Chapter 6: The Skeletal System

Bone layers

Peri Spongy Compact endos veins arteries marrow

6 main functions

Support- structural framework for the body, supports soft tissues, points of attachment for tendons of skeletal muscles Protection- protects internal organs, cranial bones protect brain, vertebrae protect spinal cord, etc. Assistance in movement- muscles contract, they pull on bones, (bones and muscles make movement together) mineral homeostasis- bone tissue stores minerals: calcium and Phosphorus, they release minerals on demand into blood to maintain mineral balances and distribution to other parts of the body Blood cell production- red bone marrow, a connective tissue in certain cells makes red blood cells, white blood cells and platelets, this is called hemopoiesis (hemo=blood, poiesis= making), red bone marrow consists of developing blood cells, adipocytes, fibroblasts, and macrophages present in developing bones of fetus, adult bones- pelvis, ribs, sternum, vertebrae, skull, ends of arm and thigh bones Triglyceride storage- yellow bone marrow- mainly of adipose cells that store triglycerides= potential chemical energy reserve also consists of a few blood cells, with age, red bone marrow turns yellow

phalanx-

a single bone of a digit ea. has ea. one has proximal base, intermediate body, distal head 2 phalanges (proximal and distal) in thumb, (pollex) and 3 phalanges (proximal, middle, and distal) in ea. of the other 4 digits commonly referred to as the index finger, middle finger, ring finger, and little finger

2 thin- scroll-shaped bones on either side of the nasal septum called the _____ and _______ 2 purposes

superior nasal concha and middle nasal concha increase vascular and mucous membrane surface in the nasal cavity, warms and moistens inhaled air before lungs. also cause air to swirl so that particles are trapped in mucus that lines the cavity so it cleanses inhaled air before it passes into the rest of passageways superior nasal conchae are near olfactory foramina of the cribriform plate where sensory receptors for smell terminate in the mucous membrane of the superior nasal conchae- increase surface area fro sense of smell

ethmoid bone

"ethmoid"= sievelike, sponge like in appearance and located in the anterior part of the cranial floor between the orbits forms part of anterior part of cranial floor, medial fall of orbits, superior portions of nasal septum ( a partition that divides the nasal cavity into right and left sides) and most of walls of nasal cavity contains 3-18 air spaces or "cells" that gives its sievelike appearance ethmoidal cells r\together form the ethmoidal sinuses also contains perpendicular plate and cribriform plate

ilium

"flank" largest of the three pelvic bones iliac crest lower surface is greater sciatic notch where the sciatic nerve passes through (longest nerve in the body)

mandibular fossa

"fossa"= depression, forms a joint with a projection on the mandible called the condylar process to form the temporomandibular joint (TMJ)

diaphysis

"growing between", bone's shaft or body, main cylindrical part of bone

epiphysis

"growing over", distal and proximal ends of the bone

2 maxillae of the face

"jawbones"- unite to form upper jawbone and articulate with every bone of the fae except the mandible (lower jaw bone) contains maxillary sinus that dumps into nasal cavity alveolar process arch that contains the alveoli (sockets) for the maxillary (upper) teeth forms the anterior ¾ s of the hard palate- forms the roof of the mouth

clavicle

"key" long, slender, S-shaped bone positioned horizontally to the first rib medial end articulates w/ sternum, lateral end articulates with acromion of scapula "acrom"=topmost

2 lacrimal of the face

"lacrim"= tear drop, smallest bones of the face, thin and roughly resemble a fingernail in size and shape

ischium

"lip" lower, posterior part of the hipbone

patella

"little dish", small, triangular bone in front of the joint between tibia and fibula (knee joint) increase leverage of the tendon, maintain postion of tendon where knee is flexed and protect the knee joint tracks (glides) upa d down the groove between the femoral condyles

foramen magnum

"magnum"=large, largest foramen in the skull, passes through the occipital bone medulla oblongata of the brain- connecting to the spinal cord, the vertebral and spinal arteries

rickets and osteomalacia

"malacia"= softness, inadequate calcification of the extracellular bone matrix, caused by Vitamin D deficiency Rickets- bones of children become soft or rubbery and easily deformed epiphyseal plates fail to ossify osteomalacia= adult counterpart to rickets

the mandible

"mand"= to chew, the lower jaw bone, largest, strongest facial bone, only movable skull bone and has a ccondylar process- articulates mandible to joint aveolar process that provide alveoli (sockets) for mandibular (lower) teeth mental foramen- hole in mandible

mastoid process

"mastoid= breast-shaped", round projection of the temporal bone posterior to the external auditory meatus serves as point of attachment for several neck muscles

medullary cavity

"medulla"= marrow or pith), OR marrow cavity- hollow, cylindrical space within diaphysis that contains fatty yellow bone marrow in adults

