© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE MUSCULAR SYSTEM Chapter 9

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Introduction Skeletal muscles: movement in environment Smooth muscles: intestines, ureters, veins and arteries Cardiac muscle: pumps blood through heart and blood vessels 40% - 50% of body weight

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE TYPES OF MUSCLE

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Types of Muscle (cont’d.) Skeletal: voluntary, striated, multinucleated Smooth: involuntary, nonstriated and uninucleated Cardiac: involuntary, striated and uninucleated

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE ANATOMY OF SKELETAL OR STRIATED MUSCLE

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Anatomy of Skeletal or Striated Muscle (cont’d.) Skeletal muscle cell surrounded by sarcolemma Fasciculi: bundles of fascicles Fascicles: individual bundles of muscle fibers Perimysium: surrounds each fascicle

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Anatomy of Skeletal or Striated Muscle (cont’d.) Epimysium: covers the perimysium Fascia: covers the epimysium Myosin: A bands Actin: I bands Z lines H zone

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Anatomy of Skeletal or Striated Muscle (cont’d.) Sarcomere: between two adjacent Z lines –Actual contraction process occurs here Sarcotubular system –T system and sarcoplasmic reticulum

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE PHYSIOLOGY OF MUSCLE CONTRACTION

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Introduction Motor unit: all muscle cells innervated by one motor neuron Muscle cell properties –Excitability –Conductivity –Contractility –Elasticity

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Neuroelectrical Factors Na + higher concentration outside muscle cell K + higher concentration inside muscle cell Resting potential: charge outside positive and inside negative Electrical potential: rush of Na+ inside cell K + moves outside cell attempting to balance

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Neuroelectrical Factors (cont’d.) Action potential –Calcium released –Troponin and tropomyosin action inhibited –Activated myosin links to actin filaments

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Chemical Interactions Myosin heads contain ATP ATP releases energy upon myosin/action link Energy released used to pull action Sodium: potassium pump pumps out sodium Resting potential restored

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Energy Sources ATP: energy source for muscle contraction ATP production –Glycolysis –Krebs citric acid cycle –Electron transport Alternate sources: fatty acids and phosphocreatine

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE MUSCLE TWITCH

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Muscle Twitch (cont’d.) Stimulus > latent period > contraction > relaxation Contraction strength depends on –Strength, speed and duration of stimulus –Weight of load –Temperature All-or-none law

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. MUSCLE TONE

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscle Tone (cont’d.) State of partial contraction throughout whole muscle Maintains pressure on abdominal contents Helps maintain blood pressure Aids digestion Types –Isotonic, isometric

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE ANATOMY OF SMOOTH MUSCLE

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Anatomy of Smooth Muscle (cont’d.) Found in hollow structures Involuntary, uninucleated, nonstriated Arrangement (two layers) –Longitudinal (outer) –Circular (inner)

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE ANATOMY OF CARDIAC MUSCLE

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Anatomy of Cardiac Muscle (cont’d.) Autonomic nervous system control Involuntary, uninucleated, striated Intercalated disks: coordinate contraction Cardiac muscles: contract, relax and contract 75 times/minute

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE NAMING AND ACTIONS OF SKELETAL MUSCLES

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Naming and Actions of Skeletal Muscles (cont’d.) Action Shape Origin and insertion Location Direction of fibers

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Naming and Actions of Skeletal Muscles (cont’d.) Origin: more fixed attachment of muscle Insertion: movable attachment of muscle Tendons: attach muscle to bone Aponeurosis: wide flat tendon

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Naming and Actions of Skeletal Muscles (cont’d.) Flexors: bend limb at a joint Extensor: straighten limb at a joint Abductors: move limb away from midline Adductors: bring limb toward midline Rotators: revolve limb around axis

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Naming and Actions of Skeletal Muscles (cont’d.) Dorsiflexors: raise the foot Plantar flexors: lower the foot Supinators: turn palm upward Pronators: turn palm downward

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Naming and Actions of Skeletal Muscles (cont’d.) Levators: raise a part of the body Depressors: lower a part of the body Prime movers or agonists: bring about an action Antagonists: oppose agonists Synergists: assist prime movers

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. THE FUNCTION AND LOCATION OF SELECTED SKELETAL MUSCLES

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Superficial Muscles Superficial muscles of the body, anterior view

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Superficial Muscles (cont’d.) Superficial muscles of the body, posterior view

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of Facial Expression Occipitalis Frontalis Zygomaticus Levator labii superioris Orbicularis oris and buccinator

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of Facial Expression (cont’d.) Muscles of the head and neck, anterior view

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of Facial Expression (cont’d.) Muscles of the head and neck, lateral view

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of Mastication Masseter Temporalis Pterygoid

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of the Eye Superior rectus Inferior rectus Medial rectus Lateral rectus Superior and inferior oblique

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Head Sternocleidomastoid –Contraction of both causes flexion of neck –Contraction of one causes rotation to left or right

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Shoulder Girdle Levator scapulae Rhomboids Pectoralis minor Trapezius Serratus anterior

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Humerus Pectoralis major Latissimus dorsi Teres minor Deltoid Supraspinatus Infraspinatus

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Elbow Brachialis Biceps brachii Brachioradialis Triceps brachii Anconeus

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Wrist Flexor carpi Extensor carpi

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Hand Supinator Pronator teres Pronator quadratus

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Thumb Flexor pollicis Extensor pollicis Adductor pollicis Abductor pollicis Opponens pollicis

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Fingers Flexor digitorum Extensor digitorum Interossei

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of the Abdominal Wall External oblique Internal oblique Transversus abdominis Rectus abdominis

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of the Abdominal Wall (cont’d.)

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles of Respiration or Breathing Diaphragm –Main muscle External and internal intercostals –Expand the ribs

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Femur Psoas Iliacus Gluteus maximus Gluteus medius Gluteus minimus Tensor fascia lata

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Knee Joint Biceps femoris Semitendinosus Semimembranosus Popliteus Gracilis Sartorius Quadriceps femoris

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Foot Gastrocnemius Tibialis posterior Soleus Peroneus longus Plantaris Tibialis anterior Peroneus tertius

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Muscles Moving the Toes Flexor hallucis Extensor hallucis Flexor digitorum Extensor digitorum Abductor hallucis Abductor digiti minimi

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Animation – Accessory Muscle Use The following animation illustrates how the accessory muscles assist with the breathing process Click Here to Play Accessory Muscle Use Animation

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Summary Described the gross and microscopic anatomy of skeletal muscle Contrasted skeletal, smooth and cardiac muscle anatomy

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Summary (cont’d.) Described muscle contraction and the role of neuroelectrical and chemical factors and energy sources Named major muscles of the body