How many types of extracellular chemical messengers or signal molecules are used for indirect cell communication in the body?

a. two
b. three
c. four
d. five
e. six


c

Anatomy & Physiology

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The countercurrent mechanism in the nephron

A) creates a highly concentrated interstitial fluid so that urine can be concentrated by the collecting ducts when they are permeable to water. B) keeps interstitial fluid hydrated to maintain blood pressure. C) is a method to move sodium to control its concentration. D) keeps the volume of water lost in the urine relatively constant.

Anatomy & Physiology

The ABCDE rule is used for classifying burns

Indicate whether the statement is true or false

Anatomy & Physiology

Which of the following is the last step in the process of fertilization?

A. A sperm fuses with the egg's plasma membrane. B. The capacitated sperm release their acrosomal enzymes to penetrate through the cells surrounding the egg. C. The sperm nucleus enters the egg, and the egg immediately prevents any further sperm from gaining access by forming a fertilization membrane that a sperm cannot penetrate. D. The nuclei of the sperm and egg rupture within the fertilized egg and the chromosomes mix to form a single nucleus.

Anatomy & Physiology

Which part of the nervous system controls the movement of your hand as you take notes during an anatomy lecture?

A. Parasympathetic division B. Sympathetic division C. Somatic sensory division D. Somatic motor division E. Peripheral nervous system

Anatomy & Physiology