Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 6: Muscular System

Similar presentations


Presentation on theme: "Chapter 6: Muscular System"— Presentation transcript:

1 Chapter 6: Muscular System
Anatomy & Physiology Kasprowicz

2 The essential function of muscle is contraction – making it responsible for almost all body movement.

3 Types of Muscle Skeletal Cardiac Smooth Types of Muscle

4 General Muscle Characteristics
muscle cells are elongated = muscle fibers (smooth, skeletal) contain myofilaments (ability to contract) terminology: myo-, mys- = muscle sarco- = flesh General Muscle Characteristics

5 exert great force, but tire easily
Very large, multinucleated cells Striated (visible stripes or banding pattern) Voluntary (conscious) control; can be reflexive too muscle fibers (cells) are bundled together by strong connective tissues  exert great force, but tire easily Skeletal Muscle

6 Connective Tissues in Skeletal Muscle
Deep fascia Connective Tissues in Skeletal Muscle

7 Connective Tissues in Skeletal Muscles
Endomysium – around single muscle fiber Perimysium – around a fascicle (bundle) of fibers Epimysium – covers the entire skeletal muscle Deep Fascia – on the outside of the epimysium Connective Tissues in Skeletal Muscles

8 Connective Tissues in Skeletal Muscle

9 Connective Tissues in Skeletal Muscles
tendon – dense connective tissue attaching muscle to bone (cord-like) aponeuroses – attach muscles indirectly to bone,cartilages or connective tissue coverings (sheet- like) Epimysium blends into a connective tissue attachment Connective Tissues in Skeletal Muscles

10 Connective Tissues in Skeletal Muscles

11 Connective Tissues in Skeletal Muscles
Aponeurosis of the external oblique Connective Tissues in Skeletal Muscles

12 Connective Tissues in Skeletal Muscles
Refer to pg. 272 in your textbook Connective Tissues in Skeletal Muscles

13 Spindle-shaped cells with one nucleus
no striations Involuntary (no conscious control) Found in hollow visceral organs Have small amount of endomysium Smooth Muscle

14 slow, sustained, tireless movement
often layers in opposite directions Smooth Muscle

15 Smooth Muscle: Stomach Wall

16 Branching cells with one nucleus connected by intercalated discs
2) Striated 3) Involuntary (no conscious control) small amounts of endomysium Cardiac Muscle

17 Cardiac Muscle Cardiac fibers are arranged in
spiral or 8- shaped bundles Cardiac Muscle

18 Producing movement Maintaining posture Stabilizing joints Support soft tissues Generating heat Guard entrances and exits Muscle Functions

19 Muscle Functions

20 Skeletal Muscle Fiber (Cell) Formation

21 Skeletal Muscle Fiber (Cell) Formation

22 Microscopic Anatomy of Muscle
Cells are multinucleate Nuclei are just beneath the sarcolemma (1) sarcolemma - specialized plasma membrane of muscle cells Microscopic Anatomy of Muscle

23 Microscopic Anatomy of Muscle
(2) Cytoplasm filled with myofibrils myofibrils – perfectly aligned, ribbon- like organelles; give muscle fiber its striped appearance Microscopic Anatomy of Muscle

24 Microscopic Anatomy of Muscle
(2) Cytoplasm filled with myofibrils A closer look at the myofibril Light (I) bands Dark (A) bands Microscopic Anatomy of Muscle

25 Microscopic Anatomy of Muscle
(2) Cytoplasm filled with myofibrils Banding Pattern: Light (I) bands contain the Z disc Dark (A) bands contain the H zone M line - holds adjacent filaments together; center of H zone Microscopic Anatomy of Muscle

26 Microscopic Anatomy of Muscle
An even closer look at the myofibril… Sarcomere - contractile unit of the myofibril - Z disc to Z disc Microscopic Anatomy of Muscle

27 Microscopic Anatomy of Muscle
An even closer look at the myofibril… Sarcomere Microscopic Anatomy of Muscle

28 Microscopic Anatomy of Muscle
Zooming in on the sarcomere… Myofilaments - special proteins that cause muscle to contract Two Types: a) myosin (thick filament) b) actin (thin filament) Microscopic Anatomy of Muscle

