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.