Each of the special senses can be expected to decline in some way over time. Describe some of the changes commonly seen in the function of the special senses with age
Olfactory receptors are reduced in number and olfactory glands decline in activity. Both changes reduce olfactory acuity. Gustatory sense declines with a decline in the number of taste buds and taste receptors. Vision suffers from a loss of retinal function, clouding of lens and cornea, and loss of lens elasticity, leading to senile hyperopia (presbyopia). Hearing declines due to accumulation of cerumen, scarring of the tympanum, arthritis of the ossicular chain, and loss of proximal hair cells in the organ of Corti, leading to high-tone deafness. Balance declines due to nerve problems, fluid problems, and vascular problems, leading to faulty or delayed vestibular information. That decline coupled with a sluggish and weak motor response increases the risk of falls and consequent trauma.
You might also like to view...
Cholesterol-containing lipoproteins are cleared from the blood by which process?
A. Na+ gradient-dependent, secondary active transport B. Clathrin-dependent, receptor-mediated endocytosis C. Simple, transcellular membrane diffusion D. Hydrophobic phagocytosis E. Second messenger-activated, sterol transgenesis
Passive movement of water and solutes from the plasma to the capsular space of kidney corpuscles is a process known as __________
Fill in the blank with correct word.
The muscle that causes an action is the
A) antagonist. B) mediator. C) synergist. D) agonist.
The descending limb of the loop of Henle is where
a. NaCl passively leaves the tubular fluid down its concentration gradient. b. NaCl is actively transported into the interstitial fluid, leaving water behind because the tubular cells are not permeable to water. c. K+ is secreted. d. aldosterone stimulates Na+ reabsorption. e. water is reabsorbed