Chapter 11-Muscles of the Body

anterior and medial muscles w/ origin on pelvis or vertebrae

Iliacus, psoas major, tensor fasciae latae

muscles of the superficial perineal space

Ischiocavernosus, Bulbospongiosus, Superficial transverse perineus.

hypothenar muscles of the hand

abductor digiti minimi, flexor digiti minimi, oppenens pollicis

abdominal hernia

abnormal protusion of abdominal contents out of the abdominal cavity through a weak point in the muscles of the abdominal wall.

shoulder surface anatomy

acromion-lateral end of the spine of the scapula. acromioclavicular joint, deltoid muscle-covers the greater tubercle of the humerus.

medial compartment of the thigh

adduct the thigh, innervation is the obturator nerve

prime mover

aka agonist. muscle that has the major responsibility for producing a specific movement. sometimes more than one muscle is the prime mover. can cause several kinds of mvmt in same joint.

muscles of pelvic diaphragm

aka pelvic diaphragm. sheet of two muscles, both support pelvic organs. Levator Ani and Coccygeus

upward rotation

allows one to lift the arm above the head

muscle power

amount of force the muscle produces (depends on arrgmt. of fascicles) depends on total number of fiber muscle contains. bipennate and multipennate muscles shortest most powerful, but not good range motion.

range of motion

amount of mvmt. produced when a muscle shortens (depends on arrgmt. of fascicles) parallel muscles have greater range of motion., not powerful though.

other structures of forearm s. anatomy

anatomical snuff box bordered by, extensor pollicis brevis, extensor pollicis longus.

function of abdominal wall

anterior flexion (sit-ups), lateral flexion, and rotation of the trunk. simultaneously pulls ribs inferiorly to compress the abdominal contents. (forced expiration) When they contract with diaphragm airway is closed. (Valsalva maneuver), promotes micturition.

flexors

anterior flexor compartment. innervated by median and ulnar nerves. originate from common tendon-medial epicondyle of the humerus

compartment syndrom

any injury to a limb muscle, traumatic or chronic, causes swelling. fascia prevents expansion, causes pain.

effort

applied force used to move a resistance (load-body part to be moved) (muscles are effort)

thenar muscles of the hand

ball of thumb: abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, adductor pollicis.

upper limb and shoulder surface anatomy-axilla

base of the axilla-where armpit hair grows, deep to the axilla-axillary lymph nodes and blood vessels. anterior axillary fold-pectoralis major. posterior axillary fold. latissiumus dorsi and teres major.

muscles of the posterior compartment of thigh (hamstrings)

biceps femoris, semitendinosus, semimembranosus

law of levers

bones are levers, joints are fulcrums. muscles contraction is effort, load is the body part moved.. when the effort arm is longer than the load arm, the lever operates at a mechanical advantage; when the effort arm is shorter than the load arm, the lever operates at a mechanical advantage. (think see saw)

forearm surface anatomy

bones:ulna-palpate entire length-styloid process and head-distal end. radius-partly covered in muscle-head of the radius proximal end, styloid process-distal end

superficial posterior muscles of the forearm

brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor carpi ulnaris.

fascicles

bundles of fibers lg. enough to see w/ naked eye

intrinsic tongue muscles

change the tongue's chape but do not really move it (classified as digestive system)

buccinator muscles

compression of cheeks

posterior compartment of the leg

contains digital and plantar flexors, innervation is the tibial nerve

anterior compartment of the leg

contains digital extensor and dorsiflexors, innervation is the deep fibular nerve

trunk extension

deep or intrinsic muscles of the back. erector spinae group. maintain normal curvatures of the spine. form a column from sacrum to the skull.

muscles crossing the shoulder joint

deltoid, pectoralis major, latissimus dorsi, supraspinatus,infraspinatus, teres minor, teres major, subscapularis

Muscle compartments of limbs

dense fibrous CT divides limb muscles into compartments. muscles in opposing compartments are agonist and antagonist pairs. each compartment is innervated by a single nerve.

popliteal fossa surface anatomy

diamond-shaped hollow on posterior knee, defined by borders of hamstring tendons and gastrocnemius.

