Fourth Unit

Here are questions on Homeostasis:

1. What is positive feedback? Give an example. Are positive feedback mechanisms usually involved in maintaining homeostasis? Explain.
2. Explain how the surface area to volume ratio of an organism has an effect on heat dissipation or heat retention.
3. What cooling mechanisms are activated when the hypothalmus senses a body temperature above the set point?
4. What mechanisms are activated when body temperature falls below the set point?

Endocrine System Questions

5. Summarize the functional relationship between the hypothalamus and the anterior pituitary gland.

6. Besides the hormones they secrete, what distinguishes the anterior and posterior pituitary glands?

7.

Sketch the specific hormonal control between the hypothalamus, anterior pituitary and an endocrine organ, and include the negative feedback pathway. see figure for an example…

8. What effect does parathyroid hormone have on the body?

9. What hormones are secreted by the adrenal medulla, and what are their functions?

10. What are the two types of hormones secreted by the adrenal cortex, and what are their functions?

11. On what organ do estradiol and progesterone act?

12. The thyroid gland produces two hormones, triiodothyronine (T3) and thyroxine (T4). Explain how a lack of iodine in the diet may result in goiter, (an enlarged thyroid gland).

13. Determine the main functions of each of the hormones in the table below.

 

 

 

 

14. How does the adrenal gland signaled by the hypothalamus to respond to i) short-term stress, ii) long-term stress.

Nervous System Questions

15. What are the labeled parts to the neuron in the image? 

16. At resting potential, what is the principal cation inside the cell? and, outside the cell?

17. At resting potential, which side of the membrane has a negative charge?

18. Label the components of the action potential, the channels, and ions in the diagram below.

19. Identify the components of the chemical synapse following the depolarization of the synaptic terminal in the diagram below. 

20. Bonus test question on function of thalmus, corpus callosum, cerebrum, medulla oblongata, cerebellum.

21. What is saltatory conduction?

Questions on the Immune System

22. How is the great diversity of B and T cells produced?

23. What prevents B cells and T cells from reacting against the body’s own molecules?

24. Describe clonal selection.

25. What is immunological memory?

26. Activated helper T cells release cytokines. What do cytokines do to promote an immune response?

27. What does a cytotoxic T cell attached to an infected body cell release?

28. Label the components in the diagram below that shows a helper T cell being activated by interaction with an antigen presenting cell, and the helper T cell’s central role in activation of humoral and cell-mediated immunity.

29. Diagram the initiation of a specific immune response from the APC (antigen-presenting cell) to the activation of helper T cells, subsequent activation of naive B-cells and/or naive cytotoxic T-cells, including the MHC presentation of antigen and the BCR and TCR (cell receptors CD4 and CD8), clonal expansion of activated cells,  cells’ specific actions to immobilize or destroy the invading pathogen, and finally the development of immunological memory.

30. What is the speed and immunological reactivity of a second exposure compared to the first exposure of an antigen.