Which muscle closes the anal opening?
A) pubococcygeus
B) external anal sphincter
C) coccygeus
D) external urethral sphincter
B
Explanation:
A) The pubococcygeus tenses the floor of the pelvis, flexes the coccygeal joints, and elevates and retracts the anus.
C) The coccygeus flexes the coccygeal joints and tenses the pelvic floor.
D) The external urethral sphincter muscle closes the urethra.
Exercise 19: Post-Lab Questions
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The reduced estrogen levels found in postmenopausal women are responsible for the onset of physical changes that affect the skeleton, called ________.
Fill in the blank(s) with the appropriate word(s).
Cell adhesion molecules that protrude from the inner endothelial lining and causes leukocytes to marginate are called ________
Fill in the blank(s) with correct word
Declination on the Celestial Sphere is analogous to _______ on Earth.
a) latitude b) longitude c) right ascension d) No answer text provided.
Energy transformations increase the entropy of a system is a statement of the ________.
A. second law of thermodynamics B. first law of thermodynamics C. law of mass action D. law of conservation of energy