anterior triangle

divided into suprahyoid and infrahyoid muscles, participate in swallowing

hand surface anatomy

dorsum-dorsal venous network, tendons of extensor digitorum

third class lever

effort is applied closer to the fulcrum than the load, eg shovel.the load arm is longer than the effort arm; thus, mechanical disadvantage. ex. flexion of the forearm (load) by the biceps brachii muscle (effort). elbow is fulcrum. most skeletal muscles are 3rd class for speed. places muscle insertions close to joint, stability to joint, fasat extensive mvtms, w/ relat. little shortening muscles. running, throwing.

movements of scapula

elevation, depression, protraction/abduction, retraction/adduction, upward rotation, downward rotation

posterior arm and forearm compartment muscles

extend the elbow and wrist. innervated by radial nerve.

posterior compartment muscle of the thigh

extend the hip and flex the knee, innervation is the tibial branch of the sciatic nerve

muscles of the foot-dorsum

extensor digitorum brevis

leg tendons are held in place by

extensor, fibular, and flexor retinacula

muscles crossing the elbow joint posterior

extensors of the forearm:triceps brachii, anconeus

abdominal wall: three muscle sheets

external oblique, internal oblique, transverus abdominis. direct continuations of the 3 intercostal muscles in thorax. run in opposing directions for strength

head surface anatomy

face, lacrimal fossa, root and bridge of the nose, auricle of the ear, zygomatic arch, masseter muscle, mandible, tempormandiubular joint

muscles of the leg-angle and toes

fascia lata of the leg surrounds muscles:tightly binds muscles, prevents swelling during exercise, aids venous return, divides leg into three compartments.

circular fascicle

fascicles arranged in concentric rings. surround external body openings, close by contracting. oris-mouth, orbicularis oculi-eyes

palpation

feeling internal structures through the skin

muscles of the lateral compartment of leg

fibularis longus, fibularis brevis, flexor halluci longus, extensor hallucis longus, fibularis tertius

intrinsic muscles of the hand

fine movement of the fingers, all located in the palm, control precise movements, include muscles of adduction, abduction, and opposition.

muscles of the foot-sole first layer

first layer: flexor digitorum brevis, abductor hallucis, abductor digiti minimi

fulcrum

fixed point leverage moves on when a force is applied to the lever (joints)

anterior compartment muscles of the thigh

flex the hip and extend the knee, innervation is the femoral nerve

anterior arm compartment muscles

flex the shoulder or arm, innervation is the musculocutaneous nerve

anterior forearm compartment muscles

flex the wrist and digits, innervation is the median or ulnar nerve

movements of the wrist

flexion, extension, abduction, and adduction

head movements

flexion-sternocleidomastoid muscles. lateral flexion and rotation-muscles on one side neck(sternocleidomastoids, deeper neck muscles. extension-trapezius muscle of the back

muscles of the foot sole-second layer

flexor accessorius, lumbricals

tendons of forearm are anchored by

flexor and extensor retinacula

muscles of the foot sole-third layer

flexor hallucis brevis, adductor hallucis, flexor digiti minimi brevis

muscles of the forearm surface anatomy

flexor muscles-anterior forearm-flexor carpi radialis, plamaris longus(absenst in 30% people), extensor muscles-posterior forearm

deep anterior muscles of the forearm

flexor pollicis longus, flexor digitorum profundus, pronator quadratus

muscles crossing the elbow joint anterior

flexors of the forearm: biceps brachii(also supinates forearm), brachialis, brachioradialis

external intercostal muscles

form most superficial layer of the wall of the thorax. inspiration lift the rib cage

internal intercostal muscles

form the intermediate muscle layer of thorax. aid forced expiration.

pelvis and perineum surface anatomy

four bony stuctures define the perineium:pubic symphysis, two ischial tuberosities, coccyx

acute compartment syndrome

from traumatic injury, immediate surgery to prevent tissue damage from ichemia (low blood supply)

first class levers

fulcrum is located between the load and the point at which effort is applied. can do either mech advant. for power, or mech disadv. for speed and distance-depends on length of load arm and effort arm. ex. atlanto-occipital joint

posterior muscles gluteal muscles-origin on pelvis or sacrum

gluteus maximus, gluteus medius, gluteus minimus

mechanical disadvantage (speed lever)

greater distance, large effort to move small load

synergists

help the prime movers, either by adding a little extra force or by reducing undesirable extra mvmts. that the prime mover may produce.

