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The Muscular System.

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Presentation on theme: "The Muscular System."— Presentation transcript:

1 The Muscular System

2 Objectives Indicate primary functions of muscles
Identify and distinguish between three types of muscle in terms of location, structure, components, appearance, purpose Describe shapes associated with muscle, list an example of each


4 The Muscular System Muscles are responsible for all movement of the body, support and strengthen the skeletal frame by connecting to bone, provide heat as a by- product There are three basic types of muscle Skeletal Cardiac Smooth

5 Info About Muscles Only body tissue able to contract
Movement created by flexing and extending joints Body energy converters (many muscle cells contain many mitochondria)

6 3 Types of Muscles

7 Classification of Muscle
Skeletal- found in limbs Cardiac- found in heart Smooth- Found in organs of body cavities (viscera) Striated, multi- nucleated Striated, 1 nucleus Not striated, 1 nucleus voluntary involuntary

8 Three types of muscle Skeletal Cardiac Smooth

9 Characteristics of Muscle
Skeletal and smooth muscle are elongated Muscle cell diff. than other “typical” cells Size (much bigger) Skeletal multinucleated

10 Characteristics of Muscle
Contraction of a muscle is due to movement of microfilaments (protein fibers) All muscles share some terminology Prefixes myo and mys refer to muscle Prefix sarco refers to flesh

11 Skeletal Muscle Most are attached by tendons to bones
Cells have more than one nucleus (multinucleated) Striated- have stripes, banding Voluntary- subject to conscious control Tendons are mostly made of collagen fibers Found in the limbs

12 Structure of skeletal muscle
Each cell (fibre) is long and cylindrical Muscle fibres are multi-nucleated Typically 50-60mm in diameter, and up to 10cm long The contractile elements of skeletal muscle cells are myofibrils

13 Skeletal muscle - Summary
Voluntary movement of skeletal parts Spans joints and attached to skeleton Multi-nucleated, striated, cylindrical fibres

14 Smooth Muscle No striations Spindle shaped Single nucleus
Involuntary- no conscious control Found mainly in the walls of hollow organs

15 Smooth muscle Lines walls of viscera
Found in longitudinal or circular arrangement Alternate contraction of circular & longitudinal muscle in the intestine leads to peristalsis

16 Structure of smooth muscle
Spindle shaped uni-nucleated cells Striations not observed Actin and myosin filaments are present( protein fibers)

17 Smooth muscle - Summary
Found in walls of hollow internal organs Involuntary movement of internal organs Elongated, spindle shaped fibre with single nucleus

18 Cardiac Muscle Striations Branching cells Involuntary
Found only in the heart Usually has a single nucleus, but can have more than one

19 Cardiac muscle Main muscle of heart Pumping mass of heart
Critical in humans Heart muscle cells behave as one unit Heart always contracts to it’s full extent

20 Structure of cardiac muscle
Cardiac muscle cells (fibres) are short, branched and interconnected Cells are striated & usually have 1 nucleus Adjacent cardiac cells are joined via electrical synapses (gap junctions) These gap junctions appear as dark lines and are called intercalated discs

21 Cardiac muscle - Summary
Found in the heart Involuntary rhythmic contraction Branched, striated fibre with single nucleus and intercalated discs

22 Shapes of Muscles Triangular- shoulder, neck Spindle- arms, legs
Flat- diaphragm, forehead Circular- mouth, anus

23 Objectives Distinguish between origin and insertion
Explain the difference between twitch and tetanus Explain the difference between isotonic and isometric contractions. Provide an example of each List the muscles associated with the muscles of the head and neck

24 Objectives cont. List, identify and describe movement associated with the 6 muscles of the face List, identify and describe movement associated with 2 muscles involved in mastication List, identify and describe movement associated with primary muscle of the neck

25 How are Muscles Attached to Bone?
Origin-attachment to a movable bone Insertion- attachment to an immovable bone Muscles are always attached to at least 2 points Movement is attained due to a muscle moving an attached bone

26 Muscle Attachments Insertion Origin
Muscles attach in at least two places in the body. *The origin is the attachment that moves the least. *The insertion is the attachment that moves the most. This diagram illustrates the origin and insertion of one of the neck muscles. Note the origin is on the clavicle and sternum. The insertion is on the skull. When the muscle contracts it will shorten the distance between the origin and insertion. The head will move when this muscle contracts. Remember the insertion is the end of the muscle that moves the most. Since the head moves the attachment on the head is called the insertion. The origin is generally on a larger body part will move the least. The chest does not move when this muscle contract. The bones in the chest are therefore the origin.