occipital bone

"occipit"=back of head, forms the posterior part and most of the base of the cranium foramen magnum- "magnum"=large, largest foramen in the skull, passes through the occipital bone medulla oblongata of the brain- connecting to the spinal cord, the vertebral and spinal arteries occipital condyles- two oval processes that are on either side of the foramen magnum that articulate (connect) with the first cervical vertebra

bone or ____ tissue

"osseus" connective tissue, contains abundant extracellular matrix that surrounds widely separated cells extracellular matrix= 25% water, 25% collagen fibers, 50% crystallized mineral salts this minerals are deposited in framework formed by the collagen fibers of extracellular matrix and they crystallize and harden- called process of calcification- initiated by osteoblasts (bone building cells) bone's hardness depends on calcification bone's flexibility depends on collagen fibers they provide tensile strength (resistance to being stretched or torn apart)

parasnasal sinuses

"para"=beside", located in certain bones near nasal cavity lined with mucus membranes that are continuous with lining of nasal cavity the skull bones that contain them are: frontal bone (frontal sinuses) sphenoid bone (sphenoid sinuses) ethmoid bone (ethmoid sinuses) maxillae (maxillary sinuses) serve as echo chamber for speech lighten weight of skull

parietal bones

"pariet"= wall, form sides and roof of cranial cavity

periosteum

"peri"=around, touch sheath of dense irregular connective tissue and its associated blood vessels surrounding bone surface, contains bone-forming cells that enable bone to grow in diameter and thickness, but not in length protects bone, assists in fracture repair, nourish bone tissue, serves as attachment point for ligaments and tendons

vomer

"plowshare", brought triangular bone on floor of nasal cavity, articulates inferiorly with both maxmillae and palatine bones on midline of the skull component of the nasal septum

patellofemoral stress syndrome

"runner's knee" normal tracking does not occur, tracks laterally instead of inferiorly and superiorly increased pressure in the joint causes tenderness or pain under patella

styloid process

"styl"= stake or pole, slender projection points downward from undersurface of the temporal bone and serves as point of attachment for muscles and ligaments of the tongue and neck

2 Temporal bones

"tempor"=temples, form the inferior sides of the cranium and part of the cranial floor zygomatic arch- formed by the temporal and zygomatic bones join to form mandibular fossa- "fossa"= depression, forms a joint with a projection on the mandible called the condylar process to form the temporomandibular joint (TMJ) external auditory meatus- canal in the temporal bone that leads to the middle ear mastoid process- "mastoid= breast-shaped", round projection of the temporal bone posterior to the external auditory meatus serves as point of attachment for several neck muscles styloid process- "styl"= stake or pole, slender projection points downward from undersurface of the temporal bone and serves as point of attachment for muscles and ligaments of the tongue and neck carotid foramen- hole through which the carotid artery passes

2 zygomatic of the face

"zygo"=yoke, cheekbones, lateral parts in wall and floor of each orbit, articulate with frontal, maxmilla, sphenoid, and temporal bones

appendicular skeleton

126 bones bones of the upper and lower limbs or appendages + the girdle bones Thorax cont. Clavicle (collarbone)- 2 Scapula (shoulder bone)-2 Upper limbs Humerus (upper arm bone)-2 Ulna (medial bone of forearm (pinky bone side))-2 Radius (other bone in forearm on thumb side)- 2 Carpals (base of your palm)- 16 Metacarpals (base of fingers)- 10 Phalanges (tips of fingers)- 28 Pelvic (hip) girdle hip or pelvic bone- 2 Lower limbs femur (thigh bone)-2 patella (knee cap)-2 fibula (shin bone)- 2 tibia (back part of shin bone)- 2 tarsals (base of feet where they meet the ankles)- 14 metatarsals (middle part of foot)- 10 Phalanges (toes)- 28

facial bones

14 form the face 2 nasal bones 2 maxillae 2 zygomatic the mandible 2 lacrimal 2 palatine 2 inferior nasal conchae vomer

pelvic hip girdle

2 hip bones the coxal bones strong stable support for the vertebral column, protects tje pelvic viscera and attaches lower limbs to axial skeleton united form pubic symphysis unite w/ sacrum at sacroiliac joint 3 bones make pelvic bone- illium, ischium, pubis

