lecture 8 appendicular skeleton Flashcards
2 parts of the appendicular skeleton
- pectoral girdle
2. pelvic girdle
- attaches the upper limbs to the trunk
- consists of clavicle and scapula
- dont encircle the body completely
- provides attachment for many muscles that move upper limb
- scapula moves freely
- clavicle articulates with axial skeleton
pectoral girdle
- attaches lower limp to the trunk
- supports visceral organs
- attaches to axial skeleton by strong ligaments
- acetabulum
- consists of paired hip bones
pelvic girdle
sternal end of clavicle articulates with
manubrium
acromial end of clavicle articulates with the
scapula
- provides attachment for muscles
- holds the scapulae and arms laterally
- transmit compression forces from the upper limbs to axial skeleton
clavicles
- lie on dorsal surface of the rib cage
- located between 2-7 ribs
- 3 borders ; superior, medial, and lateral
- 3 angles ; lateral, superior, and inferior
scapulae
- 30 bones from each upper limb
1. grouped into 3 sections
upper limbs
- arm, forearm and hand
-region of upper limb between the shoulder and elbow
arm
- only bone of the arm
- longest and strongest bone of upper limb
- articulates with scapula at the shoulder
- articulates with the radius and ulna at the elbow
humerus
- formed by radius and ulna
- proximal ends articulate with the humerus
- distal ends articulate with carpals
forearm
interconnects radius and ulna
interosseous membrane
radius is lateral and ulna is medial
in anatomical position
- main bone responsible for forming the elbow joint with the humerus
- hinge joint allows forearm to bend on arm
- plays little to no role in hand movement
ulna
major landmarks of the ulna
- olecranon
- radial notch
- trochlear notch
- coronoid process
- ulnar styloid process
- superior surface of the head of the radius articulates with capitulum
- medially the head of the radius articulates with the radial notch of the ulna
- contributes heavily to the wrist joint
radius
major landmarks of the radius
radial tuberosity and radial styloid process
bones of the hand
- wrist
- palm
- fingers
- carpus
- metacarpals
- phalanges
- forms the true wrist
- proximal region of the hand
- gliding movements occur between carpals
- composed of 8 marble- sized bones
carpus
8 bones of the carpus
-arranged in two irregular rows
Scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, and hamate
Sally left the party to take carmen home
Scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, and hamate
a deep cut that holds the head of the femur
- lower limbs have less freedom of movement
- more stable than the arm
acetabulum
pelvic girdle consists of 3 separate bones
ilium, ischium, and pubis
- long flaring bone
- forms the superior region of the coal bone
- site of attachment for many muscles
- articulation with the sacrum forms sacroiliac joint
ilium
- forms posteroinferior region of the coal bone
- anteriorly joins the pubis
ischium
strongest part of the hip bone
ischial tuberosities
-forms the anterior region of the coal bone
-lies horizontally in anatomical position
-pubic symphysis
-joined by fibrocartilage in the middle
-pubic arch
angle helps distinguish male vs female
pubis
inferior to the pubic symphysis
pubic arch
bony pelvis divided into 2 regions
- false pelvis
- true pelvis
bounded by ale of the iliac bones
false pelvis
inferior to pelvic brim
-forms a bowl containing the pelvic organs
true pelvis
- delineated by pelvic brim
- largest in diameter right to left
pelvic inlet
- inferior margin of true pelvis
- largest in diameter anteroposteriorly
pelvic outlet
- carries the entire weight of the erect body
- bones of __ are thicker and stronger than those of upper limb
- divided into 3 segments ; thigh, leg, foot
lower limb
-region of lower limb between the hip and knee
thigh
single bone of the thigh
- longest and strongest bone of the body
- ball shaped head of the femur articulates with acetabulum
femur
- embedded in the tendon that secures the quadricep muscles
- protects knee anteriorly
- improves leverage of thigh muscles across knee
sesamoid bone
- refers to the region of the lower limb between the knee and the ankle
- composed the tibia and fibula
- interosseous membrane
leg
- more massive medial bone of the leg
- receives weight of the body. from the femur
tibia
sticklike lateral bone of the leg
fibula
connects the tibia and fibula
interosseous membrane
tibia articulates with femur at superior end and forms
knee joint
tibia articulates with talus at the inferior end forms
the ankle joint
fibula does not contribute to the knee joint
stabilizes the ankle joint
- composed of tarsus, metatarsus, and phalanges
- important functions
- supports body weight
- acts as lever to propel body forward when walking
- segmentation makes foot pliable and adapted to uneven ground
the foot
- makes up posterior half of foot
- contains seven bones called tarsals
- body weight is borne primarily by the talus and calcaneus
tarsus
site of articulation with the tibia
trochlea of the talus
- consists of small bones (5) called metatarsals
- first ___ supports body weight
metatarsus
- 14
- similiar to structure of phalanges of fingers
phalanges of the toes
3 important arches of the foot
- media longitudinal arch
- lateral longitudinal arch
- transverse arch
“keystone” bones of arches
-talus and cuboid (medial and lateral ) longitudinal arch
head of the femur slips out of acetabulum
hip dysplasia
soles of the feet turn medially
clubfoot
