6. Skeletal System

Name the 4 SKELETAL SYSTEM FUNCTIONS

1. Structural support to the body 2. Protection of various regions of the body 3. Mineral storage, especially calcium 4. Formation of blood cells in the marrow

What do all types of cartilage have in common?

A. Dense Extracellular matrix B. Avascular C. CHONDROCYTES within spaces called LACUNAE D. Surrounded by dense irregular fibrous connective tissue called PERICHONDRIUM.

Name the spaces that Chrondrocytes are within

LACUNAE

Name the 3 types of cartilage Where in the body is each type found?

1. Hyaline Cartilage: joints 2. Elastic Cartilage: ear 3. Fibrocartilage: vertebral discs

Which cartilage has many elastin fibers?

ELASTIC CARTILAGE

What is an immature cartilage cell called?

An immature cartilage cell is called a chondroblast

What is a mature cartilage cell called?

A mature cartilage cell is called a chondrocyte

How does fibrocartilage differ from other cartilage?

Fibrocartilage has more collagen fibers than other cartilages

How does cartilage grow?

Appositional = (growth in diameter) 1. Increased activity of the chondroblasts 2. extracellular matrix is added on the sides. Interstitial = (growth in length) 1. Increased activity of the chondrocytes 2. Extracellular matrix is added between the cells

What gives bone flexibility?

Collagen fibers

What gives bone strength?

Minerals

Name the 3 bone cells and their function

Osteoblasts: lay down new bone Osteocytes: mature bone cell; found in lacunae Osteoclasts: break down bone; take the calcium out of the bone and put it into the blood, especially when blood calcium levels are too low.

What is bone's Extracellular matrix made up of?

Mineral salts with lots of phosphate.

What is calcification?

The deposit of calcium salts within a tissue.

What is ossification?

the process of laying down new bone by osteoblasts. It occurs in bone, cartilage or fibrous connective tissue.

What is osteogenesis?

new bone growth

What is osteolysis?

destruction on bone by osteoclasts

What is the functional unit of Compact bone?

OSTEON.

What is the end of the long bone called?

proximal and distal EPIPHYSIS (where spongy bone is)

What is the shaft of a long bone called?

DIAPHYSIS

What is in the center of the bone?

MEDULLARY CANAL

What is the MEDULLARY ("middle") CANAL filled with?

yellow marrow (adipose tissue)

what is the function of yellow marrow?

function is to store fat.

Where does RBC production take place?

Red marrow (spongy bone)

What is the name of the growth plate in children, and what is this structure called in adults?

Children: epiphyseal plate Adults: epiphyseal line

What tissue surrounds the whole bone, and what is its function?

PERIOSTEUM: serves as the attachment site for tendons and ligaments

Where are bone marrow transplants taken from?

Flat bones (sternum), but also the iliac crest and vertebrae bodies

What is a SESAMOID BONE?

a specialized short bone that occurs within a tendon, such as the patella (kneecap).

What is the name of the process of bone growth?

Ossification

What is endochondral ossification?

When the hyaline cartilage is replaced by bone. (Common in long bones). This process begins in fetal development when the skeleton is hyaline cartilage.

What processes occur during endochondral ossification?

1) Osteoblasts differentiate within hyaline cartilage 2) Osteoblasts lay down the organic component of the matrix 3) Blood vessels enter the nutrient foramen to supply the growing tissues 4) The bone grows in length

What are the two types of endochondral ossification (where cartilage turns into bone, as in a fetus)?

• Primary Ossification - Secondary Ossification

Where does primary ossification occur?

In the diaphysis

Where does secondary ossification occur?

In the epiphysis

What is INTRAMEMBRANOUS OSSIFICATION, and where does it occur?

Fibrous connective tissue (dense regular ct) turns into bone. Occurs in the skull bones

What is BONE REMODELING, and how does it occur?

Change in shape and size in bone with time; due to forces. Osteoblasts and osteoclasts are sensitive to pressure. Increase pressure, osteoblasts increases bone. No pressure,

What does exercise do to bone?

Exercise increases bone.

What happens if you don't have enough calcium in the blood?

The body's calcium needs will come out of the bone by an increase in osteoclast activity. The osteoclasts will dissolve some bone material and release it into the blood.

What is osteoporosis? 40. What causes OSTEOPOROSIS? 41. What's the best way to prevent osteoporosis?

Osteoporosis is a condition where there is less mineralization in the extracellular matrix. Caused by increased activity of osteoclasts (more so than osteoblasts).The spongy bone is affected more than compact bone. Prevent it by exercise!

What is the most common bone used for a bone graft?

the iliac bone of the hip.

What are the stages of healing after a BONE FRACTURE?

Bleeding, then hematoma (blood clot) Then a fibrocartilage callus forms Then a bony callus forms. Osteoclasts then finish remodeling the bone.

Which type of cell divides readily after a bone is damaged?

osteoprogenitor cell

What is the function of an osteoprogenitor cell?

Produce new osteoblasts

What is a lateral curve in the spine?

SCOLIOSIS

What is a hunchback curve?

KYPHOSIS

What is a swayback in the lower region?

LORDOSIS

What is severe arthritis in the spine, causing the vertebrae to fuse?

ANKYLOSIS