1. Anatomy and Physiology, Seventh Edition
Rod R. Seeley Idaho State University
Trent D. Stephens Idaho State University
Philip Tate Phoenix College
Chapter 10
Lecture Outline*
*See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. Muscular System Gross Anatomy
Chapter 10
Muscular System Gross Anatomy

3. General Principles Tendons: attach muscles to bones Muscle terminology
Aponeurosis: a very broad tendon
Muscle terminology
Origin or head: muscle end attached to more stationary of two bones
Insertion: muscle end attached to bone with greatest movement
Belly: largest portion of the muscle between origin and insertion
Agonist: muscle that, when it contracts, causes an action
Antagonist: a muscle working in opposition to agonist
Example: the biceps brachii can be used to lift weights and is the agonist, but when you move a bowling ball back to prepare to bowl, the biceps is the antagonist
Synergists: muscles that work together to cause a movement
Prime mover: plays major role in accomplishing movement
Fixators: stabilize joint/s crossed by the prime mover; prevent movement of the origin of the prime mover.

4. Muscle attachment

5. Muscle Types

6. Examples of Muscle Shapes

7. Nomenclature Muscles are named according to:
Location: pectoralis gluteus, brachial
Size: maximus, minimus, longus, brevis
Shape: deltoid, quadratus, teres
Orientation: rectus
Origin and insertion: sternocleidomastoid, brachioradialis
Number of heads: biceps, triceps
Function: abductor, adductor, masseter

8. Muscle Movements
Muscles and their tendons and bones act together as lever systems to move either parts of the body or the whole body. Muscle contractions are a pull or force by relative positions of
Lever: rigid shaft or bone
Fulcrum: pivot point or joint
Weight or resistance (force of gravity either in the form of the weight of the body parts or the weight of an object being lifted, pulled, or pushed)

9. Classes of Levers Class I Class II Class III
Fulcrum between force and weight
Seesaw
Head movement at the atlantooccipital joint
Class II
Weight is between fulcrum and pull
Wheelbarrow
Standing on toes; metatarsophalangeal joint
Class III
Pull located between fulcrum and weight
Person using a shovel
Most common: biceps brachii with elbow as fulcrum
Classes of Levers

10. Muscle Anatomy: Anterior View

11. Muscle Anatomy: Posterior View

12. Head and Neck Muscles
Flexion: muscles deep within the neck along the anterior margins of the vertebral bodies
Extension: posterior neck muscles attached to occipital bone
Rotation and abduction: lateral and posterior groups
Examples: sternocleidomastoid, trapezius, splenius muscles

13. Posterior Deep Neck Muscles

14. Muscles of Facial Expression
Cutaneous; origin and insertion in the superficial fascia.
Confined primarily to head and neck.
Move the skin; some act as sphincters.
Examples: orbicularis oris, orbicularis oculi, platysma.

15. Muscles of Mastication and Hyoid
Mastication: chewing. Involves elevation/depression of the mandible and excursion to grind the teeth together
Act with the muscles of hyoid in movement of the mandible
Muscles of the cheek and tongue aid mastication by pushing the food under the teeth
Examples: masseter, temporalis, pterygoids, digastrics

16. Muscles of the Hyoid

17. Tongue Movements Important in speech: changes shape Swallowing
Moves food around in mouth
Holds food in place during grinding
Pushes food up to palate and back toward pharynx
Intrinsic: entirely within the tongue and allow change in shape
Extrinsic: insert in tongue and allow change in shape and movement

18. Swallowing and the Larynx
Hyoid muscles: infra- and suprahyoid groups
Suprahyoid muscles fix the hyoid, then thyrohyoid can elevate larynx
When infrahyoid group fixes hyoid, suprahyoid muscles can help depress the mandible
Swallowing: Elevation of pharynx and larynx
Constriction of the pharynx from superior to inferior
Salpingopharyngeus opens auditory tubes to equalize pressure between middle ear and atmosphere

19. Muscles of Larynx

20. Extrinsic Muscles of the Eye
Rectus muscles: insert on sclera anterior to center of sphere. Move eyeball and thus pupil laterally, superiorly, inferiorly, and medially
Oblique muscles: insert onto the posterolateral margin of the eyeball and both laterally deviate the eyeball. The superior oblique passes through a pulley-like trochlea

21. Muscles that Move the Vertebral Column
Muscles that extend, laterally flex, and rotate the vertebral column. Used to produce erect posture
Divided into deep and superficial groups
Deep group: from vertebra to vertebra
Superficial group extend from vertebrae to ribs

