Muscles of the Human Body PDF

Muscles of the Human Body Human Anatomy Pittsburgh Institute of Mortuary Science Course Objective Demonstrate technical skills in embalming and restorative art that are necessary for the preparation and handling of human remains Lecture Objective Locate and identify selected skeletal m...

Muscles of the Human Body Human Anatomy Pittsburgh Institute of Mortuary Science Course Objective Demonstrate technical skills in embalming and restorative art that are necessary for the preparation and handling of human remains Lecture Objective Locate and identify selected skeletal muscles MYOLOGY - the study of muscles “If you can build a muscle, you can build a mindset” - Jay Shetty  Functions of Muscles 01 Movement Muscles attach to and move bones 02 Posture Occurs via tonic contraction 03 Heat production Result of chemical energy à mechanical energy Necessary body functions 04 Digestion, breathing, speaking, pumping blood, etc.  01 Types of Muscle  Smooth vs. Striated Muscle Smooth (Involuntary) Skeletal (Voluntary) ★ Not under our control ★ Consciously controlled ★ Widely distributed ★ Striated ★ Non-striated ★ Also called visceral muscle Cardiac Muscle Myocardium ★ Cardiac or heart muscle ★ Found only in the heart ★ Striated ★ Involuntary  02 Skeletal Muscle Basics  Associated Structures 01 Tendons anchor muscles to bones 02 Bursae provide protection for bones and joints 03 Fascia is connective tissue that surrounds and secures structures Aponeuroses 04 are attachment points connecting bone to flat muscles Other Classifications of Muscles Sphincters are circular muscles constricting an orifice Pectoral means pertaining to the front of the chest, e.g., pectoralis major muscles  Muscle Structure The belly of a muscle is the widest/largest portion The muscle attachment to the bone that is stationary during the movement is the origin The muscle attachment to the bone that moves during a movement is the insertion  Muscle Naming Basis Shape & location Temporalis, trapezius Divisions & attachments Zygomaticus major, intercostals, omohyoid Direction of fibers Transversus abdominis, Superficiality & depth Flexor digitorum superficialis, internal oblique Size Adductor longus, gluteus maximus Action Levator palpebrae superioris 03 Movement  Flexion Extension Decrease in the angle between Increase in the angle between two bones at their joint two bones at their joint Abduction Adduction Movement away from the midline Movement towards the midline of of the body the body  Rotation Circumduction Movement around a longitudinal axis Movement of distal portion in a circle Supination Pronation Palms of hands faces anteriorly Palms of hands faces posteriorly Inversion Eversion Ankle turns, sole of foot Ankle turns, sole of foot faces faces midline away from midline Constriction Dilation Vessel becomes more narrow Vessel expands or widens Elevation Depression Movement in a superior Movement in an inferior direction direction myofibrils are threads that combine to form Structure muscle fibers muscle fibers are skeletal muscle cells muscle fibers combine to form fascicles fascicles combine to form muscles Myofibrils & Muscle Movement Myofibrils are divided into sarcomeres Sarcomeres contain two types of proteins or myofilaments: actin & myosin (thin filament) & (thick filament) Muscle contraction occurs when the sarcomere contracts which happens when actin & myosin attach to one another  Sliding Filament Model 01 Muscle is at rest, actin & myosin are not touching 02 Brain sends a signal or action potential 03 Calcium is released, calcium binds with troponin 04 Tropomyosin is released by actin  Sliding Filament Model, cont’d 05 Myosin binds with ATP 06 ATP changes to ADP 07 Myosin binds with actin 08 Sarcomere shrinks, muscle contracts  Sliding Filament Model, cont’d 09 ADP unbinds 10 ATP binds with myosin again 11 Myosin releases actin 12 Muscle relaxes  04 Skeletal Muscles Muscles of the Face  Chewing Muscles Temporalis muscle of mastication which Temporalis helps to close the mandible Masseter muscle of mastication which Masseter closes the mandible  Chewing Muscles, cont’d Buccinator principle muscle of the cheek which compresses the cheeks and forms the lateral wall of the mouth Buccinator  Eyebrow Muscles Occipitofrontalis Occipitofrontalis (epicranius) draws the scalp posteriorly and inferiorly and raises eyebrows Orbicularis oculi Orbicularis oculi closes eyelids & compresses lacrimal sacs  Eyebrow Muscles Corrugator Corrugator Procerus a pyramid-shaped muscle of facial expression which draws the eyebrows inferiorly and medially (draws brows together) Procerus muscle that draws the skin of the forehead inferiorly (draws brows together) Eyebrow Muscles, cont’d Levator palpebrae superioris muscle that raises upper eyelid Levator palpebrae superioris  “False” Smiling Muscles Levator labii superioris elevates and extends upper lip Levator anguli oris elevates the angle of the mouth Levator Risorius Levator labii anguli oris superioris narrow superficial band of Risorius muscle that pulls the angle of the mouth laterally  “Real” Smiling Muscles Zygomaticus major draws superior lip posteriorly & superiorly Zygomaticus minor Draws upper lip anteriorly Zygomaticus major & superiorly Zygomaticus minor  Other Mouth Muscles Orbicularis oris closes and puckers lips Quadratus labii superioris large muscle from the cheekbone and lower rim of the eye socket which raises the upper lip Levator labii superior alaeque nasi elevates the upper lip and dilates the nostril opening  Other Mouth Muscles Depressor anguli oris depresses the angle of the mouth Depressor