Human AnatomyHuman Anatomy

Skin, Bones, and MusclesSkin, Bones, and Muscles

Ch 27 Ch 27 Ch 33 Ch 33

Organ SystemsOrgan Systems

• Integumentary systemIntegumentary system..• Includes the largest organ in your Includes the largest organ in your

body . . . . body . . . . • Skin – important for maintaining Skin – important for maintaining

homeostasishomeostasis..• Internal physiological stability.Internal physiological stability.

Skin StructureSkin Structure

• Two main layers – Two main layers – • Epidermis – outermost layerEpidermis – outermost layer, ,

consists of mostly dead cells that consists of mostly dead cells that continuously shedcontinuously shed

• Also contains Also contains melanin – skin melanin – skin pigmentpigment

Skin Structure cont.Skin Structure cont.

• Dermis – below epidermisDermis – below epidermis, made of , made of fibrous connective tissuefibrous connective tissue

• Gives skin it’s strength and Gives skin it’s strength and elasticityelasticity

• Contains hair follicles, sweat Contains hair follicles, sweat glands, nerves, blood vesselsglands, nerves, blood vessels

Skin Structure cont.Skin Structure cont.

• Hypodermis is below the dermisHypodermis is below the dermis..• Hypodermic needlesHypodermic needles

Hair and nails – Hair and nails – • Made of a protein called keratinMade of a protein called keratin..

Skeletal SystemSkeletal System

• 206 bones and 206 bones and connective tissues – connective tissues – ligaments and cartilageligaments and cartilage

• At birth humans have At birth humans have 270 bones, but many of 270 bones, but many of these fuse together these fuse together during growth.during growth.

FunctionsFunctions

• SupportSupport – holds up the body, gives – holds up the body, gives muscles a place to attachmuscles a place to attach

• ProtectionProtection – rib cage, spine, skull – rib cage, spine, skull protect important organs.protect important organs.

• Produces blood cellsProduces blood cells• StorageStorage – of emergency calcium – of emergency calcium

and fatand fat

Structure of BoneStructure of Bone

• Spongy bone and compact boneSpongy bone and compact bone

Structure cont.Structure cont.

• Compact boneCompact bone• Osteocytes (bone cellsOsteocytes (bone cells) need ) need

nourishment too!!nourishment too!!• Central cavity contains yellow Central cavity contains yellow

marrow - fatmarrow - fat

Structure cont.Structure cont.

• Spongy boneSpongy bone contains contains red marrowred marrow in places. in places.

• This is where This is where red and red and white blood cells are white blood cells are made.made.

DevelopmentDevelopment

• In the second month, bone starts to In the second month, bone starts to form where before the embryo only form where before the embryo only had cartilage.had cartilage.

• Cartilage Cartilage bone = ossification bone = ossification                                                      

GrowthGrowth

• Bone growthBone growth takes place takes place at both at both endsends of the bone. of the bone.

• These regions are called These regions are called epiphyseal epiphyseal platesplates..

• These plates contain a layer of These plates contain a layer of cartilage that undergoes mitosis.cartilage that undergoes mitosis.

Growth cont.Growth cont.

• Cell division causes Cell division causes cartilage to grow, bones cartilage to grow, bones lengthen as cells ossify.lengthen as cells ossify.

• Although bones continue Although bones continue to grow in width to grow in width throughout life, growth throughout life, growth in length stops at around in length stops at around 25, or sooner.25, or sooner.

JointsJoints

• The point where bones meetThe point where bones meet..• Can be moveable or immovable.Can be moveable or immovable.• Four main typesFour main types of joints – of joints – • Hinge -- elbowHinge -- elbow, knee, knee• Pivot -- neckPivot -- neck• Ball–and–socketBall–and–socket -- hip, -- hip, shouldershoulder• Gliding – carpelsGliding – carpels and tarsals and tarsals

Joints (continued)Joints (continued)

• Cartilage and a lubricant Cartilage and a lubricant called synovial fluid keep called synovial fluid keep joints moving smoothly.joints moving smoothly.

Joints (continued)Joints (continued)

• Ligaments hold bones Ligaments hold bones together.together.

• A stretch or tear of a A stretch or tear of a ligamentligament is called a is called a sprainsprain..

Bone DiseasesBone Diseases

• ArthritisArthritis – joints become swollen – joints become swollen and painful, different types.and painful, different types.

• Rheumatoid arthritisRheumatoid arthritis – – cartilage cartilage gets inflammed, ossifiesgets inflammed, ossifies, limits , limits movement.movement.

Bone Diseases cont.Bone Diseases cont.

• Osteoarthritis – cartilage wears Osteoarthritis – cartilage wears awayaway and bones rub together. and bones rub together.

• Osteoporosis – Losing bone density Osteoporosis – Losing bone density as one gets olderas one gets older..

Bones You Need 2 KnowBones You Need 2 Know

• Skull – head, noggin, melon, Skull – head, noggin, melon, noodle, beannoodle, bean

• Vertebrae – spineVertebrae – spine• Clavicle – collar boneClavicle – collar bone• Scapula – shoulder bladeScapula – shoulder blade• Sternum – breast boneSternum – breast bone• Ribs – good with BBQ sauce.Ribs – good with BBQ sauce.

More Bones to KnowMore Bones to Know

• Humerus – upper arm bone, Humerus – upper arm bone, think funny bonethink funny bone

• Ulna – elbow to pinkie fingerUlna – elbow to pinkie finger• Radius – next to ulna, Radius – next to ulna,

– inner elbow to thumb, twistyinner elbow to thumb, twisty• Carpels – wristCarpels – wrist• Metacarpels - handMetacarpels - hand

More BonesMore Bones

• Pelvis – hipsPelvis – hips• Femur – thigh boneFemur – thigh bone• Patella – knee bonePatella – knee bone• Tibia – ShinTibia – Shin• Fibula – next to tibia, bump on your Fibula – next to tibia, bump on your

ankleankle

Bones cont.Bones cont.

• Tarsals – ankle Tarsals – ankle bonesbones

• Metatarsals – feet Metatarsals – feet bonesbones

• Phalanges – Phalanges – fingers and toesfingers and toes