Muscles and Their Functions Flashcards

Upper Limb Muscles

• Flexor Carpi Ulnaris: Wrist flexor located along the ulna.
• Extensor Digitorum: Muscle responsible for extending the fingers.
• Flexor Digitorum Superficialis: Muscle that flexes the fingers.
• Biceps Brachii: Facilitates elbow flexion (bending).
• Triceps Brachii: Muscle that extends the elbow.

Shoulder Muscles

• Deltoid: Powerful muscle for shoulder abduction and elevating the arm overhead.
• Trapezius: Muscle that enables shoulder shrugging and head extension.
• Latissimus Dorsi: Adducts the shoulder and helps extend the shoulder joint.
• Infraspinatus: Aids in lateral arm rotation.
• Teres Minor: Assists in lateral arm rotation, smaller muscle than infraspinatus.

Core Muscles

• External Oblique: Tenses abdominal wall and compresses abdominal contents; forms external sides of abdomen.
• Rectus Abdominis: Known as the "straight muscle" of the abdomen.
• Internal Oblique: Tenses abdominal wall; forms internal sides of abdomen.
• Transversus Abdominis: Compresses abdominal contents; runs horizontally through the abdominal cavity.

Respiratory Muscles

• External Intercostal: Muscles that help with inhalation by raising ribs.
• Internal Intercostal: Pulls ribs inward and downward, facilitating exhalation.
• Diaphragm: Major muscle involved in inhalation.

Facial and Jaw Muscles

• Zygomaticus: Muscle used for smiling.
• Buccinator: Helps manipulate food and allows sucking in of cheeks.
• Orbicularis Oculi: Muscle responsible for winking.
• Frontalis: Forms horizontal frown creases in the forehead.
• Orbicularis Oris: Known as the "kissing muscle."
• Masseter: Prime mover for jaw closure.
• Temporalis: Synergist in jaw closure.

Neck and Hip Muscles

• Sternocleidomastoid: Prominent in head flexion; has two origins.
• Iliopsoas: Hip flexor made of two muscles, located deep in the pelvis.

Lower Limb Muscles

• Gluteus Maximus: Engaged during hip extension, particularly in climbing stairs.
• Gastrocnemius: Known as the "toe dancer's" muscle; a two-bellied calf muscle.
• Tibialis Anterior: Responsible for foot inversion and dorsiflexion.
• Adductors: Muscle group draws legs to the midline—important for standing at attention.
• Quadriceps: Muscle group that extends the knee.
• Hamstrings: Muscle group involved in thigh extension and knee flexion.
• Peroneus Longus: Muscle group that plantar flexes and everts the foot.
• Sartorius: A weak thigh flexor known as the "tailor's muscle," recognized for its strap-like structure.