Written Response #1. 1. Based on what you know about Latin root words, what do you think these terms refer to?

Transcription

1 Muscular System

2 Written Response #1 1. Based on what you know about Latin root words, what do you think these terms refer to? Sarcomere Sarcoplasm Myofibril Epimysium Perimysium Endomysium 2. What structure connects muscle to bone?

3 Muscles muscle = myo- or mys- sarco- = flesh - also refers to muscles

4 Main Functions of Muscles 1. Produce movement 2. Maintain posture & body position 3. Stabilize joints 4. Generate heat Additional functions: protect organs, valves, dilate pupils, raise hairs

5 Written Response #2 1. Describe how connective tissue is part of a skeletal muscle. 2. Describe the general structure of a skeletal muscle fiber. 3. Explain why skeletal muscle fibers appear striated. 4. Explain the relationship between the sarcoplasmic reticulum and the transverse tubules.

6 Types of Muscle Skeletal voluntary, striated, multinucleated The word striated means striped. Smooth visceral (lines hollow organs), nonstriated, involuntary Cardiac (heart) striated, involuntary

7 Special Characteristics of Muscle Excitability can receive and respond to stimuli Contractility can shorten forcibly Extensibility can be stretched or extended Elasticity can recoil and resume resting length after being stretched

8 Gross Anatomy of Skeletal Muscle 1 muscle = 1 organ Each muscle served by a nerve, artery and vein Rich blood supply: need energy & oxygen Connective tissue sheaths: wraps each cell and reinforce whole muscle Attachment is either 1. directly to bone 2. by tendons or aponeuroses to bone, cartilage, or other muscles

9 Muscles and Muscle Fiber Structure Muscles are composed of many FIBERS that are arranged in bundles called FASCICLES

10 Individual muscles are separated by FASCIA, which also forms tendons

11 Muscle Structure EPIMYSIUM = outermost layer, surrounds entire muscle. PERIMYSIUM = separates and surrounds fascicles (bundles of muscle fibers) ENDOMYSIUM = surrounds each individual muscle fiber The model to the right uses straws to represent fibers: Green = endomysium Yellow/Brown = perimysium Blue = epimysium

12 Muscle Layers

13 Perimysium Epimysium Endomysium

14 Muscles / Cells Sarcolemma = muscle fiber membrane Sarcoplasm = inner material surrounding fibers (like cytoplasm) Myofibrils = individual parallel muscle fibers, within sarcoplasm

15 Sarcoplasmic Reticulum (SR): specialized smooth ER, surrounds each myofibril Stores and releases calcium T Tubule: part of sarcolemma, conducts nerve impulses to every sarcomere Triggers release of calcium from SR

16 Myofibrils are made of ACTIN = thin filaments MYOSIN = thick filaments Fibers found in muscles.

17 Myofilaments Myofilaments: ACTIN (thin) and MYOSIN (thick) form dark and light bands A band = dark thick (myosin) I band = light thin (actin)

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19 Sacromere The function unit of the muscle fiber. Bundled within the myofibril that runs the entire length of the muscle fiber and attaches to the sarcolemma at its end.

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21 Skeletal Muscle Structures Written Response #3 1. What are the names of the junction points between sarcomeres? 2. What are the names of the subunits within the myofibrils that run the length of skeletal muscle fibers? 3. What is the double strand of pearls described in the video? 4. What gives a skeletal muscle fiber its striated appearance?

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23 Written Response #4: It is important to remember the hierarchy fascicles myofibrils myofilaments actin myosin

24 Sarcomere Filament Coloring - Handout

25 Written Response #5 1. What is the definition of a motor unit? 2. What is the structural and functional difference between a large motor unit and a small motor unit? 3. Give an example of a large motor unit and a small motor unit. 4. Why is the neurotransmitter acetylcholine degraded after binding to its receptor?