27 Types of Responses Twitch- Tetanus A single brief contraction
Not a normal muscle function Tetanus One contraction immediately followed by another Muscle never completely returns to a relaxed state Effects are compounded “Disease” caused by bacteria entering dirty wound complication includes severe cramping due to cont. tetanic contractions

28 Where Does the Energy Come From?
Energy is stored in the muscles in the form of ATP ATP comes from the breakdown of glucose during Cellular Respiration This all happens in the Mitochondria of the cell When a muscle is fatigued (tired) it is unable to contract because of lack of Oxygen

29 Exercise and Muscles Isotonic- muscles shorten and movement occurs ( most normal exercise) Isometric- tension in muscles increases, no movement occurs (pushing one hand against the other, pushing against a wall); energy is still used! Athletes use this to strengthen joints, burn calories while minimizing enlargement of muscle mass

30 The Skeletal Muscles There are about 650 muscles in the human body
The Skeletal Muscles There are about 650 muscles in the human body. They enable us to move, maintain posture and generate heat. In this section we will only study a sample of the major muscles. There are about 650 muscles in the human body. They enable us to move, maintain posture and generate heat. In this unit will only study a sample of the major muscles.

31 Naming of Muscles Each named in terms of appearance, location, action or relation to other structures Latin or Greek in origin

32 Muscles of the Head and Neck
Includes muscles that provide facial expressions, muscles involved in chewing and muscles in the neck that aid in movement Muscles of Facial Expression Muscles of Mastication Neck Muscle

33 Muscles of Facial Expression
Several muscles act on facial structures to provide manipulation of facial movement Frontalis Occipitalis Orbicularis Orbicularis oris Buccinatior Zygomaticus

34 Muscles of Facial Expression
Frontalis Forehead Raises the eyebrows Occipitalis Located on lower back of head Pulls scalp backward

35 Muscles of Facial Expression
Orbicularis oculi Surrounds each eye Closes eye, squinches eye Orbicularis oris Surrounds mouth Closes mouth

36 Muscles of Facial Expression
Buccinator In conjuction w/orbicularis oculi and orbicularis oris enables mouth to pucker Also flattens cheeks to enable whistling/blowing


38 Muscles of Facial Expression
Zygomaticus Corner of mouth Smiling


40 Muscles of Mastication
Two major muscles involved in chewing (mastication) Masseter Extends from zygomatic process of temporal bone to the mandible Closes mouth; can be felt on inside jaw during chewing Temporalis Occupies most of temporal bone Closes mouth


42 Neck Muscle Sternocleidomastoid Anterior and posterior sides of neck
From anterior view, origin of the two sternocleidomastoids forms a “V” at base of neck Allows movement of the head; contraction of both muscles will flex the head, contraction of one will cause rotation

43 Neck Muscle - Sternocleidomastoid
Allows head movement

44 Objectives Define trapezius in terms of description, location, movement List 4 muscles associated with pectoral girdle and their overall purpose Define pectoralis major, latissimus dorsi and deltoid in terms of description, location, movement and any abbreviations each may have

45 Objectives List purpose of rotator cuff muscles
Define triceps and biceps in terms of description, location, number of origins, movement Differentiate between posterior and anterior movement of wrist and fingers

46 Upper Limb Muscles Include those that attach and support the pectoral girdle, upper limb and those those move the arm, forearm and hand Muscles of Pectoral Girdle Muscles that Move the Arm Muscles that Move the Forearm Muscles that move the Fingers

