1. 1 THE MUSCULAR SYSTEM STRUCTUREANDFUNCTION

2. 2 MUSCLE TISSUE Three types of Muscle tissue Three types of Muscle tissue Skeletal muscle (voluntary) Skeletal muscle (voluntary) Cardiac muscle Cardiac muscle Smooth muscle Smooth muscle Muscle fibers are threadlike, cylindrical cells appearing in bundles with many crosswise stripes and multiple nuclei Muscle fibers are threadlike, cylindrical cells appearing in bundles with many crosswise stripes and multiple nuclei Fascia sheet-like membrane the covers & protects muscle Fascia sheet-like membrane the covers & protects muscle

3. 3 MICROSCOPIC MUSCLE

4. 4 CHARACTERISTICS OF MUSCLE Excitability: irritability, the ability to respond to stimulus such as nerve impulse Excitability: irritability, the ability to respond to stimulus such as nerve impulse Contractibility: fibers stimulated by nerves contract or shorten Contractibility: fibers stimulated by nerves contract or shorten Extensibility: the ability to be stretched or elongate Extensibility: the ability to be stretched or elongate Elasticity: allows the muscle to return to its’ original shape Elasticity: allows the muscle to return to its’ original shape

5. 5 SKELETAL MUSCLE Composed of striated muscle cells and connective tissue Composed of striated muscle cells and connective tissue Attaches to two bones that have a movable joint, under voluntary control Attaches to two bones that have a movable joint, under voluntary control One of the bones is usually One of the bones is usually stationary, called the “origin” stationary, called the “origin” The other bone is usually mobile, called the muscle’s “Insertion” The other bone is usually mobile, called the muscle’s “Insertion”

6. QUICK QUIZ 1.Name 3 types of muscle tissue. 1.Name 3 types of muscle tissue. 2.What is Fascia? 2.What is Fascia? 3.Explain excitability. 3.Explain excitability. 4.What is contractibility? 4.What is contractibility? 5.Explain extensibility. 5.Explain extensibility. 6.What is Elasticity? 6.What is Elasticity? 7. What is the “origin” of a muscle? 7. What is the “origin” of a muscle? 8.What is the “insertion” of a muscle? 8.What is the “insertion” of a muscle? 6

7. 7 TENDONS Tendons anchor muscles firmly to bones Tendons anchor muscles firmly to bones Made of dense, fibrous connective tissue in the shape of heavy cords Made of dense, fibrous connective tissue in the shape of heavy cords Have great strength Have great strength They do not tear or pull away from the bone easily They do not tear or pull away from the bone easily Bursae lie between some tendons and the bones underneath & makes it easier for a tendon to slide over a bone Bursae lie between some tendons and the bones underneath & makes it easier for a tendon to slide over a bone

8. 8 TENDONS AT WORK

9. 9 FUNCTIONS OF SKELETAL MUSCLE PROVIDE VOLUNTARY MOVEMENT PROVIDE VOLUNTARY MOVEMENT MAINTAIN POSTURE OR MUSCLE TONE MAINTAIN POSTURE OR MUSCLE TONE HEAT AND ENERGY PRODUCTION HEAT AND ENERGY PRODUCTION PROTECT INTERNAL ORGANS PROTECT INTERNAL ORGANS

10. 10 SKELETAL MUSCLE MOVEMENT Muscles move bones by pulling on them Muscles move bones by pulling on them The insertion portion of the muscle moves toward the origin The insertion portion of the muscle moves toward the origin Muscle contraction is responsible for body movements Muscle contraction is responsible for body movements Skeletal muscles contract and become shorter, while others relax Skeletal muscles contract and become shorter, while others relax Muscles Work in coordinated teams, not singly Muscles Work in coordinated teams, not singly This coordinated action makes movement smooth and graceful This coordinated action makes movement smooth and graceful

