Human Anatomy and Physiology I Laboratory Gross Anatomy of the Muscular System (Two weeks) 1 This lab involves study of the laboratory exercise Gross Anatomy of the Muscular System. Complete the Review Sheet for the exercise and fill in the muscle tabels and illustrations in the Lab Manual. Take the relevant quiz. This lab is designed to be done over two weeks. In the first week the student should study the upper body muscles of the head and neck, arms and shoulders. In the second week the study is of the muscles of the abdomen, back, and legs. The quizzes for these sections are separate as well. There is a good web site for studying the location and action of each muscle: http://www.meddean.luc.edu/lumen/meded/grossanatomy/dissector/mml/index.htm Click on the sound icon for the audio file (mp3 format) for each slide. There is also a link to a dowloadable mp4 video which can be played on an ipod. 1
Muscle Actions Antagonists muscles which perform opposite movements Synergists muscles which work together to perform a movement. Often this movement is different from that which either would perform when acting alone. Fixators Muscles which act to hold a part of the body steady. 2 2
Zygomaticus Orbicularis oris Antagonists in in action on on mouth: O. O. oris pulls corners inward (puckering); Zygomaticus raises corners in in smiling. 3 These muscles of facial expression insert on connective tissues at the corners of the mouth. 3
Temporalis Orbicularis oris Synergists in in closing the jaw Buccinator Synergists in in compressing cheek and puckering Masseter 4 4
The Trapezius Upper portion helps to to extend head. Lowers jaw Tenses skin of of neck Platysma Trapezius Muscles identified in blue are shown on the LUMEN muscle 5 site:http://www.meddean.luc.edu/lumen/meded/grossanatomy/dissector/mml/index.htm Many large muscles can contract certain portions alone. The trapezius can contract the upper portion alone to extend the head and neck. Muscles identified in blue are shown on the LUMEN muscle site http://www.meddean.luc.edu/lumen/meded/grossanatomy/dissector/mml/index.htm 5
SCM unilaterally rotates the head, bilaterally they flex the neck. Mastoid process Sternocleidomastoid Scalenes Raise ribcage in in forced inspiration. Head must be be fixed. 6 6
Mastoid process Splenius capitus Forceful extensor of of head when acting bilaterally. 7 7
Extensors of the Vertebral Column Longissimus capitus Semispinalis capitus With what muscles are these two synergists, in in extending the head? Erector spinae Quadratus lumborum 8 The longissimus capitus and semispinalis capitus are extensors of the head, synergistic with the splenius capitus and upper trapezius. The erector spinae consists of three groups of muscles which extend the vertebral column. They are important postural muscles, along with the quadratus lumborum which bilaterally helps to extend the lumbar vertebrae, and unilaterally abducts them. It is the quadratus which is often strained with improper heavy lifting. 8
Elevates ribs and expands thorax in in forced inspiration (scapula fixed). Pectoralis minor 9 9
External intercostals Internal intercostals Expand the ribcage in in forced inspiration. Compress the ribcage in in forced expiration. 10 10
The Diaphragm Radially arranged fibers Enlarges thorax in restful inspiration. 11 11
Synergists in in forced expiration. Flexes vertebral column Rectus abdominus { Transverse abdominus Internal oblique External oblique Compress abdomen, rotate trunk. 12 12
Synergists in in adduction of of brachium: Abducts the brachium (upper arm) Deltoid Pectoralis major Adducts and medially rotates Subscapularis Adducts and medially rotates Coracobrachialis 13 13
Subscapularis Coracobrachialis 14 14
Adduct and medially rotate the brachium. Latissimus dorsi Anterior insertion Teres major 15 15
The Rotator Cuff Abductor Supraspinatus Infraspinatus Teres minor Subscapularis Adductors 16 16
Muscles Acting on the Scapula Levator scapulae Rhomboids: minor major Adducts (retracts) and fixates the scapula Elevates and fixates the scapula 17 17
Biceps brachii Flexes elbow; slight adductor of brachium. 18 18
Biceps brachii O: O: coracoid and glenoid of of scapula. I: I: radial tuberosity. 19 19
Brachialis Flexes elbow; synergist with biceps b. b. 20 20
Triceps brachii: lateral head long head Extends the elbow 21 21
Medial epicondyle origin of most lower arm flexors Brachioradialis Flexes and abducts wrist, fixates wrist in in abducted position. Flexor carpi radialis Palmaris longus Flexor carpi ulnaris Flexor retinaculum 22 The flexor retinaculum is tendinous band which holds the flexor tendons in position. The small groove through which these tendons pass is called the carpal tunnel, and tendonitis in this region is called carpal tunnel syndrome. 22
Lateral epicondyle Extensor carpi radialis longus Flexor digitorum superficialis Flexor digitorum profundus 23 23
Lateral epicondyle origin of extensors Extensor carpi radialis longus brevis Extensor digitorum Extensor carpi ulnaris 24 24
Lab Protocol for the Upper Body Muscles 1) Study the muscles indicated in the lab manual for this lab. a) Use the links from the Muscle Actions Page b) Use the ADAM software as indicated in the lab manual 2) Take the quiz for the upper body muscles. 25 25
Quadratus lumborum Iliacus Iliopsoas{ Psoas major Unilaterally abducts vertebral column; bilaterally extends and fixates vertebrae. Flexes thigh 26 26
Gluteus maximus Extends the thigh, and fixates thigh in in extended position. Important in in climbing and running, but not in in walking. Iliotibial tract 27 27
The Hamstrings: Knee Flexors Iliotibial tract Semimembraneosus Semitendinosus Biceps femoris: Long head Short head 28 28
Gluteus medius Gluteus minimus Piriformis Abduct thigh and stabilize the thigh when taking steps, as as in in walking. Gluteus maximus 29 29
Tensor fascia latae Abducts knee and thigh Iliotibial tract Sartorius Adducts knee; flexes and laterally rotates thigh. Adductors: brevis longus magnus Gracilis 30 30
Quadriceps femoris Extends the knee. Rectus femoris Vastus lateralis Vastus medialis Vastus intermedius 31 31
Peroneus (fibularis) longus Tibialis anterior 32 32
Tibialis Anterior Dorsiflexion and inversion 33 33
Synergists in Plantar Flexion Gastrocnemius Primary action is is plantar flexion. Soleus Fixates foot in in a plantar flexed position Peroneus (fibularis) longus Plantar flexion and eversion 34 34
Peroneus (Fibularis) Longus 35 35
Peroneus (Fibularis) Brevis 36 36
Gastrocnemius (medial and lateral heads) Tendon of the calcaneus 37 37
Plantaris Soleus Gastrocnemius (cut) 38 38
Lab Protocol for the Lower Body Muscles 1) Study the muscles indicated in the lab manual for this lab. a) Use the links from the Muscle Actions Page b) Use the ADAM software as indicated in the lab manual 2) Take the quiz for the lower body muscles. 39 39