Leg Muscle Labelling and Functions

Leg Muscle Labelling and Functions

• Quadriceps Femoris: A group of four muscles in the front of the thigh, extending the knee joint.
  • Rectus Femoris
  • Vastus Lateralis
  • Vastus Medialis
  • Vastus Intermedius
• Hamstrings: Located on the back of the thigh, flexing the knee and extending the hip.
  • Biceps Femoris
  • Semitendinosus
  • Semimembranosus
• Gluteus Maximus: The largest buttock muscle, extending and externally rotating the hip.
• Gluteus Medius and Minimus: Deep to gluteus maximus, abducting and medially rotating the hip.
• Adductors: Inner thigh muscles, adducting (bringing together) the thighs.
• Gastrocnemius: Calf muscle, plantar flexing the ankle (pointing toes down).
• Soleus: Deeper calf muscle, plantar flexing the ankle.
• Tibialis Anterior: Front lower leg muscle, dorsiflexing the ankle (pulling toes up) and inverting the foot.
• Peroneus Longus and Brevis: Lateral lower leg muscles, everting the foot.
• Tibialis Posterior: Deep lower leg muscle, plantar flexing the ankle and inverting the foot.

General Main Muscles of the Body and Their Functions

• Biceps Brachii: Flexes the elbow and supinates the forearm (turns palm up).
• Triceps Brachii: Extends the elbow joint.
• Pectoralis Major: Adducts and flexes the arm, internally rotates it.
• Latissmus Dorsi: Extends, adducts, and medially rotates the arm.
• Trapezius: Elevates, retracts, and rotates the scapula (shoulder blade).
• Deltoid: Abducts the arm, assisting in flexion and extension.
• Rectus Abdominis: Flexes the trunk.
• Erector Spinae: Extends the spine.
• Gluteus Medius & Minimus: Abducting the hip.
• Iliopsoas: Hip flexor.
• Diaphragm: Primary muscle of respiration.
• Intercostals: Assist with respiration.

Different Types of Muscle Cells

• Skeletal Muscle: Voluntary, striated, multinucleated. Attached to bones, responsible for movement.
• Smooth Muscle: Involuntary, non-striated, single nucleus. Found in internal organs (e.g., digestive tract, blood vessels), responsible for involuntary movements.
• Cardiac Muscle: Involuntary, striated, single nucleus. Found only in the heart, responsible for pumping blood.

McArdle Syndrome

• Description: A genetic muscle-metabolic disorder.
• Cause: Deficiency in glycogen phosphorylase, an enzyme for breaking down glycogen into glucose.
• Symptoms:
  • Muscle pain (myalgia) and cramps after exercise
  • Muscle weakness and fatigue after exertion
  • Difficulty with prolonged exercise
  • Exercise intolerance
  • Possible cardiac arrhythmias
• Diagnosis: Based on symptoms, physical examination, muscle biopsies, and genetic testing.
• Treatment:
  • Symptom management, minimizing pain and fatigue.
  • Dietary strategies to prevent intense workouts.
  • Lifestyle modifications, like pacing exercise, to manage symptoms.
  • Currently no drugs to directly address the syndrome.
• Prognosis: Symptoms vary significantly, depending on severity and treatment timing.

Test your knowledge on the various muscles of the leg, including their locations and primary functions. This quiz covers key muscles like the quadriceps, hamstrings, and calf muscles. Gain a better understanding of anatomy through labelling and functional identification.