47 Upper-Limb Muscles Muscles of the Pectoral Girdle
Connection of girdle to thorax supported by group of muscles Trapezius Diamond shaped, extends from base of the skull to the middle of the back Contraction causes scapula to move up and down; rotates shoulder

48 Upper-Limb Muscles

49 Upper Limb Muscles Levator scapulae Rhomboids Serratus anterior
Origin:1st four cervical vertebrae Rhomboids Origin: 7th cervical and 1st five thoracic vertebrae Serratus anterior Origin: 1st eight ribs Pectoralis minor Origin: Ribs 3-5 Hold together scapula when arm muscles contract

50 Upper Limb Muscles Levator Scapulae Rhomboid

51 Upper Limb Muscles

52 Muscles That Move the Arm
Pectoralis Major Forms upper chest Flexes arm; adducts and medially rotates arm Activities: climbing, throwing, push ups Pectoralis Major

53 Muscles That Move the Arm
Latissmus dorsi – “lat” “swimmers muscle” Upper back Extend arm; adduct and medially rotates arm Activities: swimming, using a hammer, pushing yourself up Deltoid Wraps over shoulder; delta shaped Abducts arm; helps extend/flex humerus Common injection site

54 Muscles That Move the Arm

55 Muscles That Move the Arm
Rotator Cuff Muscles Each of the following originate on scapula and help form cap over end of humerus Rotator cuff injury involves injury to one or more of these muscles Subscapularis Supraspinatus Infraspinatus Teres minor

56 Muscles That Move the Arm

57 Muscles That Move the Forearm
Divided into anterior and posterior Triceps brachii Brachioradialis Biceps brachii Brachialis

58 Muscles That Move the Forearm
Triceps Back of upper arm Three origins – two back of humerus, one on scapula Movement extends elbow joint Brachioradialis Help anterior muscles flex forearm

59 Muscles That Move the Forearm
Biceps brachii Front of upper arm Two origins – both on scapula Flexes forearm; supinates the hand Brachialis Helps posterior muscles flex the forearm

60 Muscles That Move the Forearm

61 Muscles That Move the Hand and Fingers
Divided anteriorly and posteriorly 20 muscles Anterior side provide flexion of wrist and digits Posterior side provide extension Tendons of these muscles can be seen through surface of forearm when muscles contract

62 Objectives Define the 3 types of muscle that are incorporated into trunk muscles List the major muscle of the vertebral column; define it’s purpose Define the 3 muscles associated with the thorax; define their individual purpose Explain the overall purpose of the abdominal muscles Define the 4 muscles associated with the abdominal region; list their location and individual purpose

63 Objectives Explain the overall purpose of the abdominal muscles
Define the 4 muscles associated with the abdominal region; list their location and individual purpose List the most prominent ab muscle and where the linea alba is located

64 Trunk Muscles Muscles of the trunk include muscle groups that move
Vertebral column Thorax Abdominal wall

65 Trunk muscles Vertebral Column Muscles Erector spinae
Allow twisting, bending, stretching Provide support, erect posture Erector spinae Originates near sacrum, extends up length of back Functions to straighten back and provides side-to-side rotation

66 Trunk Muscles Muscles of the Thorax Mainly involved in breathing
External intercostals Elevate the ribs during inspiration  thorax expansion Internal intercostals Depress the ribs during forced expiration Diaphragm Expands the thorax by compressing the abdomen for inspiration

67 Trunk Muscles

68 Trunk Muscles

69 Trunk Muscles Breathing

70 Trunk Muscles Muscles of the Abdominal Wall Multilayered
Provides support to upper body, aids in breathing, protects inner organs, helps posture Rectus Abdominis External oblique Internal oblique Transverse abdominis

71 Trunk Muscles Rectus Abdominis Most well-known and prominent ab muscle
Long, flat muscle extends vertically between pubis and 5-7th rib Provides curvature of spine, allows pelvic tilt movement