___ bones in the body in 2 divisions:

206 bones in axial skeleton and appendicular skeleton

metatarsals

5 bones #ed 1-5 from medial to lateral positions form the skeleton of the metatarsus ea. has proximal base, intermediate body, distal head big toe (hallux) has 2 large phalanges proximal and distal other toes have 3 phalanges: proximal, middle, and distal arches- bones of foot arranged this way enable foot to support weight of body, leverage while walking longitudinal arch- extends from front to back of the foot and has 2 parts- medial and lateral transverse arch- formed by navicular, 3 cuneiforms, bases of 5 metacarpals

cranial bones

8 called the cranium altogether, forms cranial cavity and protects brain functions to protect brain- membranes MENINGES, stabilize positions of the brain, blood vessels and nerves, their outer surfaces provide large areas for muscle attachment that move in the head 1. Frontal bone 2. Occipital bone 3. Sphenoid Bone 5. 2 Parietal bones 7. 2 Temporal bones 8. Ethmoid bone

axial skeleton

80 bones lie on longitudinal axis of the body, imaginary line that runs through center of gravity from head to space between the feet skull, ears, ribs, sternum, vertebrae Skull Cranium- 8 Face- 14 Hyoid- 1 Auditory ossicles- 6 Vertebral column- 26 Thorax Sternum-1 Ribs- 24

__% of skeleton= compact bone __% of the skeleton= spongy bone

80% 20%

Fontanels

Anterior between 2 parietal bones and the frontal bone roughly diamond-shaped and largest of fontanels, closes 18-24 months after birth Posterior between 2 parietal bones and the occipital bone diamond shaped, considerably smaller than anterior font. and close 2 months after birth Anterolateral one on each side of skull between frontal, parietal, temporal and sphenoid bones small and irregular in shape, close 3 months after birth Posterolateral one on each side of the skull between parietal, occipital, and temporal bones irregularly shaped, close 1 or 2 months after birth, closure is generally not complete until 12 month

bone growth factors minerals

Calcium and Phosphorus- make bone extracellular matrix hard Magnesium- helps form extracellular matrix Fluoride- helps strengthen bone extracellular matrix Manganese- activates enzymes involved in synthesis of bone extracellular matrix Vitamins Vit. A- needed for activity of osteoblasts during remodeling of bone, deficiency stunts bone growth toxic in high doses Vit. C- needed for synthesis of collagen, the main bone protein deficiency leads to decreased collagen production- slows down bone growth and delays repair of broken bones Vit. D- active form (calcitriol) is produced by the kidneys helps build bone by increasing absorption of calcium from gastrointestinal tract into blood deficiency cause faulty calcification and slows down bone growth may reduce risk of osteoporosis but toxic in high doses must have sun to get Vit. D and have to absorb calcium- interferes with calcium metabolism Vitamins K and B12- needed for synthesis of bone proteins deficiency leads to abnormal protein production in bone extracellular matrix and decreased bone density

2 palatine

L-shaped, "palat"= roof of mouth, fused and form the posteriori portion of the hard palate, part of the floor and lateral wall of the nasal cavity adn small portion of floors of orbits

aging and bones

Sex hormones diminish especially in women after menopause, bone resorption by osteoclasts outpaces bone deposition by osteoblasts- leads to decrease in bone mass and increased risk of osteoporosis

tarsus

ankle of the foot 7 bones (tarsals) talus- "ankle bone", and calcaneus (largest and strongest of the tarsals) "heel bone" located on posterior part of the foot anterior part of ankle= cuboid, navicular, and 3 cuneiform bones called first, second, and third cuneiforms talus = only bone in foot articulates with fibula and tibia- w/ medial malleolus of tibia and w/ lateral malleolus of the fibula

Fractures (and types)

any break in the bone partial- incomplete break across the bone like a crack complete- complete creak across the bone so that the bone is broken in 2 or more pieces closed (simple)- fractured bone does not break through the skin open (compound)- the broken ends of the bone protrude through the skin Repair of a fracture phagocytes remove dead bone tissue chondroblasts form fibrocartilage at the fracture site that bridges the broken ends of the bone fibrocartilage is converted to spongy bone by osteoblasts and bone remodeling occurs which dead portions of bone are reabsorbed by osteoclasts and spongy bone converted to compact bone

lordosis

bent backward, exaggeration of lumbar curve at the vertebral column called "hollow back"

invertebral discs

between cervical and sacrum and they are outer ring of fibrocartilage and elastic interior, strong joints, various movements permitted during walking and running, help protect vertebrae from breaks

perforating (Volksmann's) canals

blood vessels, lymphatic vessels, and nerves from the periosteum penetrate compact bone through the transverse perforating volkmann's canals connect with medullary cavity, periosteum, and central haversian canals

