Muscular System

1. Muscular System

2. Structure of muscle • Individual muscles are separated from other muscles and held in position by Fascia – a dense connective tissue surrounding muscle. • A sheath of tissue around a muscle, similar to periosteum around bone • Fascia will project beyond the end of the muscle to form a tendon – connects muscle to bone. • Tendonitis - irritation or inflammation of a tendon. • Coloring sheet 35

3. Structure of muscle • Individual muscles are separated from other muscles and held in position by Fascia – a dense connective tissue surrounding muscle. • A sheath of tissue around a muscle, similar to periosteum around bone • Fascia will project beyond the end of the muscle to form a tendon – connects muscle to bone. • Tendonitis - irritation or inflammation of a tendon. • Coloring sheet 35

4. Structure of muscle • Individual muscles are separated from other muscles and held in position by Fascia – a dense connective tissue surrounding muscle. • A sheath of tissue around a muscle, similar to periosteum around bone • Fascia will project beyond the end of the muscle to form a tendon – connects muscle to bone. • Tendonitis - irritation or inflammation of a tendon. • Coloring sheet 35

5. Structure of muscle • Muscles work by contracting (not flexing). • Pull on bones to move joints • Create movement by shortening • They can only shorten and lengthen

6. Structure of muscle • Surrounding the entire muscle group is the epimysium – “epi” outside, “mysium” muscle • The belly of a muscle is made of large clusters of muscle tissue – fascicle • Around a fascicle is perimysium – “peri” around, “mysium” muscle • Dividing the fascicle into smaller cluster of muscle fibers is endomysium –”endo” inside, “mysium” muscle. • Muscle fibers are made of clusters of myofibrils – the unit of muscle that actually contracts allowing muscle movement.

7. Structure of muscle • Myofibrils, which are the contracting element of muscles are made of 2 parts • Thick myosin • Thin actin • Coloring sheet 10

8. Structure of muscle • Myofibrils, which are the contracting element of muscles are made of 2 parts • Thick myosin • Thin actin • Coloring sheet 10

9. Structure of muscle • Myofibrils, which are the contracting element of muscles are made of 2 parts • Thick myosin • Thin actin • Coloring sheet 10

10. Structure of muscle • Myofibrils, which are the contracting element of muscles are made of 2 parts • Thick myosin • Thin actin • Coloring sheet 10

11. Contraction of muscle • Sliding Filament Theory – the theory that explains how muscles contract. • Sarcomereis functional unit of skeletal muscle • Actin slides past myosin shortening the sarcomere. • H-bands and I-bands shorten • Musclular contraction

12. Structure of muscle • Each muscle is stimulated by a motor neuron – nerve responsible for muscular action • The site of connection – Neuromuscular Junction – • Each muscle fiber has 1 motor neuron • Together, the neuron and muscle fiber are a motor unit. • The signal to contract is called a neurotransmitter – a chemical that causes a body response (kind of like a hormone). • Acetylcholine (Ach) – used in skeletal muscle. • Coloring Sheet 36

13. Structure of muscle • ATP and Calcium are necessary for muscle contraction and relaxation. • This is why it is cellular respiration and lactic acid fermentation are important (ATP), as well as Calcium stores in the bones. • If O2 is present, cellular respiration may occur. In lack of O2, lactic acid fermentation happens.

14. Structure of muscle • Types of muscular contraction • Isotonic muscular contraction - movement • Concentric – shortening of muscle • Eccentric – lengthening of muscle • Isometric Muscular contraction – no movement • Muscle tension increases, but length stays the same. • Both types are needed • Walking - isometric is required to create stability and keep upright, isotonic are required to move.

15. Structure of muscle • Muscle tone – continuous contraction of muscles • It is necessary to have slight contraction in muscles all the time. • Why would it be important to have muscle tone? • Core musculature

16. Structure of muscle • Slow-twitch muscles (type I) – cellular respiration, efficiently use O2 to resist fatigue • Long distance runners, aerobic • Often called red fibers – because they contain red oxygen storing pigment called myoglobin. • Fast-twitch muscles (type IIa) – lactic acid fermentation, lack O2 • Fewer mitochondria than type I fibers • Hand muscles, eye muscles • aka White fibers – lacks myoglobin

17. Structure of muscle • Fast-twitch fatigue-resistant muscles (type IIb) – • Speed associated with white fibers, but use O2 like red fibers • We usually try to call groups fast-twitch or slow-twitch but all muscle groups have a combination of all types, but % of each may vary.

