ANAPHY: Skeletal System

Bones, Cartilages, Tendons, Ligaments

Components of the Skeletal System

ligaments

bone → bone

tendons

bone → muscles

Support, Protection, Movement, Storage, Blood Cell Production

Functions of Skeletal system

collagen, ground substance, water and minerals

The skeletal system matrix always contains:

Collagen

tough, rope-like protein that gives strength and toughness

Ground Substance

calcium and phosphorus

Water

serves as moisturizer and avoid friction

Tendons and Ligaments

These components have an ECM of large amounts of collagen fibers

Collagen and Proteoglycans

ECM of Cartilage

Collagen

ECM of Cartilage that makes it tough

Proteoglycan

ECM of Cartilage that makes it smooth and resilient

Cartilage

Relatively rigid, but springs back to its original

Collagen and Minerals

ECM of bone

Collagen

ECM of bone that lend flexible strength

Minerals

ECM of bone that lend compression strength

Long, Short, Flat, Irregular

Shape Classification of Bones

Long

Long than wide

Long

Shape of tibia, fibula, femur, radius, ulna

Short

long as they are wide

Short

shape of carpal and metacarpal

Flat

Relatively thin and flat

Flat

Shape of skull, scapula, sternum

Irregular

not short, not long, not flat

Irregular

shape of vertebrae and facial bones

Diaphysis

shaft; bone tissue outside

Epiphysis

round ends that is spongy

Metaphysis

space between diaphysis and epiphysis

Articular Cartilage

Covers the epiphysis; reduces friction

Epiphyseal Line

juvenile; young individuals

Epiphyseal Plate

found in adults

Compact Bone

heavy bone found at the margins

Medullary Cavity

Space in diaphysis; location of red and yellow marrow

Red Bone Marrow

Juvenile; where RBC is produced

Yellow Bone Marrow

Adults; fats and adipose are produces

Periosteum

Thin layer that surrounds the bone (outer and inner)

Endosteum

Thin layer that surrounds the inner alignment of the bone

Compact bone

outer part of the diaphysis

Osteon

structural unit of compact bone

Lamella

ring/layers in the bone

Lacunae

spaces between the lamella; where bone cells are located

Canaliculus

tiny canal-like; cracks in the lamella; transports nutrients and removes wastes through diffusion

Central canal

center of osteon; contains blood vessels

Spongy bone

located at the epiphysis of long bones and center of other bones

Spongy bone

It has no osteons

Trabeculae

interconnecting rods; spaces containing marrow; filled with blood vessels

Osteoblasts

formation, repair and remodeling of bone; creates new bone matrix

Osteocytes

maintain the bone matrix and form osteoblast

Osteoclast

Repair and remodeling by removing existing bone

Bone reabsorption

Process of repair and remodeling by removing existing bone in Osteoclast

Intramembranous ossification

Bone formation that occurs within the connective tissue

Endochondral Ossification

Bone formation that occurs within the hyaline cartilage

ossification

formation of bone by osteoblasts

Intramembranous ossification

Osteoblast lines up on the surface of connective tissue fibers and begin depositing bone matrix to form trabeculae

Ossification centers

Where Intramembranous ossification process begins

trabeculae

radiates out from the centers; constantly remodeled; enlarge or replace

Anencephaly

inborn baby without skull

Endochondral Ossification

bone formation is within a cartilage model

Cartilage model

is replaced by bone during endochondral ossification

Primary ossification center

It is intially formed; bone formation in the diaphysis of a longbone

Secondary ossification center

Bone center formation in the epiphysis

Bone growth

occurs by the deposition of new bone lamellae onto existing bone or connect

Appositional growth

As osteoblasts deposit a new bone matrix on the surface of bones between the periosteum and the existing bone matrix, the bone increases in width, or diameter.

Bone growth in length

Which is the major source of increased height in an individual, occurs in the epiphyseal plate.

Endochondral ossification

Bone growth in length occurs through

Chondrocytes

It increase in number on the epiphyseal side of the epiphyseal plate

Epiphyseal plate

The osteoblasts start forming bone by depositing bone lamellae on the surface of the calcified cartilage.

Bone repair

Broken bone causes bleeding and a blood clot forms.

Callus

It forms a fibrous network between 2 fragments

Cancellous bone

This is slowly remodeled to form compact and cancellous bone.

Bone

 is a major storage site for calcium.

Calcium

moves into bone as osteoblasts build new bones.

Calcium

moves out of bone as osteoclasts break down other bones.

Calcium homeostasis

Is maintained by parathyroid hormone (PTH) and calcitonin. 

Parathyroid hormone and calcitonin

Calcium homeostasis by

Foramen

Hole

Process

Projection

Condyle

Smooth and rounded end

Meatus

canal-like passageway

Tubercle

lump of bone

80 bones

How many bones in the Axial skeleton

skull, vertebrae column, thoracic cage

Axial skeletons consists of

20 bones

how many bones in skull

8 bones

how many bones in cranial

14 bones

how many bones in facial

Mandible

this facial bone moves freely

6 bones - 3 each

how many bones in Auditory ossicle

26 bones

how many bones in vertebral column

25 bones

how many bones in thoracic cage

Hyoid

It is considered to be a floating bone

Frontal

Anterior part of cranium

Parietal

sides of cranium

Occipital

posterior/floor of cranium

Temporal

Inferior to parietal bones

Sphenoid

Forms part of cranium floor; lateral position of eye orbits

Ethmoid

Anterior position of cranium; roof of nasal cavity

Maxillae

forms upper jaw; anterior of hard palate; also known as maxillary sinus

Palatine

posterior position of the hard palate

Zygomatic

cheek bones; lateral wall of each eye orbit