gluteal region surface anatomy

iliac crestss, posterior superior iliac spine, sacroiliac joint, prominences of the buttocks, cheeks, formed from subcutaneous fat and the gluteal muscles

depression

inferior movement of the scapula, weight of arm

muscles of the urogenital diaphragm

inferior to the muscles of the pelvic floor, urogenital diaphragm formed from: sphincter erithrae and the deep transverse perineus.

rectus abdominis

inserts at the linea alba, straplike

digastric and mylohyoid

jaw-opening muscles are activated by

elbow surface anatomy

lateral and medial epicondyles of the humerus, ulnar nerve-funny bone runs across medial epicondyle, olecranon process of the ulna, cubital fossa (antecubital fossa)-forms anterior surface of forearm

muscles of facial expression

lie in the face and scalp, thin and variable in shape, often insert in the skin-not on bones, innervated by cranial nerve Vii-the facial nerve.

muscles and other abdominal features

linea alba=white line extending from xiphod process to the pubic symphysis, rectus abdominis:linea semilunaris-lateral margin of rectus abdominis

second class lever

load and the effort are on the same side of the fulcrum, effort is applied farther away from the fulcrum than the load, eg. wheelbarrow. the effort arm is longer than the load arm., mechanical advantage. eg standing on your toes. the metatarsophalangeal joint (fulcrum), calf muscles (effort), elevating the body (load) small muscular effort moves a much larger load.

criteria used to name muscles

location, shape, relative size, direction of fascicles and muscle fibers, location of attachments, number of origins, action

parallel fascicle

long axes of fascicles run parallel to the long axis of the muscle, fibers extend from origin to insertion. either fusiform w/ belly (eg biceps brachii) or straplike (eg sartorious of lower limb).

midpalmar muscles of the hand

lumbricals, palmar interossei, dorsal interossei

four main pairs of muscles involved in mastication

masseter and temporalis, pterygoid muscles, buccinator muscles, digastric and mylohyoid (innervated by mandibular division of the trigeminal nerve -cranial nerve V

thigh surface anatomy

medial and lateral condyles of the femur, patella, three group of muscles: quadriceps femoris-anterior thigh-vastus lateralis-injection site. adductors-medial thigh, hamstrings-posterior thigh.

diaphragm

most important muscle of respiration, forms a complete partition btwn the thoracic and abdominopelvic cavities. inspiration.also aids in eleminiation, lift heavy weights.

extrinsic muscles of tongue

move tongue laterally, anteriorly, posteriorly, all innervated by cranial nerve XII-the hypoglossal nerve

muscles of the forearm

movements of the wrist, hand, and fingers. most forearm muscles arise from the distal humerus. wrist and fingers are operated by muscles in the forearm.

protraction/abduction

moves it laterally and anteriorly, as in punching

retraction/adduction

moves it medially and posteriorly.

mechanical advantage (power lever)

moves only small distance, small effort

muscle actions and interactions

muscle cannot reverse the movement it produces. another muscle must undo the action. muscles wth opposite actions lie on opposite sides of a joint.

ebryonic muscle groups

muscle of the visceral organs, pharyngeal arch muscles, axial muscles. all muscles develop from the mesoderm germ.

movements at the hip joint

muscles that flex the thigh originate on vertebral column or pelvis. muscles that extend the thigh arise posterior to the hip joint. adductors originate medial to the hip joint, abductors originate lateral to the hip joint

trunk flexion

muscles that lie anterior to the vertebral column

antagonists

muscles that oppose or reverse a particular movement act. must be developed evenly, otherwise reduces flexibility. (muscle bound)

lower limb and gluteal region surface anatomy

natal cleft (gluteal cleft) vertical midline btwn cheeks, gluteal fold-horizontal fold below each cheek. ischial tuberosities, greater trochanter of the femur-located at the lateral hip

muscles of anterior neck and throat-swallowing

neck is divided into anterior and posterior triangles by the sternocleidomastoid muscle

torticollis

neck stays rotated to one side, keeping the head tilted in that direction. problems in sternocleidomastoid muscle on one side of neck.

muscles of the abdominal wall

no ribs, just muscles. has lateral and anterior abdominal wall, composed of 3 sheets, and rectus abdominis pair.

