Chapter 11: Axial Musculature Quiz

Muscles of the Head

• Occipitofrontalis: Consists of two bellies - occipital and frontal, involved in facial expressions.
• Levator Palpebrae Superioris: Responsible for elevating the upper eyelid.
• Orbicularis Oculi: Facilitates eyelid closure and helps in blinking.
• Buccinator: Assists in chewing by keeping food between teeth.
• Orbicularis Oris: Controls movement of the mouth and lips.
• Temporalis: Key muscle in mastication, elevating the mandible.
• Masseter: Another major muscle for chewing, primarily elevating the mandible.

Muscles of the Neck & Back

• Sternocleidomastoid: Rotates and flexes the head; notable for its prominent position.
• Pharyngeal muscles: Involved in swallowing and the movements of the pharynx.
• Suprahyoid muscles: Include geniohyoid, mylohyoid, and digastric, aiding in actions like swallowing.
• Infrahyoid muscles: Include sternohyoid, sternothyroid, and thyrohyoid, help in depressing the hyoid bone.
• Erector Spinae: A group consisting of iliocostalis, longissimus, and spinalis, crucial for spine extension and posture.

Muscles of the Abdominal Wall

• Rectus Abdominis: Abdominal muscle important for flexing the spine.
• Rectus Sheath: Protects the rectus abdominis muscles.
• Linea Alba: Fibrous structure running down the midline of the abdomen.
• External/Internal Abdominal Oblique: Rotates and flexes the torso.
• Transversus Abdominus: Deepest abdominal muscle, stabilizing the trunk.

Inguinal Region

• Inguinal Ligament and Canal: Passage for structures like the spermatic cord in males.
• Contents of Inguinal Canal: Includes blood vessels, nerves, and spermatic cord.
• Herniation:
  • Direct inguinal herniation: Protrudes through abdominal wall.
  • Indirect inguinal herniation: More common, through the inguinal canal.

Muscles of the Pelvic Floor

• Pelvic Diaphragm: Supports pelvic organs, composed of levator ani and coccygeus.

Perineum: General

• Borders: Defined anatomical area with specific regions.
• Sub Regions:
  • Urogenital Triangle: Contains reproductive organs.
  • Anal Triangle: Contains the anal canal.

Upper Limb: Axioappendicular Muscles

• Trapezius: Moves the scapula and supports shoulder elevation.
• Latissimus Dorsi: Extends, adducts, and internally rotates the shoulder.
• Rhomboid Major and Minor: Retract the scapula towards the spine.
• Levator Scapulae: Elevates the scapula, involved in neck movement.
• Pectoralis Major and Minor: Muscles of the chest involved in moving the shoulder.
• Deltoid: Major shoulder muscle responsible for arm abduction.
• Serratus Anterior: Key for scapular rotation; can lead to "winged scapula" if paralyzed.

Upper Limb: Rotator Cuff

• Subscapularis, Supraspinatus, Infraspinatus, Teres Minor: Stabilize and support shoulder joint movement.

Upper Limb: Anterior Arm

• Biceps Brachii: Flexes elbow and supinates forearm.
• Brachialis: Primary elbow flexor.

Upper Limb: Posterior Arm

• Triceps Brachii: Involved in extending the elbow.

Upper Limb: Forearm

• Anterior Compartment: Major muscles including
  • Pronator teres
  • Flexor Carpi Radialis
  • Palmaris Longus
  • Flexor Carpi Ulnaris
  • Flexor Digitorum Superficialis
• Posterior Compartment: Focused on extension, includes
  • Brachioradialis
  • Extensor Carpi Radialis Longus
  • Extensor Digitorum
  • Extensor Carpi Ulnaris

Lower Limb: Gluteal Region

• Gluteus Maximus: Main extensor of the hip.
• Gluteus Medius and Minimus: Important for hip stabilization and abduction.
• Hip Stabilizers: Such as piriformis, key for pelvic stability during movement.