The Skeletal SystemSam FaycurryKatie CalmeynBob Napoleon  

Function

● Supports the body (picture on previous slide).

● protects innards (ex. brain) ● production of blood cells (red blood cells

made by red bone marrow) ● Locomotion (a place for the muscles to

attach)● stores minerals and salts (calcium)

LOCOMOTION   

Homeostasis

● calcium homeostasis ● body regulates the

release of calcium from your bones into your body as you need it)

● also restores the calcium into your bones for when you body needs it again.

Evolution

● 3 types of skeleton 

○ hydrostatic skeleton○ Exoskeleton○ Endoskeleton

 

● invertebrates● consists of a fluid-filled cavity (coelom or

gastrovascular cavity) surronded by muscles● pressure of fluids aids in movement and

allows animals to change shape● Cnidarians, flatworms, roundworms,

annelids  

Hydrostatic Skeleton

Exoskelton

● invertebrates● external, rigid skeleton protects and

supports ● Common form of exoskeleton is a shell

○ contain chitin and calcium carbonate● exoskeleton serves as attachment site for

muscles● jointed appendages allow flexible

movements● Mollusks and Arthropods

Endoskeleton

● living tissue, bones, cartilage, soft tissue● growths within animals● protection to vital organs● also jointed appendages to allow flexible

movement● Porifera, echinoderms, vertebrates

(humans) 

On the Cellular Level

● Three main cell types in bone:○ Osteoblasts○ Osteocytes○ Osteoclasts

Osteoblasts

● bone-forming cell● function by secreting a substance called

osteoid, which is also known as the bone matrix

● This substance is then mineralized with substances like calcium and phosphate, which forms the substance we know as bone

● Once the bone is created, the become bone lining cells○ regulate passage of minerals in and out of bone

Osteocytes

● Mature bone cells○ made from osteoblasts

● Most important job is to maintain Calcium levels

● bone is the body's primary reservoir of calcium

● they control the release/storage of calcium in the bloodstream

Osteoclasts

● Primarily responsible for dissolving bone tissue

● They are formed by white blood cells that fuse together

 

Stem Cells

● undifferentiated cell of a multicellular organism that make indefinitely more cells of the same type

● contained in bone marrow● become red blood cells, white blood cells,

or platelets● offer new possibilities for treating patients

with various diseases 

Basic Anatomy and Physiology

Working In towards the center of the bone these are the layers-------------> ;) Periosteum: strong outer-covering of bone/contains blood vessels for the red blood cells made by the bone marrow to travel to the rest of the body!! MAKES SENSE!! compact bone: strong dense bone/ made of osteocytes/ 

spongy bone: less dense yet still strong/ structurally appears to look like a sponge your mom uses to wash her dishes! OMG! twinsies!  Red and yellow bone marrow: red marrow makes the red blood cells. and if you ask me ill tell you a cool thing about red and yellow bone marrow. but only if you ask.

Parts of the bone

● epiphysis: knobs at the end of the bone

● diaphysis: shaft that connects the knobs

● parts of the bone, like the epiphysis which make frequent contact with other bone contain cartilage. Cartilage kinda acts like a lubrication. so bones are not scraping against each other and causing pain and damage. (articular cartalage)

Joints

Joints are the connection of bone to bone. Normally the articular cartilage is found in abundance here to keep the bones from rubbing against each other.

Interacts with Other Systems

The skeletal system interacts mainly with the muscular system.Muscles connect to the skeleton and help your body move.Tendons, which are bands of connective tissue, connect muscles to the skeleton.The muscles have to connect to bone in order to give them support while contracting.

Abnormalities

● The most common skeletal abnormalities include:

● achondroplasia● craniostenosis● clubfoot (talipes)● scoliosis

 

Achondroplasia

● autosomal dominant genetic disorder commonly called dwarfism

● caused by a change in DNA that results in abnormal cartilage formation

● arms and legs are short in proportion to body length

● the head is often large and the trunk is normal size

Craniostenosis

● premature synostosis of cranial bone sutures occurs, normal head growth is inhibited

● usually only causes odd head shape but may cause brain damage because of pressure on brain

● Craniosynostosis is more likely in:● Babies who lie in a breech position while in the

uterus.● Babies whose mothers smoke or live at a high

altitude during pregnancy.● Babies who are twins.

 

Clubfoot (Talipes)

● Clubfoot is when the foot turns inward and downward.

● It is a congenital condition, which means it is present at birth.

● Cause is not known  

Scoliosis

● abnormal curving of the spine● most often affects girls● The spine might look like the letter “C” or

“S.”  

Skeletal Injuries

● Herniated Disk● Knee Injuries● Shoulder Injuries 

Bibliography

-slackerbiz channel on youtube: "Skeletal System Structures and Functions."-Campbell / Reece Biology Book-http://www.buzzle.com/articles/skeletal-system/-http://www.livestrong.com/human-skeletal-system/-http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookmusskel.html