Lecture+10-MuscularSystem
Muscular System Overview
Page 1: Chapter Introduction
Muscles constitute nearly half of the body’s weight.
Muscles are critical in health care and fitness fields.
Page 2: Structural and Functional Organization of Muscles
Approximately 600 human skeletal muscles.
Three types of muscle tissue: Skeletal, Cardiac, Smooth.
Function: Convert chemical energy in ATP into mechanical energy.
Myology: Study of the muscular system.
Page 3: Functions of Muscles
Movement: Mobility, body parts movement, breathing, circulation, digestion, and communication (speech and expressions).
Stability: Maintains posture, prevents unwanted movements (antigravity muscles), stabilizes joints.
Page 4: Additional Functions of Muscles
Control of openings: Sphincters manage movement of food, blood, and other materials.
Heat production: Skeletal muscles can produce up to 85% of body heat.
Glycemic control: Absorption and storage of glucose help regulate blood sugar levels.
Page 5: Connective Tissues of Muscle
Endomysium: Loose connective tissue surrounding each muscle fiber.
Perimysium: Thicker tissue wrapping fascicles (bundles of muscle fibers).
Epimysium: Fibrous sheath surrounding the entire muscle.
Fascia: Connective tissue separating muscles or muscle groups.
Page 6: Muscle Shapes and Fascicles
Fascicle orientation affects muscle strength and pull direction:
Fusiform
Parallel
Triangular
Unipennate
Bipennate
Multipennate
Circular
Page 7: Muscle Compartments
Muscle compartment: Group of related muscles surrounded by fascia; contains nerves and blood vessels.
Intermuscular septa: Thick fascia separates compartments.
Page 8: Muscle Attachments
Indirect attachment: Tendons connect muscles to bones, continuous with collagen fibers.
Aponeurosis: Broad, flat tendon.
Direct attachment: Muscle has little separation from bone; appears to emerge from it.
Page 9: Muscle Origins and Insertions
Origin: Stationary bone attachment of muscle.
Belly: Thicker, middle region of muscle.
Insertion: Mobile bone attachment of muscle.
Page 10: Functional Groups of Muscles
Prime mover: Main muscle for action (e.g., brachialis in flexion).
Synergist: Assists the prime mover (e.g., biceps brachii).
Antagonist: Opposes the prime mover (e.g., triceps brachii).
Fixator: Stabilizes the origin of the prime mover (e.g., rhomboids).
Page 11: Intrinsic and Extrinsic Muscles
Intrinsic muscles: Entirely contained within a region.
Extrinsic muscles: Originates outside the region but acts on it (e.g., forearm muscles affecting fingers).
Page 12: Muscle Innervation
Innervation: Identifies nerve stimulating the muscle; essential for diagnosing injuries.
Spinal nerves: Emerge from spinal cord, innervate below the neck.
Cranial nerves: Emerge from brain stem, innervate muscles of head and neck.
Page 13: Blood Supply to Muscles
The muscular system receives about 1.24 L of blood per minute at rest, increasing to over 11 L/min during heavy exercise.
Capillary networks ensure all muscle fibers receive oxygen and nutrients.
Page 14: Muscle Nomenclature
Latin names often describe muscle features, structures, locations, or functions.
Access to pronunciation aids available online.
Page 15-20: Muscles of Facial Expression and Function
Muscles insert into the dermis of the face; responsible for facial expressions.
Innervated by the facial nerve (CN VII).
Significant for communication and emotions; paralysis can affect facial symmetry.
Page 21-27: Muscles Involved in Chewing and Swallowing
Intrinsic and extrinsic muscles of the tongue are crucial for chewing (mastication) and swallowing (deglutition).
Include masseter, temporalis, and other muscles that assist in movement and processing food.
Page 28-30: Neck and Respiratory Muscles
Neck flexors (sternocleidomastoid) and extensors (trapezius) facilitate head movement.
Important respiratory muscles include the diaphragm and intercostal muscles, assisting in breathing.
Page 31-35: Muscles of the Anterior Abdominal Wall
Muscles such as rectus abdominis, internal and external obliques function in movement and support.
Aponeurosis and tendons play roles in muscle stability and effectiveness.
Page 36-41: Muscles of the Back and Pelvic Floor
Back muscles manage postural extension and rotation of the vertebral column.
Pelvic floor muscles are essential for support, control of bodily functions, and sexual function.
Page 42-47: Muscles Acting on the Shoulder and Arm
Muscles including pectoralis major, deltoid, and rotator cuff muscles are key for shoulder stability and motion.
They assist in lifting, reaching, and other shoulder movements.
Page 48-54: Muscles Acting on the Forearm
Include flexors and extensors located both in the arm and forearm, facilitating various motions.
Biceps brachii and triceps brachii are principal flexor and extensor muscles respectively.
Page 55-60: Muscles Acting on the Hip and Lower Limb
Significant muscles like gluteus maximus and iliopsoas provide strength for locomotion and balance.
Major muscle groups facilitate movement across hip and lower limb joints.
Page 61-67: Muscles Acting on the Foot
Includes intrinsic and extrinsic muscles providing support for foot movement and balance, aiding in walking and running.
Muscles like gastrocnemius and soleus are vital for plantar flexion.
Page 68-71: Common Athletic Injuries and Prevention
Muscles and tendons are prone to strain and injury; common issues include compartment syndrome and tennis elbow.
Proper warming up and conditioning are crucial to minimize risks.