Unit V - Movement Muscle Movement Biomechanics Chapter 10

Muscle Functions Movement Stability Urinary system 0.7% Respiratory system 1.7% Nervous system 2% Digestive system 6% Lymphatic system 0.3% Reproductive system 0.15% Endocrine system 0.15% Cardiovascular system 9% Integumentary system 16% Skeletal 20% Muscular system 44% Movement Stability Center of gravity is low and centered Lower lumbar area Control of openings and passageways Heat production

Connective Tissues of Muscle Perimysium Muscle fascicle Endomysium Epimysium Nerve Muscle fibers Blood vessels Muscle fiber and nerves Tendon Capillary Myofibril Myosatellite cells Axon of neuron Endomysium Fascicles Perimysium Epimysium Fascia

Deep and Superficial Fascia Tendon Deep fascia Epimysium Perimysium Superficial Fascia Fascicle Endomysium Deep Fascia

Attachment to Bone Two forms: Direct (fleshy) attachment Ex. intercostal muscles Indirect attachment E.x. biceps brachii Aponeurosis E.x. scalp, abdominal, lumbar, hand and foot muscles Retinaceum E.x. wrist

General Anatomy of Muscles Origins Origins Origin stationary attachment Insertion mobile attachment Belly thicker, middle region Humerus Scapula Bellies Extensors: Flexors: Triceps brachii Biceps brachii Long head Brachialis Lateral head Insertion Radius Insertion Ulna

4 Types of Muscles Classified according to their actions: Prime mover or agonist E.x. biceps brachii when elbow is flexed Synergist E.x. brachioradialis in flexing the elbow Antagonist E.x. triceps brachii in flexing the elbow Fixator E.x. muscles attached to scapula prevent its movement when biceps brachii contracts MUSCLES CANNOT PUSH – ONLY PULL!

5 Types of Muscles Based on orientation of fascicles: Pennate Sphincter Temporalis (Quadriceps) Sartorius Masseter Gastrocnemius Orbicularis oris

Intrinsic and Extrinsic Muscles Intrinsic muscles (hand) Extrinsic muscles Seen in tongue, larynx, back, hands, and feet

Names of Muscles Terms used to name muscles levator = elevates a body part Inferior = bottom quadriceps = having 4 heads sternocleidomastoid = bones attached to

Biomechanics Lever – an elongated, rigid object that rotates around a fixed point called the fulcrum. Rotation occurs when an effort applied to one point on the lever overcomes a resistance at some other point. fulcrum – joint effort – applied by a muscle resistance – an object the body is working against Mechanical Advantage (MA) – ratio of its output force to its input force MA = LE/ LR LE = the length of the effort arm LR = the length of the resistance arm If MA > 1.0 the lever produces more force but has less speed or distance If MA < 1.0 the lever produces more speed or distance but less force

Types of Levers First Class Fulcrum is in the middle Atlanto-occipital joint

The resistance is in the middle Types of Levers Second Class The resistance is in the middle Mandible

Types of Levers Third Class The effort is applied in the middle The forearm when flexing the elbow

Range of Motion Degrees through which a joint can move Determined by: structure of the articular surfaces strength and tautness of ligaments, tendons and joint capsule action of the muscles and tendons Resting muscle maintains a state of tension – muscle tone

Final Exam! Unit V: Chapters: 4, 9, 10 Lab: muscle tissue and manual questions names of muscles and action produced (lab pgs 124-126) OR: Cumulative: (same amount of points) First 4 units - tests, quizzes, in class review questions Unit 5 Lab: muscle tissue and manual questions