29 Microscopic Anatomy of Muscle
Two Types: a) myosin (thick filament) protein with heads that form cross bridges b/t thick & thin filaments during muscle contraction Contain ATPase enzymes Microscopic Anatomy of Muscle

30 Microscopic Anatomy of Muscle
Two Types: b) actin (thin filament) Made of the contractile protein actin & some other regulatory proteins Microscopic Anatomy of Muscle

31 Microscopic Anatomy of Muscle
Zooming in around the H zone…. Microscopic Anatomy of Muscle

32 Microscopic Anatomy of Muscle
(5) Sarcoplasmic reticulum (SR) specialized smooth ER surrounding each myofibril stores calcium which is released when muscle is stimulated to contract Microscopic Anatomy of Muscle

33 Microscopic Anatomy of Muscle
Sarcoplasmic reticulum (SR) Microscopic Anatomy of Muscle

34 Microscopic Anatomy of Muscle
Sarcoplasmic reticulum (SR) Microscopic Anatomy of Muscle

35 Let’s put this all together….
Microscopic Organization of Muscle: Level 1 (refer to Fig. 10-6, pg. 278) Let’s put this all together….

36 Let’s put this all together….
Microscopic Organization of Muscle: Level 2 Let’s put this all together….

37 Let’s put this all together….
Microscopic Organization of Muscle: Level 3 Let’s put this all together….

38 Let’s put this all together….
Microscopic Organization of Muscle: Level 4 Let’s put this all together….

39 Let’s put this all together….
Microscopic Organization of Muscle: Level 5 Let’s put this all together….

40 Skeletal Muscle Activity: Initiating the Contraction

41 Special Functional Properties of Muscle
Irritability – ability to receive and respond to a stimulus (a property shared with neurons) Contractility – ability to shorten when an adequate stimulus is received Special Functional Properties of Muscle

42 Skeletal muscles must be stimulated by a nerve to contract (motor neuron).

43 Quick Review of Neurons & Synapses

44 Quick Review of Neurons & Synapses

45 Quick Review of Neurons & Synapses

46 Nerve Stimulus to Muscle
Motor unit: One neuron & the muscle cells stimulated by that neuron Nerve Stimulus to Muscle

47 Nerve Stimulus to Muscle
Neuromuscular junctions the neuron & muscle fibers do NOT touch separated by a gap called the synaptic cleft which is filled w/ interstitial fluid Nerve Stimulus to Muscle

48 Nerve Stimulus to Muscle
Neuromuscular junctions Nerve Stimulus to Muscle

49 Transmission of Nerve Impulse to Muscle
Neurotransmitters chemical released by neurons used to “carry” the impulse across the synaptic cleft Acetylcholine (ACh) is the neurotransmitter used at the neuromuscular junction of skeletal muscle Transmission of Nerve Impulse to Muscle

50 Transmission of Nerve Impulse to Muscle
Steps in Impulse Transmission ACh is released by the pre-synaptic axon terminal of the motor neuron ACh crosses the synaptic cleft & attaches to receptors on the sarcolemma Sarcolemma becomes permeable to sodium (Na+) Transmission of Nerve Impulse to Muscle

51 Transmission of Nerve Impulse to Muscle
Steps in Impulse Transmission Sodium floods into the cell generating an action potential (electrical current) Once started, muscle contraction cannot be stopped !! ACh is broken down by the enzyme acetylcholinesterase This prevents continued contraction of the muscle cell in the absence of additional nerve impulses. Transmission of Nerve Impulse to Muscle

52 Transmission of Nerve Impulse to Muscle
Steps in Impulse Transmission When an action potential sweeps along the sarcolemma and a muscle cell is excited, calcium ions are released from the sarcoplasmic reticulum Transmission of Nerve Impulse to Muscle

53 Transmission of Nerve Impulse to Muscle
Steps in Impulse Transmission The flood of Ca+ ions is the final trigger for the contraction of the muscle Transmission of Nerve Impulse to Muscle

