The Muscular System: Axial Musculature Chapter 10 Lecture Chapter 10 The Muscular System: Axial Musculature Frederic Martini Michael Timmons Robert Tallitsch

The axial musculature arises on the axial skeleton. Introduction The axial musculature arises on the axial skeleton. It positions the head and vertebral column. It moves the rib cage. It does not play a role in the movement or stabilization of the pectoral or pelvic girdles or the limbs. Roughly 60% of the skeletal muscles in the body are axial muscles.

Introduction The axial muscles fall into four groups based on location and/or function: Muscles of the head and neck: Laughing Talking Frowning Smiling Whistling Muscles of the vertebral column Oblique and rectus muscles: diaphragm Muscles of the pelvic floor Sucking Chewing Swallowing Contractions of the eye muscles

Superficial Skeletal Muscles Figure 10.1 Anterior Muscles Figure 10.2 Posterior Muscles

Muscles of the Head and Neck The muscles of the head and neck can be subdivided into several groups. Muscles of facial expression Extra-ocular muscles Muscles of mastication Muscles of the tongue Muscles of the pharynx Anterior muscles of the neck

Muscles of Facial Expression Figure 10.3a Anterior Muscles Figure 10.4a Lateral Muscles

Extra-ocular Muscles Figure 10.5a Lateral, Right Eye Figure 10.5b Medial, Right eye

Extra-ocular Muscles Figure 10.5c Anterior, Right Eye Figure 10.5d Anterior, Right Orbit

Muscles of Mastication Figure 10.6a Lateral Muscles Figure 10.6b Deep Lateral Muscles

Muscles of the Tongue Figure 10.8 Muscles of the Tongue

Muscles of the Pharynx Figure 10.9a Lateral View Figure 10.9b Midsagittal View

Anterior Muscles of the Neck Figure 10.10a Anterior Muscles Figure 10.10b Superior View

Muscles of the Head and Neck Summary of the head and neck muscles PLAY The Head and Neck

Muscles of the Vertebral Column The muscles of the back form three distinct layers: Superficial: move the neck Intermediate: extend the vertebral column Deep: interconnect vertebrae

Muscles of the Vertebral Column: Superficial and Intermediate Layers Figure 10.12a Superficial and Intermediate Muscles

Summary of the erector spinae muscles PLAY The Erector Spinae Muscles

Muscles of the Vertebral Column: Deep Layer Figure 10.12b Intervertebral Muscles

Muscles of the Vertebral Column: Spinal Flexors Figure 10.12c Anterior Vertebral Muscles

Oblique and Rectus Muscles The muscles of the oblique and rectus groups lie between the vertebral column and the ventral midline. The oblique muscles can compress underlying structures or rotate the vertebral column, depending on whether one or both sides are contracting. The rectus muscles are important flexors of the vertebral column, acting in opposition to the erector spinae.

Oblique and Rectus Muscles Figure 10.13a Anterior View Figure 10.13b Horizontal Section

Oblique and Rectus Muscles: The Diaphragm Figure 10.14a Inferior View

Oblique and Rectus Muscles: The Diaphragm Figure 10.14b Superior View

Muscles of the Pelvic Floor Muscles of the pelvic floor have three main functions: Support the organs of the pelvic cavity Flex the joints of the sacrum and coccyx Control the movement of materials through the urethra and anus

Muscles of the Pelvic Floor Figure 10.15a Female

Muscles of the Pelvic Floor Figure 10.15b Male