Skeletal System: Goss Anatomy of Long Bones

long bones

• most common bone shape in the body

• support soft tissue in limbs

• typically contains both compact and spongy bone

• endosteum lines medullary cavity

  • periosteum lines external surface of bone shaft

endosteum lines what

medullary cavity

periosteum lines what

external surface of bone shaft (diaphysis)

diaphysis

shaft

• elongated usually cylindrical

• provides for leverage and major weight support

• composed of composed of long bone, while spongy bone extends internally in form of spicules

• houses hollow cylindrical space called medullary cavity

how is spongy bone in diaphysis

extend internally in the form of spicules

what color all children bone marrow

red

where is red bone marrow in adults

ribs, breastbone, shoulder blades, collarbones, hip bones, skull, and spine

epiphysis

• expanded knobby region at the end of each long bone

• composed of a thin outer layer of compact bone

• inner extensive region of spongy bone

  • thin layer of hyaline cartilage covers the joint surface on an epiphysis

outer layer of epiphysis

compact bonei

inner layer of epiphysis

spongy bone

articular cartilage

thin layer of hyaline cartilage covering the joint surface of an epiphysis

metaphysis

region of a long bone between diaphysis and epiphysis

• transfers forces between them

metaphysis in a growing bone

contains epiphyseal plate (growth plate), thtin layer of hyaline cartilage that provides for the continual lengthwise growth of the bone

metaphysis in adult

epiphyseal line, the remnant of the plate as an adult

• thin area of compact bone

periosteum

tough sheath that covers the outer surface of the bone except for the areas covered by articular cartilage

2 layers of periosteum

outer and inner layero

outtter layer of periosteum

outer fibrous layer of protective dense irregular connective tissue

• anchors blood vessels and nerves to surface of the bone

• serves as an attachment site for ligaments and tendons

inner layer of periosteum

includes osteoprogenitor cells, osteoblasts and osteoclasts

• osteoprogenitor cells and osteoblasts produce circumfriential layers of bone matrix and responsible for bone width growth

perforating fibers

collagen fibers that anchor the periosteum to the bone

• run perpendicular to the diaphysis

endosteum

thin layer of connective tissue containing osteoprogenitor cells, osteoblasts and osteoclasts.

• covers ALL internal surfaces of bone within the medullary cavity.

  • active during bone growth repair and remodeling

when is the endosteum active

bone growth

bone repair

bone remodeling

short/flat/irregular anatomy

external surface generally composed of compact bone

• interior fully spongy bone

  • no medullary cavity

how vascularized is spongy bone

extremely

is bone vascularized

yes

vascularized

filled with blood vessels

one of what enters and exits the bone

nutrient vein

nutrient foramen

small opening where nutrient arteries/veins enter and exist

what do blood vessels do for bones

supply nutrients and oxygen required by cells and remove waste products from bone cells

what accompanies blood vessels through nutrient foramen

nerves… innervate the bonew

what gets innervated

bones, endosteum and marrow cavityw

what kinds of nerves

mainly sensory nerves

• relay impulses from the skeleton when injured