26 NEUROMUSCULAR JUNCTION - where a nerve and muscle fiber come together MOTOR END PLATE - folded area where muscle and neuron communicate SYNAPTIC CLEFT - gap between the neuron and motor end plate SYNAPTIC VESICLES - where neurotransmitters are stored these are released into the cleft and tell the muscle to contract

27 How Muscles Work with the Nervous System

28 Motor Unit or Neuromuscular Junction Motor Unit (Neuromuscular Junction) 1. Neuron 2. Sarcolemma (or motor end plate) 3. Vesicle 4. Synapse 5. Mitochondria 6. Receptors 7. Acetylcholine

29 The neurotransmitter that crosses the gap is ACETYLCHOLINE. ACH is broken down by CHOLINESTERASE Acetylcholine is stored in vesicles This is what activates the muscle.

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31 Written Response #6 1. Which biochemical provides the energy to regenerate ATP? 2. What are the sources of oxygen for aerobic respiration? 3. How are lactic acid, oxygen debt, and muscle fatigue related? 4. What is the relationship between cellular respiration and heat production?

32 Sliding Filament Theory (Model) The theory of how muscle contracts is the sliding filament theory. The contraction of a muscle occurs as the thin filament slide past the thick filaments. What is needed: ATP Calcium Myosin & Actin Acetylcholine Cholinesterase

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34 Contraction of Muscle Cell 1. Action potential travels down sarcolemma along T-Tubules 2. Calcium is released from SR 3. Calcium binds to troponin changes shape myosin binding sites exposed on actin 4. Myosin cross-bridge forms with actin 5. Myosin head pivots and pulls actin filament toward M line 6. ATP attaches to myosin and cross-bridge detaches 7. Myosin can be reactivated

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36 Lab: Muscle Fatigue

37 Hank explains muscles and the sliding filament model.

38 Energy Source ATP is produced by CELLULAR RESPIRATION occurs in the mitochondria Creatine phosphate increases regeneration of ATP Only 25% of energy produced during cellular respiration is used in metabolic processes - the rest is in the form of HEAT. maintains body temperature.

39 Written Response #7: Why might products like Pro-Creatine claim to increase energy? ATP = adenosine triphosphate ADP = adenosine diphosphate

40 Other Muscle Terms 1. Threshold Stimulus 2. All-or-None Response 3. Motor Unit 4. Recruitment 5. Muscle Tone 6. Muscular Hypertrophy 7. Muscular Atrophy 8. Muscle Fatigue 9. Muscle Cramp 10. Oxygen Debt

41 Threshold Stimulus: Minimal strength required to cause a contraction Motor neuron releases enough acetylcholine to reach threshold All-or-None Response Fibers do not contract partially, they either do or don't

42 Motor Unit The muscle fiber + the motor neuron Recruitment more and more fibers contract as the intensity of the stimulus increases Muscle Tone Sustained contraction of individual fibers, even when muscle is at rest

43 Hypertrophy Muscles enlarge (working out or certain disorders) Atrophy muscles become small and weak due to disuse

44 Muscle Fatigue muscle loses ability to contract after prolonged exercise or strain Muscle Cramp a sustained involuntary contraction Oxygen Debt oxygen is used to create ATP, -- not having enough oxygen causes Lactic Acid to accumulate in the muscles Soreness Magic School Bus

45 Case Study: The Tired Swimmer Handout Pick up a case study from the front counter. Read and complete independently. Turn in when you have completed.

46 Other Handouts to Complete (Notebook): Muscle Groups Coloring Naming of Muscles Crosswords Muscle Physiology and

47 Written Response #8 1. What is rigor mortis? 2. Explain why rigor mortis occurs after death at the physiological level. Think about what we have learned with the sliding filament theory and respiration to answer this question.

48 Rigor Mortis A few hours after a person or animal dies, the joints of the body stiffen and become locked in place. This stiffening is called rigor mortis. Depending on temperature and other conditions, rigor mortis lasts approximately 72 hours. Crime Scene Investigation

49 Disorders of Muscular System What is tetanus? Tetanus causes cholinesterase to not break down the acetylcholine in the synapse. This results in a person's muscles contracting and not relaxing. A tetanus shot must be administered shortly after exposure to the bacteria. Once you develop tetanus, there is no cure.