endochondral ossification

bone forms within hyaline cartilage that develops from mesenchyme development of cartilage model- cells of mesenchyme crowd together at the site in the shape of the future bone and develop into chondroblasts (secrete cartilage extracellular matrix)- produces cartilage model- consists of hyaline cartilage and perichondrium develops around the cartilage model growth of cartilage model- chondroblasts deeply buried in extracellular matrix become chondrocytes, increase in size and the extracellular matrix begins to calcify, other chondrocytes in in the calcifying cartilage die because they cannot deliver nutrients fast enough through the extracellular matrix, lacunae form and merge into small cavities when chondrocytes die development of primary ossification center- ossification proceeds inward from exterior surface of bone, nutrient artery past the perichondrium and the calcifying cartilage model in the id region of it, stimulates osteogenic cells cells to differentiate into osteoblasts perichondrium starts to form bone- known as the periosteum primary ossification center- region where bone tissue will replace most cartilage osteoblasts deposit bone extracellular matrix all over calcified skeleton forming spongy trabeculae primary ossification center spreads to both ends of cartilage model Development of the medullary cavity- marrow cavity, as primary ossification center grows toward ends of the bone, osteoclasts break down the newly formed spongy bone trabeculae, this activity leaves a cavity- medullary cavity, in the diaphysis (shaft) most of wall of diaphysis is diaphysis is replaced by compact bone Development of secondary ossification center when blood vessels enter the epiphyses, these develop (around time of birth usually), helps spongy bone remain in the interior of epiphysis proceeds outward from center of epiphysis to outer surface of bone Formation of Articular Cartilage and epiphyseal plate hyaline cartilage that covers epiphyses becomes articular cartilage before adulthood, hyaline cartilage= between epiphyses and diaphyses as the epiphyseal (growth) plate, responsible from lengthwise growth of long bones

calcification

bone hardens because it is storage for Calcium

osification

bone making process

Comparison of male and female skeletons

bones of male= larger and heavier than female and points of muscle attachment= larger pelvis of female is wider and shallower

phalanges

bones of the digits 14 in the hand #ed 1-5 beginning with the thumb

2 hormones that regulate calcium homeostasis

calcitonin parathyroid hormone

external auditory meatus

canal in the temporal bone that leads to the middle ear

osteoclast

cell that cleans up- breaks down supplies

growth in thickness

cells in perichondrium differentiate into osteoblasts which secrete bone matriz, osteoblasts develop into osteocytes and lamellae is added to surface of the bone,and new osteons of compact bone are formed osteoclasts in the meantime are destroying bone tissue in endosteum in medullary cavity but this is at a slower rate than the bone formation on the outside so the medullary cavity is enlarging as the bone increases in thickness

strongest type of bone tissue

compact bone found beneath periosteum of all bones and makes bulk of diaphyses in long bones provides protection and support and resists stress produced by weight and movement

osteon

compact bone cell

lower limb

composed of 30 bones femur, patella, tibia and fibula, 7 tarsals, 5 metatarsals, 14 phalanges in the foot

spina bifida

congenital defect of vertebral column in which laminae fail to unite @ midline protrusions of meninges around spinal cord may produce partial or complete paralysis, loss of urinary bladder control, absence of reflexes associated with low level of folic acid (on of B vits), women encoiuraged to take folic acid supplements

osteogenic sarcoma

connective tissue tumor bone cancer that primarily affects osteoblasts and occurs most often in teenagers during growth spurt

Upper limb

consists of 30 bones humerus in upper arm and ulna and radius in lower arm 8 carpals (wrist bones), 5 metacarpals (palm bones) and 14 phalanges (finger bones) in the hand

skull

contains 22 bones, rests on top on the vertebral column

compact bone tissue

contains few spaces and arranged in repeating structural units called osteons or haverisan systems- each osteon consists of a central haversian canal with concentrically arranged lamellae central or haversian canal= channel that contains blood vessels, nerves, and lymphatic vessels, run longitudinally through the bone around the cells are concentric lamellae- rings of hard, calcified extracellular matrix like a tree spaces between lamellae= lacunae- "little lakes", lacuna= singular that contain osteocytes radiating in all directions from the lacunae are the canaliculi- small channels filled with extracellular fluid also contain slender, fingerlike, processes of osteocytes connect lacunae together and with central canals all of this= so many intricate systems and pathways for oxygen and nutrients to travel- important because diffusion through lamellae= slow

bunion

deformity of the great toe typically caused by wearing tightly fitting shoes inflammation of bursae

bone scan

diagnostic procedure that takes adv. that bone is living tissue- small amount radioactive tracer compound that is readily absorbed by bone- injected intravenously degree of uptake of the traver is related to amount of blood flow to the bone scanning device (gamma camera) measures radiation emitted from bones, information is transmitted into an x-ray kind of photograph that can be read normal bone tissue= a gray color and darker or lighter = bone abnormalities darker="hot spots" increased metabolism that absorb more of radioactive tracer due to increased blood flow bone cancer, abnormal healing fractures, abnormal bone growth lighter= "cold spots", decreased metabolism that absorb less of the tracer due to decreased blood flow degenerative bone disease, decalcified bone, fractures, bone infections, Paget's disease, rheumatoid arthritis less radiation than an xray, important for scanning osteoporosis in females

pelvic brim

divides upper and lower pelvic portions above pelvic brim= false (greater) pelvis and part below is the true (lesser) pelvis upper opening is called pelvic inlet and lower opening is the pelvic outlet

