The muscular system (part b), This chapter presents the following content: Muscles of the thorax, muscles of the abdominal wall, muscles of the pelvic floor, muscles of the perineum, superficial muscles of the thorax, superficial muscles of the posterior thorax.
Trang 1PowerPoint ® Lecture Slides
prepared by Janice Meeking, Mount Royal College
C H A P T E R
Copyright © 2010 Pearson Education, Inc.
10
The Muscular System:
Part B
Trang 2Muscles of the Thorax
elevate ribs for inspiration
expiration
• Partition between thoracic and abdominal cavities
• Most important muscle in inspiration
Trang 3Copyright © 2010 Pearson Education, Inc Figure 10.10a
External intercostal
intercostal
Trang 4Muscles of the Thorax
PLAY A&P Flix™: Internal intercostals
PLAY A&P Flix™: External intercostals
Trang 5Copyright © 2010 Pearson Education, Inc Figure 10.10b
Foramen for esophagus Costal cartilage
Lumbar vertebra
Xiphoid process of sternum
Diaphragm
Quadratus lumborum Psoas major
Foramen for inferior
Trang 6Muscles of the Abdominal Wall
• Four paired muscles; their fasciae and
aponeuroses form the lateral and anterior abdominal wall
• Internal obliques
• External obliques
• Transversus abdominis
• Rectus abdominis
Trang 7Copyright © 2010 Pearson Education, Inc Figure 10.11a
Rectus abdominis
Inguinal ligament (formed by free inferior border of the external oblique aponeurosis)
Serratus anterior
Trang 8Muscles of the Abdominal Wall
• Fascicles of these muscles run at angles to one another, providing added strength
• All are innervated by intercostal nerves
• Actions of these muscles
• Lateral flexion and rotation of the trunk
• Help promote urination, defecation, childbirth, vomiting, coughing, and screaming
Trang 9Copyright © 2010 Pearson Education, Inc Figure 10.11b
Transversus abdominis
Inguinal ligament
Lumbar fascia
Lumbar fascia
Internal oblique
Pubic tubercle
Rectus abdominis External
oblique
(b)
IIiac crest
Trang 10Muscles of the Abdominal Wall
PLAY A&P Flix™: Internal obliques
PLAY A&P Flix™: External obliques
PLAY A&P Flix™: Rectus abdominis
PLAY A&P Flix™: Transversus abdominis
Trang 11Copyright © 2010 Pearson Education, Inc.
Muscles of the Pelvic Floor
• Pelvic floor (pelvic diaphragm) is composed of two paired muscles
• Levator ani
• Both are innervated by sacral nerves
Trang 12Muscles of the Pelvic Floor
• Functions of the pelvic diaphragm
• Seals the inferior outlet of the pelvis
• Supports pelvic organs
• Lifts pelvic floor to help release feces
• Resists increased intra-abdominal pressure
Trang 13Copyright © 2010 Pearson Education, Inc.
Muscles of the Perineum
• Urogenital diaphragm
• Anterior half of perineum, inferior to pelvic
floor
• Deep transverse perineal muscle
• External urethral sphincter (voluntary control of urination)
Trang 15Copyright © 2010 Pearson Education, Inc Figure 10.12b
Inferior pubic ramus
External urethral sphincter
Urethral opening Vaginal opening
Deep transverse perineal muscle
Central tendon Anus
External anal sphincter
Male
Trang 16Muscles of the Perineum
• Muscles of superficial perineal space
• Ischiocavernosus
• Superficial transverse perineal muscles
• External anal sphincter (in posterior half of perineum)
Trang 17Copyright © 2010 Pearson Education, Inc Figure 10.12c
opening
Bulbospongiosus Superficial
transverse perineal muscle Levator ani
(c)
Gluteus maximus
Trang 18Superficial Muscles of the Thorax
• Most are extrinsic shoulder muscles
• Act in combination to fix the shoulder girdle
(mostly the scapula) and move it to increase range of arm movements
• Actions include elevation, depression, rotation, lateral and medial movements, protraction, and retraction
• Two groups of muscles: anterior and posterior
Trang 19Copyright © 2010 Pearson Education, Inc.
Superficial Muscles of the Thorax
• Anterior extrinsic shoulder muscles
PLAY A&P Flix™: Muscles of the pectoral girdle (b)
PLAY A&P Flix™: Muscles of the pectoral girdle (a)
Trang 21Copyright © 2010 Pearson Education, Inc.
Superficial Muscles of the Thorax
PLAY A&P Flix™: Serratus anterior
PLAY A&P Flix™: Pectoralis minor
Trang 22Superficial Muscles of the Posterior Thorax
• Posterior extrinsic shoulder muscles
• Trapezius
• Levator scpulae
• (Latissimus dorsi considered later with
muscles that act on the humerus)
PLAY A&P Flix™: Muscles of the pectoral girdle (c)
Trang 23Copyright © 2010 Pearson Education, Inc Figure 10.13c
Trapezius
(c)
Levator scapulae
Supraspinatus Clavicle
Spine of scapula Infraspinatus Teres minor
Trang 24Superficial Muscles of the Posterior Thorax
PLAY A&P Flix™: Levator scapula
PLAY A&P Flix™: Trapezius
PLAY A&P Flix™: Rhomboid major
PLAY A&P Flix™: Rhomboid minor