Exam 4 (Muscle + Nervous Tissue)

Which of the following surrounds the individual muscle cell?

• endomysium

• epimysium

• fascicle

• perimysium

What is the role of calcium ions in muscle contraction?

• form hydroxyapatite crystals

• reestablish glycogen stores

• increase levels of myoglobin

• bind to regulatory sites on troponin and to remove contraction inhibition

The oxygen-binding protein found in muscle cells is _____

• ATP

• hemoglobin

• immunoglobin

• myoglobin

What is the role of acetylcholinesterase (AChE)?

• destroy ACh a brief period after its release by the axon endings

• stimulate the production of ACh

• act as a transmitting agent

• amplify or enhance the effect of ACh

Which of the following is one of the steps that ends contraction?

• an action potential spread across the entire surface of the muscle fiber

• ACh is broken down by AChE

• calcium ions bind to troponin

• sarcoplasmic reticulum absorbs sodium ions

What produces the striations of a skeletal muscle cell?

• the T tubules

• a difference in the thickness of the sarcolemma

• the sarcoplasmic reticulum

• the arrangement of myofilaments

Why are skeletal muscles called voluntary?

• These muscles maintain a constant rhythm of contraction

• contraction of specific muscles occurs to maintain body posture and body position

• their contractions can be consciously controlled

• only these muscles are stimulated to contract by the CNS

Skeletal muscles fibers differ from "typical cells" in that these muscle fibers

• lack a plasma membrane

• are very small

• lack mitochondria

• have many nuclei

During muscle contraction, myosin cross bridges attach to which active sites?

• thick filaments

• actin filaments

• Z discs

• myosin filaments

AChE is found within the ______

• nucleus

• synaptic cleft

• myofibril

• sarcolemma