54 Skeletal Muscle Activity: Sliding Filament Theory of Muscle Contraction

55 Mechanism of Muscle Contraction
Sliding Filament Theory: Overview Myosin heads form cross bridges with binding sites on actin Myosin heads detach & then bind to the next site on actin Resting Sarcomere Sarcomere Contracts Mechanism of Muscle Contraction

56 Mechanism of Muscle Contraction
Sliding Filament Theory: Overview This action continues, causing the myosin & actin to slide past each other Resting Sarcomere Sarcomere Contracts Mechanism of Muscle Contraction

57 Mechanism of Muscle Contraction
Sliding Filament Theory: Overview Collective shortening of the muscle cell sarcomeres = muscle contraction Resting Sarcomere Sarcomere Contracts Mechanism of Muscle Contraction

58 The Contraction Cycle : The Nitty Gritty
Step 1: Ca+ ions released from the SR attach to the troponin- tropomyosin complex Binding sites on the actin filament are exposed The Contraction Cycle : The Nitty Gritty

59 The Contraction Cycle : The Nitty Gritty
Step 1: The Contraction Cycle : The Nitty Gritty

60 The Contraction Cycle : The Nitty Gritty
Step 2: myosin heads attach to actin binding sites, forming cross bridges ATP was required to prep the myosin head (ATP  ADP + P) The Contraction Cycle : The Nitty Gritty

61 The Contraction Cycle : The Nitty Gritty
Step 2: The Contraction Cycle : The Nitty Gritty

62 The Contraction Cycle : The Nitty Gritty
Step 3: ADP + P released from myosin head myosin head flexes/pivots = “power stroke” The Contraction Cycle : The Nitty Gritty

63 The Contraction Cycle : The Nitty Gritty
Step 3: The Contraction Cycle : The Nitty Gritty

64 The Contraction Cycle : The Nitty Gritty
Step 4: ATP binds to myosin head, causing it to detach from the actin filament The Contraction Cycle : The Nitty Gritty

65 The Contraction Cycle : The Nitty Gritty
Step 5: myosin head re-energized (ATP  ADP + P) Step 6: Ca+ ions pumped back into the SR troponin-tropomyosin complex moves back to its original position The Contraction Cycle : The Nitty Gritty

66 The Contraction Cycle : The Nitty Gritty

67 The Contraction Cycle : The Nitty Gritty

68 Muscle Contraction Animations
Muscle Contraction 3-D Animation Action Potentials & Muscle Contraction https://highered.mcgraw-hill.com/sites/ /student_view0/chapter10/animation__breakdown_of_atp_and_crossbridge_movement_during_muscle_contraction.html Break Down of ATP & Cross Bridge Attachment https://highered.mcgraw-hill.com/sites/ /student_view0/chapter10/animation__sarcomere_contraction.html Sarcomere Contraction

69 Contraction of the Whole Muscle
The “all-or-none” response of muscle contraction refers to the muscle cell, NOT the whole muscle Whole muscle reacts with a graded response (different degrees of shortening) Contraction of the Whole Muscle

70 Contraction of the Whole Muscle
Graded responses are produced in 2 ways: Change the frequency of stimulation Change the # of muscle cells stimulated/time - more activated muscle cells stronger FORCE of contraction Contraction of the Whole Muscle

71 Contraction of the Whole Muscle
Changing Stimulation Frequency Muscle Twitch – 1 stimulus; single, brief, jerky contraction 1 Contraction of the Whole Muscle

72 Contraction of the Whole Muscle
Changing Stimulation Frequency 2 Wave Summation– frequency of stimulus increases; less time to relax; contraction strength “summed” Contraction of the Whole Muscle

73 Contraction of the Whole Muscle
Changing Stimulation Frequency 3 Incomplete Tetanus – frequency of stimulation increases even more Contraction of the Whole Muscle

74 Contraction of the Whole Muscle
Changing Stimulation Frequency 4 Tetanus – frequency of stimulation very rapid; no evidence of relaxation; smooth, sustained contraction Contraction of the Whole Muscle