72 Trunk Muscles Rectus Abdominis Most well-known and prominent ab muscle
Long, flat muscle extends vertically between pubis and 5-7th rib Provides curvature of spine, allows pelvic tilt movement Divided down the middle by linea alba (white line) and horizontally at three location by tendinous inscriptions ‘washboard’ look

73 Trunk Muscles

74 Trunk Muscles

75 Trunk Muscles External Oblique Internal Oblique
Lower eight ribs; located on each side of rectus abdominis Allows torso to turn side to side, compression of abdomen Internal Oblique Deep muscles (just below) external oblique Allow flexing of spine, trunk rotation, compression of abdomen

76 Trunk Muscles Transverse Abdominis
Deepest layer of abdominal muscle; wraps around torso from ribs to pelvis Helps with respiration and breathing

77 Trunk Muscles

78 Objectives List three muscles that flex the thigh, know what side of the leg they are associated with List location of the IT band Define the two groups of muscles associated with the leg Differentiate between anterior thigh muscles and posterior thigh muscles in terms of individual muscles and muscle movement List the different grades of muscle injury

79 Objectives List the Muscles that move the foot and toes based on the three groups Define muscles in each of the three groups in terms of individual muscles and movements where applicable

80 Lower-limb Muscles Muscles that move the thigh
Muscles that move the leg Muscles that move the foot and toes

81 Lower Limb Muscles Muscles that move the thigh Iliopsoas
Anterior side Flex thigh Tensor fasciae latae Lateral side of the pelvis Abducts, flexes, medially rotates thigh Flexes the iliotibial-tract tendon (IT band)

82 Lower Limb Muscles

83 Lower Limb Muscles Gluteus maximus Posterior side of the pelvis
Abducts and medially rotates thigh Common site for injection

84 Muscles That Move the Leg
Muscles that move the leg are located in the thigh Two groups Anterior Thigh Muscles Extend the leg and flex thigh Posterior Thigh Muscles Flex the leg and extend thigh

85 Muscles That Move the Leg
Anterior Thigh Muscles Sartorius Long, narrow muscle “Tailor’s muscle” – flexing thigh and leg, rotating leg laterally Quadriceps femoris (4 muscles) Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius Originate from four different origins “quad”

86 Muscles That Move the Leg

87 Muscles That Move the Leg
Posterior Thigh Muscles Hamstring Muscles Flex leg and extend thigh Biceps femoris, Semitendinosus, Semimembranosus Name from Butcher shop Pig tendons suspended ham during curing

88 Muscles That Move the Leg
Common injury in athletes One or more hamstring muscles or tendons become overstretched leading to tear pulled hamstring Grade 1: Mild strain, Few muscle fibers torn Grade 2 : Moderate strain, definite loss in strength Grade 3: Complete tear

89 Muscles That Move the Foot & Toes
Divided into three groups Anterior Posterior Lateral

90 Muscles That Move the Foot & Toes
Anterior Muscles Extensors – provide dorsiflexon of foot, extension of toes Tibialis anterior, extensor digitoum longus Posterior Muscles Gastrocnemius Soleus

91 Muscles That Move The Foot & Toes

92 Muscles That Move The Foot & Toes
Lateral Muscles Peroneus longus Plantar flexion Peroneus tertius Dorsiflexion

93 http://www. fofweb. com/activelink2. asp

94 Objectives MD- origin, pathology, symptoms, treatment
Charley horse –pathology, symptoms ALS – origin, pathology, symptoms, treatment Myalgia – origin, treatment Fibromyalgia – origin, pathology, symptoms, diagnosis, treatment

95 Muscle Conditions Muscular Dystrophy Charley Horse ALS Myalgia

96 Muscle Conditions Muscular Dystrophy
Origin:1860- boys w/common progressively worsening muscle condition documented; French neurologist Duchenne gave detailed account of 13 boys w/severe form Duchenne Muscular Dystrophy Group of inherited muscle diseases in which muscle fibers are unusually susceptible to damage Muscles(voluntary) become progressively weak Most common type due to genetic deficiency of muscle protein dystrophin

