Muscle Tissue Flashcards
What is acetylcholine?
ACh - The neurotransmitter released at a neuromuscular junction.
The characteristic that allows muscles to pull on bones and organs to create movement is called:
contractility
How does muscle contraction occur?
The overlapping of myofilaments increases, shortening the overall sarcomere.
What type of muscle cells have a fusiform shape and taper to a point at the end?
Smooth
What does the sliding filament theory describe?
Muscle contraction
Name three characteristics of cardiac muscle cells.
They contract with regular rhythm, they are resistant to fatigue, and they contract nearly in unison, it is rich in myoglobin, it has large stores of glycogen, it uses aerobic respiration almost exclusively
What is acetylcholinesterase?
The enzyme that breaks down acetylcholine.
What is the enzyme that breaks down acetylcholine?
acetylcholinesterase
What is a motor unit?
All of the muscle fibers innervated by a single motor nerve fiber.
Tell whether cardiac, smooth, and skeletal muscle are voluntary or involuntary
Cardiac: involuntary; smooth: involuntary; skeletal: voluntary
When muscles stretch and recoil, they recoil to a shorter length. What is this property called?
Elasticity.
What type of contraction involves the development of tension but no change in length?
Isometric
What type of contraction involves the development of tension with a change in length
Isotonic
How do smooth muscle myocytes differ from cardiocytes?
Smooth muscle myocytes have no T tubules while cardiac muscles do.
What is the portion of a myofibril from one Z disc to another?
Sarcomere
The step in which muscle fiber develops tension and may shorten is called what?
Contraction
List the steps of muscle relaxation in order:
1: The nerve signal ceases. 2: AChE breaks ACh down. 3: Active transport pumps in the sarcoplasmic reticulum begin to pump calcium back into cisternae. 4: Calcium releases from troponin. 5: Tropomyosin covers the myosin binding sites.
Describe some characteristics of smooth muscle.
Has no T-tubules, has little SR, is uninucleated, typically slow to contract and slow to relax
What is the difference in electrical charge between one point and another?
electrical potential