75 Energy for Muscle Contraction
Initially, muscles used stored ATP for energy ATP is hydrolyzed into ADP + P Only 4-6 seconds worth of ATP is stored by muscles After this, other metabolic pathways must be used to produce ATP Energy for Muscle Contraction

76 Energy for Muscle Contraction
Pathway 1: Direct Phosphorylation Muscle cells contain creatine phosphate (CP) CP is a high-energy molecule that transfers energy to ADP, regenerating ATP CP supplies are exhausted in about 20 seconds Energy for Muscle Contraction

77 Energy for Muscle Contraction
Pathway 1: Direct Phosphorylation Energy for Muscle Contraction

78 Energy for Muscle Contraction
Pathway 2: Anaerobic Respiration (a.k.a. lactic acid fermentation) breaks down glucose without oxygen Glucose is broken down to pyruvic acid; 2 ATP are produced Pyruvic acid  lactic acid Energy for Muscle Contraction

79 Energy for Muscle Contraction
Pathway 2: Anaerobic Respiration (lactic acid fermentation) Energy for Muscle Contraction

80 Energy for Muscle Contraction
Pathway 2: Anaerobic Respiration This reaction is not as efficient, but it is fast Huge amounts of glucose are needed Lactic acid produces muscle fatigue Duration: seconds Energy for Muscle Contraction

81 Energy for Muscle Contraction
Pathway 3: Aerobic Respiration Series of metabolic pathways that occur in the mitochondria & require oxygen Glucose is broken down to carbon dioxide and water releasing energy This is a slower reaction that requires continuous oxygen High energy pay-off: 36 ATP Energy for Muscle Contraction

82 Energy for Muscle Contraction
Pathway 3: Aerobic Respiration Energy for Muscle Contraction

83 Muscle Fatigue & Oxygen Debt
When a muscle is fatigued, it is unable to contract The common reason for muscle fatigue is oxygen debt Oxygen must be “repaid” to tissue to remove oxygen debt Oxygen is required to get rid of accumulated lactic acid Increasing acidity (from lactic acid) and lack of ATP causes the muscle to contract less Muscle Fatigue & Oxygen Debt

84 Types of Muscle Contraction
Isotonic Muscle Contraction The myofilaments slide past each other  muscle shortens  movement occurs Examples: bending knee, rotating the arms, smiling Types of Muscle Contraction

85 Types of Muscle Contraction
Isometric Muscle Contraction muscle is not able to shorten muscle tension keeps increasing Examples: lifting a 1000 lb. object alone; pushing against an object that doesn‘t move Types of Muscle Contraction

86

87 Muscle Tone state of continuous partial contractions
Different fibers contract at different times to provide muscle tone muscle remains firm, healthy & ready for action Increasing muscle tone increases metabolic energy used, even at rest Muscle Tone

88 Muscle Tone

89 If the nerve supply to a muscle is destroyed, the muscle is no longer stimulated in this manner, and it loses tone and becomes paralyzed. Soon after, it becomes flaccid (soft and flabby) and begins to atrophy (waste away). Muscle Tone

90 Muscle Tone

91 “use it or lose it” Effects of Exercise
Aerobic (Endurance) Exercise Examples: jogging, biking, swimming stronger, more flexible muscles w/ greater resistance to fatigue Effects of Exercise

92 Effects of Exercise Aerobic (Endurance) Exercise Physiological Effects
1) increased blood supply to muscles 2) more mitochondria 3) increased metabolism 4) keeps bones strong 5) improves neuromuscular coordination Effects of Exercise

93 “use it or lose it” Effects of Exercise
Resistance (Isometric) Exercise Examples: weight training increased muscle size and strength Effects of Exercise

94 Effects of Exercise Aerobic (Endurance) Exercise Physiological Effects
1) increased # of myofilaments  increased size of muscle fibers 2) more connective tissue 3) keeps bone strong Effects of Exercise

95 “Golden Rules” of Skeletal Muscle Activity
All (almost ) skeletal muscle cross a least one joint Most of a skeletal muscle lies proximal to the joint crossed All skeletal muscles have at least 2 attachments: the origin and the insertion Skeletal muscles can only PULL (create tension) When a muscle contracts, the insertion moves toward the origin “Golden Rules” of Skeletal Muscle Activity

