Olfaction
Smell.
Olfaction Process
Receptor → Cribriform Plate → Olfactory Bulb → Olfactory Tract → Olfactory Cortex (Temporal Lobe).
Gustation
Taste.
Main Tastes
Sour, Bitter, Salty, Sweet, Umami.
Which two tastes are most sensitive and a survival advantage.
Sour and Bitter.
Gustation Process
Tongue → Taste Bud → Gustatory Cells → Cranial Nerves → Gustatory Cortex.
Eyelid
Lubricates, keeps foreign objects out, and protects from the sun.
Eyelashes
Helps to keep foreign objects out of the eye.
Superficial epithelium (conjunctiva)
A thin layer of skin membrane that covers the front surface of the eye and lines the inside of the eyelids.
Lacrimal glands
Glands on eyelashes that produce tears, which help to give oxygen and nutrients to the conjunctiva.
Fibrous layer
The outermost layer of the eye, consisting of the sclera (white of the eye) and the cornea (transparent front part of the eye).
Vascular layer
The middle layer of the eye, consisting of the iris, choroid, and ciliary body.
Inner layer
The innermost layer of the eye, consisting of the retina, which contains the photoreceptor cells.
Anterior Cavity
Aqueous humor (watery).
Posterior Cavity
Vitreous humor (gel-like, ball shape)
Cornea
The transparent front part of the eye that refracts light.
Pupil
The opening in the center of the iris that allows light to enter the eye by changing the diameter of the opening.
Melanocytes in iris
Controls Pigments.
Lens
A transparent structure behind the iris that helps to focus light onto the retina and is accommodated by the ciliary body.
Fovea centralis
The central focus, provides the clearest image when the light bends and hits just above the optic nerve.
Dilation
The process of enlarging or widening the pupil.
Expansion
The process of increasing in size or expanding the pupil.
Accommodation
The ability of the lens to change shape in order to focus on objects at different distances from a clearer vision.
When an object is ______ the lens are rounded by muscle contraction of the ciliary body.
Close.
When an object is ______ the lens are flattened by muscle relaxation of the ciliary body.
Distant.
Presbyopia
The higher the age, the less lens elasticity.
Photoreceptors in the retina include ______.
Rods, cones, and a blind spot.
Rods
Photoreceptor cells in the retina that are responsible for vision in dim light and dull images in black and white vision.
Cones
Photoreceptor cells in the retina that are responsible for color vision and clear images in intense light.
Blind Spot
The area on the retina where the optic nerve exits the eye, which lacks photoreceptor cells in the optic disc.
Cones primary colors are ____.
Blue, green, red.
Vitamin A
A nutrient that is important for night vision, particularly for the function of the rods in the retina.
Retinol
A form of vitamin A that is found in the rods of the retina.
Visual cortex
The region of the brain, located in the occipital lobe, where visual information is processed.
Emmetropia
The normal condition of clear vision.
Myopia
Nearsightedness, where objects close to the viewer appear clear, but objects farther away appear blurry.
Hyperopia
Farsightedness, where objects farther away appear clear, but objects close to the viewer appear blurry.
Auricle (pinna)
The external part of the ear that funnels sound into the ear canal.
External Acoustic Meatus
The ear canal, which leads from the auricle to the eardrum.
Tympanic Membrane
The eardrum, a thin membrane that vibrates in response to sound waves.
Auditory Ossicles
The three small bones in the middle ear (malleus, incus, and stapes) that transmit sound vibrations from the eardrum to the inner ear.
Auditory Tube
A tube that connects the middle ear to the back of the throat, helping to equalize pressure on both sides of the eardrum.
Semicircular canals
Structures in the inner ear that are responsible for detecting rotational movements of the head and maintaining balance.
Vestibule
A structure in the inner ear that is responsible for detecting changes in linear acceleration and gravity.
Cochlea
A spiral-shaped structure in the inner ear that is responsible for hearing.
Functions of hearing in the cochlea
Captures and funnels sound → Vibrates → Senses sound & sends to brain via CNVIII (vestibulocochlear nerve).
In the cochlea there are ____.
Hair cells.
Function of equilibrium in the vestibule & semicircular ducts
It can sense gravity, acceleration, and rotation by not having stabilized fluid, which sends signals to your cerebellum.
Decibel
A unit used to measure the intensity of sound.