50 Muscular System Disorders What is Myotonia? Delayed relaxation of the skeletal muscles after voluntary contraction, electrical stimulation, or even being startled. These fainting goats have myotonia congenita

51 Muscular System Disorders What is myasthenia gravis? Means "grave muscular weakness." Autoimmune disease Acetylcholine receptors are damaged Symptoms A drooping eyelid Blurred vision Slurred speech Difficulty swallowing Weakness / Fatigue

52 Muscular System Disorders What is muscular dystrophy? Muscles progressively get weaker, often resulting in inability to walk, talk or breathe. Duchenne MD occurs in boys (sex-linked inheritance pattern) Video: Gower s Sign

53 Muscular System Disorders ALS, or amyotrophic lateral sclerosis, is a progressive neurodegenerative disease. A-myo-trophic comes from the Greek language. "A" means no. "Myo" refers to muscle, and "Trophic" means nourishment "No muscle nourishment." When a muscle has no nourishment, it "atrophies" or wastes away. The motor nerves that are affected are the motor neurons (motor unit) that provide voluntary movements and muscle control.

54 Poisons that Affect the Neuromuscular Junction Botulism Botulism: rare but serious illness caused by a toxin (from bacteria) that attacks the body s nerves and causes difficulty breathing, muscle paralysis, and even death. Neurotoxin (botulinum) enters nerve cells and eventually interferes with the release of acetylcholine so the nerve cannot stimulate the muscle to contract

55 Poisons that Affect the Neuromuscular Junction Botox? Botox: injectable treatment derived from botulinum. Neurotoxin (botulinum) blocks the release of acetylcholine. Remember botulism

56 Article: If Looks Could Kill Handout Read the article. Complete a summary about the article in 1-2 paragraphs. In another paragraph, choose a stance on whether botox is safe for humans or not and explain your reasoning. This means you should have a total of 2-3 paragraphs.

57 Poisons that Affect the Neuromuscular Junction Strychnine Lowers the threshold level for an action potential, making it more likely the muscles will contract Death occurs from convulsions and asphyxia

58 Poisons that Affect the Neuromuscular Junction Curare Classified as a neuromuscular blocking agent: produces flaccidity (limpness) in skeletal muscle by competing with the neurotransmitter acetylcholine at the neuromuscular junction

59 Pushing the Limits

60 Developmental Aspects Muscles develop from myoblasts (embryonic cells) Muscle fibers formed when myoblasts fuse Newborn: uncoordinated movements, reflexive Regeneration: skeletal & cardiac (very limited); smooth muscle (throughout life) Muscle in Men and Women Women: 36% body mass Men: 42% body mass difference due to testosterone

61 Aging & Muscles With age, muscle mass decreases & become more sinewy (braided and thin) Strength decreases by 50% by age 80 Exercise helps retain muscle mass and strength

62 Types of Contractions Isotonic same tension Muscle length changes Concentric: shortens Eccentric: lengthens Eg. bicep curl, bend knee, smiling Isometric same length Muscle length stays same Tension increases Moving against heavy load or immovable object Eg. lifting heavy weights

63 Isotonic Contractions

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65 How Do Muscles Grow? TEDed

66 Five Golden Rules of Skeletal Muscle 1. All muscles cross at least one joint (a few exceptions). 2. The bulk of muscle lies proximal to the joint crossed. 3. All muscles have at least two attachments: origin and insertion 4. Muscle can only pull; they never push. 5. During contraction, the muscle insertion moves toward origin.

67 Muscle Origin & Insertion Every skeletal muscle is attached to bone or connective tissue at two or more points Origin: attached to immovable (or less movable) bone Insertion: attached to movable bone

68 Muscle Origin & Insertion Origin and Insertion Example: the biceps brachii has two origins (or heads) Action Potential the change in electrical potential, passage of an impulse along the membrane (sarcolemma) of the muscle cell

69 Muscles and Body Movements

70 Types of Ordinary Body Movements Flexion Decreases the angle of the joint Brings two bones closer together Typical of hinge joints like knee and elbow Extension Opposite of flexion Increases angle between two bones

71 Types of Ordinary Body Movements - Hyperextension

72 Types of Ordinary Body Movements Rotation Movement of a bone around its longitudinal axis Common in ball-andsocket joints Example is when you move atlas around the axis vertebra (shake your head no )

