C HAPTER 6 – T HE M USCULAR S YSTEM. M USCLE V OCABULARY Bi = 2; Tri = 3; Quad = 4; Ceps = Heads...
-
Upload
primrose-rachel-dalton -
Category
Documents
-
view
219 -
download
0
Transcript of C HAPTER 6 – T HE M USCULAR S YSTEM. M USCLE V OCABULARY Bi = 2; Tri = 3; Quad = 4; Ceps = Heads...
CHAPTER 6 – THE MUSCULAR SYSTEM
MUSCLE VOCABULARYBi = 2; Tri = 3; Quad = 4; Ceps =
Heads Biceps = 2 Heads Triceps = 3 Heads Quadriceps = 4 Heads
Brachium = Arm Example: Brachialis
Communis = Common Example: Extensor Digitalis
Communis
MUSCLE VOCABULARY, CONT’D
Deltoid = Triangle Example: Deltoideus
Digastric = Two Bellies Extrensic = From the Outside Fascia = Band or Girdle
Example: Superficial Fascia; Deep Fascia
Femoris = Thigh or Femur Example: Biceps Femoris
MUSCLE VOCABULARY, CONT’D
Glossus = Tongue Gluteus = Pertaining to the Buttocks
Example: Gluteus Maximus, Gluteus Medias, Gluteus Minimus
Dorsi = On or of the Back Example: Latissimus Dorsi
Intrinsic = Within or Inside Gracilis = Slender Infra = Below or Inferior
MUSCLE VOCABULARY, CONT’D
Latissimus = WidestExample: Latissimus Dorsi
Longissimus = Longest Masseter = Chewer Maximus = Largest Minimus = Smallest Myology = Study of Muscles Oblique = Slanted Orbicularis = An Orb or Circle
MUSCLE VOCABULARY, CONT’D
Pectoralis = Breasts and Chest Quadratus = Four Sides or Square
Example: Quadrilaterals Rectus = Straight Semi = Prefix denoting Half
Example: Semipermeable Membrane
Supra = Above or upon Example: Supraspinatus
I. OVERVIEW OF MUSCLE TISSUES
~ Muscles make up approximately 40% of Body Mass~
A.Characteristics of MusclesSkeletal and smooth muscle cells are elongated (muscle cell = muscle fiber)
Contraction of muscles is due to the movement of microfilaments (myofibril)
All muscles share some terminologyPrefixes myo and mys refer to “muscle”
Prefix sarco refers to “flesh”
Muscle Types (Know anatomy of skeletal muscle #1 – diagram and terms)
I. OVERVIEW OF MUSCLE TISSUES…CONT’D
TendonBelly
Epimysium
PerimysiumEndomysium
Fiber (Cell)
Bundle
Sarcolemma – Cell MembraneSarcoplasm – Cell Cytoplasm
I. OVERVIEW OF MUSCLE TISSUES…CONT’D
B.Muscle Functions1. Produces movement2. Maintains posture3. Stabilizes joints4. Generates heat
II. PROVIDING ENERGY FOR MUSCLE
CONTRACTIONS ~ ATP – Source of energy for contractions~A.Muscle Fatigue – unable to
contract while being stimulated. Due to:Oxygen Debt
Depends on blood supplyLactic Acid builds up (sore & tired muscles)
Oxygen debt payback rapid, deep breathing
Low supply of ATP
B.Types of ContractionsIsotonic – muscle shortens & movement occursex: bending knee, rotating arm, smiling
Isometric – tension increases; muscle does not shortenex: pushing against a wall
II. PROVIDING ENERGY FOR MUSCLE CONTRACTIONS, CONT’D
C.Muscle ToneSustained partial contractionDue to nerve supplyKeeps muscle healthy & ready to react
Paralysis – no stimulation; muscle becomes flaccid & atrophy
II. PROVIDING ENERGY FOR MUSCLE CONTRACTIONS, CONT’D
D. Effects of Exercise on Muscle“Use it or Lose it”Aerobic (endurance) Exercise
Does little to increase massStronger, Flexible, Less fatigueBenefits: skeletal muscle, metabolism, digestion (elimination), neuromuscular coordination, skeleton, blood vessels, lungs
Ex: jogging, biking, aerobics
II. PROVIDING ENERGY FOR MUSCLE CONTRACTIONS, CONT’D
D. Effects of Exercise on Muscle, Cont’d…
Resistance exercise – isometricMuscles contract with force
Enlarges muscle cellsEx: Weightlifting
II. PROVIDING ENERGY FOR MUSCLE CONTRACTIONS, CONT’D
1.All muscles cross at least one joint.2.Typically, the bulk of the muscle lies
proximal to the joint crossed.3.All muscles have at least two
attachments: the origin and th insertion.
4.Muscles can only pull; they never push.
5.During contraction, the muscle insertion moves toward the origin.
THE 5 GOLDEN RULES OF SKELETAL MUSCLE ACTIVITY: (TABLE 6.2)
III. MUSCLE MOVEMENTS, TYPES & NAMES
A. Types of Body MovementsOrigin: attached to the immovable or less movable bone
Insertion: attached to movable bone
III. MUSCLE MOVEMENTS, TYPES & NAMES, CONT’D
Flexion – Decreases the angle of the joint
Extension – increases the angle
Abduction – moving away from midline
Adduction – moving toward midline
III. MUSCLE MOVEMENTS, TYPES & NAMES, CONT’D
Rotation – movement around longitudinal axis
Circumduction – circular motion
Depression – movement downward
Pronation – face down
III. MUSCLE MOVEMENTS, TYPES & NAMES, CONT’D
Supination – face upDepression – movement
downwardElevation – movement
upwardRetraction – movement
posteriorly
III. MUSCLE MOVEMENTS, TYPES & NAMES, CONT’D
Inversion – sole faces medially
Eversion – sole faces laterally
Dorsiflection – heel down, sole up; “flex”
Plantar Flexion – toe down, heel up; “point”
III. MUSCLE MOVEMENTS, TYPES & NAMES, CONT’D
B. Types of MusclesPrime Mover: muscle with major responsibility for a particular motion
Antagonists: muscle that acts in opposition to prime moverEx: Elbow flexion
Biceps – Prime MoverTriceps - Antagonist
III. MUSCLE MOVEMENTS, TYPES & NAMES, CONT’DB. TYPES OF MUSCLES, CONT’D
Synergist: muscles cooperating with another to produce a movement; stabilize jointsEx: Finger flexors; make fist without bending wrist
Fixators: stabilize the origin of a prime moverEx: Muscles that anchor scapula to thorax
III. MUSCLE MOVEMENTS, TYPES & NAMES, CONT’D
B. Naming Skeletal Muscles1. Direction of muscle fiber2. Relative size of the muscle3. Location of the muscle4. Number of origins5. Location of origin &
insertion6. Shape of Muscle7. Action of the muscle
IV. DEVELOPMENTAL ASPECTS OF THE
MUSCULAR SYSTEMMuscle develops early in embryo –
16th weekCongenital disease – muscular
dystrophyMuscle fibers degenerate and
atrophyEx: Duchenne Muscular
DystrophyMost common and seriousMales 2-6; wheelchair 12;
death – young adult
IV. DEVELOPMENTAL ASPECTS OF THE MUSCULAR SYSTEM
Muscle ControlReflex – at birth (nervous system
must mature)Develops – cephalic to caudal and
proximal to distalSkeletal muscles – rich in blood
supply; resist infectionAging – muscle tissue decreases Decreased body weight Decreased strength