22. Deep Muscles of the Vertebrae

23. Thoracic Muscles Involved in breathing
Four groups associated with rib cage
Scalenes: elevate first two ribs during inspiration
External intercostals: elevate the ribs
Internal intercostals: depress ribs during expiration
Transversus thoracis: depresses ribs during expiration
Diaphragm: major movement of inspiration. Flattens during contraction and increases the volume of the thoracic cavity

24. Abdominal Wall
Flex and rotate vertebral column, decrease volume of abdominal and thoracic cavities
Aid in forced expiration, vomiting, defecation, urination, childbirth
Crossing pattern of muscles adds strength to abdominal wall to support organs

25. Abdominal Wall Rectus Abdominis
Linea alba in center
Covered by rectus sheath
Tendinous intersections divided muscle into sections
Flexes vertebral column
External abdominal oblique: flexes and rotates abdomen
Internal abdominal oblique: flexes and rotates abdomen
Transversus abdominis: compresses abdominal wall

26. Muscles of Pelvic Floor and Perineum
Pelvic diaphragm: Funnel-shaped, supports the pelvic viscera. Pierced by anal canal, urethra and (vagina).
Perineum: diamond-shaped area inferior to pelvic diaphragm. Anterior half of diamond is urogenital triangle; posterior half is anal triangle

27. Scapular Movements
Muscles that attach the upper limb to the body and move or stabilize the scapula and clavicle.
Originate on the axial skeleton.
Trapezius, levator scapulae, rhomboideus, serratus anterior, pectoralis minor

28. Arm Movements
Muscles that attach arm to thorax: pectoralis major, latissimus dorsi
Deltoid and pectoralis major both act as flexors and extensors of the shoulder
Deltoid abducts and medially and laterally rotates arm

29. Rotator Cuff Primary muscles holding humerus in the glenoid cavity
Form a cuff or cap over the proximal humerus
Involved in flexion, extension, abduction, adduction, rotation and circumduction
Infraspinatus, subscapularis, supraspinatus, teres minor

30. Forearm Movement Movements at the elbow
Extension: triceps brachii and anconeus
Flexion: biceps brachii, brachioradialis, and brachialis
Supination and pronation:
Supination: supinator and biceps brachii
Pronation: pronator quadratus and pronator teres

31. Wrist, Hand, and Finger Movements
Muscles on anterior surface of forearm: flexion as well as abduction and adduction of the wrist.
Muscles on posterior surface of forearm: extension and abduction.
Retinacula- bands of deep fascia which hold tendons of muscles of forearm, blood vessels, and nerves close to wrist.
Flexor retinaculum (transverse carpal ligament): on the flexor surface
Extensor retinaculum (dorsal carpal ligament): on the extensor surface
Wrist, Hand, and Finger Movements

32. Intrinsic Muscles of the Hand
Originate and insert in hand.

33. Thigh Movement Originate on coxa; insert onto femur
Anterior, posterolateral, deep
Anterior: flex hip. Iliacus and psoas major often referred to as iliopsoas since they share a tendon of insertion
Posterolateral: gluteals and tensor fasciae latae Extension of thigh
Deep: thigh rotators

34. Leg Movements Quadriceps femoris: anterior surface of thigh
Extension of the leg at the knee.
Rectus femoris also flexes the hip.
Insert by common tendon (patellar tendon) on and around the patella
Patellar tendon extends from patella to tibial tuberosity
Sartorius: flexes hip and knee, laterally rotates thigh
Medial thigh muscles: adduction
Posterior thigh muscles: hamstrings. Flexion and rotation of the knee

35. Muscles that Move the Leg

36. Ankle, Foot, and Toe Movements
Extrinsic foot muscles
Three leg compartments
Anterior compartment: extensors involved in dorsiflexion and eversion/inversion of foot; extension of toes. Dorsiflex foot, extend toes.
Lateral compartment: plantar flexion and eversion.
Posterior compartment-
Superficial muscles (plantar flexion) have common tendon of insertion called the calcaneal (Achilles) tendon. Gastrocnemius, plantaris
Deep muscles: plantar flex and invert foot
Ankle, Foot, and Toe Movements

37. Extrinsic Muscles of the Foot

38. Extrinsic Muscles of the Foot

39. Intrinsic Muscles of the Foot
Analogous to intrinsics of hand, but serve in support and locomotion
Flexion, extension, abduction and adduction of toes
Deep fascia forms plantar aponeurosis.