This is a timed quiz. You will be given 60 seconds per question. Are you ready?
All these statements are true of fast-twitch muscles except that they are used for aerobic exercises; rather, they are used for anaerobic ones such as spiking a volleyball. Their speed of shortening and force development is much faster than the slow-twitch muscles.
The nodes of Ranvier allow for saltatory conduction. This is when an electrical impulse jumps from one node to the next as it progresses along the myelinated axon.
The cardiovascular system is responsible for transport of nutrients, removal of waste and overall environmental maintenance to support the body’s function.
The sarcoplasm stores glycogen and myoglobin and is made up of lipids, enzymes and cellular organelles. It is comparable to the cytoplasm in other cells, but has more specific functions. The stored glycogen is a source of energy, and the myoglobin is used for oxygen binding.
The all-or-none principle is at play when the electrical threshold of the nerve cell membrane is reached, causing the propagation of the action potential. As the potential travels the length of the nerve, saltatory conduction occurs as the potential proceeds from one node of Ranvier to the next, all the way to its target organ or muscle.
The Golgi tendon organs sense changes in the tension of the muscle. When activated, they send messages that indicate that the muscle is about to engage in dangerous action resulting from extreme tension.
Ossification occurs at the epiphyseal plate. This is the process of longitudinal bone growth which occurs when cartilage at the end of the bone is replaced with bone.
The three types of muscle tissue are cardiac, smooth and skeletal. Cardiac and smooth are involuntary muscles, which perform basic bodily functions, whereas skeletal muscles move by conscious stimulation.
Proprioceptors relay information to the central nervous system about changes in the body and limbs’ positions due to muscular motions. They are specialized to help maintain balance and posture and are found in the muscles, tendons and joints.
Autonomic nerves excite the organ systems, such as digestive and circulatory. These effects are involuntary and are not consciously controlled. Somatic nerves are those that innervate the skeletal muscles and are voluntarily controlled.
Catecholamines are not part of the heart’s electrical conduction system. They are hormones that assist in the contraction of the ventricle and increased emptying of the heart.
The lighter band containing only actin within the myofibril is called the I band. The I band region becomes smaller during concentric muscle actions.
Bone formation is outpaced by resorption in the elderly, causing decreased bone density and an increase in the risks associated with falling.
Fascia is the tissue that has a form call serous, which is fluid-filled. This type of fascia makes up protective membranes that cover the internal viscera. Other types of fascia that do not have specific names relating to their functions are superficial and deep fascia.
During muscle contraction, the myosin cross-bridges bind, actin slides over myosin and Z lines are pulled together. Myofilaments do not change in length, but the sarcomere does.
Pacinian corpuscles are located near the musculotendinous junction and provide input regarding bodily movements or pressure. They assist in preventing muscle actions that are excessive and may cause injury.
All these facts are true about skeletal muscles except for C. Skeletal muscles can only be stretched up to 150% of their resting length, not up to 250%. There are over 600 different skeletal muscles in the body and they work in pairs and groups to perform movement.
Compact, or cortical, bones make up the Haversian system and comprise up to 80% of skeletal mass. This type of osseous tissue is located near the outer layer of the bone, and is made up of bone cells, nerves, blood and lymph vessels.
Stroke volume is the amount of blood pumped out by the left ventricle during one beat of the heart. This, along with the heart rate, helps to determine overall cardiac output.
Cancellous bone is porous osseous tissue that consists of trabeculae that form a lattice structure. This type of tissue structure allows the storage of fat and bone marrow and provides strength to the bone.
Hematopoiesis and calcium and phosphate storage occur in osseous tissue. Hematopoiesis, or the creation of red and white blood cells, mostly occurs in cancellous bone due to its make-up, which is more supportive of physiological functions than of structural ones.
The correct order of structures of a muscle from smallest to largest is: muscle fiber, endomysium, fascicles, perimysium, epimysium.
The sarcolemma is responsible for depolarization of the surface of the fiber and protection and insulation of the fiber from others around it. The sarcolemma is a thin membrane that connects with the endomysium and contains structures that are important for internal functions and growth.
The sinoatrial node controls the rhythm of the heart’s electrical stimulations, and thus its pumping action. This is accomplished by cooperation between the sympathetic and parasympathetic nervous systems, which control the rate of discharge of the electrical impulses.
The sodium-potassium pump controls the process of changing membrane potential in the nerve cell membrane by allowing sodium ions to rush into the cell. This causes a dramatic change in voltage, which in turn causes an action potential to be conducted along the length of the axon.
In exercise principles in the body, the parts of a lever operate as follows: joints are the axis, skeletal muscle contractions cause force to be applied, and the moving portion (limb and any weights carried) are the resistance. Any time the location of the resistance changes in reference to the axis, the exercise can be progressed or regressed.
Slow-twitch muscles are more resistant to fatigue during exercise because they have less developed sarcoplasmic reticula, which release calcium more slowly. This causes a slower rate of ATP hydrolysis, so they do not tire as quickly.
Fascia does not assist in the conduction of the action potential from the nervous system to a muscle to make it move. All other answers correctly describe the three functions of fascia.
Muscle spindles protect the muscle from injury due to excessive or rapid stretching. They do this via feedback to the nervous system about the speed and length of change in a muscle fiber.
Of the three types of muscle action, the one that has a speed of shortening and lengthening that is constant is isometric muscle action. In this type of motion, the muscle is able to resist the force exerted against it, but it cannot overcome that force; therefore there is no discernible movement, but rather there is stability. This action does not cause joint movement.
A second-class lever has the resistance between the effort force and the axis of rotation with the force arm greater than the resistance arm. An example is the way a wheel barrow is configured.
Collagen is an inelastic tissue composed of protein and is a structural part of all living tissue. Collagen has a great amount of tensile strength and makes up tendons.
The motor endplate is the anatomical name for the location on a muscle fiber where a nerve impulse is received. This location contains neurotransmitter receptors. Neurotransmitters bind to the muscle cell membrane and cause depolarization.
Ligaments are composed of collagen and can be found in sheets, cords or band-like structures. They are similar to tendons in their internal structure and strength, but they also contain elastin, which makes them stretch safely and still return to their normal shape.
During muscle stimulation, calcium binds with troponin, which subsequently shifts the tropomyosin off the binding sites, freeing them up for the myosin cross-bridges to attach themselves.
