Skeletal System – Skeletal System – Structure and FunctionStructure and Function

By: Alec DroussiotisBy: Alec Droussiotis

Skeletal System: Main Points of Skeletal System: Main Points of StructureStructure

• Cranium – Protects the BrainCranium – Protects the Brain• Spine – Allows the transport of Spine – Allows the transport of

brainwaves through the body.brainwaves through the body.• Ribs – Protect vital organs in the TorsoRibs – Protect vital organs in the Torso• Pelvis – Allows the connection of the Pelvis – Allows the connection of the

Legs to the TorsoLegs to the Torso• The Skeletal System is a System of The Skeletal System is a System of

206 bones206 bones

Types of Bones in the Skeletal Types of Bones in the Skeletal SystemSystem

• Long BonesLong Bones – Bones that are greater – Bones that are greater length than width and are a variable of a length than width and are a variable of a number of extremitiesnumber of extremities

• Short BonesShort Bones – “cube shaped” and have – “cube shaped” and have equal length and widthequal length and width

• Flat BonesFlat Bones – thin shaped bones that – thin shaped bones that provide considerable mechanical provide considerable mechanical protection and extensive surfaces for protection and extensive surfaces for muscle attachmentsmuscle attachments

Types of Bones in the Skeletal Types of Bones in the Skeletal System (continued)System (continued)

• Irregular BonesIrregular Bones – Complicated shaped – Complicated shaped bones that are shaped due to the function bones that are shaped due to the function i.e. the Vertebraei.e. the Vertebrae

• Sesamoid BonesSesamoid Bones – Bones that form in – Bones that form in tendons where there is a considerable tendons where there is a considerable amount of friction, tension, and physical amount of friction, tension, and physical stress; vary from person to personstress; vary from person to person

• Sutural BonesSutural Bones – Very small bones located – Very small bones located within the sutural joints between the within the sutural joints between the cranial bones; vary from person to person cranial bones; vary from person to person

Inside of the BonesInside of the Bones

• Bone marrowBone marrow– Red Marrow – consisting mainly of myeloid Red Marrow – consisting mainly of myeloid

tissuetissue• RBCs, platelets, and most WBCs are developed hereRBCs, platelets, and most WBCs are developed here

– Yellow Marrow – consisting mainly of fat cellsYellow Marrow – consisting mainly of fat cells• Some WBCs develop in the yellow marrowSome WBCs develop in the yellow marrow

• Stroma Stroma – The connective, functionally supportive The connective, functionally supportive

framework of a biological cell, tissue, or organframework of a biological cell, tissue, or organ

Functions of the Skeletal Functions of the Skeletal SystemSystem

• 1. Support1. Support

• 2. Protection2. Protection

• 3.Assissitance of Movement3.Assissitance of Movement

• 4. Storage of Minerals4. Storage of Minerals

• 5. Production of Blood Cells5. Production of Blood Cells

• 6. Storage of Chemical Energy6. Storage of Chemical Energy

Support and ProtectionSupport and Protection

• SupportSupport– The Skeleton is the framework of the bodyThe Skeleton is the framework of the body– It supports the softer tissuesIt supports the softer tissues– It provides points of attachment for most It provides points of attachment for most

skeletal musclesskeletal muscles

• ProtectionProtection– Provides mechanical protection for many of the Provides mechanical protection for many of the

body’s internal organsbody’s internal organs– The Bones reduced the risk of injury to these The Bones reduced the risk of injury to these

organsorgans

Assisting Movement and Assisting Movement and Storing MineralsStoring Minerals

• Assisting MovementAssisting Movement– The Skeletal Muscles are attached to bonesThe Skeletal Muscles are attached to bones– When these Muscles contract they cause bones When these Muscles contract they cause bones

to moveto move

• Storing MineralsStoring Minerals– Bone tissues store several types of minerals, Bone tissues store several types of minerals,

including calcium and phosphorusincluding calcium and phosphorus– Bone releases minerals into the blood when it Bone releases minerals into the blood when it

is neededis needed• This facilitates the balance of minerals in the bodyThis facilitates the balance of minerals in the body

Producing Blood Cells and Producing Blood Cells and Storing Chemical EnergyStoring Chemical Energy

• Producing Blood CellsProducing Blood Cells– The Red Bone Marrow inside the bones The Red Bone Marrow inside the bones

produces blood cellsproduces blood cells• Red Blood Cells, White Blood Cells, and PlateletsRed Blood Cells, White Blood Cells, and Platelets

• Storing Chemical EnergyStoring Chemical Energy– With the bone marrow ageing it changes from With the bone marrow ageing it changes from

‘red marrow’ to ‘yellow marrow’‘red marrow’ to ‘yellow marrow’– Yellow bone marrow is composed of adipose Yellow bone marrow is composed of adipose

cells, and a few blood cellscells, and a few blood cells• This chemical change is very important for a This chemical change is very important for a

functioning human bodyfunctioning human body

In ConclusionIn Conclusion

• The Skeletal System is one of the The Skeletal System is one of the most important systems used in the most important systems used in the human bodyhuman body

• It creates many types of blood cells, It creates many types of blood cells, stores these blood cells, protects stores these blood cells, protects internal organs, and assists in internal organs, and assists in movementmovement

• Without this system it would be Without this system it would be difficult for a human being to livedifficult for a human being to live