18. Structure of muscle • Skeletal muscle – consciously controlled • Smooth muscle – not consciously controlled, normally associated with organs and organ systems

19. Structure of muscle – coloring sheet 9 • Smooth muscle shape is different than skeletal muscle. • Skeletal muscle – elongated, cylindrical shaped, many nuclei in each fiber • Smooth muscle – shorter, fat center with tapered ends, single nucleus

20. Structure of muscle – coloring sheet 9 • Smooth muscle shape is different than skeletal muscle. • Skeletal muscle – elongated, cylindrical shaped, many nuclei in each fiber • Smooth muscle – shorter, fat center with tapered ends, single nucleus

21. Structure of muscle – coloring sheet 9 • Smooth muscle shape is different than skeletal muscle. • Skeletal muscle – elongated, cylindrical shaped, many nuclei in each fiber • Smooth muscle – shorter, fat center with tapered ends, single nucleus

22. Structure of muscle • Visceral Smooth Muscle – • Visceral – organs, subconsciously controlled • Sheets of muscle controlled by a single nerve, so impulse is passed through cells. Unlike skeletal muscle • Contraction is rhythmic and wave-like • Peristalsis – occurs in tubular organs such as digestive tract. • Rhythmic waves of contraction to move something • Digestive tract, reproductive systems, urinary system

23. Structure of muscle • Visceral Smooth Muscle – • Neurotransmitters – Ach, and norepinephrine • Each will stimulate some smooth muscles and excite others • That is why during stress or exercise the digestive system slows down, but then speeds up during rest. Yet heart works the exact opposite. • Hormones affect smooth muscle contraction • Oxytocin stimulates uterus to contract during child birth. • Stretching can induce contractions – urinary bladder and intestines

24. Structure of muscle • Cardiac muscle – only in heart • Has characteristics of both smooth and skeletal muscle • The ends of cardiac muscle cells connect and form cross-bands called intercalated disks

25. Structure of muscle • Cardiac muscle – only in heart • Has characteristics of both smooth and skeletal muscle • He ends of cardiac muscle cells connect and form cross-bands called intercalated disks

26. Structure of muscle • Cardiac muscle – only in heart • Has characteristics of both smooth and skeletal muscle • He ends of cardiac muscle cells connect and form cross-bands called intercalated disks

27. Indentifying Skeletal muscles • Origin – immovable attachment of a muscle • Insertion – movable end of a muscle • Biceps Brachii has to origins, hence the term biceps (2 heads) • Orign – glenoidfossa and coracoid process • Insertion – Radial tuberosity, just distal to the head

28. Indentifying Skeletal muscles – coloring sheet 37 • Prime Mover – large muscle mostly responsible for movement • Synergists – muscles that contract to help prime mover • Antagonist – muscles that resist prime mover. • All work to move and stabilize joints. Prime movers are responsible for movement while synergists and antagonists support joints. It is impossible not to contract biceps while bench pressing, but it is not a biceps lift. In this case, it is an antagonist. Core muscles also help to support and assist contraction.

29. Muscles of face - coloring sheet 38 • Facial expression – innervated by Facial Nerve • Epicranius(frontalis & occipitalis) – o. occipital bone, i. skin around eyes, f. raise eyebrows as in surprise • OrbicularisOculi – o. maxillary and frontal bones, i. skin around eyes, f. close eyes as in blinking • OrbicularisOris – o. Muscles near mouth, i. skin of lip, f. closes lips, protrudes lips • Buccinator – o. outer surface of maxilla and madible, i. Orbicularisoris, f. Compressischeecks inward when blowing air or sucking on a straw.

