2 So what do muscles do?Muscles move cows, snakes, worms and humans. Muscles move you!Without muscles you couldn't open your mouth, speak, shake hands, walk, talk, or move your food through your digestive system.There would be no smiling, blinking, breathing. You couldn't move anything inside or outside you.
3 Do I have lots of muscles? On average, probably 40% of your body weight is in muscles.You have over 630 muscles that move you.Muscles can't push. They pull. Muscles often work in pairs so that they can pull in different or opposite directions.
4 How do muscles move?The cells that make up muscles contract and then relax back to original size.Tiny microscopic fibers in these cells compress by sliding in past each other like a sliding glass door being opened and then shut again.The cells of your muscles use chemical energy from the food you eat to do this.Without food, and particular kinds of nutrients, your muscles wouldn't be able to make the energy to contract!
5 Some muscles are known as "voluntary" -- that is, they only work when you specifically tell them to. Do you want to say something? Or swing a bat? Or clap your hands? These are voluntary movements.Others, like the muscular contracting of your heart, the movement of your diaphragm so that you can breathe, or blinking your eyes are automatic. They're called involuntary movements.And how do any of these muscles move? Through signals from your nerves, and, in some cases, your brain, as well.
6 Can you hurt muscles? Yes If you hear someone say that they "pulled" a muscle, they have, in fact, torn a muscle in the same way that you can tear a ligament or break a bone.
7 Muscle FactsYou have over 30 facial muscles which create looks like surprise, happiness, sadness, and frowning.Eye muscles are the busiest muscles in the body. Scientists estimate they may move more than 100,000 times a day!The largest muscle in the body is the gluteus maximus muscle in the buttocks.
8 3 Types of Muscles 1. CARDIAC MUSCLE: The cardiac muscles is the muscle of the brain itself.The cardiac muscle is the tissue that makes up the wall of the heart called the mydocardium. Also like the skeletal muscles, the cardiac muscle is striated and contracts through the sliding filament method.However it is different from other types of muscles because it forms branching fibers.Unlike the skeletal muscles, the cardiac muscle is attached together instead of been attach to a bone.
9 2. SKELETAL MUSCLE:The skeletal muscle makes up about 40 % of an adults body weight.It has stripe-like markings, or striations.The skeletal muscles is composed of long muscle fibers.Each of these muscles fiber is a cell which contains several nuclei.The nervous system controls the contraction of the muscle.Many of the skeletal muscle contractions are automatic. However we still can control the action of the skeletal muscle. And it is because of this reason that the skeletal muscle is also called voluntary muscle.
10 3. SMOOTH MUSCLE:Much of our internal organs is made up of smooth muscles.They are found in the urinary bladder, gallbladder, arteries, and veins.Also the digestive tract is made up of smooth muscle as well.The smooth muscles are controlled by the nervous system and hormones. We cannot consciously control the smooth muscle that is why they are often called involuntary muscles.
13 DELTOIDORIGIN Lateral third of clavicle, acromion, spine of scapula to deltoid tubercleINSERTION Middle of lateral surface of humerus (deltoid tuberosity)ACTION Abducts arm, anterior fibers flex and medial rotate, posterior fibers extend and lateral rotate NERVE Axillary nerve (C5, 6) (from posterior cord)
14 TRAPEZIUSORIGIN Medial third superior nuchal line, ligament nuchae, spinous processes and supraspinous ligaments to T12INSERTION Upper fibers to lateral third of posterior border of clavicle; lower to medial acromion and superior lip of spine of scapula to deltoid tubercleACTION laterally rotates, elevates and retracts scapula. If scapula is fixed, extends and laterally flexes neckNERVE Spinal accessory nerve (C1-5)(spinal nerves C3 and C4 for proprioception)
15 STERNOCLEIDOMASTOIDORIGIN Anterior and superior manubrium and superior medial third of clavicleINSERTION Lateral aspect of mastoid process and anterior half of superior nuchal lineACTION Flexes and laterally rotates cervical spine. Protracts head when acting together . Extends neck when neck already partially extendedNERVE Spinal accessory nerve (lateral roots C1-5)
