Exam 3 Anatomy

Isotonic Contractions Occur when-----

• Maintaining upright posture

• Doing push ups

• Walking up stairs

• Jumping rope

Isometric contractions occur when

• Maintaining an upright posture

• Doing pushing

• Swimming

• Walking

During depolarization, the change in the sarcolemma's membrane potential is due to the influx or entry of--- Ions. The inside of sarcolemmas become less----.

• sodium; Negative

• Potassium; negative

• Potassium; positive

• Sodium; positive

If we Increase the load for skeletal muscle fibers, The velocity ( speed) decreases but the duration of the muscle fiber contraction increases.

• False

• True/ False

• NEither

• True

Which metabolic pathway produces lactic acid in muscle tissue? How many ATP are produced?

• Direct Phosphorylation of creatine phosphate; one

• None

• Anaerobic respiration of glucose( or glycogen); two

• aerobic respiration; approximately 32

smooth muscle fibers contain-- that are analogous to z discs in skeletal muscle fibers.

• gap junctions

• diffuse junctions

• varicosities

• dense bodies

The sarcolemma of smooth muscle fibers have caveolae that----

• store and release neurotransmitters

• Allow muscle fibers to contract as a single unit

• activate myosin kinase and cause the phosphorylation of myosin so that cross-bridge formation may occur.

• Possess calcium channels so that calcium can enter the cytoplasm or sarcoplasm of the cell.

which of the following is Not a feature of unitary (single unit or visceral) muscle tissue?

• Innervated any varicosities of an autonomic nerve fibers

• Electrically coupled by gap junctions

• Found in brooch, large arteries, and ciliary muscle of the eye

• contracts as a single unit

Sprinters typically possess more muscle fibers that are moderately fatigue resistant

• fast white glycolytic

• Fast white glycolytic

• Slow white oxidative

• fast red to pink oxidative.

Each muscle twitch goes through three phases. During this period, an action potential is initiated causing calcium to be released by the sarcoplasmic reticulum into the sarcoplasm.

• Latent period

• period of relaxation

• period of contraction

• refractory period.