30. Muscles of face • Facial expression – innervated by Facial Nerve • Zygomaticus – o. zygomatic bone, i. Orbicularisoris, f. Raises corner of mouth as when smiling • Platysma –o. Fascia of upper chest, i. border of mandible, f. Draws angle of mouth downward when frowning

31. Muscles of face – coloring sheet 39 • Mastication – Eating, innervated by Trigeminal Nerve • Masseter – o. Zygomatic bone, i. Mandible, f. Elevates mandible • Temporalis – o. Temporal bone, i. Mandible, f. Elevates mandible • Medial pterygoid– o. Sphenoid, palatine, and maxillary bone, i. Medial surface of mandible, f. Elevates mandible and moves it side to side • Lateral pterygoid – o. Sphenoid bone, i. Anterior mandible, f. Protracts mandible and moves side to side

32. Muscles of neck • Sternocleidomastoid – o. Anterior sternum and clavicle, i. Mastoid process of temporal bone, f. Turn head to side and pulls head to chest • coloring sheet 40

33. Muscles of neck • Sternocleidomastoid – o. Anterior sternum and clavicle, i. Mastoid process of temporal bone, f. Turn head to side and pulls head to chest • coloring sheet 40

34. Muscles of pectoral girdle – coloring sheet 46 • Trapezius (aka trap) – o. occiputal spine, i. clavicle and acromion process of scapula, f. Rotate scapula, raise scapula and pull shoulder and scapula downward. • Rhomboid major – o. Upper thoracic spine, i. Medial border of scapula, f. Raises, adducts scapula • Levator scapulae – o. cervical spine, i. Medial scapula, f. Elevate scapula

35. Muscles of pectoral girdle – coloring sheet 46 • Trapezius (aka trap) – o. occiputal spine, i. clavicle and acromion process of scapula, f. Rotate scapula, raise scapula and pull shoulder and scapula downward. • Rhomboid major – o. Upper thoracic spine, i. Medial border of scapula, f. Raises, adducts scapula • Levator scapulae – o. cervical spine, i. Medial scapula, f. Elevate scapula

36. Muscles of pectoral girdle – coloring sheet 46 • Trapezius (aka trap) – o. occiputal spine, i. clavicle and acromion process of scapula, f. Rotate scapula, raise scapula and pull shoulder and scapula downward. • Rhomboid major – o. Upper thoracic spine, i. Medial border of scapula, f. Raises, adducts scapula • Levator scapulae – o. cervical spine, i. Medial scapula, f. Elevate scapula

37. Muscles of pectoral girdle – coloring sheet 46 • Trapezius (aka trap) – o. occiputal spine, i. clavicle and acromion process of scapula, f. Rotate scapula, raise scapula and pull shoulder and scapula downward. • Rhomboid major – o. Upper thoracic spine, i. Medial border of scapula, f. Raises, adducts scapula • Levator scapulae – o. cervical spine, i. Medial scapula, f. Elevate scapula

38. Muscles of pectoral girdle – coloring sheet 46 • Serratus Anterior – o. outer surface of upper ribs, i. Ventral surface of scapula, f. Pulls scapula anterior and downward • Pectoralis minor – o. Sternal end of upper ribs, i. Coracoid process of scapula, f. Pull scapula forward.

39. Muscles of pectoral girdle – coloring sheet 46 • Serratus Anterior – o. outer surface of upper ribs, i. Ventral surface of scapula, f. Pulls scapula anterior and downward • Pectoralis minor – o. Sternal end of upper ribs, i. Coracoid process of scapula, f. Pull scapula forward.

40. Muscles of pectoral girdle – coloring sheet 46 • Serratus Anterior – o. outer surface of upper ribs, i. Ventral surface of scapula, f. Pulls scapula anterior and downward • Pectoralis minor – o. Sternal end of upper ribs, i. Coracoid process of scapula, f. Pull scapula forward.

41. Muscles of pectoral girdle – coloring sheet 46 • Serratus Anterior – o. outer surface of upper ribs, i. Ventral surface of scapula, f. Pulls scapula anterior and downward • Pectoralis minor – o. Sternal end of upper ribs, i. Coracoid process of scapula, f. Pull scapula forward.

42. Muscles that move the arm – coloring sheet 48 • Coracobrachialis – o. Coracoid process, i. Shaft of humerus, f. Flex and adduct arm. • Pectorais major –o. clavicle, sternum, costal cartilage of upper ribs, i. Humerus, f. Flex adduct and rotate arm medially • LatissimusDorsi (aka lats) – o. spine, iliac crest, lower ribs, i. Humerus, f. Extend, adduct arm, pulls shoulder downward and back. • Deltoid – o. acromion process, spine of scapula and clavicle, i. Deltoid tuberosity of humerus, f. Abduct, extend and flex arm.

