The ability of a specific tissue or organ to respond to a hormone is dependent on…

Which cell type is in the central nervous system and is most responsible for controlling the chemical environment around neurons, especially by reinforcing the blood-brain barrier?

The perineurium…

Which brain structure contains the major centers that control heart rate, blood pressure, and breathing?

Movement of which of the following ions is the most important in establishing resting membrane potential?

Bone is a dynamic tissue, with new bone deposition and bone resorption occurring every day. This process is called

Glands, such as the thyroid, that secrete their products directly into the blood rather than through ducts are classified as ____________ glands.

The wide variety of possible structures of proteins allows them to have a wide variety of functions.

Name the two myofilaments that make up a sarcomere. Describe the structure of these two filaments in detail. (3 pts) Describe how these two filaments interact to enable a muscle to contract. Discuss what steps need to take place in order for the filaments to interact and how they interact during contraction.  (4 pts) Imagine an individual whose skin did not produce vitamin D. Vitamin D is essential for calcium absorption from ingested foods. How would a lack of vitamin D production affect muscle contraction within this individual? (2 pts) A soil bacterium has the ability, under low-oxygen conditions, to release a toxin that causes increased binding of acetylcholine to receptors on the sarcolemma. How might this toxin affect muscles? (1 pt)

Extra Credit: A deceased individual was found on the beach of the Pacific Ocean. The number of solutes in ocean water (saltwater) is higher than the number of solutes in human cells. Your job is to determine if this individual drowned in the Pacific Ocean or in a body of freshwater with less solutes than human cells (bathtub, pond, lake, etc.). A person who drowned in freshwater but found in saltwater is indication of a potential homicide. During the autopsy, lung cells are found swollen, and many had ruptured (lysed). In what type of water, freshwater or seawater, did the individual drown? Explain how you reached your conclusion for full credit.