Muscle System 1
Includes all skeletal muscle tissue that can be controlled voluntarily Muscular system 2
Classification of Skeletal Muscles 3
Muscles can be classified by action Agonist (prime mover) Primary responsible for the movement Antagonist Opposes the agonists Synergist Aids the action of agonists Fixator Types of Muscles 4
Muscles can be identified by origin, insertion and action Origin = stationary end Insertion = movable end Origins and Insertions 5
Names give clues to muscle characteristics Location of muscle’s origin and insertion Sternohyoid Direction of fibers Tranverse, oblique, rectus Number of origins Biceps, triceps Names of skeletal muscles 6
Size of the muscle Maximus, minimus Shape Deltoid, trapezius Action Adductor, flexor Location of the muscle Frontalis, orbicularis 7
Organization of skeletal muscle fibers Parallel muscle Convergent muscle Pennate muscle Unipennate Bipennate Multipennate Circular muscle (sphincter) 8
Organization of skeletal muscle fibers 9
Muscles of the Head and Neck 10
Head 11
Muscles of the head and neck Epicranius muscles Occipital O: occipital bone I: galea aponeurotic A: pulls the scalp posteriorly Frontal O: galea aponeurotic I: skin of the eyebrow A: raise the eyebrow 12
Muscles of the head and neck Orbicularis oculi O: frontal and maxillary bones I: eyelid A: closes eyes Corrugator supercilli O: frontal bone I: skin of eyebrow A: draws eyebrow inferiorly and medially 13
Muscles of the head and neck Levator labii superioris O: zigomatic and maxilla bones I: upper lip A: raises upper lips Depressor labii inferioris O: mandible I: lower lip A: pulls lower lip inferiorly 14
Muscles of the head and neck Depressor anguli oris O: mandible I: angle of mouth A: pulls corner of mouth down and laterally Mentalis O: mandible I: skin of chin A: protudes lower lip 15
Muscles of the head and neck Zigomatics O: zigomatic bone I: corner the mouth A: smiling muscle Risorius O: masseter I: angle of the mouth A: pulls corner of lips laterally 16
Orbicularis oris O: maxilla and mandible I: lips A: compresses lips Buccinator O: maxilla and mandible I: orbicularis oris A: compresses the cheek (whistling) Muscles of the head and neck 17
Muscles of Mastication 18
Masseter muscles O: zigomatic and maxilla bones I: mandible A: closes the jaw Temporalis muscles O: temporal fossa I: mandible A: closes the jaw Muscles of mastication 19
Muscles of mastication Pterygoids O: sphenoid, palatine and maxillary bones I: mandible A: elevates mandible, grinding the teeth Buccinator 20
Muscles of the head and neck Platysma O: fascia of chest and deltoid I: mandible, skin, corner of the mouth A: depresses mandible, pulls lip back and down Sternocleidomastoid O: manubrium and clavicle I: temporal and occipital bones A: flexion forward of the neck 21
Neck 22
Neck 23
Muscles of the head and neck Scalenes – anterior, middle, posterior O: cervical vertebrae I: first 2 ribs A: elevates first 2 ribs Digastric O: mandible and mastoid process I: hyoid A: elevates hyoid bone 24
Muscles of the head and neck Mylohyoid O: mandible I: hyoid bone A: elevates hyoid bone Sternohyoid O: manubrium and clavicle I: hyoid bone A: depresses hyoid bone 25
26
Inferior and superior rectus muscles Lateral and medial rectus muscles Inferior oblique muscles Elevates the eye and turns it laterally Superior oblique muscles Depresses the eye and turns it laterally Extrinsic eye muscles 27
Chapter 25 Muscles of the Trunk 28
Muscles of the trunk and shoulder Serratus anterior muscles O:ribs I: scapula (anterior surface) A: fixates, protracts the scapula Pectoralis minor muscles O: ribs I: scapula A: ribs fixed: moves scapula forward and inferiorly and with scapula fixed it moves up the rib cage 29
Muscles of the trunk and shoulder Deltoid muscles O: clavicle and scapula I: humerus A: abduction of the shoulder Pectoralis Major O: clavicle, sternum, ribs I: humerus A: agonist for shoulder flexion 30
Muscles of the thorax (front) 31
Muscles of Respiration External intercostal O: rib above I: rib below A: elevates rib cage Internal intercostal O: rib below I: rib above A: depresses rib cage 32
Muscles of Respiration 33
Muscles of Respiration Diaphragm O: ribs and its cartilage, sternum, vertebrae I: central tendon of the diaphragm A: prime action in inspiration 34
Diaphragm 35
Muscles of the Trunk (back) 36
Muscles of the trunk (back) and shoulder Supraspinatus muscles O: scapula I: humerus A: synergist for arm abduction Infraspinatus muscles O: scapula I: humerus A: helps to hold the head of the humerus in the glenoid cavity, lateral rotation of humerus 37
Muscles of the trunk (back) and shoulder Teres major O: scapula I: humerus A: adducts humerus, medial rotation of humerus Teres minor muscles O: scapula I: humerus A: helps to hold the head of the humerus in glenoid cavity, lateral rotation of the humerus 38
Trapezius muscles O: occipital bone, vertebrae I: scapula, clavicle A: extend head, elevate scapula Rhomboids O: vertebrae I: scapula A: adduct and stabilize scapula Muscles of the trunk (back) and shoulder 39
Muscles of the trunk (back) and shoulder Levator scapulae O: vertebrae I: scapula A: elevates scapula Latissimus dorsi muscles O: vertebrae, ribs, ilium I: humerus A: agonist for shoulder extension 40
