1. Muscular System
Chapter 7

2. 640 muscles in our bodies! Muscles All muscles contract
A contraction or shortening of a muscle causes movement
We have….
640 muscles in our bodies!

3. Types of Muscles Smooth Muscle Cardiac Muscle
Located in the walls of hollow internal organs.
These muscles are involuntary or uncontrolled
Cardiac Muscle
Forms the heart wall
Involuntary
Have intercalated disks – contractions spread quickly

4. Types of Muscles

5. Types of Muscles

6. Types of Muscles Skeletal Muscle
Located all over the body and they attach directly to the skeleton
These muscles are voluntary and controlled by the nervous system

7. Types of Muscles

8. Functions of Skeletal Muscles
Support the body
Allows movement
Help maintain body temperature
Assists blood circulation
Protect internal organs

9. Skeletal Muscle Physiology
A muscle fiber is the same as a muscle cell
Muscle fibers are composed of two main protein filaments:
Myosin – thick filaments
Actin – thin filaments

11. Skeletal Muscle Physiology
The actin and myosin fibers overlap to make a sarcomere.
The sarcomere is the functional unit of the muscle

12. Skeletal Muscle Physiology
When a nerve stimulates a muscle fiber calcium is released
The actin and myosin fibers slide over each other
The sarcomere then
shortens
That is a contraction!

13. Skeletal Muscle Physiology
Contracted muscles can only “relax” when an opposing muscle contracts.
Ex. biceps vs. triceps
Rigor mortis – all of the muscles contract when a body dies

14. Muscle Contraction Animation

15. Skeletal Muscle Physiology
Slow twitch fibers
Darker in color (more blood vessels and mitochondria)
Aerobic, steady power, endurance
Fast twitch fibers
Lighter in color
Anaerobic, explosive power, fatigue easily
Marathon runner vs. Body builder

16. Muscle Basics Each muscle has a name, origin, insertion, and movement.
The origin is the stationary point where the muscle attaches. Usually a bone.
The insertion is the attachment on the bone that moves
When a muscle contracts it brings the insertion closer to the origin
Naming is usually based on size, shape, and location of the muscle

17. Muscles of the Body

18. Muscles of the Face Frontalis Corrugator supercilii O – Parietal
I – skin of eyebrows
A – Wrinkle forehead
Corrugator supercilii
O – Nasal
I – skin of forehead

19. Muscles of the Face Orbicularis oculi Nasalis
O – Frontal bone, Lacrimal bone
I – Outer eye
A – Closes eye
Nasalis
O – Maxilla
I – Nose
A – Nostril movement

20. Muscles of the Face Zygomaticus major Platysma O – Zygomatic bone
I – corner of mouth
A – Draws up corner of the mouth
Platysma
O – under clavicle
I – Skin of cheek, mandible
A – Neck flexion, lateral mouth stretch

21. Muscles of the Face Temporalis Masseter O – Parietal bone I – Mandible
A – Closes jaw
Masseter
O – Zygomatic and maxilla

22. Muscles of the Face Orbicularis oris Buccinator I – Skin around lips
O – Maxilla, mandible
I – Skin around lips
A – Puckers lips (kissing)
Buccinator
I – Orbicularis oris
A – Compresses cheeks (blowing & chewing)

23. Muscles of the Face Sternocleidomastoid O – Sternum, clavicle
I – Temporal bone
A – Rotate and flexes head and neck

24. Muscles of the Core External intercostals Internal intercostals
O – Upper rib
I – Lower rib
A – Elevate ribs for inhaling
Internal intercostals
A – Depresses ribs for exhaling

25. Muscles of the Core External intercostals Internal intercostals
O – Upper rib
I – Lower rib
A – Elevate ribs for inhaling
Internal intercostals
A – Depresses ribs for exhaling

26. Muscles of the Core Transverse abdominis Internal oblique
O – Ilium, lower rib cartilage
I – Pelvis and linea alba
A – Compresses ribs, core stabilization
Internal oblique
O – Ilium
I – Linea alba, sternum, and inferior ribs
A – Spinal rotation and abdomen compression

27. Muscles of the Core External oblique Rectus Abdominis O – Lower ribs
I – Pelvis
A – Flexion and rotation of the spine
Rectus Abdominis
O – pelvis
I – sternum and ribs

28. Muscles of the Core Trapezius Latissimus Dorsi
O – Cervical-Thoracic vertebrae, cranium
I – Clavicle & Scapula
A – Elevate, rotate, and adduct scapula
Latissimus Dorsi
O – T vertebrate, pelvis, lower ribs
I – Humerus
A – Extends, adducts, and internally rotates shoulder

29. Muscles of the Core Gluteus Maximus Gluteus Minimus
O – Pelvis and Sacrum
I – Femur
A – Extension and lateral rotation of hip
Gluteus Minimus
O – Pelvis
A – Abducts and laterally rotates hip