97 Muscle Conditions Symptoms Treatment Muscle weakness
Apparent lack of coordination Progressive crippling, loss of mobility Treatment No cure PT/OT/Speech Therapy Orthopedic instruments (wheelchairs standing frames) Medications can slow progression

98 Muscle Conditions

99 Muscle Conditions Charley horse
Injury to muscle resulting in its tearing, leading to intense, prolonged pain; bleeding can occur Frequently occurs at quadriceps Contact sports- athlete struck by opponents knee (like being kicked by a horse) Nuance term for severe cramping in leg/foot Hormonal imbalances, dehydration, low potassium/calcium, sign of ALS

100 Muscle Conditions

101 Muscle Conditions ALS Amyotrophic lateral sclerosis/ Lou Gehrig’s disease Degeneration of neurons Causes death to motor nerve cell that transmits messages to muscles

102 Muscle Conditions

103 Muscle Conditions Symptoms Treatment
Muscle atrophy- lose ability to initiate and control all voluntary movement Weakness in one or more of the following: Hands, arms, legs or muscles of speech Difficulty swallowing, gags or chokes easily Fasciculation (twitching) Spasticity Treatment No cure Drug(s) used to control symptoms and help QOL

104 Muscle Conditions Myalgia Muscle pains
Most people experience it at least once in lifetime Can range from mild to severe, lasting days to months Accompanies many infectious diseases Influenza, measles, toxoplasmosis Treatment NSAID(ibuprofen) reduce swelling Gentle exercise if due to inactive lifestyle

105 Muscle Conditions Fibromyalgia
Long term, body wide pain and tenderness in joints, muscles, tendons, soft tissue Pain areas are called tender points. Pain radiates out from these spots: Neck (back) Shoulders Chest Lower back Hips Shins Knees

106 Muscle Conditions

107 Muscle Conditions Diagnosed if wide spread pain >3 months and pain in multiple areas Treatment PT, Exercise program, light massage If above don’t work: antidepressant, muscle relaxant Goal of med: Improve sleep and pain tolerance

108 Case #1 A 51year old woman developed an unusual gait related to ‘calf stiffness’. After several months of progressive weakness, she developed a right foot drop. She also described having difficulty writing out checks and fasciculation in her right leg. What could a potential diagnosis be? What symptoms are leading you to believe this? What medications/therapy would you recommend?

109 Case #2 An 18-month-old boy was referred to a specialist after his mother noticed he tired more easily than other children his age. He had full range of motion in his arms and legs and was walking by himself. Although he moved fairly well from sitting to standing he used a modified Gower’s maneuver. (Pushing up with hands on knees/legs with bottom up to achieve standing position). His neck muscle and upper extremity strength was satisfactory. His cognitive function appeared to be normal.

110 Case #2 cont. What is potential diagnosis?
What signs/symptoms help you reach this? What are your therapy/medication recommendations? What are future options?

111 Case #3 A 56 year-old woman reports to her doctor that she has trouble getting up in the morning. She often has “morning stiffness” that lasts throughout the day leading to her not wanting to get out of bed. Some mornings are worse than others leaving her feeling as though she has the flu but no irregular temperature or vomiting is present. When she is asked where she feels pain she signals to her back and shoulders. She appears to be in otherwise healthy condition including normal BMI and vitals.

112 Case #3 cont. What could a potential diagnosis be?
What symptoms helped you identify this? What treatment should be recommended?

113 Case #4 Richard is a 42 year old man who seems to be in good health as of last year. He is at a normal BMI, has acceptable vitals and a stress free job. Recently he has started to have trouble doing leisure activities like playing golf and fishing. His complaint includes an inability to grip the club or pole as well and he's more likely to drop it while using it. He decided to see a doctor from the constant requests of his wife. He says he has no other complaints.

114 Case #4 continued What are some further questions you would like to ask? (Hint: Think about the diseases -ask questions to eliminate possibilities) Question 1: Question 2: What do you think a potential diagnosis could be? What symptoms? What recommendations would you make?

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