spongy bone tissue

does NOT contain osteons consists of trabeculae- "little beans", irregular latticeworks of thin columns of bone, macroscopic spaces between trabeculae filled with red bone marrow inside the trabeculae= concentric lamellae, osteocytes in the lacunae, canaliculi radiating from lacunae makes up most of bone tissue of short, flat, and irregular bones also forms epiphyses and narrow rim around medullary cavity on diaphyses of long bones

deviated nasal septum

does not run along midline of nasal cavity deviates to one side can block airflow to affected side

mesenchyme

embryonic issue that forms bone, blood, and lymph

bone growth factors hormones

estrogen- sex hormones produced in the ovaries androgens- sex hormones produced in testes in males and adrenal glands in both sexes Hormones Human growth hormone (hGH)- secreted by anterior lobe of pituary gland promotes general growth of all body tissues including bone mainly by stimulated production of insulin like growth factors Insulin-like growth factors (IGFs)- secreted by liver, bones and other tissue upon stimulation of hGH promotes natural bone growth by making osteoblasts and increasing synthesis if proteins needed to build new bone Thyroid hormones (thyroxine and triiodothyronine)- secreted by thyroid gland, promote natural bone growth by stimulating osteoblasts Insulin - secreted by pancreas, promotes normal bone growth by increasing synthesis of bone proteins Sex hormones- secreted by ovaries in women (estrogen) and testes in males (testosterone) stimulate osteoblasts to promote sudden "growth spurt" in teenage yrs. shut down at epiphyseal plates around age 18-21 causing lengthwise growth of bone to end contribute to bone remodeling during adulthood by slowing bone resorption and promoting deposition Parathyroid hormone (PTH)- secreted by parathyroid glands, promotes bone resorption by osteclasts, enhances recovery of calcium ions from urine promotes function if active form of vitamin D Calcitonin (CT)- secreted by thyroid gland, inhibits bone resorption by osteoclasts

kyphosis

exaggeration of thoracic curve on vertebral column degeneration of vertebral column in elderly leads to kyphosis or caused by osteoporosis, rickets and poor posture

vertebral arch

extend backwards from body of vertebra, form by 2 short process called pedicles that project backward to unite with the laminae (flat parts of the arch that land in single sharp projections called spinous process vertebral foramen = hole between vertebral arch and body and all form vertebral cavity

2 nasal bones of the face

form part of bridge of nose while rest of supporting tissue consists of cartilage\

zygomatic arch

formed by the temporal and zygomatic bones join to form

frontal bone

forms the forehead (anterior part of cranium), the roofs of the orbits (eye sockets), and anterior part of cranial floor frontal sinuses lie deep within the frontal bone mucous membrane-lined cavities act as sound chambers and give voice resonance

cribriform plate

forms the roof of the nasal cavity contains the olfactory foramina (holes through which fibers of the olfactory nerves pass) projects upward from the cribriform plate is the crista galli "cok's comb", serves as point of attachment for meninges that cover brain

perpendicular plate

forms the upper portion of the nasal septum

acetabulum

hip socket "vinegar cup"

obturator foramen

hole in the bone of the ischium and pubis largest foramen in the skeleton

carotid foramen

hole through which the carotid artery passes

pelvic axis

imaginary curved line passing through true pelvis, joins central points of the planes of the pelvic inlet and outlet course taken by baby's head in childbirth

suture

immovable joint that holds skull bones together coronal suture: "coron"=crown, unites the frontal bone and 2 parietal bones sagittal suture: "sagitt"=arrow, unites the 2 parietal bones lambdoid suture: shape resembles that of the Greek letter lambda (like upside down V) and it unites the parietal bones to the occipital bone squamous suture: "squam"= flat, unite the parietal bones to the temporal bones

cleft palate

incomplete fusion of the palatine bones

osteomyelitis

infection of bone characterized by high fever, sweating , chills, pain, nausea, pus formation, edema, warmth over affected area bacteria causes it

sinusitis

inflammation of the mucous membrane of one or more paranasal sinuses caused by microbial infection (virus, bacteria, or fungus), allergic reactions, nasal polyps, severely deviated nasal septum fluid pressure could build up in sinuses and sinus headache could develop symptoms= nasal congestion, oral decongestants, nasal antibiotics, warm compresses, surgery

long bones developed by _________

intermembranous ossification

radius

lateral aspect (thumb side) of the forearm disc shaped head @ proximal head that articulates with capitulum of humerus and radial notch of the ulna has raised, roughened area- radial tuberosity point of attachment for biceps distal end of radius articulates with 3 carpal bones and there is styloid process

