous structures of the inner ear and their main function.
1. fluid between bone and membrane
2. fluid within membranous structures
3. Cochlea (snail shape/hearing), Utricle (Equilibrium), Saccule (Equilibrium), Semicircular canals (Equilibrium)
Free nerve endings in the dermis are receptors for: pain, heat, itch, cold.
Encapsulated nerve endings are receptors for what?
Touch and Pressure
Which cranial nerves are responsible for taste and in what lobes of the brain are their impulses interpreted?
facial and glossopharyngeal
Parietal and Temporal
Below are the functions of the different parts of the retina, what are they:
1. Detect light and are abundant toward periphery of retina.
2. Detect color; abundant in center of retina.
3. In the center of the macula lutea; contains only cones; area of best color vision.
4. No rods or cones; optic nerve passes through eyeball
1. Rods
2. Cones
3. Fovea
4. Optic disc
In front of the hypothalamus; the medial fibers of the optic nerves cross here, this allows for binocular vision.
Optic chiasma
Contains the organ of Corti.
Hair cells (Stereocilia).
Cochlear duct
Receptors for hearing within the organ of Corti
Visceral pain that is felt as cutaneous pain?
Referred Pain
Receptors for hunger and thirst (visceral/internal sensations) are located where?
Hypothalamus
Name the part of the eye with each of the following functions:
1. Change the shape of the lens?
2. Contains the rods and cones?
3. Forms the white of the eye?
4. Form the optic nerve?
5. Changes the size of the pupil?
6. Absorbs light within the eyeball to avoid glare?
1. Ciliary body (Muscle)
2. Retina
3. Sclera
4. Ganglion neurons
5. Iris (Two sets of smooth muscle fibers)
6. Dark blue pigment (Choroid layer)
1. Summarize the nerve pathway for the optic tracts
2. Summarize how the visual area creates one image
1. Branches take impulses to the midbrain, converge at the thalamus and continue to the occipital lobe.
2. Each area receives impulses from both eyes, both areas create one image from the slightly different areas, both areas right the upside down retinal image.
Summarize how soundwaves/vibrations are transmitted through the ear
Ear drum, malleus, incus, stapes, oval window of the inner ear, perilymph and endolymph within the cochlea, ripples in the Basilar membrane which push hair cells of the organ of corti against the tectorial membrane, this generates impulses that are carried from the 8th cranial nerve to the brain, to the temporal lobe, where sounds are heard and interpreted.