Exam 1 bio 202
1. What is an endocrine gland?
An endocrine gland is a ductless gland that releases hormones into the bloodstream.
2. What is an exocrine gland?
An exocrine gland releases substances through ductsonto a surface or into a body cavity.
3. What is the main difference between endocrine and exocrine glands?
Endocrine = hormones into blood.
Exocrine = secretions through ducts.
4. How does neural control differ from hormonal control?
Neural control uses electrical impulses, is usually rapid, and has short-lasting effects. Hormonal control uses hormones in the blood, is generally slower, and has longer-lasting effects.
5. What are the major endocrine organs?
Hypothalamus, pituitary gland, thyroid, parathyroid glands, adrenal glands, pancreas, pineal gland, thymus, ovaries, and testes.
6. Where is the pituitary gland located?
At the base of the brain, just below the hypothalamus.
7. Where is the thyroid gland located?
In the front of the neck, below the larynx.
8. Where are the adrenal glands located?
On top of the kidneys.
9. Where is the pancreas located?
Behind the stomach.
10. How are most hormones regulated?
Through negative feedback, where the hormone's effects reduce the original stimulus for hormone release.
11. What is negative feedback?
A response that reduces or reverses the original stimulus.
12. What is positive feedback?
A response that increases the original stimulus.
13. What is the relationship between the hypothalamus and pituitary gland?
The hypothalamus controls the pituitary and links the nervous system to the endocrine system.
14. What does the anterior pituitary produce?
GH, TSH, ACTH, FSH, LH, and prolactin.
15. What hormones are released by the posterior pituitary?
ADH and oxytocin.
16. Where are ADH and oxytocin actually produced?
They are produced by the hypothalamus and stored/released by the posterior pituitary.
17. What does ADH do?
It helps the kidneys retain water, helping regulate blood volume and blood pressure.
18. What does oxytocin do?
It stimulates uterine contractions and milk ejection.
🧬 LESSON 2 — Hormones
19. What are the two major chemical categories of hormones?
Steroid and nonsteroid hormones.
20. What are steroid hormones made from?
Cholesterol.
21. Can steroid hormones cross the cell membrane?
Yes. They are lipid-soluble and can cross the membrane.
22. Where do steroid hormones bind to receptors?
Inside the cell, usually in the cytoplasm or nucleus.
23. Can nonsteroid hormones cross the cell membrane easily?
No. They usually bind to receptors on the cell membrane.
24. What is a second messenger?
A molecule inside a cell that carries a hormone's signal from a membrane receptor to the inside of the cell.
25. What is a circulating hormone?
A hormone that enters the bloodstream and travels to distant target cells.
26. What is a local hormone?
A hormone that acts near the site where it was released.
27. What is a paracrine?
A local chemical messenger that acts on nearby cells.
28. What is an autocrine?
A chemical messenger that acts on the same cell that released it.
Thyroid
29. What hormones does the thyroid produce?
T3 and T4 and calcitonin.
30. What do T3 and T4 do?
They increase metabolic activity and are important for growth and development.
31. What does calcitonin do?
It helps lower blood calcium levels.
32. What does PTH do?
Parathyroid hormone raises blood calcium levels.
33. What hormones are produced by the adrenal cortex?
Aldosterone, cortisol, and adrenal androgens.
34. What does aldosterone do?
It promotes sodium and water retention and helps regulate blood pressure.
35. What does cortisol do?
It helps the body respond to stress and affects metabolism and blood glucose.
36. What hormones are produced by the adrenal medulla?
Epinephrine and norepinephrine.
37. What do epinephrine and norepinephrine do?
They help produce the fight-or-flight response, including increased heart rate.
Pancreas
38. What does insulin do?
Lowers blood glucose by helping cells take up glucose.
39. What does glucagon do?
Raises blood glucose by stimulating glucose release into the blood.
Gonads
40. What hormones do the ovaries produce?
Primarily estrogen and progesterone.
41. What hormone do the testes primarily produce?
Testosterone.
Other glands
42. What does the pineal gland produce?
Melatonin.
43. What does melatonin help regulate?
The sleep-wake/circadian rhythm.
44. What is the function of the thymus?
It produces hormones involved in T-cell development and immune function.
45. How does aging affect the endocrine system?
Hormone production and the body's sensitivity to some hormones can change, affecting metabolism, reproduction, glucose regulation, and stress responses.
🩸 LESSON 3 — Blood
46. What is extracellular fluid?
Fluid located outside cells.
47. What are the two major extracellular fluid compartments?
Plasma and interstitial fluid.
48. What is whole blood made of?
Plasma and formed elements.
49. What are the formed elements of blood?
Red blood cells, white blood cells, and platelets.
50. Why is blood classified as connective tissue?
Because it consists of cells suspended in an extracellular matrix, which is plasma.
