The Ear 1
What are the three divisions of the ear and what do they include?
Outer: pinna to tympanic membrane
Middle: past tympanic membrane to oval window
Inner: cochlea
What is the pathway of a sound wave?
See notes
Describe the process of light activating the retina.
Light goes Ganglion -> Bipolar Cells -> Photoreceptors, then Signal goes Photoreceptors -> Bipolar Cells -> Ganglion -> optic nerve
What is glaucoma? (Vision)
Describe the cAMP pathway.
See p. 32 of notebook
What is the structure and function of the vestibule?
For balance. Saccule and utricle. Contain maculae- hair cells in hair gel with otoliths- that sense linear motion.
What is the organ of corti and how does it work?
In the scala media, hair cells extend into endolymph and touch the tectorial membrane. Frequencies of vibration bend the basilar membrane and cause the hair cells to bend against the tectorial membrane, leading to depolarization and a nerve impulse.
List the three tunics of the eye and what they are made of.
Fibrous: sclera, cornea
Vascular: choroid, iris, ciliary body
Sensory: retina
Explain three ways that endocrine glands can be stimulated.
Environmental/humoral: body chemistry; Neural: e.g. cortisol; Other hormones: tropism
Describe the PIP2 pathway.
See page 32 of notebook.
What is otitis media and how does it affect the ear?
Infection of the middle ear; can block eustachian tube so that middle ear pressure increases and ossicles don't move properly.
What are some potential causes of conduction deafness?
tympanic membrane rupture, arthritis of ossicles
What are the macula lutea, the fovea centralis, and the optic disc?
Regions of the retina. The fovea centralis is in the center of the macula lutea, and is the region of clearest vision (highest density of cones). The optic disc is where the optic nerve exits the eye, and it is a blind spot.
Compare and contrast the mechanisms of action for amino acid hormones and steroid hormones.
Amino acid hormones use a second messenger system. They bind to a receptor and activate a signal transducer, leading to an effector enzyme.
Steroid hormones enter the cell and form a hormone-receptor complex which binds to DNA and affects transcription. They work slower.
Describe the Renin Angiotensin Aldosterone pathway.
See p. 32 of notebook.
Anterior: yes
Lateral: no
Posterior: I don't know
What are some potential causes of nerve deafness?
cochlear nerve damage, presbycusis (damage to hair cells)
Compare and contrast rods and cones.
Rods: low light, high convergence, peripheral, rhodopsin
Cones: high light, low convergence, color vision, 3 types, iodopsins
What is the main function of the thymus, and where is it located?
Immune system maturation. It is located over the heart.
Stress causes the hypothalamus to secrete ______, which causes the anterior pituitary gland to secrete _____.
corticotropin-releasing factor, adrenocorticotropic hormone
What is motion sickness caused by?
What does tonotopic organization mean?
High-pitched sounds stimulate hair cells near the base of the cochlea; low-pitched sounds stimulate hair cells near the tip of the cochlea.
What are hyperopia and myopia and how are they corrected?
Hyperopia: far-sightedness, light does not focus within eye. Corrected with converging lens.
Myopia: near-sightedness, light focuses before reaching the retina. Corrected with diverging lens.
Which gland is the main regulator of sleep and wake cycles?
The pineal gland- melatonin
What causes Grave's disease and what are the symptoms?
Antibody acts like TSH to cause overactive thyroid. High metabolic rate, high heart rate, and weight loss.