Physiology Exam 2 05/04/2016 Bones are constantly undergoing resorption for various reasons. Which of the following cells accomplishes this process? osteogenic cell osteoclast osteocyte osteoblast Which cells participate in the process of bone deposition? osteoblasts osteoclasts osteocytes lacuna What tissue serves as the model for bones formed during endochondral ossification? compact bone hyaline cartilage spongy bone fibrocartilage What stimulates the release of parathyroid hormone (PTH)? low blood calcium ion levels high levels of vitamin C high levels of vitamin D high blood calcium ion levels Smooth muscle and skeletal muscle both possess: myosin and actin filaments. troponin. transverse tubules (T-tubules). motor end plates. As a result of the increase of testosterone at puberty for males: intramembranous ossification increases. osteoblasts increase the rate of bone resorption. appositional bone growth increases. epiphyseal plates widen rapidly. [AdsenseImage] Which protein does NOT belong in a thin filament? troponin actin myosin tropomyosin The hormone that is primarily involved in the control of bone resorption is parathyroid hormone (PTH). True False Why are collagen fibers a critical component of bone? Collagen fibers help the bone resist compression. Collagen fibers act as “glue” to bind components together. Collagen fibers help bone resist torsion. Collagen fibers help trap water in the ECM. What do skeletal muscle contractions share in common with smooth muscle contractions? Both types of contractions result from thick and thin filaments sliding past one another. Both types of contractions generate little force or a weak force. Both types of contractions consume very little ATP. Both types of contractions do not require calcium ions for a contraction to occur. The function of the sarcoplasmic reticulum (SR) is to store and release calcium ions. True False During muscle contraction, myosin crossbridges bind to active sites on: tropomyosin. T-tubules. troponin. actin. When muscle fibers are stimulated so frequently they do not have an opportunity to relax, they are experiencing: unfused or incomplete tetanus. wave summation. fused or complete tetanus. twitch. Which of the following does NOT correctly depict the effects of parathyroid hormone (PTH)? PTH stimulates the intestines to absorb calcium ions. PTH decreases blood calcium ion concentration. PTH weakens the bones. PTH stimulates osteoclast activity. Blood cells are made in the red bone marrow of bones, a process known as: hematopoiesis. bone resorption. ossification. osteoporosis. Hematopoiesis occurs in both the red and yellow marrow of bones. True False The storage and release of calcium ions is the key function of the: sarcoplasm. sarcolemma. mitochondrion. sarcoplasmic reticulum. [AdsenseImage] Which of the following promotes the depolarization stage? hydrolysis of ATP opening of voltage-gated potassium ion channels and potassium ions exit the cell closure of voltage-gated sodium ion channels opening of voltage-gated sodium ion channels and sodium ions enter the cell Calcitonin functions to: stimulate osteoclast activity. increase bone deposition. increase blood calcium ion levels. stimulate bone resorption. What do skeletal muscle tissue and cardiac muscle tissue share in common? Both skeletal and cardiac muscle tissues are voluntary. Both skeletal and cardiac muscle tissues perform peristalsis. Both skeletal and cardiac muscle tissues are striated. Both skeletal and cardiac muscle tissues possess intercalated discs. What is a necessary reactant for glycolytic, or anaerobic, catabolism to proceed? glucose creatine phosphate myoglobin oxygen What prompts the closure of the epiphyseal plate around age 18-21? ossification of the zone of proliferation chondrocytes increase in size and mature chondrocytes actively divide mitosis in the zone of calcification Clostridium botulinum is a bacterium that produces botulinum toxin that inhibits the release of acetylcholine. Which description best fits how muscle cells will respond to a lack of acetylcholine? Muscle cells will produce sustained contractions without relaxation when there is a lack of acetylcholine. Muscle cells will experienced fused or complete tetanus when there is a lack of acetylcholine. Muscle cells will become paralyzed when there is a lack of acetylcholine. Muscle cells will produce greater tension when there is a lack of acetylcholine. What is required for excitation-contraction coupling? neither calcium ions nor ATP calcium ions only calcium ions and ATP ATP only Bone resorption requires the activity of: osteoclasts. chondrocytes. osteoblasts. osteocytes. [AdsenseImage] Place the following events of excitation in the correct order. 