Muscles of Abdominal Wall 41
Rectus abdominis O: pubis I: xiphoid process, ribs A: flexes vertebral column,increase abdominal pressure External oblique, O: ribs I: linea alba, pubis, ilium A: see above, helps trunk rotation and lateral flexion Muscles of Abdominal Wall 42
Muscles of Abdominal Wall Internal oblique O: lumbar fascia, ilium, inguinal ligament I: linea alba, pubis, ribs A: same as external oblique Transversus abdominis O: ribs, inguinal ligament, ilium, lumbar fascia I: linea alba, pubis A: compresses abdominal content 43
Posterior muscles of the back 44
Chapter 25 Muscles of the Arm 45
Biceps brachii muscle O: scapula, shoulder joint I: radius A: agonist for flexion of the elbow Muscles of the arm 46
Muscles of the arm 47
Muscles of the arm Brachialis O: humerus I: ulna A: flex the elbow Brachioradialis O: humerus I: radius A: synergist for flexion of the elbow 48
Muscles of the arm 49
Muscles of the arm Triceps brachii muscle O: scapula, humerus I: ulna A: agonist for extension of the elbow 50
Muscles of the arm 51
Muscles of the arm 52
Rotator Cuff Muscles Supraspinatus, infraspinatus, teres minor, and subscapularis Function mainly to reinforce the capsule of the shoulder 53
54 Rotator Cuff Muscles
Flexion of the wrist (O: humerus) Flexor carpi ulnaris I: metacarpus and carpus Flexor carpi radialis I: metacarpus Palmaris longus I: palm of the hand A: also extends the palm of the hand Muscles of the forearm 55
Muscles of the arm and forearm 56
Muscles that affect the wrist Extension of the wrist (O: humerus) Extensor carpi radialis I: metacarpus Extensor carpi ulnaris I: metacarpus Pronation of the forearm (I: radius) Pronator teres muscle O: humerus 57
Muscles of the forearm 58
Muscles of the forearm 59
Muscles of the forearm Extensors of the digitus Extensor digitorum O: humerus I: phalanges 60
Chapter 25 Muscles of the Leg 61
Gluteus maximus O: ilium, sacrum, coccyx I: femur A: extension of thigh (climbing stairs) Gluteus medius and minimus O:ilium I: femur A: abducts thigh, steadies pelvis Muscles of the pelvis and lower limbs 62
Muscles of the leg Tensor fascia latae O: ilium I: fascia latae A: flexes, abducts the thigh; tenses the fascia latae 63
Muscles of the leg 64
Formed from the merging of the psoas major and the iliacus muscles O: ilium, vertebrae I: femur Flexes trunk on thigh, flexes thigh Iliopsoas muscle 65
Muscles of the Leg 66
Sartorios O: ilium I: tibia A: flexes the thigh and helps in crossing the leg Adductors of the leg O: pubis I: femur Muscles of the leg 67
Muscles of the pelvis and lower limbs Gracilis O: pubis I: tibia A: adducts, flexes and medially rotates the thigh 68
Muscles of the leg Quadriceps (I: tibia; A: extends the knee) Rectus femoris O: ilium Vastus medialis, intermedius, lateralis O: femur 69
Leg 70
Leg 71
Muscles of the leg The hamstrings (O: ischium; I: tibia; A: extend thigh, flexes knee) Biceps femoris muscles Semimembranosus muscles Semitendinosis muscles 72
Plantar flexion (I: calcaneal tendon) Gastrocnemius muscle O: femur Soleus muscle O: fibula and tibia Eversion and plantar flexion Fibularis muscle O: fibula I: metatarsal bones (lateral side) Muscles of the lower leg 73
Muscles of the lower leg 74
Popliteus O: femur I: tibia A: unlocks the knee joint Muscles of the lower leg 75
Muscles of the leg 76
Muscles of the lower leg Tibialis anterior O: tibia I: metatarsus and cuneiforme A: dorsiflexion of the foot Tibialis posterior O: tibia I: tarsal and metatarsal bones A: foot inversion 77
Muscles of the lower leg Extensor digitorum O: Tibia and fibula I: Digitus A: Extends the digits 78
Chapter 25 Cat Dissection 79
Skinning the Cat Leave the skin of the back attached. Do not skin paws, tail, genital area, or head. Remove fat if possible. When you are done, use the skin to wrap the cat in. Use the pencil and tape to label the bag. 80
Skinning the Cat Cut the bag from the top to allow you to store the cat in it. Keep as much embalming fluid as possible in the cat for it’s preservation. Use several rubber bands; if one breaks, the bag will remain closed. Clean and dry tray, tools and lab bench before leaving. 81
Cat Dissection – Neck Muscles Mylohyoid Digastric Sternohyoid Sternothyroid Thyrohyoid 82
Cat Dissection – Thoracic Muscles Anterior muscles Pectoralis Major and Minor Serratus anterior Intercostals Internal External 83
Cat Dissection – Thoracic Muscles Posterior muscles Trapezius Latissimus dorsi Rhomboids Supraspinatus Infraspinatus 84
Cat Dissection – Abdominal Muscles External oblique Internal oblique Rectus abdominis Transversus abdominis 85
Cat Dissection – Arm Muscles Brachial muscles Biceps brachii Triceps brachii Long head Lateral head 86
Cat Dissection – Arm Muscles Antebrachial muscles Pronator teres Flexor carpi ulnaris Palmaris longus Flexor carpi radialis Extensor carpi ulnaris Extensor digitorum Extensor carpi radialis 87
Cat Dissection – Leg Muscles Upper leg Sartorius Gracilis Rectus femoris Vastus lateralis Vastus medialis Adductors 88
Cat Dissection – Leg Muscles Semimembranosus Semitendinosus Biceps femoris Lower leg Gastrocnemius Soleus Tibialis anterior Extensor digitorum Fibularis 89