appendicular skeleton

Question 1

what is the appendicular skeleton

Answer 1

• bones of upper and lower limbs (30 bones = arm)

- pectoral and pelvic girdles

Question 2

what is the pectoral girdle

Answer 2

• shoulder (clavicles, scapula, surrounding muscles)
• attachment site for muscles
• sternoclavicular: synovial saddle, biaxial
• acromioclavicular: synovial plane (immobile)
• glenohumeral: ball and socket, synovial, many ligaments (coracohumeral - support upper limb weight and glenohumeral (3) - weak anterior reinforcements, stability), tendon of biceps brachii (runs inside joint, stability of head of humerus), bursa (reduce friction)
• dislocation: humerus falls forward (traction / counter traction)

Question 3

what is the clavicle

Answer 3

• collar bone, weak bone, superficial
• flattened acromial ends (articulate with scapula)
• cone shape sternal end (medial) articulates with sternum
• brace, holds scapula and arm laterally
• fracture: children / elderly, middle third, indirect injury, comminuted fracture (broke in more than 3 places), sling / bandage, surgery if open

Question 4

what is the scapula

Answer 4

• dorsal surface of rib cage ( between ribs 2-7)
• flat triangular with three borders (superior, medial and lateral)
• three angles (inferior, lateral and superior)
• many fossa, main (infraspinous, supraspinous and subscapular)

Question 5

what are the rotator cuff muscles

Answer 5

• subscapularis: rotates humerus medially (endorotation)
• supraspinatus (abducts humerus)
• infraspinatus (laterally rotates and adducts humerus)
• teres minor: laterally rotates and adducts humerus

Question 6

what is the humerus

Answer 6

• largest, longest bone of upper limb
• articulates superiorly with glenoid cavity of scapula
• articulates inferiorly with radius and ulna

Question 7

what is the elbow joint

Answer 7

• synovial hinge, monoaxial
• formed by trochlea notch of ulna and trochlea of humerus
• annular ligament: surrounds head of radius (supination / pronation)
• two capsular: ligaments restrict side to side movement (ulnar / radial collateral ligament)

Question 8

what are the bones of the forearm

Answer 8

• ulna: medial bone, major portion of elbow
• radius: lateral bone, head articulates with capitulum of humerus and radial notch of ulna
• interosseous membrane: fibrous, allows pronation / super nation, connects the two along entire arm length
• joints: proximal and distal radioulnar joints

Question 9

what are the bones of the wrist / hand

Answer 9

• proximal: scaphoid, lunate, truiqetrum, pisiform
• distal: trapezium, trapezoid, capitate and hamate
• metacarpal: 1-5 from the thumb (form palm)
• phalanges: each finger (except thumb) has 3 phalanges = 14 (distal, middle and proximal), fingers = 1-5 beginning with thumb (pollex)
• thumb has no middle phalanx

Question 10

fractures of the wrist / hand

Answer 10

• pisiform: fall on outstretched hand, wrist in extension, avulsion / linear fracture
• scaphoid: 60-70% of hand fractures, fall onto outstretch hand

Question 11

types of dislocations

Answer 11

• cause: pain, swelling, inflammation, inability to move (misalignment)
• luxation / dislocation: bones forced out of alignment, sprains
• subluxation: partial dislocation of joint, common in spine following rotational trauma

Question 12

what is / what are the types of fractures

Answer 12

• when a force exerted on bone is stronger / more flexible than it can structurally withstand
• depend on: degree / direction of force, bone involved and age of individual
• common: wrist, ankle, hip and clavicle
• simple: closed, no broken skin, easily healed
• compound: open, broken skin, surgery, increased risk of infection
• incomplete: only one side of bone is broken, hairline (superficial fracture, surface of bone, overuse, runners foot) and greenstick (children, flexible bones)
• complete: both sides broken, complete split

Question 13

pelvic vs pectoral girdle

Answer 13

• pelvic: more strength than mobility, bigger than pectoral

- pectoral: dot not articulate with vertebrae, provides mobility than strength (weak)

