Exam #3
Arrange the following structures from the smallest to the largest (use numbers provided) presuming all structures are from the same skeletal muscle. 1—Fascicle; 2—A Muscle Cell; 3—A thick filament; 4—A myofibril 30Nissl body or rough ER30.
3-4-2-1
A motor neuron may supply 1,000 or more muscle fibers. A motor unit consists of one motor neuron and all the muscle fibers it innervates. The above two statements are ____ and ____, respectively. (A) true; true; (B) true; false; (C) false; true; (D) false; false
A. true; true
Receptive region of the neuron is called ________ which mostly receive incoming signals. (A) axons; (B) myelin sheath; (C) cell body; (D) dendrites; (E) axon terminals
D. dendrites
The _____ is defined as collection of nerve cell bodies found outside the CNS. (A) interneuron; (B) glial cell; (C) afferent neuron; (D) efferent neuron; (E) ganglion
E. Ganglion
Which of the following is an example of a hinge joint? (A) hip joints; (B) radiocarpal joint of the wrist; (C) radioulnar joint at the elbow; (D) trapeziometacarpal joint at the base of the thumb; (E) interphalangeal joints
E. Interphalangeal joints
The sensory division carries signals from various _____ to the central nervous system. (A) sympathetic division; (B) somatic motor division; (C) visceral motor division; (D) effectors; (E) receptors
E. Receptors
Which of the following statements is NOT a function of muscles? (A) movement; (B) glycemic control; (C) heat production; (D) stability; (E) none of the above
E. none of the above
Deeper Insight--Exercise and Articular Cartilage) When synovial fluid is warmed by exercise, it becomes thicker (more viscous). Because cartilage is nonvascular, repetitive compression during exercise is important to its nutrition and waste removal. The above two statements (sentences) are ___ and ____, respectively. (A) true; true; (B) true; false; (C) false; true; (D) false; false
C. False; True
The glial cells that fight infections and form blood-brain barrier are _____ and ______, respectively, in the CNS. (A) astrocytes; oligodendrocytes; (B) oligodendrocytes; microglia; (C) microglia; astrocytes; (D) ependymal cells; microglia; (D) oligodendrocytes; astrocytes; (E) none of the above
C. Microglia; astrocytes
Before a muscle fiber can contract, ATP must bind to _____. (A) a Z disc; (B) actin; (C) the myosin head; (D) tropomyosin; (E) troponin
C. The myosin head
Arrange the following steps in correct order according to the muscular tissue handout. 1—Cocking of myosin head; 2—Apart of cross-bridge resulting from binding of new ATP; 3—Attach of myosin head to actin and formation of cross-bridge; 4—Pull (or power stroke) resulting in sliding thin filament over thick filament. (A) 2—3—4—1; (B) 1—4—3—2; (C) 3—2—4—1; (D) 1—3—4—2
D. 1-3-4-2
Which of the following joints cannot be circumducted? (A) coxal; (B) glenohumeral; (C) carpometacarpal; (D) interphalangeal; (E) metacarpophalangeal
D. Interphalangeal
A circular muscle that closes a body opening is called a/an __________.
sphincter
Multiple sclerosis and Tay-Sachs disease are degenerative disorders of the ________. (Hint: two words)
Myelin Sheath
A. As skeletal muscle contracts, one or more bands of the sarcomere become narrower and disappear, and one or more of them remain the same width. Which bands will change—A, H, or I?
The A bands remain the same width. The H bands become narrower and may disappear. The I bands become narrower and may disappear.
B. Explain why specifically for A bands and then for H and I bands.
(2 points) The A bands remain the same width because they are defined by the length of the thick filamentswhich do not shorten during muscle contraction. (2 points) The H and I bands become narrower and may disappear. These are the regions in which actin and myosin do not overlap in relaxed muscle. During contraction, they are eliminated by the increasing myofilament overlap.
A. What two basic physiological properties do a nerve cell and a muscle cell have in common?
A. (4 points; 2 point each)— Nerve cells and muscle fibers share the properties of excitability (2 points) and conductivity (2 points).
Acetylcholine receptors are found mainly in _____. (A) junctional folds; (B) thin filaments; (C) thick filaments; (D) terminal cisterns; (E) synaptic vesicles
A. Junctional holds
Deeper Insight—Neuromuscular Toxins and Paralysis) Curare can compete with ACh (Acetylcholine) for receptor sites but does not stimulate the muscle causing flaccid paralysis. The above statement is ___. (A) true; (B) false
A. True
Saltatory conduction occurs only in myelinated nerve fibers. The above statement is ____. (A) true; (B) false
A. True
The fasciae are not components of the muscles themselves, but package groups of functionally related muscles into muscle compartments and stand between the muscles and the overlying hypodermis and skin; some of these fasciae are particularly thick and are called intermuscular septa. The above statement is _____. (A) true; (B) false
A. True
Deeper Insight—Compartment Syndrome) Mounting pressure on the muscles, nerves, and blood vessels triggers a sequence of degenerative events called compartment syndrome. Compartment syndrome is treated by immobilizing and resting the limb and, if necessary, making an incision to relieve the pressure. The above two statements are ____ and ____, respectively. (A) true; true; (B) true; false; (C) false; true; (D) false; false
A. True; true
B. Name a physiological property of each that the other one lacks.
B. (3 points; 1 point each; got both 3 pts.)—(1 point) Neurons also carry out secretion or graded local potential .(1 point) Muscle fibers undergo contraction or glycemic control.
A resting neuron has a higher concentration of sodium ions in its cytoplasm than in the extracellular fluid surrounding it. The above statement is ____. (A) true; (B) false
B. False
Smooth muscle lacks striations because it does not have thick and thin myofilaments. The above statement is _____. (A) true; (B) false
B. False
The ____ is an example of plane suture. (A) squamous suture; (B) palatine process of the maxillae; (C) lambdoid suture; (D) coronal suture; (E) none of the above
B. Palatine Process of the maxillae
Regarding categories of muscle action, a/an _____ is a muscle that produces most of the force during a particular joint action. (A) synergist; (B) agonist; (C) antagonist; (D) fixator; (E) none of the above
B. agonist
Give one specific example of syndesmoses according to the textbook or a handout of joints.
Between the tibia and fibula OR between radius and ulna
ID #5
Block and reveal active sites of G actins
ID #3
Brachialis and Lateral head of triceps brachii (1 pt. each; 3 pts. if got both)
ID #7
Nissl Body or Rough ER
ID #2
Quadriceps femoris tendon
ID #8
Repolarization
ID #1
Retraction
ID #4
Sartorius; Parallel (1 pt. each; 3 pts. if got both correct)
ID #6
Transmit action potential and regulate calcium release into the cytoplasm
