Chapter 10 The Muscular System

1. Chapter 10The Muscular System • Muscles of the head and neck • Muscles of the trunk • Muscles acting on the shoulder and arm • Muscles acting on the hip and leg

2. The Functions of Muscles • 600 Human skeletal muscles • Movement of body parts and organ contents • Maintain posture and prevent movement • Communication - speech, expression & writing • Control of openings and passageways • Body heat production

3. Connective Tissues of a Muscle Tendon Deep fascia Epimysium Perimysium Endomysium

4. Connective Tissues of a Muscle • Epimysium • covers whole muscle belly • Perimysium • surrounds a bundle of cells called a fascicle • Endomysium • thin layer surrounding each cell • oPEN

5. Muscle Attachments • Direct attachment to bone • epimysium is continuous with periosteum • intercostal muscles • Indirect attachment to bone • epimysium continues as tendon • biceps brachii

6. Parts of a Skeletal Muscle • Origin • attachment to stationary end of muscle • First in a muscle name (if the name allows it) • Insertion • attachment to mobile end of muscle • End of the muscle name (if the name allows it)

7. Coordinated Muscle Actions • AGONIST: the muscle that causes a desired action, also called the Prime Mover. • ANTAGONIST: produces an opposite action (Anti to agonist) • SYNERGIST: steady a movement, thus preventing unwanted movements and helping the agonist • the extensor carpi muscles act as synergists for the flexor digitorum muscles (Try it) • FIXATORS: synergist muscles which stabilize the origin of the agonist so that it can act more efficiently (shoulder muscles)

8. Muscle Actions during Elbow Flexion • Prime mover (agonist) = biceps brachii m. • Synergist = brachialis m. • Antagonist = triceps brachii m. • Fixator = muscle that holds scapula firmly in place such as rhomboideus m. * *

9. Learning Strategy • Know the names of the muscles, say the names aloud (check your pronunciation) while pointing to them on yourself • Know the Origin/ Insertion and Action • Using the information in this chapter. • Increase your retention & understanding by: • examining models and photographic atlases • palpating yourself using the images in Atlas B • observe an articulated skeleton

10. Muscles of the Face I(Fig. 10.7) Frontalis Occipitalis Occipitofrontalis is found in the scalp. Frontalis m. raises the eyebrows while Occipitalis m. fixes the galea aponeurotica

11. Muscles of the Face II(Fig. 10.7) • Orbicularis oris encircles mouth (Orbicularis = round circle) • Masseter chews • Orbicularis oculi closes the eye. Masseter Orbicularis oris

12. Q. What Muscle?(Think of your Aunt’s Sunday Dinner) • A. The platysma muscle makes us grimace

13. Scalenes/ Sternocleidomastoid (SCM)(Fig. 10.10)

14. Shoulder muscles I(Fig. 10.17) Upper Trapezius Deltoid Middle and lower Trapezius

15. Shoulder Muscle II(Fig. 10.15 a) Pectoralis major

16. Pectoralis Minor ribs 3-5 to coracoid process of scapula Deep to ________ Serratus Anterior ribs 1-8 to medial border of scapula Shoulder muscles III (Fig. 10.15 b)

17. SITS muscles (Rotator Cuff) Supraspinatus- Infraspinatus Teres minor Subscapularis SITS Muscles(Fig 10.22) Supraspinatus Subscapularis “M” medial rotation of humerus Infraspinatus Teres minor “L” lateral rotation of humerus

18. ARM MUSCLES(Fig 10.22) • Principal flexor • biceps brachii • inserts on radius and ulna • Two origins and insertions • Synergistic flexor • brachioradialis • Teres Major • Majors are below the minors • Prime extensor • triceps brachii • inserts onto ulna • Three origins

19. Digitorum = inserts into fingers Carpi = inserts onto metacarpal bones Pollicis (means thumb)= inserts into thumb Intrinsic is of the hand, extrinsic is in the forearm Brevis = short, Longus = ________ Ulnaris = on ulna side Radialis = on ________ side Thenar group = fleshy base of thumb muscles Hypothenar group = base of little finger muscles Hand/ wrist Extensor and FlexorsTerms

20. (Fig. 10.28)

21. Rhomboideus mm. Latissimus Dorsi Back Muscles(Fig. 10.17)

22. HIP MUSCLES I(Fig. 10.34) Gluteus medius • Gluteus maximus • forms mass of the buttock • prime hip extensor • provides most of lift when you climb stairs Gluteus maximus

23. Gluteus minimus HIP MUSCLES II(Fig. 10.31) Piriformis • Deep muscles of the hip • Important in walking to shift body weight when foot is lifted • Sciatic nerve lines deep to the ______ muscle

24. HIP MUSCLES III (Fig. 10.30)Iliopsoas • Iliopsoas muscle • crosses anterior surface of hip joint & inserts on femur • iliacus portion arises from iliac fossa • psoas portion arises from lumbar vertebrae (L1-L5) • major hip flexor Iliopsoas

25. HIP MUSCLES IV(Fig 10.30) Adductors of the Hip Joint • Adductor magnus is also an extensor of hip joint • Pectineus, Adductor brevis and Adductor longus adduct the femur • (Just know them generally as adductors) Pectineus Adductor brevis Adductor longus Adductor magnus

26. LEG MUSCLES I(Fig. 10-32 b) • QUADS • 4 headed muscle attaches to tibial tuberosity • extends knee joint • rectus femoris arises from ilium so flexes hip joint • 2 joint muscle • quadriceps femoris tendon attaches to patella • patellar ligament attaches to tibia

27. LEG MUSCLES II(Fig. 10.34)

28. LEG MUSCLES III(Fig. 10.32 a)

29. LOWER LEG MUSCLES I(Fig. 10.35) Tibialis anterior • ANTERIOR • Extensor hallucis longus = extension of big toe & ankle • Tibialis anterior = dorsiflexes and inverts foot Extensor hallucis longus

30. LOWER LEG MUSCLES II(Fig. 10.37) Gastrocnemius Soleus • POSTERIOR • Gastrocnemius = flexes knee and plantar flexes ankle • Soleus = plantar flexes ankle

31. Diaphragm (Fig. 10.13)Rectus Abdominis(Fig. 10.15) • Rectus abdominis • vertical, straplike • tendinous intersections • LINEA ALBA • Diaphragm • Muscular dome between thoracic and abdominal cavities, breathing

32. Linea Alba Linea Negra

33. A Diamond and Two Triangles • Muscles of the Pelvic Floor are in a region called the perineum or pelvic diaphragm • One diamond and two triangles • diamond region bounded by pubic symphysis, coccyx and ischial tuberosities • urogenital triangle • anterior • contains the urethra & vagina • anal triangle • posterior • contains the anal canal

34. Pelvic diaphragm = 2 muscles levator ani m. supports viscera & functions during defecation Muscle of the Pelvic Diaphragm Levator ani

35. General Muscles of the Deep Back Erector spinae group

36. Athletic Injuries • Proper conditioning and warm-up is needed • Common injuries • shinsplints • pulled hamstrings • tennis elbow • Treat initially with rest, ice, compression and elevation (RICE) • “No pain, no gain” is a dangerous misconception.

37. Hernias • Protrusion of viscera through muscular wall of abdominopelvic cavity • Inguinal hernia • most common type of hernia (rare in women) • viscera enter inguinal canal or even the scrotum • Umbilical hernia • viscera protrude through the navel

38. Surface Anatomy

39. Surface Anatomy Anatomy Game Show