Aging and the Skeletal System

levels of sex hormone diminish in middle age- decrease in bone mass occurs because bone destruction outpaces bone formation higher incidence of osteoporosis in women 1. bones become brittle and lose mass 2. decrease in rate of protein synthesis and a decrease in production of HGH diminish production of collagen fibers that give bones strength and flexibility loss of bone mass= demineralization and begins after age 30 in females

flatfoot

ligaments and tendons weakened holding position of foot arch may decrease or "fail" may lead to inflammation of deep fascia of sole (plantar fasciitis)

herniated disc

ligaments of intervertebral discs become injured or weakened- resulting pressure can rupture surrounding fibrocartilage material may herniate (protrude) a "slipped" disc at lumbar region most often because part of vertebral column with much weight of the body with most bending

4 main types of bones

long bones: greater length than width have shaft and variable number of ends curved for strength thigh (femur), leg (tibia and fibula), arm (humerous), forearm (ulna and radius), finger & toes (phalanges) short bones: cube-shaped and equal in length and width wrist and ankle bones flat bones: thin and afford considerable protection, extensive surfaces for muscle attachment cranial bones, sternum, ribs, scapulae (shoulder blades) irregular bones: complex shapes and cannot be grouped into any of the other categories vertebrae and some facial bones

humerus

longest and largest bone of upper limb anatomical neck- former site of the epiphyseal plate a groove distal to the head surgical neck- below anatomical neck because fractures occr often here body- roughened, V-shaped area called deltoid tuberosity where deltoid muscle attaches distal end the capitulum- "small head", rounded knob articulates with head of radius radial fossa- depression that receives head of radius when forearm is flexed trochlea- spool shaped surface articulates with ulna coronoid fossa- depression that receives part of the ulna when forearm flexed olecranon fossa- depression back of the bone that receive olecranon of the ulna when forearm is extended

femur

longest, heaviest strongest bone in the body proximal end articulates with hip bone distal end articulates with tibia and patella neck- constricted region below the head greater trochanter- projection felt and seen in front of hollow on side of the hip where some thigh and butt muscles attach @ distal end= medial and lateral condyles with the tibia patellar surface between the 2 condyles

osteopenia

low bone mass

pubis

lower, anterior part of the hipbone

osteocytes in _____ cells

mature

pelvimetry

measurement of size of inlet and outlet of birth canal by ultrasonography or physical examination important because fetus must pass through a narrower opening of the pelvis at birth cesarean section is planned if pelvic inlet deemed too small for passage of baby

ulna

medial aspect (little finger side) of the forearm and longer than the radius @ proximal end is the olecranon which forms the prominence of the elbow coronoid process with olecranon receives the trochlea of the humerus and also fits into the trochlear notch= large curved area between olecranon and coronoid process radial notch- depression for head of radius styloid process- at the distal end of the ulna

clawfoot

medial part of longitudinal arch is abnormally elevated

Initial bone formation in embryo and fetus

mesenchyme shaped bones and they are sites where ossification occurs begins during 6th week of embryonic development and follows 1 of 2 patterns intramembranous ossification: forms directly with mesenchyme arranged in sheetlike layers that resemble membranes simpler of the 2 methods flat bones of skull, face bones, mandible, clavicle, "soft spots" of fetal skull which allow skull to pass through birth canal harden through this process later 1. development of ossification center- @ site where bone will develop (ossification center), cells of mesenchyme cluster together and differentiate into osteogenic cells then osteoblasts- secretion of extracellular matrix 2. Calcification- secretion of extracellular matrix stops and these cells are now osteocytes and they lie in lacunae so they extend their processes into canaliculi radiating from it and in a few days, calcium and other mineral salts are deposited and the extracellular matrix hardens or calcifies 3. Formation of trabeculae- bone extracellular matrix is forming, it develops into trabeculae that fuse to form spongy bone, blood vessels grow in the spaces connective tissue in the blood vessels differentiate into red bone marrow 4. development of periosteum- mesenchyme condenses at the periphery and develops into periosteum, thin layer of compact bone replaces surface layers of spongy bone then endochondral ossification

calcium main job

muscle contraction

carpal tunnel sydrome

narrowing of the carpal tunnel median nerve is compressed nerve compression cause pain, numbness, tingling, muscle weakness in the hand

bone remodeling

ongoing replacement of bone tissue by new bone tissue bone resorption- removal of minerals and collagen from bone by osteoclasts DESTRUCTION OF BONE EXTRACELLULAR MATRIX bone deposition- addition of minerals and collagen fibers to bone by osteoblasts FORMATION OF BONE EXTRACELLULAR MATRIX if too much new tissue is formed, bone become thick and heavy if too much material is deposited in the bone, the surplus may form bumps called spurs on the and interfere with joint movement

osteogenic cell

only one to undergo mitosis (eventually turn into osteoblasts)

