cartilage, joints, and minerals

chondrocytes

cells responsible for cartilage formation

amorphous gel-like matrix

secreted by chondroblasts and contains collagens, proteoglycans, and non-collagenous proteins

perichondrium

similar to periosteum but around cartilage; Dense fibrous layer lined by cells that have the capacity to secrete hyaline matrix

outer fibrous layer

provides protection, mechanical support, and attaches cartilage to other structures

inner cellular

involved in growth and maintenance of cartilage

hyaline

bulk of cartilage found in animals; found on: ventral ends of ribs, in tracheal rings and larynx, articulating surfaces of bones, and in growth plates in growing animals; randomly oriented but little elastin

elastic cartilage

relatively scarce but found in external ear and epiglottis; has a ton of elastic fibers embedded in it

fibrocartilage

found at site of insertion of many of larger ligaments onto bone, intervertebral disks, and symphysis of pubis; Proportion of dense collagen bundles oriented parallel; Cells occupy lacunae arranged in rows between coarse bundles of collagen

interstitial

process of growth that occurs through the addition of new cells within existing tissue; involves mitosis (previously discussed); increases tissue size since adds new cells; occurs throughout life

apponsitional

process of growth that involves the addition of new cells to surface of the tissue; involves differentiation of stem cells; increases tissue size by increase in new layers; occurs during growth

type II collagen

main collagen form in cartilage; accounts for >50% of dry weight in most cartilaginous tissues; only found in cartilage

type IX

on surface of type II and does not form fibrils, functions to regulate spatial arrangement of type II

type X

found in chondrocytes within growth plates in long bones

joints

junction between any 2 bones; attaches bone to bone; allows bone to move freely with little resistance

synovial joints

contained in capsule; outer fibrous layer of collagen fibers that run from periosteum of 1 bone to another; lends side-to-side stability to joint

synovial fluid

Inner surface of capsule composed of synovial membranes; provides lubrication to joint

ligament

connects bones together; tough, elastic bands of connective tissue that surround joint to give support and limit movement

tendons

connects muscles to bones; another type of tough connective tissue that’s on each side of a joint and attaches to muscles that control movement of the joint

bursas

help cushion the friction in a joint; fluid-filled sacs between bones, ligaments, or other nearby structures

menisci

most common in areas bearing weight; special areas of dense fibrocartilage that exist between articulating cartilage surfaces on some bones

pivot joint

Freely moveable joint that allows only rotary movement around a single axis; moves in a rotation pattern within ring formed by 2nd bone and ligament

joint between atlas and axis (turning of head); radius and ulna at elbow and carpus

pivot joint

hinge joint

Primarily only allows movement in 1 plane, but can in small movements in other directions

toes, elbows, stifles, tarsi

hinge joint

ball-and-socket joint

Joint where rounded surface of a bone moves within a depression on another bone

shoulders and hips joint

ball-and-socket joint

condyloid joint

1 articular surface of bone there has an ovoid convexity which articulates with other bone having an ellipsoidal (circular or elliptical) cavity

jaw

condyloid joint

plane joint

Type of structure formed between 2 bones where articular surfaces of bones are flat or nearly flat → allows bones to slide over each other

metacarpals and cuneiform (wedge-shaped) bones or foot

plane joint

Ca2+

formation of skeletal tissues, transmission of neural impulses, excitation of skeletal and cardiac muscle contraction, blood clots formation, and component in milk

extracellular Ca2+

skeletal, nerve membrane potential, necessary for clotting factor pathway, muscular membrane potential, cardiac muscle

intracellular Ca2+

initiation of muscle contraction, second messenger to relay info from outside of cell

calmodulin

Ca2+ binds to it and used to stimulate ion channels, enzyme activity, or DNA transcription

hypocalcemia

loss of Ca2+ in ECF

hypercalcemia

increase of Ca2+ in ECF

parathyroid hormone (PTH)

gland on trachea near thyroid, monitor carotid artery Ca2+ concentrations; prevents osteoblasts from entering reversal phase and osteoblasts from laying new matrix

phosphrous function

combine with oxygen to form phosphate anions (form most often used); 2nd most important bone mineral; necessary for acid-base buffer system

Na+ function

Maintain osmotic pressure and water content of circulation; plays key role in acid-base balance of body; determines electrical potential of nervous tissue and transmission of nerve impulses; absorption of carbohydrates and amino acids dependent on Na+-coupled transport

Cl- function

Maintains osmotic pressure and water content of circulation plays key role in acid-base balance; small role in electrical potential of nervous tissue; renal excretion that’s in excess of what’s needed for stomach acid, intestinal secretions, sweat, and maintain acid-base balance

K+ function

most important in determining resting membrane potential of cells, necessary for growth, needed for insulin secretion (glucose and K+ enter cells), needed for blood acid-base balance

intracellular Mg function

neccessary cofactor for enzymatic reaction in metabolic pathway; forms Mg-ATP used for many kinase-catalyzed reactions

extracellular Mg function

needed for nerve condition, bone formation also requires it

iodine function

necessary for synthesis of thyroid hormones (thyroxine and triiodothyronine), regulates energy metabolism, hormone production increased during cold weather to improve basal metabolic rate

iron function

component of heme (found in hemoglobin and myoglobin), supports growth and development, deliver oxygen, maintain energy levels, keeps levels of oxygen in our blood

hepcidin

hormone produced by liver that downregulates ferroportin complex to reduce iron absorption