Anatomy of Human Muscles

Transcription

1 Anatomy of Human Muscles PURPOSE: To develop skill in identifying muscle names and locations relative to other regional structures. To determine origin, insertion and principle action of muscles through analysis of muscle location, shape and arrangement. PROCEDURE Skeletal muscles, mainly under voluntary control are the muscles of most interest in gross anatomy for many reasons (muscle building, body contouring, sports training to name a few). They are attached at each end either to bone or connective tissue mostly via tendons (cordlike dense regular connective tissue) and aponeuroses (wide thin tendons). The origin is the attachment to the stationary bone which serves as the stronghold. The insertion is the attachment to the movable bone where the force applied by muscle contraction causes a specific movement. Each muscle attachment is relative with respect to body movements. In two different muscles, these attachments may be reversed. Muscle names are generally descriptive using one or more of seven criteria: 1. the location of the muscle 2. the relative size of the muscle 3. the shape of the muscle 4. the muscle origin and insertion 5. the direction of the muscle fascicles (bundles of muscle fibers), i.e. rectus (along a longitudinal axis), transverse (perpendicular to a longitudinal axis), oblique (across a longitudinal axis at an angle different than perpendicular) 6. the arrangement of fascicles within the muscle (pennate, orbicularis) 7. the principle action of the muscle The action of a muscle is the movement caused by that muscles contraction. Generally the movements possible are the following (16 mostly paired opposites): flexion or extension adduction or abduction medial rotation or lateral rotation supination or pronation inversion or eversion elevation or depression protrusion (protraction) or retrusion (retraction) opposition 1

2 circumduction Review these actions from your Anatomy 35 text and notes. Using Gilroy s Atlas of Anatomy and Clemente s Anatomy Dissector as your 1 st references, and your Anatomy 35 Human Anatomy text as your 2 nd reference, you will describe the position of each muscle listed in the following tables relative to other regional structures. Other references will be available in the cadaver lab to assist you in this research. Each student will fill in the following characteristics found in the heading of each table: origin, insertion, (Principle) Action, and Primary Nerve. By following each muscle to its attachments on a prosected cadaver, you will also see the origin and insertion. The principle action of the muscle can be determined by looking at the position, shape, angle, and attachments. Verify all of your findings with your references. Students will also be expected to determine the major blood vessels supplying the muscles listed. Prompts for this information can be found following the data tables. I. MUSCLES OF THE HEAD AND NECK 1. Muscles of Facial Expression Occipitofrontalis (frontal belly) Occipitofrontalis (occipital belly) Orbicularis oculi Levator labii superioris Zygomaticus major/minor Buccinator Orbicularis oris Levator anguli oris Depressor anguli oris Depressor labii inferioris Mentalis Platysma Risorius 2

3 the aorta and major tributaries to the internal and/or external jugular vein. 2. Muscles of Mastication Temporalis Masseter 3. Muscles of the Submandibular Region Digastric anterior belly Digastric posterior belly Stylohyoid Mylohyoid Geniohyoid the aorta and major tributaries to the internal and/or external jugular vein. 3

4 4. Muscles of the Anterior Neck Sternocleidomastoid Omohyoid (superior belly) Omohyoid (inferior belly) Sternohyoid Sternothyroid Thyrohyoid NOTE: 1. The anterior triangle of the neck has several subdivisions. What are these subdivisions? Identify the muscles from the previous tables that are found in each of these subdivisions. What other important structures are found in these subdivisions? the aorta and major tributaries to the internal and/or external jugular vein. 4

5 II. Muscles of the Trunk 1. Muscles of the Thoracic Wall Anterior Scalene Posterior Scalene Middle Scalene External intercostal Internal intercostal the aorta and major tributaries to the azygous vein and/or superior vena cava. 2. Intrinsic Back Muscles Splenius capitus Erector Spinae: a. Iliocostalis b. Longissimus c. Spinalis NOTE: What are the 3 portions of the semispinalis muscle? the aorta and major tributaries to the azygous vein. 5

6 3. Muscles of the Posterior Abdominal Wall Diaphragm Quadratus lumborum Psoas major Iliacus the aorta and major tributaries to the azygous and/or inferior vena cava. 4. Muscles of Anterolateral Abdominal Wall External oblique Internal oblique Transversus abdominis Rectus abdominis the aorta and major tributaries to the azygous and/or inferior vena cava. 6

7 II. Muscles of the Upper Limb 1. Anterior Muscles of the Shoulder and Arm Pectoralis major Pectoralis minor Subclavius Serratus anterior Subscapularis Biceps brachii Coracobrachialis Brachialis Triceps brachii the aorta and major tributaries to the superior vena cava. 7

8 2. Posterior Muscles of the Shoulder and Arm Trapezius Latissimus dorsi Levator scapulae Rhomboid minor Rhomboid major Deltoid Supraspinatus Infraspinatus Teres minor Teres major NOTE: What is the rotator cuff? Which of these muscles compose the rotator cuff? the aorta and major tributaries to the azygous and/or vena cavae. 8

9 3. Anterior Forearm Muscles Pronator teres carpi radialis Palmaris longus carpi ulnaris digitorum superficialis digitorum profundus pollicus longus Pronator quadratus the aorta and major tributaries to the superior vena cava. 9

10 4. Posterior Forearm Muscles Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris Anconeus Supinator Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis the aorta and major tributaries to the superior vena cava. 10

11 5. Intrinsic Hand Muscles Abductor pollicis brevis pollicis brevis Opponens pollicis Palmaris brevis Abductor digiti minimi digiti minimi Opponens digiti minimi the aorta and major tributaries to the superior vena cava. 11

12 IV. Muscles of the Lower Limb 1. Anterior Thigh Muscles Psoas major Iliacus Tensor fascia latae Sartorius Rectus femoris Vastus lateralis Vastus medialis Vastus intermedius the aorta and major tributaries to the azygous vein and/or the inferior vena cava. 12

13 2. Medial Thigh Muscles Pectineus Adductor longus Adductor magnus Gracilis the aorta and major tributaries to the inferior vena cava. 13

14 3. Muscles of the Gluteal Region Gluteus maximus Gluteus medius Gluteus minimus Piriformis Gemellus superior Gemellus inferior Quadratus femoris the aorta and major tributaries to the inferior vena cava. 14

15 4. Posterior Thigh Muscles Semitendinosus Semimembranosus Biceps femoris the aorta and major tributaries to the inferior vena cava. 15

16 5. Muscles of the Anterolateral Leg Tibialis anterior Extensor hallucis longus Extensor digitorum longus Fibularis longus Fibularis brevis the aorta and major tributaries to the inferior vena cava. 16

17 6. Muscles of the Posterior Leg Gastrocnemius Soleus Plantaris Popliteus hallicus longus digitorum longus Tibialis posterior the aorta and major tributaries to the inferior vena cava. 17

18 7. Muscles in Sole of Foot Abductor hallucis digitorum brevis digitorum longus Abductor digiti minimi Quadratus plantae hallucis brevis Adductor hallucis digiti minimi brevis Extensor digitorum brevis 18