Skeletal System (LAB)

cartilages found in the skeletal system

hyaline, elastic, and fibrocartilage

what makes up the axial skeleton?

• skull

• vertebral column

• thoracic cage (ribs and sternum)

what makes up the appendicular skeleton?

• arm/shoulder

• leg/pelvis

types of tissues in bones

• predominant tissue is osseous tissue

• cartilage

• fibrous connective tissue

• muscle cells

• nervous tissue

• epithelial cells in blood vessels

two types of osseous tissue classification

• compact (cortical)

• spongy (cancellous)

three levels of bone structure

• gross

• microscopic

• chemical

compact bone

dense outer layer on every bone that appears smooth and solid

spongy bone

inner layer in bone made up of a honeycomb of trabeculae

trabeculae

small, needle like or flat pieces of bone that make up spongy bone

open spaces between trabeculae are filled with

red or yellow bone marrow

osteon

the structural unit of compact bone that consists of an elongated cylinder that runs parallel to long axis of bone; aka haversian system

osteons act as

tiny weight-bearing pillars

osteons consist of

llamellae

lamellae

rings of bone matrix that contain collagen fibers running in different directions in adjacent rings

where are bone salts found

between collagen fibers of lamellae

canals in compact bone

• central (haversian) canal

• perforating (Volkmann’s) canals

canals in the compact bone contain

blood vessels and nerves

lacunae

small cavities that contain osteocytes

canaliculi

hairlike canals that connect lacunae to each other and central canal

interstitial lamellae

lamellae that are not part of osteon, fill gaps between forming osteons

circumferential lamellae

extend around entire surfaces of diaphysis and help long bone to resist twisting

spongy bone is sandwiched between

two thin layers of compact bone

spongy bone appears poorly organized but is actually organized along

lines of stress to help resist any stress

trabeculae confer __ to bone

strength

osteocytes in spongy bone are interconnected by

canaliculi

perichondrium

layer of dense connective tissue surrounding cartilage

the perichondrium helps resist

outward expansion

is cartilage vascular or avascular

avascular

the perichondrium connects blood vessels for

nutrient delivery to cartilage

cartilage is made up of

chondrocytes

chondrocytes

cells encased in lacunae within jelly-like extracellular matrix

most abundant type of cartilage

hyaline

fibers in hyaline cartilage

collagen

hyaline cartilage is found in

• joints (articular)

• ribs (costal)

• larynx and trachea (respiratory)

• nose tip (nasal)

hyaline cartilage provides

support, flexibility, and resilience

fibers in elastic cartilage

elastic

where is elastic cartilage found

external ear and epiglottis

fibers in fibrocartilage

thick collagen fibers

fibrocartilage provides

great tensile strength

where is fibrocartilage found

vertebral discs, pubic symphysis, and menisci of knee

long bones

longer than they are wide

long bones are found in

limb bones

short bones

cube shaped bones

short bones vary in ___ in different individuals

size and number

sesamoid bones form within

tendons

short bone location example

patella

flat bone

thin, flat, slightly curved

examples of flat bone locations

sternum, scapulae, ribs, and most skull bones

irregular bones

complicated shapes

examples of locations of irregular bones

vertebrae and hip bones

joint

site where two or more bones meet

joints are also called

articulations

functions of joints

give the skeleton mobility and hold the skeleton together

two classifications of joints

1. structural

2. functional

Structural classification is joints is based on

what material binds the joints and whether a cavity is present

Functional classification of joints is based on

the movement joints allow

Examples of structural classification of joints

• fibrous

• cartilaginous

• synovial

Examples of functional classification of joints

• synarthroses

• amphiarthroses

• diarthroses

Fibrous joints

bones joined by dense fibrous connective tissue

do fibrous joints have a joint cavity

no

three types of fibrous joints

• sutures

• syndesmoses

• gomphosis

suture joints

fibrous joints held together with very short, interconnecting fibers, and bone edges interlock

suture joints are only found

in the skull

what is the functional classification of

synarthrosis

synarthrosis

immoveable joint

amphiarthroses

slightly immoveable joint

diarthroses

freely moveable joint

coronal suture

joint connecting frontal bone to parietal bone

squamous suture

joint connecting temporal bone to parietal bone

lambdoid suture

joint connecting occipital bone to parietal bone

sagittal suture

joint connecting parietal bone to parietal bone

syndesmoses joint

fibrous joints held together by a ligament

in syndesmoses joints, fibrous tissue can vary in length but is longer than in

sutures

functional classification of syndesmoses joints

amphiarthrosis

example of syndesmoses joint

inferior tibiofibular joint

gomphosis joint

“peg in socket” fibrous joint

example of gomphosis joints

periodontal ligament that holds tooth in socket

functional classification of gomphosis joints

synarthrosis

cartilaginous joints

joints where bones are united by cartilage

do cartilaginous joints have a bone cavity?

no

functional classification of cartilaginous joints

amphiarthrosis

two types of cartilaginous joints

• synchondroses

• symphyses

synchondroses joint

joint where bones are united by hyaline cartilage

examples of synchondroses joint

epiphyseal plate (temporary hyaline cartilage joint) and joint between rib and sternum

symphyses joint

joint united by fibrocartilage

examples of symphyses joints

pubic symphysis and fibrocartilaginous intervertebral discs

synovial joints

joints where bones are separated by a fluid filled joint cavity

functional classification of synovial joints

diarthrotic

synovial joints include almost all __ joints

limb

the stability of synovial joints is influenced by

3 ligaments

synovial joints have ___ and __ associated with them

bursae and tendon sheaths

6 general features of synovial joints

1. articular cartilage

2. joint (synovial) cavity

3. articular (joint) capsule

4. synovial fluid

5. 3 types of reinforcing ligaments

6. nerves and blood vessels

articular cartilage

cartilage that consists hyaline cartilage that covers the end of bones, preventing crushing of bone ends

joint (synovial) cavity

small, fluid filled space in synovial joints

two layers of articular (joint) capsule

• external fibrous layer

• inner synovial membrane

external fibrous layer of articular (joint) capsule is made of

dense irregular connective tissue

inner synovial membrane of articular (joint) capsule is made of

loose connective tissue that makes synovial fluid

synovial fluid

viscous, slippery filtrate of plasma and hyaluronic acid in synovial joints

synovial fluid lubricates and nourishes

articular cartilage

synovial fluid contains __ to remove microbes and debris

phagocytes