DENT111 Anatomy - Muscular System PDF

DENT111 ANATOMY MUSCULAR SYSTEM The Muscular System: The muscular system refers to the voluntary skeletal muscle system: The skeletal muscle tissue and connective tissues that make up individual muscle organs The muscular system is a complex collection of tissues, each with a...

DENT111 ANATOMY MUSCULAR SYSTEM The Muscular System: The muscular system refers to the voluntary skeletal muscle system: The skeletal muscle tissue and connective tissues that make up individual muscle organs The muscular system is a complex collection of tissues, each with a different purpose. Understanding the components of the muscular system, including the various types of connective tissues, helps to understand how bodies and physical movement work. Function of the Muscular System: Movement/Locomotion Maintenance of uprigth posture Helps for the breathing Communication Constriction of organs and vessels Protect and keep in place our abdominal organs Heart beat Production of body heat Types of Muscles: Skeletal: ◦ Attached to bones ◦ Makes up 40% of body weight ◦ Responsible for locomotion, facial expressions, posture, respiratory movements, other types of body movement– ◦ Voluntary in action; controlled by somatic motor neurons Smooth: ◦ In the walls of hollow organs, blood vessels, eye, glands, uterus, skin ◦ Some functions: propel urine, mix food in digestive tract, dilating/constricting pupils, regulating blood flow ◦ In some locations, auto rhythmic ◦ Controlled involuntarily by endocrine and autonomic nervous systems Cardiac: ◦ Heart: major source of movement of blood ◦ Controlled involuntarily by endocrine and autonomic nervous systems  Muscular Attachment Sites: Origin: the attachment of a muscle tendon to the stationary bone Insertion: the attachment of the other muscle tendon to the movable bone The portion of the muscles between the origin and insertion is called belly (gaster) At the bone, the fibres of the tendonare embedded in the PERIOSTIUM of the bone. Bone markings present where tendons meet bones Tubercles, trochanters, and crests  Properties of Muscles: Contractility: ability of a muscle to shorten and generate pulling force. Excitability: capacity of muscle to respond to a stimulus. Extensibility: muscle can be stretched back to its original length. Elasticity: ability of muscle to recoil to original resting length after stretched. How do our muscles work? Three main types of muscular contraction: 1. Isotonic and concentric: muscles shorten as they contract. The ends of the muscle move closer together 2. Isotonic and eccentric: muscles lengthen as they contract under tension. The ends of the muscle move further apart 3. Isometric: muscles stay the same length as they contract. There is no movement, so the ends of the muscles stay the same distance apart Arrangement of Fascicles: Head and Neck Muscles Sternocleidomastoid: Scalenes: Anterior Middle Posterior Anterior Scalene: Middle and Posterior Scalene Masseter: Temporalis: Suprahyoids and Digastric: Infrahyoids: Platysma: Occipitofrontalis: Medial and Lateral Pterygoids: Longus Capitis and Longus Colli: Muscles of the Mouth: Muscles of the Mouth: Muscles of the Mouth: Muscles of the Mouth: Muscles of the Mouth: Muscles of the nasal region: Muscles of the nasal region: Muscles of the eyes: Muscles of the scalp: Columna Vertebralis Thoracic cage Muscles of the Spine and Thorax Erector Spinae Group: M. Spinalis M. Longissimus M. Iliocostalis M. Spinalis: M. Spinalis Cervices M. Spinalis Thoracis M. Longissimus: M. Longissimus Capitis M. Longissimus Cervices M. Longissimus Thoracis M. Iliocostalis: M. Iliocostalis Cervicis M. Iliocostalis Thoracis M. Iliocostalis Lumborum Transversospinalis Group: M. Multifidus M.Rotatores M. Semispinalis Capitis M. Multifidus and M. Rotatores: M. Semispinalis Capitis: M. Splenius Capitis and Cervicis: Suboccipitalis: M. Rectus capitis posterior major M. Rectus capitis posterior minor M. Obliques capitis superior M. Obliques capitis inferior M. Quadratus Lumborum: Abdominals: M. Rectus Abdominis M. External obliques M. Internal obliques M. Transversus abdominis M. Rectus Abdominis: M. External obliques: M. Internal obliques: M. Transversus abdominis: Diaphragm: M. Intercostalis: M. Serratus Posterior Superior and Inferior: M. Intertransversarii: M. Interspinalis: References: Palastanga, N. and Soames, R. (2012). ‘Anatomy and Human Movement: Structure and Function.’ 6th ed. Elsevier: Churchill Livingstone. Biel A. (2014). ‘ Trail Guide to the Body’. 5th ed. Books of Discovery.