30. Muscles of the Core Gluteus Medius O – Pelvis I – Femur
A – Abducts hip and rotates femur

31. Muscles of the Core Levator Scapula Rhomoideus O – Cervical vertebrae
I –Scapula
A – Elevates scapula and rotates and extends neck
Rhomoideus
O – Thoracic vertebrate
I – Scapula
A – Retracts scapula

32. Muscles of the Core Teres Major Erector spinae O – Inferior scapula
I – Humerus
A – Adducts, medial rotation, and arm extension
Erector spinae
O – Sacrum, Ilium, Lower vertebrae
I – Ribs & upper vertebrae
A – Spinal extension and side-bending

33. Muscles of the Core Teres Major Erector spinae O – Inferior scapula
I – Humerus
A – Adducts, medial rotation, and arm extension
Erector spinae
O – Sacrum, Ilium, Lower vertebrae
I – Ribs & upper vertebrae
A – Spinal extension and side-bending

34. Muscles of the Core Pectoralis Minor Pectoralis Major O – Middle ribs
I – Scapula
A – moves scapula forward and downward
Pectoralis Major
O – Clavicle, sternum, costal cartilage
I – Humerus
A – Shoulder adduction, protraction, arm rotation

35. Muscles of the Arm Deltoid Biceps Brachii O – Clavicle and scapula
I – Humerus
A – abducts arm
Biceps Brachii
O – Scapula
I – Radius
A – Flexes elbow and supinates forearm

36. Muscles of the Arm Brachialis Triceps Brachii O – Humerus I – Ulna
A – elbow flexion
Triceps Brachii
O – Scapula and humerus
A – elbow extension

37. Muscles of the Arm Brachialis Triceps Brachii O – Humerus I – Ulna
A – elbow flexion
Triceps Brachii
O – Scapula and humerus
A – elbow extension

38. Muscles of the Arm Supinator Pronator Teres O – Ulna and Humerus
I – Radius
A – Supinates forearm
Pronator Teres
A – Pronates forearm

39. Muscles of the Arm Pronator Quadratus O – Distal ulna
I – Distal radius
A – Pronates forearm

40. Muscles of the Arm Extensor carpi radialis Extensor carpi ulnaris
O – Humerus
I – Metacarpal
A – extends wrist
Extensor carpi ulnaris
O – Posterior ulna and humerus

41. Muscles of the Arm Flexor carpi radialis Flexor carpi ulnaris
O – Humerus
I – Metacarpals
A – flexes wrist
Flexor carpi ulnaris
O – Ulna and humerus
I – pisiform, hamate, and metacarpals

42. Muscles of the Arm Extensor digitorum Flexor digitorum profundus
O – Humerus
I – Phalanges
A – Extends fingers and wrist
Flexor digitorum profundus
O – Ulna
I – phalanges
A – flexes wrist and fingers

43. Muscles of the Leg Tensor Fasciae latae Iliopsoas I – Femur
O – lumbar vertebrae
I – Femur
A – Flex and rotate leg
Tensor Fasciae latae
O – Ilium
I – Iliotibial tract (IT band)
A – Hip flexion, abduction and medial rotation

44. Muscles of the Leg Adductor longus Adductor magnus I – Femur
O – Pelvis
I – Femur
A – Hip adduction and flexion
Adductor magnus
A – Hip adduction and extension

45. Muscles of the Leg Adductor longus Adductor magnus I – Femur
O – Pelvis
I – Femur
A – Hip adduction and flexion
Adductor magnus
A – Hip adduction and extension

46. Muscles of the Leg Sartorius Rectus Femoris I – Tibia
O – Pelvis
I – Tibia
A – Thigh flexion, abduction, and lateral rotation
Rectus Femoris
O –Ilium
I – Patella and tibia
A – Extends knee and flexes hip

47. Muscles of the Leg Vastus medialis Vastus Lateralis
O – Femur
I – Patella and tibia
A – Knee extension
Vastus medialis
A – Knee extension

48. Muscles of the Leg Biceps femoris Vastus intermedius O – Femur
I – Patella and tibia
A – Knee extension
Biceps femoris
O – Pelvis and Femur
I – Fibula
A – Knee flexion and hip extension

49. Muscles of the Leg Semimembranosus Semitendinosus I – Tibia
O – Pelvis
I – Tibia
A – Knee flexion and hip extension
Semimembranosus

50. Muscles of the Leg Gastrocnemius Tibialis Anterior
O – Tibia
I – Cuneiform and metatarsal
A – Dorsiflexion and inversion
Gastrocnemius
O – Femur
I – Calcaneus
A – Plantar flexion and knee flexion

51. Muscles of the Leg Soleus O – Fibula and Tibia I – Achilles Tendon
A –Plantar flexion and inversion

52. Muscles of the Leg Flexor halliucis longus Extensor Halliucis longus
O – Fibula
I – Big Toe (phalange)
A – Extends big toe
Flexor halliucis longus
I – Big toe (phalange)
A – Flexes big toe