Skeletal System Flashcards
The Human skeletal system comprises of?
all bones, tendons, cartilage and ligaments of the body.
Human Skeletal makes up nearly ______ of average human’s body weight.
20%
It composed of around _____ bones at birth = fuse together overtime = _____ by the time human reaches adulthood.
270
206
It provides the structural support for the human body and protects all the organs.
Skeletal System
Skeletal System is separated into 2 categories depending on purpose and location .
Axial Skeleton Appendicular skeleton
Axial Skeleton has how many bones?
80 bones
Axial Skeleton includes the following:
- Skull
- Rib cage
- Spine
Axial Skeleton forms the central structure of the skeleton which aims to protects the following organs like:
- Heart
- Lungs
- Spinal cord
- Brain
Appendicular Skeleton has how many bones?
126 bones
Appendicular Skeleton includes the following:
- Arms
- Legs
- Pelvic girdle
- Shoulder girdle
The lower portion of the appendicular skeleton protects the major organs:
- Digestion
- Reproduction
It provides stability for the human body during periods of motion (walking, running)
Appendicular Skeleton
The __________ also allows for a greater range of motion when human body is lifting and carrying objects of great weight
upper portion
Four components of the skeletal system:
- Bones
- Cartilage
- Tendons
- Ligaments
Functions of Skeletal System
- Body support
- Organ protection
- Body movement
- Mineral storage
- Blood cell production
Cartilage provides a firm yet flexible support within certain structures such as?
nose, external ear, thoracic cage, trachea.
strong bands of fibrous connective tissue that hold bones together.
Ligaments
If blood levels of these minerals ________, the minerals are released from bone into the blood (calcium, phosphorus= essential for many physiological process).
decrease
Bones contain ________ filled with red bone marrow, which gives rise to blood cells and platelets.
cavities
Is composed of cartilage cells within an extensive and relatively rigid matrix.
Cartilage
The surface of nearly all cartilage is surrounded by layer odd dense irregular connective tissue =__________= protective connective tissue sheath
perichondrium
- hyaline cartilage that covers the ends of bones where they come together to form joints
- no perichondrium, blood vessels, or nerves.
Articular Cartilage
Three types of Cartilage:
- Hyaline cartilage
- Fibrocartilage
- Elastic cartilage
This type of cartilage growth:
- chondroblasts in in the perichondrium
add new cartilage to the outside edge of the existing cartilage.
- chondroblasts lay down new matrix and add new chondrocytes to the outside of the tissue.
Appositional growth
This type of cartilage growth:
chondrocytes in the center of the tissue
divide and add more matrix in-between the existing cells
Intestinal growth
In bone, as in other connective tissues, the bone cells produce the ___________ and become entrapped within it. The cells also break down old matrix so that new matrix can replace it.
bone matrix
Bone matrix composition is responsible for?
the characteristics of bone
Bone Matrix by weight, normally about?
35% organic and 65% inorganic material
Bone Matrix’s organic material consists primarily of?
collagen and proteoglycans.
Bone Matrix’s Inorganic material consists primarily of a calcium phosphate crystal called __________ which has the molecular formula Ca10(PO4)6(OH)2.
hydroxyapatite
_________ and _________ components are responsible for the major functional characteristics of bone.
collagen and mineral
If all the mineral is removed from a long bone, collagen becomes the primary constituent and the bone is?
overly flexible
if the collagen is removed from the bone, the mineral component becomes the primary constituent and the bone is?
very brittle
formation of new bone by osteoblasts
Ossification or osteogenesis
- bone-forming cells, have an extensive endoplasmic reticulum and numerous ribosomes.
- produce collagen and proteoglycans, which are packaged into vesicles by the Golgi apparatus and released from the cell by exocytosis
Osteoblasts
Osteoblast releases?
matrix vesicles (Ca2+ and PO4 3−)
an osteoblast has secreted enough bone matrix to become surrounded by it the cell is referred to as an?
osteocyte
the spaces without matrix but occupied by the osteocyte cell bodies
lacunae
the spaces occupied by the osteocyte cell extensions are called?
Canaliculi
the cells and their extensions form a ______ around which the matrix is formed.
“mold”
● are bone-destroying cells
● these cells perform reabsorption, or breakdown, of bone that mobilizes crucial Ca2+ and phosphate ions for use in many metabolic processes
Osteoclasts
The osteoclast cell membrane then further differentiates into a highly folded form = _____________
ruffled border
the first type of bone that osteoblasts form during ossification is fairly weak bone.
Woven bone
________ woven bone formation, osteoclasts break down the woven bone and osteoblasts build new matrix
after
the process of removing old bone and adding new bone
bone remodeling
Woven bone is remodeled into a stronger, more permanent type called?
lamellar bone
is mature bone that is organized into thin, concentric sheets or layers approximately 3–7 micrometers (μm) thick called lamellae
lamellar bone
appears porous, has less bone matrix and more space than compact bone
Spongy bone
SP consists of interconnecting rods or plates of bone called _________ (50-400 um) between the __________ are spaces, which in life are filled with bone marrow and blood vessels.
trabeculae
has more bone matrix and less space than spongy bone
compact bone
Blood vessels enter the substance of the bone itself, and the _________________ are primarily oriented around those blood vessels.
lamellae of compact bone
the functional unit of a long bone is an ________ or __________ system
osteon or haversian
center portion of the bone
Diaphysis
hollow center surrounded by compact bone
Medullary Cavity
ends of long bones
Epiphysis
cartilage covering the end of a long bone
Articular cartilage
located between the epiphysis and the diaphysis
Epiphyseal plate/Growth plate
connective tissue membrane covering the outer surface of a bone
Periosteum
a single cell layer of connective tissue that lines the internal surfaces of all cavities within bones,
Endosteum