4 major types of cells in bone tissue

osteogenic cells: "genic"= producing, unspecialized stem cells derived from a mesenchyme- tissue from which connective tissues are formed only kind of bone cell to undergo CELL DIVISION so they develop into osteoblasts found along inner portion of endosteum, and in canals with blood vessels osteoblasts- "blasts"= buds or sprouts, bone building cells, they synthesize and create collagen fiber sna doter organic components to build the extracellular matrix of bone tissue osteoblast surrounds itself with extracellular matrix, become trapped in their secretions and become osteocytes, (BLASTS IN BONE OR ANY OTHER CONNECTIVE TISSUE SECRETE EXTRACELLULAR MATRIX) osteocytes- "cytes"-=cells, mature bone cells, main cells of bone tissue and maintain daily metabolism, such as exchange of nutrients and wastes with the blood, (CYTES IN BONE OR ANY OTHER TISSUE MAINTAIN THE TISSUE) osteoclasts- "clast"= break, huge cells derived from the fusion of many as 50 monocytes (type of white blood cell), concentrated in the endosteum release powerful, lysosomal enzymes and acids that digest the protein and mineral components of the bone extracellular matrix breakdown of bone extracellular matrix= resorption, part of normal development, growth, maintenance, repair of bone

metacarpus

palm of hand has 5 bones called metacarpals "meta"= after or beyond ea. one has proximal base, intermediate body, distal head #ed 1-5 starting w/ lateral thumb bone heads of metacarpals= knuckles

fibula

parallel and lateral to the tibia considerably smaller head articulates with lateral condyle of the tibia below knee joint lateral malleolus @ distal end connects with talus of the ankle forms prominence on the lateral surface of the ankle articulates with tibia and the fibular notch

_____ hormone stimulates osteoblasts to produce new bone

parathyroid hormone

mesenchyme will eventually become the __________

periosteum

hemiarthroplasty

procedure of replacing either femoral head of the femur or acetabulum replacement of both = total hip replacement

ossification (4 situations)

process by which bone is formed occurs in 4 principal situations 1. initial formation of bones in embryo and fetus 2. growth of bones during infancy- adulthood 3. remodeling of bone (replacement of old bone tissue) 4. repair of fractures

metaphyses

regions in mature bone where diaphyses joins epiphyses in a growing bone, each metaphyses has a epiphyseal (growth) plate layer of hyaline cartilage that allows diaphyses to grow in length, when growing stops, cartilage is replaced by bone and resulting structure is called epiphyseal line

growth in length

related to activity of epiphyseal plate young chondrocytes are constantly dividing, new chondrocytes are formed on the epiphyseal side of the plate while old chondrocytes on the diaphyseal side of the plate are replaced by bone thickness of epiphyseal plate remain constant, but the bone on the diaphyseal side increases in length adolescence comes to an end- new cells and extracellular matrix formation comes to an end so the bone stops growing and bone replaces all the cartilage and there is just a epiphyseal line bone fractures on the epiphyseal plate can damage the growth of the bone so that the bone will not reach the designated length when it reaches adult size damage to cartilage accelerates closure of the epiphyseal plate- inhibits growth of bone

2 inferior nasal conchae

scroll-like bones in the nasal cavity that project into nasal cavity below the superior and middle nasal conchae of ethmoid bone

tibia

shin bone larger, meddial weight- bearing bone of the leg articulates proximal end w/ femur and fibula and distal end with fibula and talus of the ankle proximal end to lateral and medial condyle to form knee joint tibial tuberosity is anterior surface below the condyles and point of attachment for patellar ligament medial surface of the distal end of the tibia= medial malleolus "little hammer", articulates talus of ankle and forms the promience that can be felt on the medial surface of your ankle

scapula

shoulder blade, large flat, triangular bone situated on posterior thorax bony articulation of scapula = acromion (lateral end of "spine" on the triangular scapula) glenoid cavity= inferior to the acromion (cavity for head of humerus to form shoulder joint) coracoid process- like a crow's beak to which muscles attach

pectoral girdles

shoulder girdles attach to bones of the upper limbs to the axial skeleton clavicle and scapula anterior clavicle articulates with sternum and posterior scapula with clavicle and humerus do not articulate with vertebral column

thoracic cage

skeletal portion of the thorax bony cage formed by the sternum, costal cartilages, ribs and bodies fo the thoracic vertebrae encloses and protects organs in thoracic cavity and provides support for the bones of the shoulder girdle and upper limbs

shin splints

soreness or pain along tibia inflammation of periosteum brought about by repeated tugging of the attached muscle and tendons- result of walking or running up and down hills

vertebral column

spine, composed of series of bones called vertebrae and is strong flexible rod that rotate and move forward, backward, sideways encloses and protects spinal cord, supports the head, serves as point of attachment for ribs pelvic girdle, muscles of back 26 vertebrae 7 cervical (neck region) movable C1-C7 2-6 are bifid (split into 2 parts) all have 3 formina- 1 vertebral and 2 transverse (through which blood vessels and nerves pass) 12 thoracic (in the chest) movable 5 lumbar (in the loin) movable 1 sacrum (sacred bone of 5 fused sacral vertebrae), not movable 1 coccyx (resembles bill of cuckoo bird), consists of 4 fused coccygeal vertebrae), not movable + invertebral discs