Conductive hearing loss
Hearing loss that occurs due to problems in the external or middle ear, which can often be temporary.
Sensorineural hearing loss
Hearing loss that occurs due to problems in the internal ear or central nervous system, which is often permanent; can use hearing aids.
Sensorineural hearing loss can be caused with damage to ____.
The Internal ear, CN VIII, or hair cells.
Which of the following statements accurately identifies disorders of the special senses?
Hearing: conductive and sensorineural hearing loss.
Which of the following is not a structure of the bony labyrinth?
Semicircular ducts.
What portion of the ear can sense gravity, acceleration, rotation, and sound?
Internal Ear.
Which cranial nerve does NOT carry gustatory information?
Hypoglossal.
Which of the following is NOT an accessory structure of the eye?
Aqueous humor.
What portion of the brain perceives visual images?
Visual cortex of the occipital lobe.
What is the term for the densely packed calcium carbonate crystals found in the macula?
Otoliths.
What is a characteristic of the middle layer of the eye?
Vascular.
Which of the following best compares olfaction and gustation?
Olfaction and Gustation are special senses. Olfaction is smelling and gustation is taste.
A blind spot occurs in the retina where ____.
Axons of ganglion cells converge at the optic nerve forming the optic disc.
Autonomic Nervous System
The part of the peripheral nervous system that controls involuntary bodily functions.
Efferent (Motor)
Nerve fibers that carry signals from the central nervous system to the peripheral nervous system.
Sympathetic
The branch of the autonomic nervous system responsible for the "fight or flight" response.
Parasympathetic
The branch of the autonomic nervous system responsible for the "rest and digest" response.
Both sympathetic and parasympathetic ____.
Lead to visceral effectors: smooth muscle, glands, cardiac muscles, and adipocytes.
Smooth muscle
Involuntary muscle found in the walls of organs and structures.
Glands
Organs that produce and secrete substances.
Adipocytes
Fat cells.
CNS
Just the cell body.
PNS
Preganglionic Neuron -> Autonomic Ganglion-> Cell body-> Postganglionic Neuron-> Visceral Effectors
Ganglia
Clusters of nerve cell bodies.
Sympathetic Structure
Ganglia close to spinal cord.
Parasympathetic Structure
Ganglia close to effector.
Sympathetic Nervous System
Excitation
Excitation
Means something is going on, isn’t always positive; stress.
Parasympathetic Nervous System
Inhibition
Inhibition
Keeps things from happening; rest.
Sympathetic Anatomy
Splanchnic Nerves
Splanchnic Nerves
Nerves that innervate the organs of the cardiopulmonary, abdominal, and pelvic regions.
Cardiopulmonary
Heart and lungs.
Abdominopelvic
Abdomen and all intestines.
Pelvic
Reproductive system and bladder.
Parasympathetic Anatomy
Vagus Nerve
Vagus Nerve
A cranial nerve that innervates the cardiac plexus, celiac plexus, and inferior mesenteric plexus.
Cardiac Plexus
Heart.
Celiac Plexus
Liver, pancreas, and gallbladder.
Inferior Mesenteric Plexus
Lower portion of organs and hypogastric plexus (below belly).
The parasympathetic nervous system can decrease _____, but can increase for the sympathetic nervous system.
Metabolism, heart rate, and blood pressure.
The sympathetic nervous system can decrease _____, but can increases for the parasympathetic nervous system.
Digestion and urinary function
Peraganglion Neurons
Sympathetic- Neurons that release acetylcholine (ACh) at the ganglion.
Preganglionic Neurons
Parasympathetic- Neurons that release acetylcholine (ACh) at the synapse with the ganglion.
Ganglion Neurons
Sympathetic- Neurons that release norepinephrine (NE) or epinephrine (E) into bloodstream and NE into the target organ.
Ganglionic Neurons
Parasympathetic- Neurons that release acetylcholine (ACh) into target organ.
Adrenergic receptors
Receptors that bind to norepinephrine (NE) and epinephrine (E); Alpha and Beta.
Alpha Receptor
NE, usually direct, and last a few seconds.
Beta Receptor
E, from bloodstream, and has a longer lasting effect.
Adrenergic receptors are usually only found in _____.
Sympathetic
Beta Blockers
Lower heart rate and contraction force, reducing heart workload.