96 Types of Body Movements
Movement occurs when a muscle contracts and moves an attached bone Muscles are attached to at least two points Origin – attachment to a immoveable bone Insertion – attachment to an movable bone Types of Body Movements

97 Types of Body Movements
When a skeletal muscle contracts, its insertion moves toward its origin Types of Body Movements

98 Body Movements: Muscle Interactions
prime mover – muscle primarily responsible for a certain movement Example: biceps, hamstrings (a.k.a. agonist) Antagonist – muscle that opposes or reverses a prime mover Triceps when biceps flexes; quads when hamstrings flex Body Movements: Muscle Interactions

99 Prime Mover – biceps Antagonist – triceps Prime Mover – triceps Antagonist – biceps

100 Body Movements: Muscle Interactions
Synergist – muscle that aids a prime mover in a movement and helps prevent rotation Example: finger flexor muscles brachioradiulus & brachialis in the forelimb Body Movements: Muscle Interactions

101

102 Types of Body Movements
Flexion decreases angle of joint, bringing 2 bones closer together common in hinge, ball & socket joints Extension increases the angle of a joint, moving the bones apart hyperextension >180° angle Types of Body Movements

103 Hyperextension Flexion & Extension

104 Flexion & Extension

105 Types of Body Movements
3) Rotation movement of a bone around its longitudinal axis common in ball & socket joints atlas (C1) around the axis (C2) Types of Body Movements

106 Rotation

107 Types of Body Movements
4) Abduction movement of a limb away from the medial plane also used to refer to fanning of finger or toes 5) Adduction movement of a limb toward the midline Types of Body Movements

108 Abduction & Adduction

109 Abduction & Adduction

110 Types of Body Movements
6) Circumduction proximal end is stationary; distal end moves in a circle limb moves in a cone shape common in ball & socket joint combo of flexion, extension, abduction & adduction Types of Body Movements

111 Circumduction

112 Special Body Movements
1) Dorsiflexion (point toes up towards shin) & Plantar Flexion (pointing the toes) Special Body Movements

113 Special Body Movements
2) Inversion (turn sole of foot medially) & Eversion (turn sole of foot laterally) Special Body Movements

114 Special Body Movements
Supination & Pronation movements of the radius around the ulna supination: palm forward; radius & ulna are parallel (anatomical position); thumb lateral pronation: palm facing back; radius crosses ulna; thumb medial Special Body Movements

115 Special Body Movements
Supination & Pronation Special Body Movements

116 Special Body Movements
Opposition movement of thumb across palm to touch fingertips Special Body Movements

117 Elevation & Depression

118 Protraction & Retraction

119 Naming Skeletal Muscles
Direction of muscle fibers in reference to an imaginary line (midline of body, long axis of limb) ie. Rectus (fibers parallel to line) Oblique (fibers at a slant to line) Naming Skeletal Muscles

120 Naming Skeletal Muscles
2) Relative Size Longus = long Longissimus = longest Teres = long and round Brevis = short Magnus = large Major = larger Maximus = largest Minor = small Minimus = smallest Naming Skeletal Muscles

121 Naming Skeletal Muscles
3) Location of the Muscle in reference to the associated bone ie. temporalis (temporal bone) frontalis (frontal bone) Naming Skeletal Muscles

122 Naming Skeletal Muscles
4) Number of origins ie. biceps, triceps, quadriceps Location of the muscle’s origin and insertion ie. Sternocleidomastoid muscle Naming Skeletal Muscles

123 Naming Skeletal Muscles
6) Shape of the muscle ie. Deltoid (triangular) 7) Action of the muscle ie. adductor muscle, extensor muscle Naming Skeletal Muscles

124 Head & Neck Muscles

125 Head and Neck Muscles Facial Muscles Frontalis
raises eyebrows and wrinkles the forehead Orbicularis Oculi close, squint, blink and wink the eyes Orbicularis Oris closes the mouth and protrudes the lips; the “kissing” muscle Head and Neck Muscles

