Week 4 - Joints and Skeletal Muscle Flashcards
(21 cards)
What is a joint?
A joint is where two or more bones meet to allow movement and hold the skeleton together.
What are the two structural classifications of joints?
Solid joints and synovial joints.
What characterizes solid joints?
Bones are connected by fibrous or cartilaginous tissue with no cavity between them.
What characterizes synovial joints?
Bones are separated by a fluid-filled cavity allowing free movement.
What are examples of fibrous solid joints?
Suture (skull), gomphosis (tooth socket), syndesmosis (radius and ulna).
What are examples of cartilaginous solid joints?
Synchondrosis (epiphyseal plate), symphysis (pubic symphysis, intervertebral discs).
What are examples of synovial joints?
Elbow, shoulder, hip, TMJ, and intercarpal joints.
What are the three types of muscle tissue?
Skeletal, cardiac, and smooth muscle.
What is the function of skeletal muscle?
Voluntary body movement via motor neuron signals.
What is the function of cardiac muscle?
Pumps blood through the circulatory system with spontaneous contraction.
What is the function of smooth muscle?
Moves materials within internal organs involuntarily.
What is the basic unit of skeletal muscle?
The muscle fiber (myocyte).
What are the connective tissue layers of skeletal muscle?
Epimysium, perimysium, and endomysium.
What is a sarcomere?
The contractile unit of muscle formed by actin and myosin filaments.
Where is calcium stored in skeletal muscle?
In the sarcoplasmic reticulum.
What is the role of calcium in muscle contraction?
Calcium binds troponin, exposing actin binding sites for myosin.
What is a neuromuscular junction?
The synapse where a motor neuron communicates with a muscle fiber.
What is excitation-contraction coupling?
The process linking muscle fiber stimulation to contraction via Ca²⁺ release.
What initiates muscle contraction at the neuromuscular junction?
Acetylcholine released from a motor neuron.
What happens after calcium is released in EC-coupling?
Calcium binds troponin, enabling myosin-actin crossbridge formation.
What ends muscle contraction?
Calcium reuptake into the SR and cessation of neuronal signals.
