Test 1 Page - Biology Test Questions PDF

- **What is the difference between Beta-1 & Beta-2 receptors**? - A. Beta-1 receptors are found in smooth muscle and cause bronchodilation, while Beta-2 receptors are found in the heart and increase heart rate (positive chronotropic effect). - **B. Beta-1 receptors ar...

- **What is the difference between Beta-1 & Beta-2 receptors**? - A. Beta-1 receptors are found in smooth muscle and cause bronchodilation, while Beta-2 receptors are found in the heart and increase heart rate (positive chronotropic effect). - **B. Beta-1 receptors are found in the heart and increase heart rate (positive chronotropic effect) and force of contraction (positive ionotropic effect), while Beta-2 receptors are found in smooth muscle and cause bronchodilation and vasodilation.** - C. Beta-1 receptors are found in the lungs and cause vasodilation, while Beta-2 receptors are found in the heart and increase the force of contraction (positive ionotropic effect). - D. Beta-1 receptors are found in the gastrointestinal tract and cause smooth muscle relaxation, while Beta-2 receptors are found in the blood vessels and increase heart rate (positive chronotropic effect). - **A 45-year-old patient with a history of asthma is prescribed a beta-adrenergic agonist. This medication primarily acts on receptors found in the lungs and smooth muscle to cause bronchodilation. Which of the following receptors is most likely being targeted by this medication?** - A. Alpha-1 - B. Beta-1 - **C. Beta-2** - D. Muscarinic - **Which autonomic receptor mediates an increase in heart rate?** - A. Adrenergic α~1~ receptors - **B. Adrenergic ß~1~ receptors** - C. Adrenergic ß~2~ receptors - D. Cholinergic muscarinic receptors - E. Cholinergic nicotinic receptors - **Myasthenia gravis is a chronic autoimmune disease characterized by which of the following mechanisms?** - A. Autoantibodies destroy acetylcholine molecules in the synaptic cleft. - B. Autoantibodies stimulate excessive acetylcholine production, leading to constant muscle contraction. - C. Autoantibodies attack dopamine receptors in the brain, causing muscle rigidity. - **D. Autoantibodies block acetylcholine receptors at the neuromuscular junction, leading to impaired muscle contractions causing fatigue & weakness.** - **A 42-year-old man with myasthenia gravis notes increased muscle strength when he is treated with an acetylcholinesterase (AChE) inhibitor. The basis for his improvement is increased** - A. amount of acetylcholine (ACh) released from motor neurons - **B. levels of ACh at the muscle end plates** - C. number of ACh receptors on the muscle end plates - D. amount of norepinephrine released from motor nerves - E. synthesis of norepinephrine in motor nerves