Upper & lower limbs (extremities or appendages), plus the bones forming the girdles that connect the limbs to the axial skeleton.
(appendic = to hang on to)
Total number of bones
(all articulate except for Hoid bone)
Functions of the skeleton...
4. hemopoesis (RBC/WBC/Platelets)
5. mineral homeostasis (Ca++, PTH - chemo receptors)
6. energy storage (yellow marrow in shaft of long bone - attipose tissue)
Types of bone tissue...
1. compact bone
2. spongy bone
1. contains few spaces
2. strongest form of bone tissue
3. found beneath the periosteum of all bone
4. makes up the bulk of the diaphyses of long bone
what is compact bone composed of?
repeating structural units called osteons or haversian system
what does a osteon conist of?
concentric lamellae arranged around a central canal or haversian canal.
circular plates of mineralized extracellular matrix of increasing diameter, surrounding a small network of blood vessels and nerves located in the central canal
these tubelike units of bone generally form a series of parallel cylinders that, in long bones, tend to run parallel to the long axis of the bone.
what do concentric lamellae resemble?
growth rings of a tree
spongy bone (trabecular or cancellous bone tissue)
does not contain osteons
always located in the interior of a bone, protected by a covering of compact bone. consists of lamellae that are arranged in an irregular pattern of thin columns called trabeculae.
spaces visible to the unaided eye between trabeculae in spongy bone are filled with what?
red bone marrow in bones that produce blood cells, and yellow bone marrow (adipose tissue) in other bones
bone marrow (red & yellow) contain
numerous small blood vessels that provide nourishment to the osteosytes
unspecialized bone stem cells. only bone cells to undergo cell division; the resuting cells develop into osteoblasts.
blasts -> build
bone building cells. synthesize and secrete collagen fibers and other organic components needed to build the extracellular matrix of bone tissue, and they initiate calcification.
mature bone cells, are the main cells in bone tissue and maintain its daily metabolism. ie exchange of nutrients & waste with the blood.
no cell devision
clasts -> breakdown
concentrated in the endosteum - on the side that faces the bone surface - deeply folded into a ruffled border. Causes RESORPTION.
have a spce called a synovial cavity or joint cavity between the articulating bones. classified functionally as freely movable. bones at a synovial joint are covered by a layer of hyaline cartilage called articular cartilage.
RELEASE POWERFUL LYOSOMAL ENZYMES & ACIDS BY THE OSTEOCLATS THAT DIGEST THE PROTEIN AND MINERAL COMPONENTS OF THE UNDERLYING EXTRACELLULAR BONE MATRIX. Part of the normal development, maintenance, and repair of bone.
classification of bone
3. flat bone
(shaped like a sesame seed) develop in certain tendons where there is considerable friction, tension, and physical stress, such as the palms and soles.
(exception - platellae)
fibrous join composed of a thin layer of dense irregular connective tissue; occur only between bones of the skull.
narrow slit between adjacent parts of bones through wh/ blood vessels or nerves pass
superior orbital fissure of sphenoid bone
opening through wh/ blood vessels, nerves or ligaments pass
optic foramen of sphenoid bone
coronoid fossa of humerus
furrow along bone surface that accommodates blood vessel, nerve, or tendon
intertubercular sulcas of humerous
external auditory meatus of temporal bone
large, round protuberance with a smooth articular surface at end of bone
lateral condyle of femur
smooth, flat, slightly concave or convex articular surface
superior articular facet of vertebra
usually rounded articular projection supported on neck (constricted portion) of bone
head of femur
prominent ridge or elongated projection
illiac crest of hip bone
epicondyle (epi = above)
typically roughened projection above condyle
medial epicondyle of femur
long, narrow ridge or border (less prominent than crest)
linea aspera of femur
sharp, slender projection
spinous process of vertebra
very large projection
greater trochanter of femur
variably sized rounded projection
greater turbercle of humerous
variably sized projection that has a rough, bumpy surface
types of cartilage
found on many joint surfaces. pearly blueish in color w/ firm consistency & has a considerable amt of collagen. no nerves or blood vessels, & its structue is relatively simple.
contains predominantly elastic fibers w/ fibroblasts between them; unstained tissue is yellowish.
lung tissue, walls of elastic arteries, trachea, bronchial tubes, true vocal cords, suspensory ligaments of penus, some ligaments between vertebrae
allows stretching between organs; is strong & can recoil to original shape after being stretched. Elasticity is important to normal functioning of lung tissue (recoils in exhaling) & elastic arteries (recoil between heartbeats to help maintain blood flow).
has chondrocytes among clearly visible thick bundles of collagen fibers within extracellular matrix; lacks perichondrium
pubic symphysis (where hip bones join anteriorly), intervertebral discs, menisci (cartilage pads) of knee, portions of tendons that insert into cartilage.
support and joining structures together. strength & rigidity make it the strongest type of cartilage.