43. Muscles that move the arm – coloring sheet 48 • Coracobrachialis – o. Coracoid process, i. Shaft of humerus, f. Flex and adduct arm. • Pectorais major –o. clavicle, sternum, costal cartilage of upper ribs, i. Humerus, f. Flex adduct and rotate arm medially • LatissimusDorsi (aka lats) – o. spine, iliac crest, lower ribs, i. Humerus, f. Extend, adduct arm, pulls shoulder downward and back. • Deltoid – o. acromion process, spine of scapula and clavicle, i. Deltoid tuberosity of humerus, f. Abduct, extend and flex arm.

44. Muscles that move the arm – coloring sheet 48 • Coracobrachialis – o. Coracoid process, i. Shaft of humerus, f. Flex and adduct arm. • Pectorais major –o. clavicle, sternum, costal cartilage of upper ribs, i. Humerus, f. Flex adduct and rotate arm medially • LatissimusDorsi (aka lats) – o. spine, iliac crest, lower ribs, i. Humerus, f. Extend, adduct arm, pulls shoulder downward and back. • Deltoid – o. acromion process, spine of scapula and clavicle, i. Deltoid tuberosity of humerus, f. Abduct, extend and flex arm.

45. Muscles that move the arm – coloring sheet 48 • Coracobrachialis – o. Coracoid process, i. Shaft of humerus, f. Flex and adduct arm. • Pectorais major –o. clavicle, sternum, costal cartilage of upper ribs, i. Humerus, f. Flex adduct and rotate arm medially • LatissimusDorsi (aka lats) – o. spine, iliac crest, lower ribs, i. Humerus, f. Extend, adduct arm, pulls shoulder downward and back. • Deltoid – o. acromion process, spine of scapula and clavicle, i. Deltoid tuberosity of humerus, f. Abduct, extend and flex arm.

46. Muscles that move the arm – coloring sheet 48 • Coracobrachialis – o. Coracoid process, i. Shaft of humerus, f. Flex and adduct arm. • Pectorais major –o. clavicle, sternum, costal cartilage of upper ribs, i. Humerus, f. Flex adduct and rotate arm medially • LatissimusDorsi (aka lats) – o. spine, iliac crest, lower ribs, i. Humerus, f. Extend, adduct arm, pulls shoulder downward and back. • Deltoid – o. acromion process, spine of scapula and clavicle, i. Deltoid tuberosity of humerus, f. Abduct, extend and flex arm.

47. Muscles that move the arm – coloring sheet 47 • Rotator cuff – 4 muscles • Supraspinatus – abducts the arm • Subscapularis – rotates the arm medially • Infraspinatus – rotates the arm laterally • Teres minor – rotates arm laterally

48. Muscles that move the arm – coloring sheet 47 • Rotator cuff – 4 muscles • Supraspinatus – abducts the arm • Subscapularis – rotates the arm medially • Infraspinatus – rotates the arm laterally • Teres minor – rotates arm laterally

49. Muscles that move the forearm- coloring sheet 49 • Biceps Brachii– o. coracoid process, i. Radius, f. flex forearm and rotate hand laterally • Brachialis – o. anterior shaft of humerus, i. Coronoid process of ulna, f. Flex forearm • Brachioradialis – o. distal lateral end of humerus, i. lateral surface of radius above styloid, f. Flex forearm at elbow • Triceps brachii – o. Inferior glenoidfossa, lateral and medial humerus, i. olecranon process of ulna, f. extend forearm

50. Muscles that move the forearm- coloring sheet 49 • Biceps Brachii– o. coracoid process, i. Radius, f. flex forearm and rotate hand laterally • Brachialis – o. anterior shaft of humerus, i. Coronoid process of ulna, f. Flex forearm • Brachioradialis – o. distal lateral end of humerus, i. lateral surface of radius above styloid, f. Flex forearm at elbow • Triceps brachii – o. Inferior glenoidfossa, lateral and medial humerus, i. olecranon process of ulna, f. extend forearm