# BIOL 281: Human Physiology - Practice Materials
## I. Homeostasis and Introduction to Physiology
### Multiple Choice Questions
1. Which of the following is an example of a positive feedback loop?
a. Regulation of body temperature
b. Regulation of blood glucose levels
c. Blood clotting
d. Regulation of blood pressure
2. The main control center of the endocrine system is the:
a. Thyroid gland
b. Adrenal gland
c. Pituitary gland
d. Hypothalamus
3. The smallest living unit of an organism is a(n):
a. Organ
b. Tissue
c. Cell
d. Molecule
### Short Answer Questions
1. Define homeostasis and explain its importance in the human body.
2. Differentiate between negative and positive feedback mechanisms, providing an example of
each.
### Essay Question
1. Describe the hierarchical organization of the human body, from the chemical level to the
organismal level. Provide specific examples at each level.
---
## II. Cell Physiology and Neurophysiology
### Multiple Choice Questions
1. The resting membrane potential of a neuron is primarily established and maintained by:
a. The sodium-potassium pump
b. Voltage-gated sodium channels
c. Ligand-gated chloride channels
d. The influx of calcium ions
2. During the depolarization phase of an action potential, which of the following is occurring?
a. Voltage-gated potassium channels are open
b. Voltage-gated sodium channels are open
c. The sodium-potassium pump is most active
d. Neurotransmitters are being released
3. The neurotransmitter responsible for stimulating skeletal muscle contraction is:
a. Dopamine
b. Serotonin
c. Acetylcholine
d. GABA
### Short Answer Questions
1. Describe the process of synaptic transmission, starting from the arrival of an action potential
at the axon terminal to the generation of a postsynaptic potential.
2. Explain the difference between an excitatory postsynaptic potential (EPSP) and an inhibitory
postsynaptic potential (IPSP).
### Essay Question
1. Detail the sequence of events that occur during an action potential, including the roles of ion
channels and the changes in membrane potential at each stage.
---
## III. Muscle Physiology
### Multiple Choice Questions
1. The functional unit of contraction in a skeletal muscle fiber is the:
a. Myofibril
b. Sarcomere
c. Sarcoplasmic reticulum
d. T-tubule
2. Calcium ions bind to which protein to initiate muscle contraction?
a. Actin
b. Myosin
c. Troponin
d. Tropomyosin
3. A motor unit consists of:
a. A single muscle fiber and all the neurons that innervate it
b. A single motor neuron and all the muscle fibers it innervates
c. All the motor neurons that innervate a single muscle
d. All the muscle fibers within a single fascicle
### Short Answer Questions
1. Explain the sliding filament theory of muscle contraction.
2. What is the role of ATP in muscle contraction and relaxation?
### Essay Question
1. Compare and contrast the structure and function of skeletal, cardiac, and smooth muscle
tissue.
---
## IV. Cardiovascular Physiology
### Multiple Choice Questions
1. The pacemaker of the heart is the:
a. Atrioventricular (AV) node
b. Sinoatrial (SA) node
c. Bundle of His
d. Purkinje fibers
2. During which phase of the cardiac cycle are all four heart valves closed?
a. Ventricular filling
b. Isovolumetric contraction
c. Ventricular ejection
d. Atrial contraction
3. Which of the following factors would cause an increase in stroke volume?
a. Increased afterload
b. Increased contractility
c. Decreased preload
d. Increased heart rate
### Short Answer Questions
1. Describe the flow of blood through the pulmonary and systemic circuits, starting from the
right atrium.
2. Explain the electrical conduction system of the heart.
### Essay Question
1. Discuss the factors that regulate blood pressure in the human body, including neural and
hormonal controls.
---
## V. Respiratory Physiology
### Multiple Choice Questions
1. The primary site of gas exchange in the lungs is the:
a. Bronchi
b. Trachea
c. Alveoli
d. Bronchioles
2. Most of the oxygen transported in the blood is:
a. Dissolved in the plasma
b. Bound to hemoglobin in red blood cells
c. Carried as bicarbonate ions
d. Bound to myoglobin in muscle cells
3. An increase in the partial pressure of carbon dioxide in the blood will lead to:
a. A decrease in blood pH
b. An increase in blood pH
c. A decrease in breathing rate
d. An increase in oxygen saturation of hemoglobin
### Short Answer Questions
1. Describe the mechanics of inspiration and expiration.
2. Explain how oxygen and carbon dioxide are transported in the blood.
### Essay Question
1. Discuss the neural and chemical regulation of respiration.
---
## VI. Renal Physiology
### Multiple Choice Questions
1. The functional unit of the kidney is the:
a. Glomerulus
b. Nephron
c. Collecting duct
d. Renal corpuscle
2. Which of the following substances is normally completely reabsorbed from the filtrate in the
proximal convoluted tubule?
a. Urea
b. Sodium
c. Glucose
d. Potassium
3. Antidiuretic hormone (ADH) promotes the reabsorption of:
a. Sodium
b. Potassium
c. Water
d. Glucose
### Short Answer Questions
1. Describe the three main processes of urine formation: glomerular filtration, tubular
reabsorption, and tubular secretion.
2. Explain the role of the renin-angiotensin-aldosterone system in regulating blood pressure and
volume.
### Essay Question
1. Discuss how the kidneys regulate blood pH.
---
## VII. Digestive Physiology
### Multiple Choice Questions
1. The digestion of which nutrient begins in the mouth?
a. Proteins
b. Fats
c. Carbohydrates
d. Nucleic acids
2. The primary site of nutrient absorption is the:
a. Stomach
b. Small intestine
c. Large intestine
d. Esophagus
3. Bile is produced by the ______ and stored in the ______.
a. Pancreas, liver
b. Liver, gallbladder
c. Gallbladder, pancreas
d. Stomach, small intestine
### Short Answer Questions
1. Describe the chemical digestion of proteins, carbohydrates, and lipids, including the enzymes
involved and the locations where digestion occurs.
2. Explain the roles of the major hormones that regulate digestion (e.g., gastrin, secretin,
cholecystokinin).
### Essay Question
1. Trace the path of a meal through the digestive system, describing the major digestive
processes that occur in each organ.
---
## VIII. Endocrine Physiology
### Multiple Choice Questions
1. Which of the following hormones is released from the posterior pituitary?
a. Growth hormone
b. Thyroid-stimulating hormone
c. Oxytocin
d. Prolactin
2. Insulin is secreted by the ______ cells of the pancreas and acts to ______ blood glucose levels.
a. Alpha, increase
b. Beta, decrease
c. Delta, increase
d. Alpha, decrease
3. Which of the following is a steroid hormone?
a. Epinephrine
b. Insulin
c. Cortisol
d. Glucagon
### Short Answer Questions
1. Compare and contrast the mechanisms of action of steroid and non-steroid (peptide)
hormones.
2. Describe the regulation of thyroid hormone secretion.
### Essay Question
1. Discuss the physiological responses of the body to stress, focusing on the roles of the adrenal
medulla and adrenal cortex.