16 PECTORALIS MAJORORIGIN Clavicular head-medial half clavicle. Sternocostal head-lateral manubrium and sternum, six upper costal cartilages and external oblique aponeurosisINSERTION Lateral lip of bicipital groove of humerus and anterior lip of deltoid tuberosityACTION Clavicular head:flexes and adducts arm. Sternal head: adducts and medially rotates arm . Accessory for inspirationNERVE Medial pectoral nerve (from medial cord) and lateral pectoral nerve (from lateral cord) (C6, 7, 8)
17 EXTERNAL ABDOMINAL OBLIQUE ORIGIN Anterior angles of lower eight ribsINSERTION Outer anterior half of iliac crest, inguinal lig, public tubercle and crest, and aponeurosis of anterior rectus sheathACTION Supports abdominal wall, assists forced expiration, aids raising intraabdominal pressure and, with muscles of opposite side, abducts and rotates trunkNERVE Anterior primary rami (T7-12)
18 GLUTEUS MAXIMUSORIGIN Outer surface of ilium behind posterior gluteal line and posterior third of iliac crest lumbar fascia, lateral mass of sacrum, sacrotuberous ligament and coccyxINSERTION Deepest quarter into gluteal tuberosity of femur, remaining three quarters into iliotibial tract (anterior surface of lateral condyle of tibia)ACTION Extends and laterally rotates hip. Maintains knee extended via iliotibial tractNERVE Inferior gluteal nerve (L5, S1,2)
19 GLUTEUS MEDIUSORIGIN Outer surface of ilium between posterior and middle gluteal linesINSERTION Posterolateral surface of greater trocanter of femurACTION Abducts and medially rotates hip. Tilts pelvis on walkingNERVE Superior gluteal nerve (L4,5,S1)
20 BICEPS FEMORISORIGIN Long head: upper inner quadrant of posterior surface of ischial tuberosity. Short head:middle third of linea aspera, lateral supracondylar ridge of femur INSERTION Styloid process of head of fibula. lateral collateral ligament and lateral tibial condyleACTION Flexes and laterally rotates knee. Long head extends hipNERVE Long head: tibial portion of sciatic nerve. Short head: common peroneal portion of sciatic nerve (both L5, S1)
21 PERONEUS LONGUSORIGIN Upper two thirds of lateral shaft of fibula , head of fibula and superior tibiofibular joint INSERTION Plantar aspect of base of 1st metatarsal and medial cuneiform, passing deep to long plantar ligamentACTION Plantar flexes and everts foot. Supports lateral longitudinal and transverse archesNERVE Superficial peroneal nerve (L5,S1)
22 TIBIALIS ANTERIORORIGIN Upper half of lateral shaft of tibia and interosseous membraneINSERTION Inferomedial aspect of medial cuneiform and base of 1st metatarsalACTION Extends and inverts foot at ankle. Holds up medial longitudinal arch of footNERVE Deep peroneal nerve (L4, 5)
23 VASTUS LATERALISORIGIN Upper intertrochanteric line, base of greater trochanter, lateral linea aspera, lateral supracondylar ridge and lateral intermuscular septumINSERTION Lateral quadriceps tendon to patella, via ligamentum patellae into tubercle of tibiaACTION Extends kneeNERVE Posterior division of femoral nerve (L3,4)
24 VASTUS MEDIALISORIGIN Lower intertrochanteric line, spiral line, medial linea aspera and medial intermuscular septumINSERTION Medial quadriceps tendon to patella and directly into medial patella, via ligamentum patellae into tubercle of tibiaACTION Extends knee. Stabilizes patellaNERVE Posterior division of femoral nerve (L3,4)
25 TRICEPSORIGIN Long head: infraglenoid tubercle of scapula. lateral head: upper half posterior humerus (linear origin). medial head: lies deep on lower half posterior humerus inferomedial to spiral groove and both intermuscular septaINSERTION Posterior part of upper surface of olecranon process of ulna and posterior capsuleACTION Extends elbow. Long head stabilizes shoulder joint. medial head retracts capsule of elbow joint on extensionNERVE Radial nerve (C7, 8) (from posterior cord ), four branches
26 LATISSIMUS DORSIORIGIN Spine T7, spinous processes and supraspinous ligaments of all lower thoracic, lumbar and sacral vertebrae, lumbar fascia, posterior third iliac crest, last four ribs (interdigitating with external oblique abdominis) and inferior angle of scapulaINSERTION Floor of bicipital groove of humerus after spiraling around teres majorACTION Extends, adducts and medially rotates arm. Costal attachment helps with deep inspiration and forced expirationNERVE Thoracodorsal nerve (C6, 7, 8) (from posterior cord)
Your consent to our cookies if you continue to use this website.