73 Types of Ordinary Body Movements Abduction Movement of a limb away from the midline Adduction Opposite of abduction Movement of a limb toward the midline Circumduction Combination of flexion, extension, abduction, and adduction Common in ball-andsocket joints

74 Special Movements Dorsiflexion Lifting the foot so that the superior surface approaches the shin Plantar flexion Depressing the foot (pointing the toes)

75 Special Movements Inversion Turn sole of foot medially Eversion Turn sole of foot laterally

76 Special Movements Supination Forearm rotates laterally so palm faces up (anterior) Pronation Forearm rotates medially so palm faces down (posterior)

77 Special Movements Opposition Move thumb to touch the tips of other fingers on the same hand

78 Major Muscles of the Head and Face A. Epicranius frontalis B. Temporalis C. Epicranius occipitalis D. Orbicularis oculi E. Orbicularis oris F. Zygomaticus G. Masseter H. Sternocleidomastoid I. Platysma J. Trapezius

79 Epicranius frontalis O: Galea aponeurotica I: skin superior to eyebrows F: raise eyebrows and wrinkle forehead Temporalis O: temporal bone I: mandible F: raises the jaw

80 Platysma O: pectoralis major fascia I: mandible F: draws corners of mouth downward and backward Orbicularis oculi O: I: F: closes eyelid

81 Orbicularis oris O: muscle surrounding opening of mouth I: skin at corner of mouth F: compresses and closes lips Zygomaticus O: zygomatic I: fascia at corner of mouth and upper lip F: raises corners of mouth

82 Masseter O: zygomatic bone I: mandible F: closes the jaw Sternocleidomastoid O: clavicle, sternum I: temporal bone, occipital bone F: flexes head; rotates head toward opposite side from muscle

83 Major Muscles of the Chest A. Deltoid B. Triceps brachii (arms) C. Pectoralis major D. Serratus anterior

84 Pectoralis major O: clavicle, sternum, ribs 1-6 I: humerus F: flexes and adducts the upper arm

85 Major Muscles of the Abdomen 1. Serratus anterior 2. External oblique 3. Rectus abdominus 4. Transverse abdominus 5. Internal oblique

86 Serratus anterior O: upper 8 ribs I: scapula F: abduct scapula, depress scapula, hold scapula against rib cage External oblique O: 5 th -12 th ribs I: iliac, abdominal aponeurosis F: depresses ribs, flexes spinal column

87 Rectus abdominus O: pubis I: 5 th -7 th rib cartilage F: compresses the abdomen Transverse abdominus O: iliac, inguinal ligament, lower 6 ribs I: abdominal aponeurosis F:

88 Internal oblique O: iliac, inguinal ligament I: lower 3 ribs, abdominal aponeurosis F: depresses ribs, flexes spinal column

89 Major Muscles of the Back 1. Levator Scapulae 2. Trapezius 3. Deltoid 4. Rhomboid Major 5. Supraspinatus 6. Infraspinatus 7. Teres Minor 8. Teres Major 9. Triceps brachii (arms) 10. Latissimus Dorsi

90 Levator scapulae O: C1-C4 vertebrae I: scapula F: elevate scapula, laterally flex head and neck, rotate head and neck to same side Trapezius O: occipital, C7-T12 vertebrae I: lateral clavicle, spine of scapula F: moves shoulder, extends head

91 Deltoid O: lateral clavicle, spine of scapula I: humerus F: abducts the upper arm Rhomboid major O: T2-T5 vertebrae I: scapula F: adduct scapula, elevate scapula

92 Supraspinatus O: scapula I: humerus F: abduct shoulder Infraspinatus O: scapula I: humerus F: laterally rotate shoulder, adduct shoulder

93 Teres minor O: scapula I: humerus F: adduct shoulder, laterally rotate shoulder Teres major O: scapula I: humerus F: extend shoulder, adduct shoulder

94 Latissimus dorsi O: inferior scapula, T6- T12 vertebrae, last three ribs, iliac I: humerus F: extend shoulder, adduct shoulder, medially rotate shoulder

95 Major Muscles of the Arms (Flexors) A. Biceps brachii B. Pronator teres C. Palmaris longus D. Flexor carpi ulnaris E. Flexor carpi radialis F. Brachioradialis