1) ion channels on the sarcolemma open and sodium ions enter the muscle fiber 2) the entry of sodium ions into the muscle fiber depolarizes the sarcolemma locally 3) acetylcholine is released from vesicles in the motor neuron into the synaptic cleft 4) an action potential arrives at the axon terminal of a motor neuron 5) acetylcholine binds to ligand-gated sodium ion channels in the motor end plate 4, 3, 5, 1, 2 3, 4, 5, 1, 2 2, 4, 3, 5, 1 4, 5, 3, 2, 1 How long does bone repair generally take? 4-6 months 12-16 weeks 2-4 weeks 6-8 weeks Whose bone marrow is mostly red? middle-aged adults elderly infants young adults The Na+/K+ ATPase (Na+/K+ pump) maintains the concentration gradients for sodium and potassium ions by moving two sodium ions out of the cell and three potassium ions into the cell. True False What is the first step of bone repair? soft callus formation bone callus formation hematoma formation primary bone is replaced with secondary bone During excitation-contraction coupling, calcium ion concentration is highest in the: sarcoplasmic reticulum. cytosol of the muscle fiber. sarcolemma. terminal cisterna. What happens when troponin and tropomyosin block the active sites of actin? The muscle relaxes. The muscle contraction increases tension. The muscle produces a weak contraction. The muscle contraction reaches peak tension. The entry of acetylcholine into a muscle cell through ligand-gated ion channels depolarizes the sarcolemma locally. True False What type of bone is adapted to withstand stresses arriving from many directions? spongy bone compact bone osteon bone lamellar bone What hormone promotes an increase in the activity of osteoclasts? estrogen calcitonin testosterone parathyroid hormone (PTH) Latrotoxin, produced by the poisonous black widow spider, increases the release of acetylcholine. How do muscle cells respond? Muscle cells will become paralyzed when excess acetylcholine exists. Muscle cells will experience fused or complete tetanus when excess acetylcholine exists. Muscle cells will twitch irregularly when excess acetylcholine exists. Muscle cells will experience a longer latent period when excess acetylcholine exists. What does the depolarization of the transverse tubules (T-tubules) promote? release of calcium from the sarcoplasmic reticulum release of acetylcholine from vesicles in the motor neuron into the synaptic cleft entry of sodium ions into the muscle fiber through voltage-gated sodium ion channels binding of acetylcholine to ligand-gated sodium ion channels [AdsenseImage] What characteristic is NOT descriptive of cardiac muscle tissue? voluntary muscle contractions intercalated discs located in the heart striations Bone growth and remodeling depends on adequate intake of: sodium, calcium, and vitamin E. calcium, magnesium, and vitamin B. vitamin A, vitamin C, and chlorine. calcium, vitamin C, and vitamin K. Correctly order the following key steps in the process of endochondral ossification. 1. Chondrocytes die. 2. Osteoblasts build the bone collar on the external surface of the bone. 3. Perichondrium is invaded by blood vessels. 4. In the primary ossification center, osteoblasts replace calcified cartilage with early spongy bone. 5. Perichondrial cells differentiate into osteogenic cells then into osteoblasts. 3, 1, 2, 3, 5 3, 1, 4, 5, 2 4, 3, 2, 1, 5 3, 5, 2, 1, 4 What vitamin deficiency causes rickets in children? vitamin C vitamin D vitamin A vitamin K Which hormone, produced by the thyroid gland, works opposite to parathyroid hormone (PTH)? thyroid hormones calcitonin estrogen testosterone Which of the following statements is the most accurate description of the sliding filament mechanism? thin filaments slide past thick filaments towards the M line. thick filaments shorten while thin filaments remain unchanged Z discs slide over the thick and thin filaments both thick and thin filaments shorten Sunset Inn & SuitesTrojan Horse Virus Infection Signs As an Amazon Associate we earn from qualifying purchases through some links in our articles.
