LESSON 8 Muscles can be classified by their function They can be classified as 1 agonists prime movers primarily responsible for producing a particular movement 2 antagonists oppose restrict or reverse a movement 3 synergists aid the action of agonists 4 fixators specialized synergists that immobilize the origin of the agonist muscle so all tension is exerted at the insertion Muscles are named on the basis of 1 Direction of muscle fiber ex rectus straight line transverse muscles right angles 2 Relative size of muscle ex maximus largest longus long 3 Location of muscle ex frontalis at frontal bone 4 Number of origins ex biceps 2 origins 5 Location of muscle origin insertion ex sternocleidomastoid origins at the sternum sterno clavicle cleido with insertion at the mastoid process 6 Shape of muscle ex deltoid triangular 7 Action of muscle ex adductor adduction action Muscles of the Head Neck Facial Expressions Epicranius frontalis frontal belly raise eyebrows ori epicranial aponeurosis ins skin of eyebrows root of nose Epicranius occipitalis occipital belly pulls scalp posteriorly ori occipital and temporal bones ins epicranial aponeurosis Orbicularis oculi close eye pull eyebrow down Orbicularis oris close protrude lips Mastication Masseter close jaw ori zygomatic arch maxilla ins angle ramus of mandible Temporalis close jaw Neck Muscles Platysma open jaw pull lower lip down ori over pectoral muscles ins lower margin of mandible skin muscle at mouth corner Sternocleidomastoid neck flexion head rotation towards shoulder ori manubrium of sternum medial portion of clavicle ins mastoid process of temporal bone superiornuchal line of occipital bone Digastric anterior and posterior belly open jaw elevate hyoid bone ori lower margin of mandible mastoid process ins connective tissue loop to hyoid bone Mylohyoid elevate hyoid bone base of tongue Sternohyoid depress larynx hyoid bone Anterior Thorax Shoulder Deltoid abduct arm flex extend rotate humerus Pectoralis major adduct rotate medially arm pulls chest upward inhalation ori clavicle sternum cartilage of ribs 1 6 aponeurosis of external obliques ins short tendons into intertubercular sulcus of humerus Pectoralis minor move scapula anterior inferior raise ribs inhalation Serratus anterior fixes scapula for arm abduction essential for raising arm pulls scapula anterior inferior Abdominal Wall Rectus abdominis flex vertebral column depress ribs compress abdomen exhalation ori pubic crest symphysis ins xiphoid process costal cartilage of ribs 5 7 External oblique flex vertebral column depress ribs rotate trunk compress abdomen exhalation Internal oblique flex vertebral column depress ribs rotate trunk compress abdomen exhalation Transversus abdominis compress abdomen exhalation Posterior Trunk Trapezius extend head adduct scapula lateral clavicle Latissimus dorsi extend adduct medial rotate arm Upper Arm Posterior compartment Triceps brachii extend forearm Anterior compartment Biceps brachii flex forearm ori short head coracoid process long head intertubercular sulcus within capsule of shoulder joint ins radial tuberosity Brachioradialis flex forearm Brachialis flex forearm Forearm Anterior compartment Pronator teres pronate weakly flex arm Flexor carpi radialis flex abduct hand at wrist Palmaris longus flex hand at wrist ori medial epicondyle of humerus ins palmar aponeurosis skin fascia of palm Flexor carpi ulnaris flex adduct hand at wrist Posterior compartment Extensor carpi radialis longus brevis extend abduct hand at wrist Extensor digitorum extends fingers hand at wrist ori lateral epicondyle of humerus ins by 4 tendons into distal phalanges of fingers 2 5 Extensor carpi ulnaris extend adduct hand at wrist Anterior Medial Thigh Iliopsoas flex trunk thigh at hip Sartorius flex abduct laterally rotate thigh ori anterior superior iliac spine ins by aponeurosis into medial aspect of proximal tibia Medial compartment Adductor group magnus longus brevis adduct flex medially rotate thigh Pectineus adduct flex and medially rotate thigh Gracilis adduct flex medially rotate thigh Anterior compartment Quadriceps femoris extend lower leg at knee flex thigh rectus femoris ori anterior inferior iliac spine superior margin of acetabulum ins tibial tuberosity and patella vastus lateralis vastus intermedius vastus medialis Tensor fasciae latae flex abduct medially rotate thigh Hip Posterior Thigh Posterior pelvis Gluteus maximus laterally rotate abduct extend thigh ori dorsal ilium sacrum coccyx ins gluteal tuberosity of femur and iliotibial tract Gluteus medius abduct medially rotate thigh Posterior compartment hamstrings Biceps femoris extend thigh laterally rotate leg flex knee Semitendinosus extend thigh medially rotates leg flex knee Semimembranosus extend thigh medially rotates leg flex knee Lower Leg Lateral compartment Fibularis Peroneus longus plantar flex evert foot ori head and upper portion of fibula ins by long tendon under foot to metatarsal 1 medial cuneiform Anterior compartment Tibialis anterior dorsiflex invert foot Extensor digitorum longus dorsiflex foot extend toes Posterior compartment Triceps surae plantar flex foot composed of Gastrocnemius plantar flex flex lower leg ori by two heads from medial and lateral condyles of femur ins calcaneus via calcaneal tendon Soleus plantar flex Flexor digitorum longus flexes toes plantar flexes inverts foot QUIZLET TO HELP WITH THE ORGINS http quizlet com 60206938 lesson 8 anpl flash cards Password BSC208501 LESSON 9 Nervous tissue is composed of 1 Neurons nerve cells that function to transmit electrical impulses 2 Neuroglia cells that support the neurons Main divisions of the nervous system 1 Central Nervous System CNS composed of the brain and spinal cord 2 Peripheral Nervous System PNS composed of the nerves that leave the CNS Overview of the structures in a neuron Soma the neuron s cell body a cluster of cell bodies in the PNS is known as a ganglion while in the CNS it is a nucleus Axon hillock tapered structure between soma and axon important for producing the action potential Dendrites processes that conduct electrical impulses towards the soma usually receives a signal from another cell Axon process that conduct electrical impulses away from the soma in the CNS a bundle of these processes form tracts in the PNS these axon bundles form nerves Axon Synaptic terminal found at the end of axon Synaptic cleft gap found between the axon of one neuron and the target cell Besides containing
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