126 Head and Neck Muscles Buccinator
flattens the cheek (whistling or playing a trumpet); also a chewing muscle Zygomaticus “smiling” muscle; raises the corners of the mouth upward Head and Neck Muscles

127 Chewing Muscles Buccinator Head and Neck Muscles Masseter
closes the jaw by elevating the mandible (prime mover) Temporalis helps masseter close the jaw (synergist) Head and Neck Muscles

128 Frontalis Temporalis Zygomaticus Masseter Buccinator Orbicularis oculi
Orbicularis oris Buccinator

129 Temporalis Frontalis Masseter Buccinator Zygomaticus Orbicularis oculi
Orbicularis oris Masseter Buccinator Zygomaticus

130 Frontalis Temporalis Zygomaticus Buccinator Masseter Orbicularis oculi
Orbicularis oris Masseter

131 Neck Muscles Head and Neck Muscles Platysma
pulls down corners of the mouth, downward sag of the mouth Sternocleidomastoid two-headed muscle; flex your neck (bowing of head); tilt head to side Head and Neck Muscles

132 Frontalis Temporalis Zygomaticus Masseter Buccinator Platysma
Orbicularis oculi Zygomaticus Masseter Orbicularis oris Buccinator Sternocleido-mastoid Platysma

133 Temporalis Frontalis Masseter Zygomaticus Buccinator Plastysma
Orbicularis oculi Orbicularis oris Masseter Zygomaticus Buccinator Sternocleidomastoid Plastysma

134 Frontalis Temporalis Zygomaticus Buccinator Masseter platysma
Orbicularis oculi Temporalis Zygomaticus Buccinator Orbicularis oris Masseter platysma Sternocleido-mastoid

135 Trunk Muscles Trunk Muscles move the vertebral column (mostly
posterior, anti-gravity muscles) anterior thorax muscles (move ribs, head & arms) muscles of the abdominal wall (help move vertebral column & form the “girdle” holding internal organs in place) Trunk Muscles

136 Anterior Muscles: Thorax
Pectoralis Major - fan-shaped muscle - origin: sternum, pectoral girdle, ribs - insertion: humerus - adduct & flex the arm Trunk Muscles

137 Pectoralis minor Pectoralis major

138 Anterior Muscles: Thorax
Intercostal Muscles - deep muscles between the ribs - aid in breathing (external – inhale, internal – forcible exhale) Trunk Muscles

139 Internal intercostals External intercostals

140 Anterior Muscles: Abdominal Girdle
Rectus abdominus - pubis to rib cage - flex the vertebral column - compression of abdominal contents Trunk Muscles

141 Anterior Muscles: Abdominal Girdle
External Oblique - lateral walls of abdomen - origin: ribs insertion: illium - flex the vertebral column, rotate/bend trunk Trunk Muscles

142 Anterior Muscles: Abdominal Girdle Internal Oblique
- origin: iliac crest insertion: ribs - function same as external oblique Transversus abdominis - deepest muscle in abdomen - fibers run horizontally - compresses the abdominal contents Trunk Muscles

143

144 Posterior Muscles Trapezius - kite-shaped muscle Trunk Muscles
- origin: occipital bone to last thoracic vertebrae insertion: scapula & clavicle - head extension & movement of scapula Trunk Muscles

145 - 2 large, flat muscles in the lower
Posterior Muscles Latissimus Dorsi - 2 large, flat muscles in the lower back - origin: lower spine & ilium insertion: proximal end of humerus - arm extension & adduction (“power stroke”) Trunk Muscles

146 - prime mover of back extension
Posterior Muscles Erector Spinae - prime mover of back extension (keep your body “erect”); control bending at the waist - paired; deep in the back - span vertebral column Trunk Muscles

147 - posterior abdominal wall
Posterior Muscles Qudratus lumborum - posterior abdominal wall - flex spine laterally, extend vertebral column - origin: iliac crest insertion: upper lumbar vertebrae Trunk Muscles

148 - triangular muscle forming shoulder
Posterior Muscles Deltoids - triangular muscle forming shoulder - origin: spine of scapula to clavicle insertion: proximal humerus - prime mover of arm abduction Trunk Muscles