11. 11 MUSCLES OF ARM FLEXION

12. Quick Quiz 9. What anchors muscle to bone? 9. What anchors muscle to bone? 10. What is the function of Bursae? 10. What is the function of Bursae? 11. Name 4 functions of skeletal muscle. 11. Name 4 functions of skeletal muscle. 12. How do muscles move bone? 12. How do muscles move bone? 13. What happens to muscle during contraction? 13. What happens to muscle during contraction? 14. What happens to muscle origin during contraction? 14. What happens to muscle origin during contraction? 15. Why is movement smooth & graceful? 15. Why is movement smooth & graceful? 12

13. 13 MEDICAL TERMS: PRIME MOVER: the MUSCLE that is mainly responsible for producing the movement PRIME MOVER: the MUSCLE that is mainly responsible for producing the movement SYNERGISTS: muscles that assist the prime mover SYNERGISTS: muscles that assist the prime mover ANTAGONISTS: muscles that have the opposing actions ANTAGONISTS: muscles that have the opposing actions

14. 14 POSTURE Poor posture makes a person tire more quickly by putting pull on ligaments,joints, & bones Poor posture makes a person tire more quickly by putting pull on ligaments,joints, & bones Poor posture crowds the heart making it harder to contract Poor posture crowds the heart making it harder to contract Poor posture crowds the lungs decreasing breathing capacity Poor posture crowds the lungs decreasing breathing capacity

15. 15 Muscle Tone Muscles are partially contracted at all times Muscles are partially contracted at all times Muscle tone: state of readiness to act Muscle tone: state of readiness to actFATIGUE If muscle cells are stimulated repeatedly without adequate rest, strength of muscle contraction decreases, resulting in Fatigue. If muscle cells are stimulated repeatedly without adequate rest, strength of muscle contraction decreases, resulting in Fatigue.

16. Quick Quiz 16. What is the muscle responsible for movement called? 16. What is the muscle responsible for movement called? 17. What is the muscle responsible for the opposite movement called? 17. What is the muscle responsible for the opposite movement called? 18. What happens when muscles are stimulated repeatedly without rest? 18. What happens when muscles are stimulated repeatedly without rest? 19. What is the “state of muscle readiness to act” called? 19. What is the “state of muscle readiness to act” called? 20. What crowds the heart & lungs & makes a person tire more quickly? 20. What crowds the heart & lungs & makes a person tire more quickly? 16

17. 17 MUSCLE MOVEMENTS FLEXION FLEXION EXTENSION EXTENSION ABDUCTION ABDUCTION ADDUCTION ADDUCTION ROTATION/CIRCUMDUCTION ROTATION/CIRCUMDUCTION SUPINATION/PRONATION SUPINATION/PRONATION DORSIFLEXION/PLANTAR FLEXION DORSIFLEXION/PLANTAR FLEXION SEE PAGE 187 SEE PAGE 187

18. 18 HEAT PRODUCTION Normal body temperature: 98.6 F Normal body temperature: 98.6 F (37 C) (37 C) Muscle Contractions produce most heat required to maintain temperature Muscle Contractions produce most heat required to maintain temperature Hypothermia: failure to maintain normal body temperature in cold environment Hypothermia: failure to maintain normal body temperature in cold environment

19. 19 BODY SYSTEMS AFFECTING MOVEMENT Skeletal Skeletal Muscular Muscular Respiratory Respiratory Circulatory Circulatory Nervous Nervous Remember the body is one Remember the body is one large interactive system each large interactive system each part depending on normal part depending on normal function of other parts function of other parts

20. 20 TYPES OF SKELETAL MUSCLE CONTRACTION Twitch..quick, jerky response to stimulus Twitch..quick, jerky response to stimulus Tetanic..sustained and steady response Tetanic..sustained and steady response Isontonic..muscle shortens and produces movement of joints Isontonic..muscle shortens and produces movement of joints Isometric..type contraction where the muscle does not shorten Isometric..type contraction where the muscle does not shorten see page 215 see page 215

