The Appendicular skeleton Flashcards
The appendicular skeleton is composed of how many bones
126
The appendicular skeleton consists of
- limbs (bones of the limbs)
- pectoral girdle
- pelvic girdle
*Pectoral (shoulder) girdle
the pectoral girdle is composed of the two bones known as
- clavicle
- scapula
the clavicle (collarbone)
articulates with the sternum medially and scapula laterally
the scapula (shoulder blade)
articulates with the clavicle at the acromioclavicular joint
the clavicle and scapula allow
the upper limb to have free movement
- what are the bones of the upper limbs
-Humerus
- Ulna
- Radius
- Radioulnar joints
- interosseous membrane
- carpals
-metacarpals
-phalanges
Humerus
forms the bone of the upper arm
- the head articulates with the glenoid cavity of the scapula to form the shoulder joint
- at the distal end trochlea and capitulum articulates with the bones of the forearm to form the elbow joint
The forearm had two bones
- Ulna (medial)
- Radium (lateral)
Ulna (medial bone)
at the proximal end the coronoid process and olecranon process articulate with the humerus
Radius (lateral bone)
at the proximal end the head articulates with the capitulum of the humerus
radioulnar joints
proximal and distal
interosseous membrane
holds them together all the way through their length
The hand consists of
- carpals
- metacarpals
-phalanges
carpals
- wrist bones
- 8 bones arranges in 2 rows of 4 bones in each hand
metacarpals
- bones of the palm
- 5 per hand
phalanges
- bones of the fingers and thumb
- 14 in each hand
- in each finger there are 3 bones
- in the thumb there are only 2 bones
- what are the bones of the lower limbs
- femur
- tibia
-fibula - interosseous membrane
-tarsals - metatarsals
- phalanges
femur
- thigh bone
- heaviest and strongest bone in the body
what is one of the most serious causes of hospitalization among elderly persons
hip fracture
The lower leg has two bones called
- tibia (medial)
-fibula (lateral)
Tibia (medially located)
- shinbone
medial and lateral condyles at the proximal end articulate with the femur to form the knee joint
Fibula (Lateral)
-think and sticklike
-has no part in the forming of the knee joint
tibiofibular joints
proximal and distal
interosseous membrane
holds the two bones all the way through their length
The foot consists of
- tarsals
- metatarsals
-phalanges
tarsals
- 7 bones
what are the 2 largest tarsals
-calcaneus (heel bone)
- talus (articulates with the tibia to form the ankle joint)
Metatarsals
- 5 bones form the sole of the foot
phalanges
- 14 bones form the toes
*joints
The human body has how many joints
230
a joint is a
functional junction, where 2 bones meet, or articulate
functions of the joints
- hold bones together
- make bone growth possible
- permits parts of skeleton to change shape during childbirth
- enables body to move in response to skeletal muscle contractions
joints are classified as
-functionally
-structurally
functionally joints
according to degree of movement they make possible
structurally joints
according to the type of tissue that binds the bones together at each junction
*functional classification of joints
There are 3 main types of functional classification of joints
-synarthrosis
-amphiarthrosis
-diarthrosis
Synarthrosis
-immovable
ex: suture between skull bones
Amphiarthrosis
- slightly moveable
ex: pubic symphysis and intervertebral joints
what is it called when radius and ulna are joined by a large fibrous tissue band that permits slight movement
fibrous amphiarthrosis
in most amphiarthrosis, cartilage is used to join the bones described as
cartilaginous joints
Diarthrosis
freely movable joints
- bones in these joints have a potential space between them called the JOINT CAVITY
Joint cavity
contains small amount of thick, colorless fluid, a lubricant called SYNOVIAL FLUID that is secreted by the lining SYNOVIAL MEMBRANE
example of diarthrosis
shoulder and hip joints
Joints are also classified based on the type of material between the adjoining bones known as
- fibrous tissue
- cartilage
- or a joint cavity
Fibrous joints
generally immovable
cartilaginous joints
for the most part amphiarthrotic
-immovable or slightly moveable
synovial joints
freely movable
What are the types of fibrous joints
-sutures
-Gomphosis
sutures
bound tightly together, immobile
ex: suture between the skull bones
and proximal and distal tibiofibular joints
gomphosis
a conical process is inserted into a socket-like portion, immobile
ex: tooth located in the alveolar process of the mandible and maxillae
Cartilaginous joints
symphysis
symphysis
slightly movable or immobile
ex: pubic symphysis, intervertebral joints, hyaline articular cartilage of long bones, cartilaginous joints between ribs and sternum
what protects the bony surfaces
a smooth layer of hyaline articular cartilage
what encloses each joint and is continuous with periosteum of the bones
joint capsule of dense connective tissue
the joint capsule is composed of
an outer layer of ligaments and an inner lining of synovial membrane
what are the types of synovial joints
- ball-and-socket joints
- condyloid joint
- gliding joint or plane joint
-hinge joint
-pivot joint
-saddle joint
ball-and-socket joint
bone with globular head that articulates with the cup-shaped cavity of another bone
- permits movement of all planes (shoulder and hip joints)
condyloid joint
oval shaped condyle of one bone fits into an elliptical cavity of another bone such as in the joints between the metacarpals and phalanges
gliding joint or plane joints
nearly flat or slightly curved
- joints of the wrist and ankle as well as between adjacent vertebrae
Hinge joint
convex surface of a bone fits into the concave surface of another
ex; elbow and joint of phalanges
pivot joint
cylindrical surface of a bone rotates within a ring formed of bone and ligament
-limited movement
ex: joint between the atlas and axis
saddle joint
forms between bones whose articulating surfaces have both concave and convex regions
ex: joints between carpal(trapezium)
and metacarpal bones of the thumb
flexion
bending parts of a joint so that the angle between them decreases and parts come closer together
(bending knee)
dorsiflexion
movement at the ankle that brings the foot closer to the shin
(walking on heels)
plantar flexion
movement at the ankle that brings the foot farther from the shin
(walking or standing on toes)
Extension
straightening parts of a joint so that the angle between them increases and the parts move farther apart
(straightening knee)
hyperextension
extension of parts of a joint beyond anatomical position
(bending the head back beyond the upright position)
abduction
moving part away from midline
adduction
moving part toward midline
inversion
turning the foot so the plantar surface faces medially
eversion
turning the foot so the plantar surface faces laterally
pronation
turning the hand so the palm is downward or facing posteriorly
supination
turning the hand so the palm is upward or facing anteriorly
rotation
moving a part around an axis
circumduction
moving part so that its end follows a circular path
The bones of the foot are arranges to form 3 strong arches
- 2 longitudinal (medial and lateral)
- one transverse
the arches’ shape is designed to
bear the weight of the body and absorbs shock
the foot’s flexibility conferred by the arches is what
facilitates everyday loco-motor functions such as walking and sprinting
