Describe the defecation reflex
What will be an ideal response?
When mass movements of the colon move fecal material into the rectum, the resultant distention of the rectum stimulates stretching receptors in the rectal wall, thus initiating the defecation reflex.?The defecation reflex causes the internal anal sphincter to relax and the rectum and sigmoid colon to contract more vigorously. If the external anal sphincter is also relaxed, defecation occurs
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A. cornea B. sclera C. choroid D. lens E. retina
Damage to the pyramidal cells of the cerebral cortex would directly affect
A) perception of pain. B) sight. C) voluntary motor activity. D) hearing. E) balance.
The Cervical Vertebrae are ________ to the Lumbar Vertebrae and ____________ to the neck muscles.
a) Superior, Deep b) Inferior, Deep c) Superior, Superficial d) Inferior, Superficial
John is a sprinter who specializes in quick and powerful bursts of speed followed by periods of rest. Jim is a marathon runner who specializes in long, steady runs. Compared to John's muscles, how are Jim's most likely to differ?
A. Jim's muscles will have more glycogen stored in his type IIb muscle fibers. B. Jim's muscles will have more mitochondria in his type I and IIa muscle fibers. C. Jim's muscles will have less myoglobin in his type I muscle fibers. D. Jim's type IIb fibers will be larger in diameter. E. Jim will have a greater proportion of type II muscle fibers and a lower proportion of type I fibers than John.