2 differences between spongy bone and compact bone

spongy bone is light- reduces overall weight of bone so that it moves more readily trabeculae of spongy bone supports and protects red bone marrow found in hip bones, ribs, breastbone, backbone, ends of long bones (sites of red blood cell production in adults)

epinephrin

staves off infection by boosting immune system fills EPIPENS

dissecting microscope

stereoscopic view depth perception, 3D view

bone's role in Calcium Homeostasis

stores 99% of calcium stored in the body cardiac arrest if Ca level too high respiratory arrest if Ca level too low many enzymes also require Ca as a cofactor parathyroid hormone- operates with a negative feedback system, stimuli detects that Ca levels decrease, PTH will increase cyclic adenosine monophosphate (cylcic AMP) so the PTH synthesis speeds up and more PTH is put in the blood higher PTH makes osteoclasts step up pace of bone resorption sot h Ca level is returned to normal also decreases loss of Ca in the urine as well as stimulates formation of Calcitriol and these 2 effects can INCREASE Ca level to normal calcitonin- decreases blood Ca by inhibiting action of osteoblasts and decreasing bone resorption

thorax

the entire chest

cleft lip

the same but involves a split in the upper lip folic acid can decrease incidence of it

typical vertebra body

thick, disc shaped front part, weight bearing part

articular cartilge

thin layer of hyaline cartilage covering epiphysis where bone forms articulation (joint), with another bone, reduces friction and absorbs shock at freely movable joints has NO perichondrium (connective tissue that envelops cartilage where it is not at a joint) = repair of damage is limited

endosteum

thin membrane that lines medullary cavity, contains single layer of bone-forming cells

palpate

to feel with your hand

7 processes from vertebral arch

transverse process on each side, a single spinous process projects from the junction of the laminae (attachments for muscles), superior articular processes of a vertebra articulate with vertebra immediately above them inferior articular process immediately below articulating surfaces of articulating processes are called facets- covered with hyaline cartilage

spongy cavity

tribiculae

osteoblast

turns cartilage to bone (bone building cells)

occipital condyles

two oval processes that are on either side of the foramen magnum that articulate (connect) with the first cervical vertebra

hyoid bone

unique component of the axial skeleton because it does not attach to any other bone suspended from styloid process of the temporal bones by ligaments and muscles located in neck between mandible and larynx supports tongue and provides attachment sites for some tongue muscles of neck and pharynx often fractured during strangulation

sphenoid bone

wedge shaped lies at the middle part of the base of the skull keystone of the cranial floor because it articulates all other cranial bones, holds them together, resembles a bat with outstretched wings contains sphenoid sinuses- drain into the nasal cavity hypophyseal fossa- contains pituitary gland 2 nerves pass through the foramina in the sphenoid bone; mandibular nerve through the foramen ovale and the optic nerve through the optic foramen (canal)

Exercise and bones

weight bearing activities stimulate osteoblasts to build thicker, stoner and slower loss of bone mass with age when put under stress, bone tissue become stronger by increased deposition of mineral salts and production of collagen fibers demineralization- loss of bone materials occurs my being bedridden, being an astronaut, and other things that prevent gravity which causes a natural stress on bones

parathyroid hormone in calcium homeostasis

when blood calc. level drops, parathyroid hormone released to cause increase in Calc. blood Ca level increase, Calcitonin is released to bring it back down too much Ca in blood= cardiac arrest too little Ca in blood= respiratory arrest Ca is a coenzyme for enzymes to work so they have to have enough

osteoclasts are _____ cells

white blood cells

carpus

wrist of the hand contains 8 small bones the carpals- held together by ligaments arranged in 2 transverse rows- 4 bones in ea. row, named for their shapes carpals from lateral (thumb) to medial (ulna) is : scaphoid "boatlike", lunate "moon-shaped", triquetrum "three-cornered", and pisiform "pea-shaped", ones in bottom row from lateral to medial: trapezium "4-sided figure with no 2 sides parallel", trapezoid "4-sided figure with no 2 sides parallel", capitate "head shaped" largest carpal bone (articulates w/ lunate), hamate "hooked" for hook shaped projection on its anterior surface carpal tunnel formed by pisiform and hamate concavity and scaphoid and trapezium----- long flexor tendons of digits and thumb pass through w/ the median nerve

stores triglycerides in the bone

yellow bone marrow