Chapter 8: Appendicular Skeleton Flashcards
What does the pectoral shoulder girdle include
clavicle and scapula
What does the medial end of the clavicle articulate with
manubrium of the sternum
What does the lateral end of the clavicle articulate with
acromion of the scapula
Scapula
the scapula is a flat bone that is located in the superior part of the posterior thorax between the second and seventh ribs
Glenoid cavity location and function
glenoid cavity of the scapula serves as an attachment point for the humerus
What is the humerus and what does it articulate with
- humerus is also called the upper arm bone
- articulates with the scapula at the glenoid cavity
- humerus articulates with the radius and ulna distally
What part of the humerus articulates with the radius and ulna
the trochlea articulates with the ulna and the capitulum articulates with the radius
Capitulum of humerus
smooth, rounded eminence on the lateral portion of the distal articular surface of the humerus
Intertubercular sulcus location
it is a groove located on the humerus
Ulna location and features
- the ulna is located on the medial side of the forearm
- the olecranon and coronoid process at the proximal end of the ulna form the trochlear notch which wraps around the trochlea of the humerus making up the elbow joint
Radius location and features
- located at the lateral (thumb) side of the forearm
- the head of the radius articulates with the capitulum of the humerus and with the radial notch of the ulna
Carpal bones and how they are attached to each other
- ## the carpal bones are 8 bones connected by ligaments and arranged in 2 rows of 4 bones each
Proximal row carpal bones
scaphoid, lunate, triquetrum, pisiform
- the scaphoid and lunate articulate with distal ends of the radius
Carpal bones DO NOT articulate with
the ulna
Distal row carpal bones
trapezium, trapezoid, capitate, hamate
- articulates with metacarpals
What is the metacarpus and how many bones is it made of
intermediate region of the hand; palm and it is made up of 5 bones
- numbered 1-5 starting at the thumb
Base and heads of metacarpals
- the base of the metacarpals articulate with the distal carpals
- the heads of the metacarpals articulate with the proximal phalanges
Phalanges
- there are 14 phalanges in total
- numbered from 1-5
- each thumb contains 2 (proximal and distal)
- other fingers contain 3 ( proximal, middle, distal)
Pelvic girdle
- made up of 2 hip bones (os coxa and coxal bones) that articulate with the sacrum posteriorly
Each hip bone is made up of …
3 individual bones: ilium, ischium, and pubis
What are the 2 bones that articulate anteriorly at the pubic bones at the joints called
pubic symphysis
What does the femur articulate with
- the head of the femur articulates with the acetabulum of the hip bone as a ball and socket joint
What is the acetabulum of the hip composed of
all 3 bones that make up the hip bone; ilium, ischium and pubis
The pelvis is divided into a superior and inferior portion by the…
pelvic inlet
Superior pelvis
- the bony pelvis superior to the pelvic inlet is known as the false (greater) pelvis
Inferior pelvis
- the area of bone pelvis inferior to the pelvic inlet is known as the true (lesser) pelvis
Differences between the male and female pelvic girdle
MALE:
- the bone of the male pelvis are usually larger and heavier
- pelvic inlet: narrow and heart shaped
- pubic arch is less than 90 degrees angle
- iliac crest: more curved
- sacrum: longer and narrower
FEMALE:
- the pelvis is wider and shallower
- light and thin
- pelvic inlet is wide and more oval
- pubic arch is greater than a 90 degrees angle
- iliac crest: less curved
- sacrum; shorter and wider
The longest, heaviest and strongest bone in the body
the femur
Articulations of the femur
- the proximal end of the femur inserts into the acetabulum of the hip bone
- the distal end of the femur articulates with the tibia and patella
Patella
- triangular bone (sesamoid bone) that develops in the quadriceps tendon
- connects to the femur and tibia
What does the patella articulate with
the posterior end of the patella articulates with the lateral medial condyles of the femur
- the patellar ligament attaches the patella to the tibia
Tibia
- the larger, medial, weight-bearing bone of the leg
- proximal end articulates with the femur
- distal end articulates with the talus bone of the ankle
- the tibial tuberosity on the anterior surface is the point of attachment for the patellar ligament
Fibula
- the smaller lateral bone of the leg
- proximal end articulates with the tibia (proximal tibiofibular joint)
- fibula does not articulate with the femur
- distal end articulates with the talus bone of the ankle
Tarsal bones
- talus, calcaneus, navicular, 3 cuneiforms and cuboid
Metatarsals
- numbered from 1-5 starting with the big toe
- metatarsals make up the plantar (sole) and dorsal(top) surface of the foot
- proximal end articulates with cuneiform bones and the cuboid
- the distal ends articulate with the proximal phalanges
Foot arches purpose
- the foot has 2 arches supported by ligaments and tendons
- purpose: to allow the foot to support the weight of the body, provide leverage while walking and distribute the body’s weight over the foot
2 arches of the foot
1) Longitudinal arch: made up of a lateral and medial portion
2) Transverse arch
What does skeletal tissue arise from
- arises from the middle primary germ layer in embryos known as the mesoderm, although most of the skull arises from the outer layer called he ectoderm
Mesoderm, ectoderm and edoderm turn into
mesenchyme which turns into connective tissue
How is the neurocranium formed and what bones are cartilaginous neurocranium
cartiaginous neurocranium undergoes endochondral ossification (forms cartilage first, then bone)
- occipital, temporal, sphenoid, and ethmoid bones
What bones are membranous neurocranium
- parietal and frontal bones
- these bones undergo intramembranous ossification; bone forms directly from connective tissue
What bones form the viscerocranium
the bones of the face (ectodermal in origin)
What facial bones are cartilaginous viscerocranium and where does it come from
- comes from cartilage of the pharyngeal arches
endochondral ossification of these cartilages forms the ear bones and hyoid bone
Membraneous viscerocranium
- comes from mesenchyme of the firs pharyngeal arch
intramembraneous ossification of these tissues forms the facial bones
Development of the skeleton: the skeleton of the limb girdles is derived from…
mesoderm
When can upper and lower limb buds be seen in developing embryo
in a 4 week embryo
when can hands and foot palates be seen in an embryo
at 6 weeks
when can free upper and lower limbs be seen in an embryo
at 8 weeks
Radius Job
articulates with the wrist
Ulna Job
makes connections at elbow
What makes up the medial malleolus (inner ankle)
tibia
What makes up the lateral malleolus (outside ankle)
fibula and it articulates with the tibia at the fibular notch
What can weakened foot arches lead to
inflammation or plantar fasciitis
Function of the talus
to bear weight of the tibia and the fibula