96 Biceps brachii O: scapula I: radius F: flexes the elbow, flexes the shoulder, supinate forearm Pronator teres O: humerus and ulna I: radius F: pronate forearm

97 Palmaris longus O: humerus I: flexor retinaculum F: tense palmar fascia, flex wrist Brachioradialis O: humerus I: radius F: flex elbow

98 Flexor carpi ulnaris O: humerus and ulna I: pisiform, hamate, 5 th metacarpal F: flex wrist, adduct wrist Flexor carpi radialis O: humerus I: base of 2-3 metacarpals F: flex wrist, abduct wrist

99 Major Muscles of the Arms (Extensors) A. Triceps brachii B. Extensor carpi radialis longus C. Extensor digitorum D. Extensor carpi ulnaris

100 Triceps brachii O: scapula, humerus I: ulna F: extends the lower arm Extensor carpi radialis longus O: humerus I: 2 nd metacarpal F: extend wrist, abduct wrist

101 Extensor digitorum O: humerus I: base of 2-5 fingers F: extend 2-5 fingers Extensor carpi ulnaris O: humerus I: 5 th metacarpal F: extend wrist, adduct wrist

102 Major Muscles of the Upper Leg (Quads) A. Sartorius B. Don t need to know C. Rectus femoris D. Vastus lateralis E. Vastus medialis F. Adductor longus G. Gracilis Rectus femoris, vastus lateralis, vastus medialis make up the quadriceps group

103 Sartorius O: iliac I: proximal, medial shaft of tibia F: flexes hip, laterally rotate hip, abduct hip, flex knee Rectus femoris O: anterior inferior iliac I: tibia F: extends knee and flexes hip

104 Vastus lateralis O: gluteal tuberosity and greater trochanter I: patella F: extend knee Vastus medialis O: medial lip of linea aspera I: patella F: extend knee

105 Adductor longus O: pubic tubercle I: medial linea aspera F: adduct hip, medially rotate hip, flex hip Gracilis O: pubis I: proximal, medial shaft of tibia F: flexes knee, adduct hip, medially rotate hip

106 Major Muscles of the Upper Leg (Hamstrings) A. Gluteus medius B. Gluteus maximus C. Biceps femoris D. Semitendinosus E. Semimembranosus Biceps femoris, semitendinosus and semimembranosus make up the hamstrings group

107 Gluteus maximus O: coccyx, edge of sacrum, iliac I: iliotibial track and gluteal tuberosity F: extends hip, abduct the hip, laterally rotate hip Biceps femoris O: ischium I: fibula head F: flex knee, laterally rotate knee, extend hip, tilt pelvis posterior

108 Semitendinosus O: ischium I: proximal, medial tibia F: flex knee, extend hip, tilt pelvis posterior Semimembranosus O: ischium I: posterior, medial tibia F: flex knee, extend hip, tilt pelvis posterior

109 Major Muscles of the Lower Leg A. Fibularis longus B. Tibialis anterior C. Extensor digitorum longus D. Gastrocnemius E. Soleus F. Flexor digitorum longus

110 Fibularis (peroneus) longus O: head of fibula and lateral fibula I: base of 1 st metatarsal, medial cuneiform F: evert foot Tibialis anterior O: tibia, proximal, lateral tibia I: cuneiform, base of first metatarsal F: invert food, dorsiflex ankle

111 Extensor digitorum longus O: tibia, proximal, anterior fibula I: middle and distal phalanges 2-5 F: extend toes 2-5, dorsiflex ankle, evert foot Gastrocnemius O: inferior femur I: calcaneus F: points toes and flexes the lower leg

112 Soleus O: posterior tibia and fibula I: calcaneus F: extends foot Flexor digitorum longus O: middle, posterior tibia I: distal phalanges 2-5 F: flex toes 2-5, invert foot

113 Frawg Dissections Labs to Complete: 4.1 Observing Skeletal Muscle Through the Microscope 4.2 Identifying The Frog s Muscles 4.3 The Muscles of the Human Body Introduction 4.5 Naming Muscle Movements