How Much Do You Know About Human Physiology?

• Skin can be divided into apical (glabrous) and non-apical (hairy) skin.
• Apical skin has high surface-to-volume ratio, controlled by sympathetic fibers, and has arterio-venous (a-v) anastomoses or AV shunts that play an important role in temperature regulation.
• Non-apical skin lacks a-vanastomoses and has two types of sympathetic neurons, vasoconstriction and vasodilation.
• White reaction and triple response are mechanical stimuli that elicit local vascular responses in the skin.
• Blood flow of the uterus parallels metabolic activity and undergoes cyclic fluctuation. Blood flow increases rapidly during pregnancy.
• Placenta has four layers and allows the transfer of many drugs and dietary substances, and also has many functions such as transfer, respiratory, excretory, nutritive, barrier, immunological, and endocrinal.
• Fetal circulation, fetal respiration, and adult circulation have differences such as the presence of shunts that allow oxygenated blood to bypass the right ventricle and pulmonary circulation.
• 55% of the fetal cardiac output goes through the placenta, and the fetal RBC contains fetal hemoglobin (hemoglobin F) that binds 2,3-DPG less effectively than hemoglobin A does.1. Fetal circulation has three shunts to supply the heart and brain.

2. Fetal cardiac output is 3 times higher than that of an adult at rest.
3. Changes in fetal circulation occur after birth.
4. The left ventricle must deliver the entire systemic cardiac output after birth.
5. Cardiovascular changes occur when standing due to gravity.
6. Compensatory mechanisms attempt to increase blood pressure to normal.
7. Muscle blood flow increases during exercise.
8. Local metabolic mechanisms regulate skeletal muscle blood flow during exercise.
9. The concentration of 2,3-DPG in the RBC is increased during exercise.
10. Potassium dilates arterioles in exercising muscle.1. Mediators released by vascular endothelium affect arteriolar tone of skeletal muscle.
11. Nitric oxide, adenosine triphosphate, adenosine, prostaglandins, and endothelium-derived hyperpolarization factors are among the regulatory molecules.
12. Nitric oxide affects arteriolar tone of skeletal muscle.
13. Adenosine triphosphate affects arteriolar tone of skeletal muscle.
14. Adenosine affects arteriolar tone of skeletal muscle.
15. Prostaglandins affect arteriolar tone of skeletal muscle.
16. Endothelium-derived hyperpolarization factors affect arteriolar tone of skeletal muscle.
17. Mediators released by vascular endothelium should probably be listed as regulatory molecules.
18. These regulatory molecules affect the arteriolar tone of skeletal muscle.
19. The regulatory molecules listed include nitric oxide, adenosine triphosphate, adenosine, prostaglandins, and endothelium-derived hyperpolarization factors.

Test your knowledge on the fascinating world of human physiology with this quiz covering diverse topics such as skin, placenta, fetal circulation, and regulatory molecules affecting arteriolar tone of skeletal muscle. Challenge yourself with questions on the differences between apical and non-apical skin, the role of AV shunts in temperature regulation, the functions of the placenta, and the shunts present in fetal circulation. Additionally, explore the regulatory molecules that affect arteriolar tone of skeletal muscle during exercise, including nit