51. What is plasma?
The fluid portion of blood.
52. What is plasma mostly made of?
Mostly water, plus proteins, electrolytes, nutrients, hormones, gases, and wastes.
53. What are the three major plasma proteins?
Albumin, globulins, and fibrinogen.
54. What does albumin do?
Helps maintain osmotic pressure and fluid balance.
55. What does fibrinogen do?
It is important for blood clotting.
RBCs
56. What is the main function of erythrocytes?
To transport oxygen and carbon dioxide.
57. What protein allows RBCs to carry oxygen?
Hemoglobin.
58. What is the shape of an RBC?
A biconcave disc.
59. Why is the biconcave shape useful?
It provides a large surface area for gas exchangeand helps the cell remain flexible.
60. Do mature RBCs have a nucleus?
No.
61. What is hematopoiesis?
The process of blood cell production.
62. Where does hematopoiesis primarily occur?
In red bone marrow.
WBCs
63. What is the main function of leukocytes?
Defense and immunity.
64. What are the five major types of WBCs?
Neutrophils, lymphocytes, monocytes, eosinophils, and basophils.
65. Which WBC is most abundant?
Neutrophils.
66. What do neutrophils do?
They primarily perform phagocytosis, especially against bacteria.
67. What do lymphocytes do?
They are important for immune responses.
68. What do monocytes become when they enter tissues?
They can become macrophages.
69. What are eosinophils associated with?
Parasites and allergic reactions.
70. What are basophils associated with?
Inflammation and histamine release.
Platelets & Clotting
71. What are platelets?
Small cell fragments involved in blood clotting.
72. Where do platelets come from?
They are fragments of megakaryocytes in bone marrow.
73. What is hemostasis?
The process of stopping bleeding.
74. What are the three major steps of hemostasis?
Vascular spasm → platelet plug formation → coagulation.
75. What happens during vascular spasm?
The damaged blood vessel constricts.
76. What happens during platelet plug formation?
Platelets stick to the damaged area and each other, forming a temporary plug.
77. What happens during coagulation?
A series of reactions produces fibrin, which strengthens the clot.
78. What is the difference between the intrinsic and extrinsic pathways?
The intrinsic pathway is activated by factors within the blood, while the extrinsic pathway is triggered by tissue damage. Both lead to the common pathway and clot formation.
Blood Types
79. What determines ABO blood type?
The presence or absence of A and B antigens on RBCs.
80. What antigens does type A blood have?
A antigens.
81. What antibodies does type A have?
Anti-B antibodies.
82. What antigens does type B have?
B antigens.
83. What antibodies does type B have?
Anti-A antibodies.
84. What antigens does type AB have?
A and B antigens.
85. What antibodies does type AB have?
Neither anti-A nor anti-B.
86. What antigens does type O have?
Neither A nor B antigens.
87. What antibodies does type O have?
Anti-A and anti-B.
Blood Disorders
88. What is anemia?
A condition involving too few RBCs or inadequate hemoglobin, reducing oxygen-carrying capacity.
89. What is leukemia?
A cancer involving blood-forming tissues and abnormal production of blood cells, especially WBCs.
90. What is thrombocytopenia?
An abnormally low platelet count, which can increase bleeding risk.
91. What is hemophilia?
An inherited disorder involving deficient clotting factors that causes impaired clotting.
❤ LESSON 4 — HEART
92. Where is the heart located?
In the mediastinum, between the lungs.
93. What direction does the apex of the heart point?
Downward and toward the left.
94. What is the pericardium?
A protective sac surrounding the heart.
95. What is the function of pericardial fluid?
It reduces friction as the heart beats.
Chambers
96. What does the right atrium receive?
Deoxygenated blood from the superior vena cava, inferior vena cava, and coronary sinus.
97. What does the right ventricle do?
Pumps deoxygenated blood to the lungs.
98. What does the left atrium receive?
Oxygenated blood from the pulmonary veins.
99. What does the left ventricle do?
Pumps oxygenated blood to the body through the aorta.
100. Which chamber has the thickest wall?
The left ventricle, because it pumps blood through the entire systemic circuit.
Valves
101. What is the tricuspid valve?
The right atrioventricular valve, between the right atrium and right ventricle.
102. What is the mitral valve?
The left atrioventricular valve, between the left atrium and left ventricle.
103. What are the two semilunar valves?
The pulmonary semilunar valve and aortic semilunar valve.
104. What is the purpose of heart valves?
To prevent backflow of blood.
105. What are the two types of heart valves?
Atrioventricular and semilunar valves.
106. Where are AV valves located?
Between the atria and ventricles.
107. Where are semilunar valves located?
Between the ventricles and major arteries.
🫁 Circuits
108. What is the pulmonary circuit?
The pathway between the heart and lungs.