labii inferioris draws lower lip inferiorly and slightly lateral Mentalis elevates and protrudes the inferior lip and wrinkles the skin over the chin  Levator labii superioris alaeque nasi Orbicularis oris Depressor anguli oris Depressor labii inferioris Mentalis Muscles of the Neck  Muscles of the Neck Platysma thin layer of muscle covering the anterior aspect of the neck Sternocleidomastoid muscle attached to the mastoid process of the temporal bone and by separate heads to the sternum and clavicle ; turns and nods head  Muscles of the Neck Omohyoid muscle attached to the hyoid bone and the scapula functioning in depressing the hyoid bone, swallowing and breathing Digastricus double bellied muscle which draws the hyoid bone superiorly Platysma  Digastricus Omohyoid Sternocleidomastoid Sternocleidomastoid Muscles of the Back  Muscles of the Back Trapezius triangular muscle that moves the head and shoulders Latissimus dorsi flat, posterior muscle that extends and adducts the shoulder Teres major adducts the humerus and assists latissimus dorsi in adducting the shoulder  Trapezius Trapezius Teres major Latissimus dorsi Latissimus dorsi Muscles of the Chest  Muscles of the Chest Pectoralis major superficial muscle that fans out across chest; adducts arms; rotates arms medially Pectoralis minor superficial muscle on the chest; depresses the point of the shoulder Pectoralis minor Pectoralis major  Muscles of the Chest Subscapularis largest strongest muscle of Subscapularis the rotator cuff that internally rotates the humerus and assists in shoulder adduction  Breathing Muscles Serratus anterior muscle forming the lateral wall of the chest Intercostals form chest wall and expand and contract to assist with respiration Diaphragm muscle allowing the chest to expand & contract  Intercostals Diaphragm Serratus anterior Intercostals  Muscles of the Abdomen Anterior/Lateral Abdominal Muscles External oblique outer, lateral abdominal muscles; flex the trunk; depress ribs Internal oblique medial to external oblique muscles; flex and bend the trunk; depress ribs Transversus abdominis medial abdominal muscle arising from the inguinal ligament Anterior Medial Abdominal Muscles Rectus abdominis top layer of abdominal muscles; flexes the spine and functions in posture  External Rectus oblique abdominis Internal oblique Transversus abdominis Transversus abdominis Posterior Abdominal Muscles Psoas major inner hip muscle that flexes and rotates the thigh and trunk Psoas major Psoas major  Muscles of the Upper Extremities  Muscles of the Upper Arm Deltoid triangular shoulder muscle that abducts the arm Coracobrachialis superior, anterior muscle that flexes and adducts the arm Brachialis flexes the elbow  Deltoid Coracobrachialis Deltoid Brachialis Muscles of the Upper Arm, Cont’d Triceps brachii Biceps brachii flexes and supinates the forearm Triceps brachii dorsal muscle that extends the forearm and adducts the arm Biceps brachii Muscles of the Forearm - Anterior Flexor carpi radialis flexes and abducts the hand Flexor carpi ulnaris flexes and adducts the hand Flexor digitorum superficialis flexes the fingers Pronator teres pronates the forearm Flexor digitorum profundus flexes & extends fingers Palmaris longus flexes wrist and functions in gripping Flexor digitorum superficialis Flexor carpi radialis Flexor carpi ulnaris Palmaris longus  Pronator teres Flexor digitorum profundus Flexor digitorum superficialis Muscles of the Forearm - Posterior Brachioradialis flexes the forearm Supinator supinates the forearm  Supinator Brachioradialis  Muscles of the Lower Extremities  Muscles of the Anterior Thigh Sartorius flexes and rotates the hip ; flexes knee Quadriceps femoris flexes hip; extends knee Iliopsoas connection between spine and lower limbs; flexes & rotates thigh ; flexes trunk at the hip Pectineus flexes, adducts, and rotates thigh Inguinal ligament attaches thigh muscles to the pelvis Inguinal ligament Quadriceps femoris Iliopsoas Pectineus Adductor longus Sartorius Quadriceps femoris  Muscles of the Posterior Thigh Gluteus maximus straightens the leg from the hip; extends leg from being flexed at the hip Biceps femoris extends & rotates thigh; flexes leg Semitendinosus extends & rotates thigh; flexes & rotates leg Semimembranosus extends & rotates thigh; flexes and rotates leg  Gluteus maximus Semitendinosus Biceps femoris Semimembranosus  Muscles of the Medial Thigh Adductor longus adducts thigh Adductor magnus adducts thigh  Adductor magnus Adductor longus  Popliteal Muscles Popliteus muscle stabilizes & allows flexibility of the knee joint Oblique popliteal ligament is the supporting ligament of the knee joint  Oblique popliteal ligament Popliteus muscle  Lower Leg Muscles - Anterior Tibialis anterior dorsiflexes foot Extensor hallicus longus extends the big toe  Extensor hallicus longus Tibialis anterior Lower Leg Muscles - Posterior Gastrocnemius plantarflexes the foot Soleus plantarflexes the foot Calcaneal tendon (Achilles heel) attaches muscles to the calcaneus  Gastrocnemius Gastrocnemius Soleus Calcaneal tendon 05 Lecture Review Vocabulary Check ★ MYOLOGY ★ PECTORAL ★ SPHINCTER Concept Review ★ Types of muscle (i.e. skeletal, cardiac) ★ Associated structures (i.e. tendons, fascia) ★ Ways to name and classify muscles ★ Muscle structure ★ Muscle movements (i.e. flexion, supination) ★ Sliding filament model ★ Specific skeletal muscles of the body Lecture Objective Locate and identify selected skeletal muscles Course Objective Demonstrate technical skills in embalming and restorative art that are necessary for the preparation and handling of human remains