convergent fascicle

orign of muscle is broad, fascicles converge toward the tendon of insertion. triangle/fan shaped. pectoralis major in anterior thorax. muscle fibers extend length of muscle , origin to insertion

chronic compartment syndrome

overuse injury. microtears in the muscle can cause swelling.

downward rotation

paddling a canoe

leg and foot surface anatomy

palpate patella to find the patellar ligament. structure of the proximal leg: tibial tuberosity, lateral and medial condyles of the tibia , head of the fibula. stuctures of the distal leg: medial malleolus, lateral malleolus.

muscles of the medial compartment of thigh

pectineus, gracilis, adductors, adductor longus, adductor brevis, adductor magnus

muscles of the thorax surface anatomy

pectoralis major, serratus anterior

superficial muscles of the anterior thorax

pectoralis minor, serratus anterior, subclavius

lateral rotators

piriformis, obturator externus,obturator internus, gemellus, quadratus femoris

muscles of the foot sole-fourth layer

plantar and dorsal interossei

lateral compartment of the leg

plantar flex and evert the foot, innervation is the superficial fibular nerve

muscle groups of the leg surface anatomy

posterior calf muscles,: gastrocnemius and soleus-calcaneal tendon-inferior end of the soleus and gastrocnemius. anterior compartment muscles: tibialis anterior, extensor digitorum, fibularis

extensors

posterior compartment of the forearm, innervated by the radial nerve, originate at a common tendon-lateral epicondyle of the humerus.

back surface anatomy

posterior media furrow-vertical groove along the midline. spinous processes of vertebrae, spine of the scapula-medial end is opposite T3, medial border of the scapula, inferior angle of the scapula, iliac crests-supracristal line-intersects L4, sacrum-superior to cleft in buttocks, coccyx-posterior to the anus.

masseter and temporalis

prime movers of jaw closure

flexion (pectoralis major)

produced by a muscle that crosses on the anterior side of a joint (

abduction (deltoid middle fibers)

produced by a muscle that crosses on the lateral side of a joint

adduction (teres major)

produced by a muscle that crosses on the medial side

extension (latissiumus dorsi)

produced by a muscle that crosses on the posterior side of a joint

superficial anterior muscles of the forearm

pronator teres, flexor carpi radialia, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis.

deep muscles of the thorax:breathing

provide mvmts. necessary for ventilation, breathing. inpiration, expiration. very short muscles. rib to rib.

living anatomy

provides info about palpation of arterial pulses, skeleton, muscles, blood vessels, sounds of the heart and lungs, where to give injections

arm surface anatomy

region between shoulder and elbow. humerus-palpitated through skin along its entire length, biceps brachii, medial bicipital groove-medial boundary of the biceps bracchi, triceps brachii

lever

rigid bar that moves on a fixed point. (bones)

muscles of the anterior compartment of thigh

sartorius, quadriceps femoris, rectus femoris, vastus lateralis, vastus medialis, vastus intermedius

pennate fascicle

short and attach obliquely to a tendon that runs the whole length of the muscle. looks like a feather. multipennate: many feathers (deltoid),, binpennate: fasicles insert into the tendon from both sides (rectus femorus) unipennate: fascicles insert into only one side of the tendon. (etensor digitorum longus

pterygoid muscles

side to side movement-mastication

pharyngeal arch muscles: 4th-7th somitomeres

skeletal muscles of the pharynx plus some from head and neck. they all develop around the embryonic pharynx from the fourth to seventh somitomeres. original function was to squeeze things through the pharynx in swallowing, but have diversified. aka branchiomeric muscles. inc. facial expression, chewing, swallowing, neck, back muscles. (dvlp partly from nearby myotomes)

axial muscles: 1st-3rd somitomeres and from myotomes

skeletal muscles of the thorax, abdoment, and pelvis, plus neck, few in head. lie anterior and posterior to the bod axis, main function to move trunk, maintain posture. develop from myotomes and some somitomeres. dorsal myotome:deep muscles of neck that extend the spine when we stand. ventral myotomes: muscles of the anterior and lateral parts of the trunk and neck, flex the spine. muscles of anterior neck, respiratory muscles of thorax, anterior abdominal wall, pelvic floor, eye muscles, tongue.