109. What is the systemic circuit?
The pathway between the heart and the rest of the body.
110. What is the purpose of pulmonary circulation?
To exchange carbon dioxide for oxygen.
111. What is the purpose of systemic circulation?
To deliver oxygen and nutrients to tissues and remove wastes.
💪 Cardiac Muscle
112. Is cardiac muscle voluntary or involuntary?
Involuntary.
113. What are intercalated discs?
Specialized connections between cardiac muscle cells that help them communicate and contract together.
114. How does cardiac muscle differ from skeletal muscle?
Cardiac muscle is involuntary, branched, and has intercalated discs, while skeletal muscle is voluntary and attached to bones.
⚡ Cardiac Impulse Generation
115. What is the natural pacemaker of the heart?
The SA node.
116. Where is the SA node located?
In the right atrium.
117. What does the SA node do?
It generates an electrical impulse that initiates the heartbeat.
118. What does the AV node do?
It briefly delays the electrical impulse, allowing the ventricles time to fill.
119. What carries the impulse from the AV node toward the ventricles?
The AV bundle/Bundle of His.
120. What are the bundle branches?
Right and left pathways that carry the impulse down toward the apex of the heart.
121. What do Purkinje fibers do?
They spread the electrical impulse through the ventricular myocardium, causing ventricular depolarization and contraction.
122. What is the cardiac conduction pathway?
SA node → AV node → AV bundle → right/left bundle branches → Purkinje fibers.
⭐ Remember:
SA = Starts
AV = Allows time
Bundle = Brings it down
Purkinje = Pushes it through ventricles
📈 ECG
123. What does an ECG measure?
The heart's electrical activity.
124. What does the P wave represent?
Atrial depolarization.
125. What does the QRS complex represent?
Ventricular depolarization.
126. What does the T wave represent?
Ventricular repolarization.
127. What does S1 ("lub") represent?
Closure of the AV valves.
128. What does S2 ("dub") represent?
Closure of the semilunar valves.
129. What causes a heart murmur?
Turbulent blood flow, often caused by a valve problem.
🧠 Autonomic Regulation
130. What does the sympathetic nervous system do to the heart?
Generally increases heart rate and contractility.
131. What does the parasympathetic nervous system do?
Generally decreases heart rate.
132. What is stroke volume?
The amount of blood ejected by a ventricle during one contraction.
133. What is cardiac output?
The amount of blood pumped by one ventricle per minute.
134. What is the cardiac output equation?
CO = HR × SV
🩸 LESSON 5 — BLOOD VESSELS
135. What are the three layers of a typical blood vessel?
Tunica interna → tunica media → tunica externa.
136. What is the tunica interna?
The innermost layer containing the endothelium.
137. What is the tunica media?
The middle layer containing smooth muscle and elastic fibers that help control vessel diameter.
138. What is the tunica externa?
The outer connective tissue layer that supports and protects the vessel.
139. What is the main difference between arteries and veins?
Arteries carry blood away from the heart; veins carry blood toward the heart.
140. Why do arteries have thicker walls?
They experience higher blood pressure.
141. Why do many veins have valves?
To prevent backflow of blood.
142. What is a capillary?
The smallest type of blood vessel and the main site of exchange between blood and tissues.
143. Why are capillary walls so thin?
They are only about one cell layer thick, allowing efficient exchange.
144. What is a capillary bed?
A network of capillaries between an arteriole and venule.
💓 Blood Pressure
145. What is blood pressure?
The force that blood exerts against the walls of blood vessels.
146. What factors influence blood pressure?
Cardiac output, blood volume, and peripheral resistance.
147. What is cardiac output?
Heart rate × stroke volume.
148. What happens to blood pressure during vasoconstriction?
Blood pressure generally increases because vessel resistance increases.
149. What happens during vasodilation?
Blood pressure generally decreases because vessel resistance decreases.
150. What happens when blood volume increases?
Blood pressure generally increases.
🫁 LESSON 6 — Special Circulation
151. What is the pathway of pulmonary circulation?
Right ventricle → pulmonary arteries → lungs → pulmonary veins → left atrium.
152. Why is pulmonary circulation important?
It allows blood to pick up oxygen and remove carbon dioxide.
153. What is the hepatic portal system?
A special circulation that carries blood from the digestive organs to the liver before returning to the heart.
154. What is the pathway of the hepatic portal system?
Digestive organs → hepatic portal vein → liver → general circulation.
155. Why does blood from the digestive tract go to the liver first?
The liver can process nutrients, store nutrients, and detoxify substances before the blood enters general circulation.
156. What changes can occur in blood vessels with aging?
Blood vessels may become stiffer, less elastic, and thicker, and fatty deposits may accumulate.
157. How can aging blood-vessel changes affect the body?
They can increase blood pressure and contribute to cardiovascular problems.