Types of muscles Flashcards
Contain intercalated discs
Found only in the heart
Are striated
Under involuntary control
Cardiac muscle
Under involuntary control.
Are not striated.
Found in stomach, gastrointestinal tract and blood vessels.
Smooth muscle
> 600 of these muscles in the body
Under voluntary control
Are striated
Skeletal muscle
A player is competing in a golf tournament. While hitting the ball, the player feels a sharp pain in a posterior muscle in their lower right leg.
Question: Which type of muscle did the player likely injure?
Skeletal
A player is competing in a golf tournament. While hitting the ball, the player feels a sharp pain in a posterior muscle in their lower right leg.
Question: Which of these muscles did the player likely injure?
Gastrocnemius
Description: A player is competing in a golf tournament. Before hitting the ball, the player takes a deep breath.
Question: Which muscle did the player NOT use in breathing?
a.
Internal intercostals
b.
Sternocleidomastoid
c.
External intercostals
d.
Diaphragm
b.
Sternocleidomastoid
Description: A player is competing in a golf tournament. After hitting the ball, the player suddenly feels a sharp pain in his abdomen. Wincing, the player sits on the ground.
Question: Which of the following muscles would contract to pull the player to a sitting position?
a.
Masseter
b.
Temporalis
c.
Rectus abdominis
d.
Splenius capitis
c.
Rectus abdominis
Description: A player is competing in a golf tournament. After hitting the ball, the player suddenly feels a sharp pain in his abdomen. Wincing, the player sits on the ground.
Question: Which muscle did the player use when wincing and closing their eyes?
a.
External oblique
b.
Gastrocnemius
c.
Orbicularis oculi
d.
Pectoralis
c.
Orbicularis oculi
What are the two types of single muscle tissue?
Single unit (visceral) smooth muscle.
Multi-unit smooth muscle.
What are the 3 characteristics of skeletal muscle cells?
Excitability
Contractility
Extensibility
What is excitability?
Muscle cells that are stimulated via electrical signal.
What is contractility?
Muscles cells that contract, or shorten and produce body movement.
What is extensibility?
Muscles cells that have the ability to extend or stretch allowing muscles to return to their resting length.
What are T Tubulars?
Transverse tubules that run across the long axis of the muscle fiber. These continually pump Ca2+ (calcium) inward from the sarcoplasm and are transportation for electrical impulses to travel deeper into the sarcolemma.
What is sarcoplasm?
Similar to cytoplasm it is the fluid component in the cell directly under the sarcolemma.
What is a sarcomere?
It is the basic unit for muscle contraction composed of thick and thin filaments.
What are myofibrils?
Numerous fine fibers packed together in a sarcomere.
What is striated muscle?
Dark stripes called A bands; light H bands run across the mid-section of each dark A band.
Light stripes called I bands; dark Z disc extends across the center of each light I band.
What is a triad?
Triplet of tubules.
What are myofilaments?
Every myofibril contains thousands of thick and thin myofilaments used for contraction.
What are the 4 different protein molecules that make up myofilaments?
Actin.
Myosin.
Tropomysin.
Troponin.
What is myosin?
Makes up nearly all of the thick filaments.
Myosin heads are called cross bridges when attached to actin.
What is actin?
Globular protein that forms two fibrous strands twisted around each other to form the bulk of the thin filament.
What is tropomyosin?
Protein that blocks the active sites on actin molecules.
What is troponin?
Protein that holds tropomyosin molecules in place.
What is a neuromuscular junction?
It is where motor neurons meet with the sarcolemma at the motor end plate. Acetylcholine (ACh) is released into the synaptic cleft that diffuses the gap stimulating receptors and initiates impulses in the sarcolemma.
What are the 4 steps to sliding filament model of contraction theory?
Myosin heads bind to exposed active sites on actin.
Myosin heads bend and pull the thin filaments past them.
Then each head releases and then binds to the next active site and pulls again.
The entire myofibril shortens.
What are the two types of muscle contraction?
Isotonic and isometric
What is isotonic contraction?
When muscle length changes the tone or tension remains the same.
What is isometric contraction?
When muscle tension or tone changes the length of the muscle stays the same.
