Anatomy Chapter 6 Notes Study Guide

skeletal cartilage

made of highly resilient, molded cartilage tissue that consists primarily of water, and contains so blood vessels or nerves

perichondrium

layer of dense ct surrounding cartilage like a girdle; it helps cartilage resist outward expansion and contains blood vessels for nutrient delivery to cartilage

Cartilage makeup

made of chondorcytes, cells encased in small cavities (lacunae) within jelly0like extracellular matrix

what are the three types of cartilage

hyaline, elastic, and fibrocartilage

hyaline cartilage

provides support, flexibility, and resilience; most abundant type, contains collagen fibers

where is hyaline found

articular joints, costal ribs, respiratory larynx, and nasal cartilage in the tip of the nose

elastic cartilage

similar to hyaline cartilage, but contains elastic fibers, and is found in the external ear and epiglotis

fibrocartilage

thick collagen fibers; has great tensile strength; found in the menisci of knee and vertebral discs

what are the 2 ways cartilage grows

appositional growth, and interstitial growth

appositional growth

cartilage forming cells in perichondrium secrete matrix against external face of existing cartilage; the new matrix is laid down on surface of cartilage

intersitial growth

chondrocytes within lacunae divide and secrete new matrix, expanding cartilage from within; new matrix is made within cartilage

when does classification of cartilage occur

during normal growth in youth, but can also occur in old age

how many bones are in the body and how are they divided

206 and divided into two groups based on location and also by shape

axial skeleton

long axis of body (ex skull, vertebral column, rib cage)

appendicular skeleton

bones of upper and lower limbs(ex girdles attaching limbs to axial skeleton)

long bones

longer than they are wide, have a shaft and two ends (ex, limb bones)

short bones

cube shaped bones (in wrist and ankle) (ex. sesamoid bones form within tendons like patella)

flat bones

thin flat, slightly curved (ex. sternum, scapulae, ribs, and most skull bones)

irregular bones

complicated shapes (ex. vertebrae and hip bones)

what are the 7 functions of bones

support, protection, movement, mineral and growth factor storage, blood cell formation, triglyceride storage, and hormone production

support

for body and soft organe

protection

protects brain, spinal chord, and vital organs

movement

levers for muscle action

mineral and growth factor storage

calcium and phosphorous and growth factors reservoir

blood cell formation

aka hematopoiesis; which occurs in red marrow cavities of certain bones

fat storage

fate used for energy source, is stored in bone cavities

hormone production

osteocalcin secreted by bones helps to regulate insulin secretion, glucose levels, and metabolism

compact bone

dense outer layer on every bone that appears smooth and solid; is covered externally by the periosteum

spongy bone

made up of a honeycomb of small, needle-like or flat pieces of bone called trabeculae, and the open spaces between the trabeculae are filled with red or yellow bone marrow. spongy bone is covered by the endosteum

structure of short irregular flat bones

consists of plates of spongy bone (dipole) covered by compact bone. the compact bone is sandwiched between connective tissue membranes: the periosteum which covers the outside of compact bone and the endosteum which covers the inside portion of compact bone; bone marrow is scattered throughout spongy bone and there is no defined marrow cavity; hyaline cartilage covers area of bone that is part of a movable joint

flat bone structure

consists of a layer of spongy bone sandwiched between 2 thin layers of compact bone

structure of typical long bone

all have a shaft (dyaphisis), both ends (epiphyses), and membranes

dyaphysis

tubular shaft that forms along axins of bone and consists of compact bone surrounding central medullary cavity that is filled with yellow marrow in adults

epiphyses

ends of long bones that consist of compact bone externally and spongy bone internally; articular cartilage covers articular joint surfaces

epiphyseal line

between the diaphysis and the epiphysis. remnant of this plate where bone growth occurs, the thicker it is the younger the person is

periosteum

white double layered membrane that covers external surfaces except joints; contains many nerve fibers and blood vessels that continue on to the shaft through nutrient foramen openings

what are the 2 layers of the periosteum

fibrous layer and osteogenic layer

fibrous layer

outer layer consisting of dense irregular connective tissue consisting of sharpeys fibers that secure to bone matrix

osteogenic layer

inner layer abutting bone that contains primitive osteogenic stem cells that gives rise to most all bone cells

osteoblasts

build new bone

osteocytes

eat or destroy bone

endosteum

delicate connective tissue membrane covering internal bone surface; it covers the trabeculae of spongy bone, and lines canals that pass through compact bone. like periosteum, contains osteogenic cells that can differentiate into other bone cells, osteoblasts, and osteoclasts

red marrow

found within trabecular cavities of spongy bone and dipole of flat bones, such as the sternum. in newborns the medullary cavities and al spongy bone contain red marrow, whereas In adults red marrow is located in the heads of the femur and humorous, but most active areas of homatopoeisis are flat bone dipole and some irregular bones such as the hip bones

yellow marrow

fat storage; can convert to red marrow id a person becomes anemic

bone markings

sites of muscle, ligament, and tendon attachment on external surfaces, areas involved in joint formation or conduits for blood vessels and nerves

