Anatomy Chapter 6 Muscular System Flashcards

Study Notes

Connective Tissue Wrappings

Endomysium: Innermost wrapping around individual muscle fibers; smallest connective tissue layer.
Perimysium: Surrounds a fascicle (bundle) of muscle fibers.
Epimysium: Envelops the entire skeletal muscle.
Fascia: Outer layer surrounding the epimysium.

Muscle Attachments

Tendon: Cord-like structure connecting muscle to bone.
Aponeurosis: A flattened, sheet-like modified tendon connecting muscle to bone.

Muscle Properties

Irritability: Muscle's ability to receive and respond to stimuli.
Contractility: Muscle's ability to shorten when adequately stimulated.

Neuromuscular Communication

Neuromuscular Junction: Synapse area where nerve and muscle meet, crucial for muscle activation.
Synaptic Cleft: Gap between the nerve and muscle fibers.
Acetylcholine: Key neurotransmitter for skeletal muscle function.
Sodium: Ion that rushes into muscle cells during contraction to generate action potential.

Muscle Contraction Mechanism

Neurotransmitter: Chemical released by nerve upon impulse arrival, triggering muscle contraction.
Actin and Myosin: Filament proteins activated during muscle contraction.

Muscle Fatigue

Results from lack of contraction due to oxygen debt, requiring aerobic replenishment to remove lactic acid accumulation.

Joint Movements

Flexion: Decreases joint angle, bringing bones close together.
Extension: Increases joint angle, creating distance between body parts.
Rotation: Movement along a joint's longitudinal axis.
Abduction: Movement of a limb away from the body’s midline.
Adduction: Movement of a limb towards the body’s midline.
Dorsiflexion: Lifting the foot towards the shin.
Plantar Flexion: Pointing toes or depressing the foot.
Inversion: Turning the sole medially.
Eversion: Turning the sole laterally.
Supination: Forearm rotation laterally, standard anatomical position.
Pronation: Forearm rotation medially.
Opposition: Thumb movement towards the forefinger.
Elevation: Movement of a body part in a superior direction.
Depression: Movement of a body part in an inferior direction.
Anterograde: Movement in the normal flow direction within the body.
Retrograde: Movement against the normal flow direction.

Muscle Roles

Prime Mover: Muscle primarily responsible for a movement.
Antagonist: Muscle that opposes or reverses action of prime mover.
Synergist: Muscle that aids prime mover in action.
Fixator: Stabilizes the origin of the prime mover.

Major Skeletal Muscles

Frontalis: Forehead muscle, raises eyebrows.
Orbicularis Oculi: Circular muscle around the eyes for blinking.
Orbicularis Oris: Circular muscle around the lips, functions in kissing.
Buccinator: Muscle in the cheek, compresses during whistling and chewing.
Zygomaticus: Smiling muscle, raises the mouth corners.
Masseter: Jaw muscle, essential for chewing.
Temporalis: Assists masseter in jaw closure.
Sternocleidomastoid: Neck muscle aiding head rotation.
Pectoralis Major: Chest muscle involved in arm adduction and flexion.
Intercostal Muscles: Muscles between ribs aiding breathing.
Rectus Abdominus: Core muscle, flexes vertebral column.
External Oblique: Lateral abdominal wall muscle aiding trunk movement.
Transversus Abdominus: Deep abdominal muscle with horizontal fibers.
Trapezius: Muscle extending across the back of the neck and shoulders.
Latissimus Dorsi: Large back muscle critical for arm movements.
Erector Spinae: Muscle group that extends the spine.
Deltoid: Shoulder muscle, primarily abductor of the arm.
Biceps Brachii: Forearm flexor, notable for bicep bulge.
Triceps Brachii: Elbow extension antagonist to biceps.
Gluteus Maximus: Hip muscle, extends hips during activities.
Gluteus Medius: Abducts thigh, located beneath gluteus maximus.
Adductors: Inner thigh muscle group that pulls thighs together.
Hamstrings: Posterior thigh muscles, extend the hip and flex the knee.
Sartorius: Diagonal thigh muscle, allows thigh flexion.
Quadriceps: Group of four anterior thigh muscles responsible for knee extension.
Tibialis Anterior: Muscle controlling foot dorsiflexion and inversion.
Fibularis Muscles: Plantar flexes and everts the foot.
Gastrocnemius: Major calf muscle, crucial for plantar flexion.

Description

Test your knowledge of the muscular system with these flashcards focused on Chapter 6 of Anatomy. Each card provides key terms and definitions related to muscle structure and connective tissues. Perfect for reinforcing your understanding of muscle anatomy.