149

150

151 Muscles of the Upper Limb
The anterior arm muscles cause elbow flexion strongest: brachialis biceps brachii “weakest”: brachioradialis posterior arm: triceps brachii Muscles of the Upper Limb

152 Muscles of the Upper Limb
Anterior Arm Muscles Biceps brachii - origin: 2 heads in pectoral girdle insertion: radius - prime mover of forearm flexion & supination Muscles of the Upper Limb

153 Muscles of the Upper Limb
Anterior Arm Muscles Brachialis - origin: humerus insertion: ulna - forearm flexion Brachioradialis - origin: humerus insertion: distal forearm Muscles of the Upper Limb

154 Muscles of the Upper Limb
Posterior Arm Muscles Triceps brachii - origin: 3 heads in pectoral girdle insertion: olecranon process of ulna - prime mover of elbow extension - biceps brachii antagonist Muscles of the Upper Limb

155

156 Muscles of the Lower Limb
cause movement of hip, knee & foot joints some of the largest, strongest muscles in the body specialized for walking & balance many of the muscles cross 2 joints and can cause movement at both Muscles of the Lower Limb

157 Muscles of the Lower Limb
Muscles that Move the Hip Joint Gluteus Maximus - forms most of the flesh of the buttock - origin: sacrum & illiac insertion: femur & iliotibial tract - hip extensor (important when climbing and jumping) Muscles of the Lower Limb

158 Muscles of the Lower Limb
Muscles that Move the Hip Joint Gluteus Medius - beneath gluteus maximus - hip abductor; steadies pelvis when walking Iliopsoas (two, fused muscles) - prime mover of hip flexion; keeps upper body from falling backward when standing Muscles of the Lower Limb

159 Muscles of the Lower Limb
Muscles that Move the Hip Joint Adductor Muscles - group of muscles; medial thigh - adduct, or press, thighs together - origin: pelvis insertion: femur - tend to get flabby Muscles of the Lower Limb

160 Iliopsoas Adductor muscles Anterior View

161 Posterior View Gluteus medius Gluteus maximus Adductor magnus
Iliotibial tract Posterior View

162 Muscles of the Lower Limb
Muscles that Move the Knee Joint Hamstring Group - group of muscles; posterior thigh - biceps femoris, semimembranosus, semitendinosus - origin: ischium insertion: tibia - prime movers of thigh extension & knee flexion Muscles of the Lower Limb

163 Muscles of the Lower Limb
Muscles that Move the Knee Joint Sartorius - thin, strap-like, relatively weak flexor - most superficial thigh muscle - synergist in sitting “criss cross applesauce” Muscles of the Lower Limb

164 Muscles of the Lower Limb
Muscles that Move the Knee Joint Quadriceps Group - group of muscles; anterior thigh - rectus femoris & 3 vastus muscles - origin: pelvis & thigh insertion: tibia via patellar ligament - prime movers of knee extension; hip flexion Muscles of the Lower Limb

165 Anterior View Iliopsoas Iliopsoas Adductor muscles Sartorius
QUADS Adductor muscles Rectus femoris Vastus lateralis Vastus medialis Anterior View

166 Posterior View

167 Muscles of the Lower Limb
Muscles that Move the Ankle & Foot Tibialis Anterior - superficial muscle of anterior leg (shin) - origin: tibia insertion: tarsals - dorsiflex & invert the foot Fibularis Muscles - plantar flexion and eversion - origin: fibula insertion: metatarsals Muscles of the Lower Limb

168 Muscles of the Lower Limb
Muscles that Move the Ankle & Foot Gastrocnemius - forms curved calf; 2 parts - origin: femur insertion: heel using Achille’s tendon - prime mover of plantar flexion Muscles of the Lower Limb

169 Muscles of the Lower Limb
Muscles that Move the Ankle & Foot Soleus - deep to gastrocnemius - origin: tibia & fibula (no effect on knee) insertion: heel using Achille’s tendon - plantar flexion Muscles of the Lower Limb

170 Posterior View Anterior View

171


Download ppt "Chapter 6: Muscular System"

Similar presentations


Ads by Google