21. 21 TONIC CONTRACTION A special type of skeletal muscle contraction used to maintain posture A special type of skeletal muscle contraction used to maintain posture Skeletal muscle tone maintains posture by counteracting the pull of gravity Skeletal muscle tone maintains posture by counteracting the pull of gravity

22. 22 MUSCLE MOVEMENT Before skeletal muscle contracts, it must be stimulated by nerve impulses Before skeletal muscle contracts, it must be stimulated by nerve impulses Motor neuron..nerve fiber that stimulates a muscle fiber Motor neuron..nerve fiber that stimulates a muscle fiber Neuromuscular junction..point of contact between nerve and muscle Neuromuscular junction..point of contact between nerve and muscle Motor unit..single neuron and the muscle cells it innervates Motor unit..single neuron and the muscle cells it innervates

23. 23 MUSCLE STIMULUS Threshold stimulus..minimal level of stimulation required to cause a fiber to contract Threshold stimulus..minimal level of stimulation required to cause a fiber to contract All or none…subjected to a threshold stimulus, muscle contracts completely All or none…subjected to a threshold stimulus, muscle contracts completely

24. Quick Quiz 21.What is a twitch? 21.What is a twitch? 22.What is a tetanic contraction? 22.What is a tetanic contraction? 23.What causes skeletal muscle to contract? 23.What causes skeletal muscle to contract? 24.What is an isotonic contraction? 24.What is an isotonic contraction? 25.What is an isometric contraction? 25.What is an isometric contraction? 26.What is the minimal level of stimulation required to cause a fiber to contract called? 26.What is the minimal level of stimulation required to cause a fiber to contract called? 27.What is the neuromuscular junction? 27.What is the neuromuscular junction? 28.What is normal body temperature? 28.What is normal body temperature? 29. What is abnormally low body temperature? 29. What is abnormally low body temperature? 24

25. Demonstrate the following: Flexion and Extension Flexion and Extension Abduction and adduction Abduction and adduction Supination and pronation Supination and pronation Rotation and circumduction Rotation and circumduction Dorsiflexion and plantarflexion Dorsiflexion and plantarflexion 25

26. 26 SKELETAL MUSCLE GROUPS Muscles of the Head & Neck Upper extremity muscles Muscles of the Trunk Muscles of the lower extremity

27. 27 MUSCLES OF THE HEAD & NECK Muscles of facial expression around eyes, mouth,nose Muscles of facial expression around eyes, mouth,nose Large mastication muscles Large mastication muscles Neck muscles connect skull to trunk, rotate head and bend neck Neck muscles connect skull to trunk, rotate head and bend neck See page 218 See page 218

28. 28 HEAD & NECK MUSCLES Facial Expression: Facial Expression: Frontal raises eyebrows, furrow forehead skin Frontal raises eyebrows, furrow forehead skin Orbicularis oculi closes eyes Orbicularis oculi closes eyes Orbicularis oris puckers lips to kiss Orbicularis oris puckers lips to kiss Zygomaticus elevates corners of mouth & lips (smiling muscles) Zygomaticus elevates corners of mouth & lips (smiling muscles) Mastication: Mastication: Masseter elevates mandible Masseter elevates mandible Temporal closes jaw see page 181 Temporal closes jaw see page 181

29. 29 HEAD & NECK MUSCLES Neck: Neck: Sternocleidomastoids flexes,tilts,rotates head Sternocleidomastoids flexes,tilts,rotates head Trapezius elevates shoulders, extends head backwards Trapezius elevates shoulders, extends head backwards See pages 218 See pages 218

30. 30 UPPER EXTREMITY MUSCLES Pectoralis major flexes upper arm Pectoralis major flexes upper arm Latissinus dorsi extends upper arm Latissinus dorsi extends upper arm Deltoid abducts upper arm Deltoid abducts upper arm Biceps brachii primary flexor of forearm Biceps brachii primary flexor of forearm Triceps brachii extensor of elbow (boxer’s muscle) see page 222 Triceps brachii extensor of elbow (boxer’s muscle) see page 222