what are the 3 types of bone markings

prokection, depression, and openings

projection

outward bulge of a bone; may be due to increase stress from muscle pull or is a modification for joints

depression

bowl or groove-like cut out that can serve as passageways for vessels and nerves, or plays a role in joints

opening

hole or canal in bone that serves as passageways for blood vessels and nerves

bone marking surfaces that help to form joints

head, facet, condyle

head

bony expansion carried on a narrow neck

facet

smooth, nearly flat articular (joint) surface

condyle

rounded articular projection; often articulates with a corresponding fossa

depression and opening bone markings for passage of blood vessels and nerves

groove, fissure, foramen, notch

groove

furrow

fissure

narrow, slit like opening

foramen

round or oval opening through a bone n

notch

indentation at the edge of a structure

depressions and openings bone markings with other functions

meatus, sinus, fossa

meatus

canal like passageways

sinus

cavity within a bone, filled with air and lined with mucous membrane

fossa

shallow basin-like depression in a bone, often serving as an articular surface

projections that are sites of muscle and ligament attachment

tuberosity, crest, trochanter, line, tubercle, epicondyle, spine, and process

tuberosity

large rounded projection; may be roughened

crest

narrow ridge of bone; usually prominent

trochanter

very large, blunt, irregularly shaped process (only examples are on the femur)

line

narrow ridge of bone; less prominent than a crest

tubercle

small rounded projection or process

epicondyle

raised area on or above a condyle

spine

sharp, slender, often pointed projection

process

any bony prominence

osteogenic cells

mitotically active stem cells in periosteum and endosteum

osteocytes

maintain bone matrix, produce matrix for remodeling of bone

compact bone

also called lamellar bine (circle/tree trunk) which consists of osteomyelitis (aversion system), canals and canaliculi, intersitial and circumferential lamallae

osteon (aversion system)

is the structural unit of compact bone. consists of an elongated cylinder that runs parallel in alternating layers to long axis of bone and acts as tiny weight bearing pillars.

osteon cylinder

consists of several rings of bone matrix called lamellae which contain collagen fibers that run in different directions in adjacent rings. the cylinder withstands stress and resists twisting. bone salts are found between collagen fibers

central canal (haversion)

runs through core of osteomyelitis, contains blood vessels and nerve fibers

perforating (Volkman’s) canals

canals lined with endosteum that occur at right angles to central canal; it connects blood vessels and nerves of periosteum, medullary cavity, and central canal

lacunae

small cavities that contain osteocytes

canaliculi

hair like canals that connect lacunae to each other and to central canal

intersitial lamellae

lamellae that are not part of osteon but fill in gaps between osteon

circumferential lamellae

just deep to periosteum, but superficial to endosteum, these layers of lamellae extend around entire surface of diaphysis (helps long bone to resist twisting)

organic components of bone

includes osteogenic cells, osteoblasts, osteocytes, bone-lining cells, osteoclasts, and osteoid

osteoid

makes up 1/3 of organic bone matrix is secreted by osteoblasts. consists of ground substance and collagen fibers, which contribute to high tensile strength and flexibility of bone

inorganic compounds

hydroxyapatite (mineral salts) which consist mainly of tiny calcium phosphate crystals in and around collagen fibers; responsible for hardness and resistance to compression

growth hormone

most important hormone in stimulating epiphyseal activity in infancy and childhood

thyroid hormone

modulates activity of growth hormone, ensuring proper proportions

testosterone and estrogen at puberty

promote growth spurts and ends growth by inducing epiphyseal plate closure

bi=one remodeling

consists of both bone deposit and bone resorption

resportion

function of osteoclasts which: form big depressions or grooves as they break down the matrix, secrete lysosomal enzymes and protons that digest the matrix, acidity converts calcium salts to soluble forms, osteoclasts also phagocytize demineralized matrix and dead osteocytes. once resorption is done osteoclasts go through apoptosis

osteoclas activation

parathyroid hormone and immune T cell proteins

bone deposit

new bone matrix is deposited by osteoblasts which occurs wherever bone is injured or added strength is needed. Hydroxyapatite, mainly calcium phosphate eventually crystalize with the help of matrix proteins and the enzyme alkaline phosphate which is shed by osteoblasts

parathyroid hormone

produced by parathyroid glands in response to low blood calcium levels. stimulates osteoclasts to resorb more, calcium is released into blood, raising levels, and pth secretion stops when homeostatic calcium levels are reached

calcium

produced by parafollicular cells of thyroid gland in response to high levels of blood clacium levels

response to mechanical stress

bones are stressed when weight bears on them or muscles pull on them

wolfs law

states that bones grow or remodel in response to demands placed on them

what underlines nearly every bone disease

imbalances between bone deposit and bone resorption

osteomalacia

inadequate mineralization, that causes soft bones

rickets

osteomalacia in children: both caused by insufficient calcium in diet or vitamin d deficiency

osteporosis

group of diseases where bone resorption outpaces bone deposit