neck surface anatomy

spinous processes of cervical vertebrae. c7 prominent. hyoid bone (anteror superior neck), laryngeal prminence (adam's apple), cricoid cartiloid-inferior to the laryngeal prominence, jugular notch-depression in the superior part of sternum

pharyngeal constrictors

squeeze food into the esophagus

triangles of neck surface anatomy

sternocleidomastoid muscles divide the neck, anterior triangle, posterior triangle.

neck muscle surface anatomy

sternocleidomastoid-most prominent neck muscle, sternal head, clavicular head. deep to the sternocleidomastaoid-common carotid artery, internal jugular vein. trapezius-posterior aspect of neck

thorax surface anatomy

sternum-portions felt through the skin: manubrium, xiphoid process, sternal angle. midaxillary line-line from the center of the axilla onto the lateral thoracic wall. midclavicular line-vertical line from midpoint of the clavicle to the groin.

abdoment surface anatomy

structures: iliac crest, anterior superior iliac spine, inguinal ligament-runs medially from anterior superior iliac spine to the pubic tubercle, pubic crest

cranium surface anatomy

superciliary arches, external occipital protuberance, mastoid process, temporalis muscle, frontalis muscle

muscles of the posterior compartment of leg

superficial muscles: triceps surae,-gastocnemius, soleus, plantaris deep muscles: popliteus, flexor digitorum longus, flexor hallucis longus, tibialis posterior

femoral triange surface anatomy

superior border-inguinal ligament, inferior borders: sartorius, adductor longus.

elevation

superior movement of the scapula, shrugging shoulders

deep posterior muscles of the forearm

supinator, abductor pollicis longus, extensor pollicis brevis and longus, extensor indicis.

swallowing process

suprahyoid muscles aid in closing the larynx, widen pharynx. pharyngeal constrictors squeeze food into esophagus. infrahyoid muscles pull the hyoid bone and larynx to original position.

fixators

synergists that hold a bone firmly in place so that a prime mover has a stable base on which to move a body.

foot surface anatomy

tendons on the dorsal surface of the foot, extensor digitorum longus tendon, extensor hallucis longus

somitomeres

the first seven myotome-like structures in the head

muscle of the visceral organs

the muscle tissue found in the visceral organs is either smooth or cardiac. develops from splanchnic mosederm around the early gut. not skeletal.

muscular system

the skeletal muscles, muscles that make up the flesh of the body and produce many types of movement

limb muscles: from myotomes

the upper and lower limbs arise from the ventral region as limb buds, limb muscles develop from the lateral parts of the nearby myotomes. lies dorsal to the limb bones becomes the extensor muscles of that limb, the muscles t/ attach the limbs to their girdles and muscles t/ attach t/ girdles to the trunk. function in locomotion and in manipulating objects. Upper limbs: extensor muscles lie on the limbs posterior side and extend its parts. flexor muscles lie on the anterior side of the limb and flex those parts. Lower limbs: the extensor muscles occupy the anterior side of the limb, extend the leg at the knee, dorsiflex the foot at the ankle, and exttend the toes. The flexor muscles occupy the posterior side of the lower limb and flex the leg at the knee, plantar flex the foot at the ankle, and flex the toes.

muscle compartments of arm and forearm

the upper limb has anterior and posterior compartments

leverage

the use of a lever to aid the movement of some object

muscles crossing the hip and knee joints

thigh and leg movements-anterior muscles:flex the thigh and extend the leg at the knee.-posterior muscles: extend the thigh and flex the leg. adductor muscle: on medial aspect of thigh, adducts thigh only. deep fascia surrounds and encloses all three g roups.

muscles of the anterior compartment of leg

tibialis anterior, extensor digitorum longus, fibularis terius, extensor hallucis longus

rectus sheath

tight enclosure of the rectus abdominis within aponeuroses. ensures that linea alba cannot snap forward like a bowstring.

intrinsic muscles of the foot

toe movement and foot support:help to flex, extend, adduct toes. support the arches. single muscle on dorsal aspect of the foot, many muscles on the plantar aspect.

muscles of the back surface anatomy

trapezius, latissiumus dorsi, erector spinae

superficial muscles of the posterior thorax

trapezius, levator scapulae, rhomboid major, rhomboid minor

surface anatomy

using landmarks to locate and id underlying muscles

linea alba

white line, tendinous raphe (seam) that runs vertically from the sternum to the pubic symphysis.