31. INTRAMUSCULAR INJECTIONS DELTOID used for injection 2ml/cc or less DELTOID used for injection 2ml/cc or less GLUTEUS MAXIMUS used for larger volume or viscous medications GLUTEUS MAXIMUS used for larger volume or viscous medications Page 221 Page 221 31

32. 32 MUSCLES OF THE TRUNK ANTERIOLATERAL ABDOMINALS ANTERIOLATERAL ABDOMINALS External oblique External oblique Internal oblique Internal oblique Transversus abdominis Transversus abdominis Rectus abdominis Rectus abdominis RESPIRATORY MUSCLES RESPIRATORY MUSCLES Intercostals Intercostals Diaphragm See page 219 Diaphragm See page 219

33. 33 MUSCLES OF LOWER EXTREMITIES Iliopsoas flexes the thigh or trunk Iliopsoas flexes the thigh or trunk Gluteus maximus supports torso in erect position, forms the buttocks,extends thigh Gluteus maximus supports torso in erect position, forms the buttocks,extends thigh Adductor muscles adduct or press the thighs together Adductor muscles adduct or press the thighs together Hamstrings flexors of the lower leg Hamstrings flexors of the lower leg Quadriceps femoris extend lower leg Quadriceps femoris extend lower leg

34. Muscle groups at work 34

35. 35 MUSCLES OF LOWER EXTREMITIES Tibialis anterior dorsiflexes foot Tibialis anterior dorsiflexes foot Gastrocnemius plantar flexes foot Gastrocnemius plantar flexes foot Soleus Plantar flexes the foot Soleus Plantar flexes the foot Peroneus group plantar flexes foot Peroneus group plantar flexes foot

36. MUSCLE DISORDERS MYALGIA… general muscle pain MYALGIA… general muscle pain MYOSITIS..muscle inflammation MYOSITIS..muscle inflammation SPASMS..Sudden, painful involuntary contraction, cramps due to fluid and electrolyte imbalance SPASMS..Sudden, painful involuntary contraction, cramps due to fluid and electrolyte imbalance STRAIN..Overstretching injury of muscle or tendon STRAIN..Overstretching injury of muscle or tendon SPRAIN.. an injury to the ligaments around a joint. SPRAIN.. an injury to the ligaments around a joint. 36

37. Sprained ankle 37

38. 38

39. CARPAL TUNNEL SYNDROME Compression of the median nerve within the passage along the ventral wrist causing muscle weakness, pain, and tingling on the thumb side of the wrist, hand, and fingers. Compression of the median nerve within the passage along the ventral wrist causing muscle weakness, pain, and tingling on the thumb side of the wrist, hand, and fingers. Treatment: Treatment: Injection of anti-inflammatory agents, steroids Injection of anti-inflammatory agents, steroids Surgical removal of the tissue pressing on the median nerve Surgical removal of the tissue pressing on the median nerve 39

40. MUSCLE DISORDERS MUSCULAR DYSTROPHY..chronic, progressive muscle atrophy resulting in disability & early death MUSCULAR DYSTROPHY..chronic, progressive muscle atrophy resulting in disability & early death POLIOMYELITIS.. A viral infection of the nerves that control skeletal muscle POLIOMYELITIS.. A viral infection of the nerves that control skeletal muscle RIGOR MORTIS… derived from the Latin, it means “stiffness of Death RIGOR MORTIS… derived from the Latin, it means “stiffness of Death 40

41. MUSCLE DISORDERS MYASTHENIA GRAVIS..chronic condition where nerve impulses are not properly transmitted to the muscles. MYASTHENIA GRAVIS..chronic condition where nerve impulses are not properly transmitted to the muscles. Affects respiratory system Affects respiratory system Can be fatal Can be fatal Thought to be autoimmune disease Thought to be autoimmune disease Progressive muscle weakness, paralysis Progressive muscle weakness, paralysis No cure, supportive treatment only No cure, supportive treatment only 41

42. 42 THE END