Chapter 9,10,11 Flashcards
What are the three types of muscle tissue?
Skeletal, cardiac, and smooth muscle.
Where is skeletal muscle found?
Attached to bones and responsible for voluntary movements.
Is cardiac muscle voluntary or involuntary?
Involuntary.
Where is smooth muscle found?
In the walls of hollow organs, such as the stomach, intestines, and blood vessels.
What are the main functions of muscle tissue?
Movement, posture maintenance, joint stabilization, and heat generation.
What is the structural unit of a muscle fiber?
The sarcomere.
What proteins form the thick and thin filaments in muscle fibers?
Myosin (thick) and actin (thin).
What is the role of the sarcoplasmic reticulum in muscle contraction?
Stores and releases calcium ions needed for muscle contraction.
What is a motor unit?
A motor neuron and all the muscle fibers it innervates.
What is the neuromuscular junction?
The site where a motor neuron communicates with a muscle fiber.
What neurotransmitter is released at the neuromuscular junction?
Acetylcholine.
What is the sliding filament theory of muscle contraction?
It describes how actin and myosin filaments slide past each other to shorten the sarcomere, causing muscle contraction.
What is an isotonic contraction?
A muscle contraction where the muscle changes length while the tension remains constant.
What is an isometric contraction?
A muscle contraction where the muscle does not change length but generates tension.
What is muscle tone?
The continuous and passive partial contraction of muscles, helping maintain posture.
What is the difference between fast-twitch and slow-twitch muscle fibers?
Fast-twitch fibers contract quickly and fatigue easily, while slow-twitch fibers contract more slowly and are more resistant to fatigue.
What is the role of ATP in muscle contraction?
ATP provides energy for the cross-bridge cycle and muscle relaxation.
What is the purpose of creatine phosphate in muscle cells?
It provides a rapid source of energy to regenerate ATP.
What causes muscle fatigue?
Depletion of energy sources, accumulation of metabolic waste products, and ion imbalances.
What is hypertrophy?
An increase in muscle size due to strength training.
What are the major muscles involved in respiration?
The diaphragm and intercostal muscles.
What is the function of the deltoid muscle?
Abducts the arm.
Which muscle group is responsible for flexing the forearm at the elbow?
The biceps brachii.
What is the function of the triceps brachii?
Extends the forearm at the elbow.
What muscle is the prime mover for flexion of the thigh?
The iliopsoas.
What are the four muscles of the rotator cuff?
Supraspinatus, infraspinatus, teres minor, and subscapularis.
What is the role of the quadriceps femoris group?
Extends the knee.
What is the function of the hamstring muscles?
Flex the knee and extend the hip.
Which muscle is known as the ‘calf muscle’?
The gastrocnemius.
What is the function of the sternocleidomastoid muscle?
Rotates and flexes the neck.
What muscle forms the bulk of the chest?
The pectoralis major.
What is the function of the latissimus dorsi?
Extends, adducts, and medially rotates the arm.
Which muscle elevates the scapula?
The levator scapulae.
What muscle compresses the abdominal contents?
The transversus abdominis.
What is the role of the gluteus maximus?
Extends and laterally rotates the hip.
Which muscle abducts the thigh?
The gluteus medius.
What is the function of the masseter muscle?
Elevates the mandible (jaw), enabling chewing.
What muscle assists in dorsiflexion of the foot?
The tibialis anterior.
What muscle assists in plantarflexion of the foot?
The soleus.
Which muscle retracts the scapula?
The rhomboids.
What is the origin of a muscle?
The point where a muscle attaches to a stationary bone.
What is the insertion of a muscle?
The point where a muscle attaches to the bone it moves.
What is a prime mover (agonist)?
A muscle that is primarily responsible for a specific movement.
What is an antagonist muscle?
A muscle that opposes the action of the prime mover.
What is a synergist muscle?
A muscle that assists the prime mover in performing its action.
What is a fixator muscle?
A muscle that stabilizes the origin of the prime mover.
What is a lever in biomechanics?
A rigid structure (bone) that moves around a fixed point (joint) when force is applied.
What are the three classes of levers?
First-class, second-class, and third-class levers.
What is an example of a first-class lever in the body?
The neck, where the atlanto-occipital joint acts as the fulcrum.
What is an example of a third-class lever in the body?
The forearm during bicep curls, where the elbow is the fulcrum, and the biceps provide the effort.
