Exam 2 Ex Phys

Immune Defenders — Chapter 6

100

Question: What is the first line of defense against pathogens?

Skin and mucous membranes.

200

Question: Which immune cells mature into plasma cells that secrete antibodies?

B lymphocytes (B cells).

300

Question: Name the four antibody protection mechanisms represented by P-L-A-N.

Precipitation, lysis, agglutination, and neutralization.

400

Question: What is the difference between acute and chronic inflammation?

Acute inflammation is short-term, usually following injury or infection. Chronic inflammation is prolonged and can contribute to disease.

500

Question: According to the J-shaped exercise model, which activity level has the lowest risk of upper respiratory tract infection, and why might excessive training increase risk?

Regular moderate exercise has the lowest risk. Excessive prolonged training may temporarily alter immune defenses, while poor sleep, stress, and inadequate nutrition can increase susceptibility.

Nervous System — Chapter 7

100

Question: Which part of a neuron carries an action potential away from the cell body?

The axon

200

Question: Which neurotransmitter is released by motor neurons at the neuromuscular junction?

Acetylcholine (ACh)

300

Question: What ions are primarily responsible for depolarization and repolarization of a neuronal action potential?

Na⁺ enters during depolarization; K⁺ leaves during repolarization.

400

Question: According to the size principle, in what order are Type I, Type IIa, and Type IIx motor units recruited as force increases?

Type I → Type IIa → Type IIx.

500

Question: Compare the roles of the primary motor cortex, cerebellum, and basal nuclei in movement?

Primary motor cortex sends voluntary movement commands; cerebellum coordinates and smooths movement; basal nuclei help initiate, regulate, and stop movement.

Muscle Mechanics — Chapter 8

100

Question: What two properties do skeletal muscle cells and neurons share?

Excitability and conductivity.

200

Question: What are the two regulatory proteins that control actin-myosin interaction?

Troponin and tropomyosin.

300

Question: During the sliding filament mechanism, what does calcium bind to, and what happens next?

Calcium binds troponin, causing tropomyosin to move and expose binding sites on actin.

400

Question: What is the difference between concentric, eccentric, and isometric muscle actions?

Concentric: muscle shortens. Eccentric: muscle lengthens under tension. Isometric: tension develops without a change in muscle length.

500

Question: According to the length-tension relationship, maximal isometric force is produced when a muscle is within this percentage range of its optimal resting length?

80%-120%

Heart & Circulation — Chapter 9

100

Question: What two variables are multiplied to calculate cardiac output?

Heart rate × stroke volume (CO = HR × SV).

200

Question: What is the correct order of electrical conduction through the heart, starting at the SA node?

SA node → atrial muscle → AV node → AV bundle → bundle branches → Purkinje fibers → ventricular muscle.

300

Question: What is the equation for mean arterial pressure (MAP) using cardiac output and total peripheral resistance?

MAP = CO × TPR.

400

Question: During exercise, what happens to systolic blood pressure and diastolic blood pressure, and why?

Systolic BP increases, mainly because cardiac output increases. Diastolic BP stays relatively constant or decreases slightlybecause blood vessels in working muscles dilate, reducing peripheral resistance.

500

Question: During exercise, cardiac output is 20 L/min and the arterial–venous O₂ difference is 15 mL O₂ per 100 mL of blood. Calculate VO₂ in L/min.

3.0 L O₂/min. Convert 15 mL/100 mL to 0.15 L O₂/L blood, then multiply 20 × 0.15.

Breathing & Oxygen — Chapter 10

100

Question: What is the difference between ventilation and respiration?

Ventilation is movement of air into and out of the lungs. Respiration involves gas exchange and cellular use of oxygen.

200

Question: What structures in the lungs exchange oxygen and carbon dioxide with pulmonary capillaries?

The alveoli.

300

Question: What is tidal volume, and what is its typical resting value in a healthy adult male?

The volume of air moved in one normal breath, approximately 500 mL.

400

Question: What happens to PO₂ as blood travels from the lungs to working muscles, and why?

PO₂ drops from about 100 mmHg to 40 mmHg or lower because muscles use oxygen. This allows oxygen to move from the blood into the muscles.

500

Question: During exercise, tidal volume is 2.0 L/breath and breathing frequency is 40 breaths/min. Calculate minute ventilation (V̇E).

80 L/min. Minute ventilation = tidal volume × breathing frequency = 2.0 × 40.