Question 14

what is the pelvic girdle

Answer 14

• hip bones (coxal)
• three fused bones (ileum, ischium and pubis)
• fuse during puberty
• sacrum / coccyx: 5 sacral vertebrae and 3-5 coccyx vertebrae
• joined posteriorly forming sacroiliac joints

Question 15

what are the pelvic bones

Answer 15

• ileum: superior ala (wing), acetabulum, iliac crest (superior), sciatic notch
• ischium: inferior / posterior part of hip bone, ischial tuberosity (most prominent)
• pubis: inferior / anterior portion, superior / inferior ramus and body
• pelvic brim: line from sacral promontory to upper pubic symphysis, above (false pelvis, abdominal cavity) and below (true pelvis, pelvic cavity, bowel, urinary / reproductive system)

Question 16

malve vs female pelvis

Answer 16

• M: tilted less forward, smaller and heart shaped, pubic arch = <90˚, support of heavier build / muscles
• F: adapted for childbearing, true pelvis = birth canal, broad, shallow, pubic arch = >90˚

Question 17

what is the hip / coxal joint

Answer 17

• ball and socket, increased motion, limited by deep socket, more stable than shoulder (deep head of femur fits entirely inside)
• head of femur articulates with acetabulum
• reinforced by ligaments (illiofemoral, pubofemoral, ischiofemoral, ligamentum teres - acetabulum to inside femur head, nutrients)

Question 18

injuries / arthroplasty of the hip

Answer 18

• dislocations = mostly posterior, huge amount of force to dislodge femur, 99% = due to car accidents
• arthroplasty: surgery to relieve pain and restore motion, realign / reconstruct joint, resection (increase ROM), surgical interposition reconstruction (prosthetic, metal on metal = metallosis = accumulation of metallic debris in soft tissue, inflammation, changes in tissue and genetic instability_

Question 19

what is the femur

Answer 19

• largest strongest bone in body
• articulates proximally with acetabulum of hip and distally with tibia and patella
• gluteal tuberosity and linea aspera (attachment site for hip muscles)
• medial and lateral epicondyles (attachment for knee muscles)
• valgus angle: <90˚, full extension and lower COG, bipedal locomotion

Question 20

what is the patella

Answer 20

• patellofemoral joint
• superior surface = base, narrower surface = apex
• increase leverage of quads femoris muscle
• sesamoid bone

Question 21

what is the tibia

Answer 21

• larger medial weight-bearing bone of leg
• lateral and medial condyles articulate with femur
• articulates distally with talus and fibula
• tibial tuberosity (attachment of patellar ligament)
• medial malleolus (medial surface of ankle joint)

Question 22

what is the fibula

Answer 22

• smaller laterally place bone of leg, non-weight bearing
• head forms proximal tibiofibular joint
• lateral malleolus (articulates with tibia and talus)

Question 23

describe the knee joint

Answer 23

• largest most complex joint of body, 3 joints surround by single cavity
• femorpatellar (plane joint, flexion of knee)
• lateral and medial tibiofemoral joints (flexion and extension)
• synovial, medial / lateral meniscus (absorb shock / stability), articular capsule (outside), cruciate ligament (between bones), synovial cavity (space / fluid), patellar ligament (front)

Question 24

describe the foot

Answer 24

• tarsals: cuboid, navicular, medial, intermediate and lateral cuneiforms
• talus: articulate with tibia and fibula, forms ankle, transfers weight from tibia to calcaneus
  metatarsals: bones 1-5, enlarged head of metatarsal 1 (ball of foot)
• phalanges: 14 = 3 in each except hallux - no middle phalanx)

Question 25

arches of the foot

Answer 25

• interlocking of foot bones, ligaments and tendons
• spring and leverage to foot when walking, flex when body weight is applied
• lateral / medial longitudinal: calcaneus to metatarsals
• transverse: tarsals / base of metatarsals
• ball of foot = 40% of body weight and heel = 60%
• human: substantial modifications to accomodate a bipedal striding gait