Anatomy and Physiology Chapter 6 Notes and Study Guide

sesamoid bones, long bones, short bones, flat bones, irregular bones, sutural bones

The adult skeleton contains 206 major bones, which are divided into six broad categories according to their individual shapes. _____________ are generally small, flat bones, such as the patella or kneecap. _____________ are relatively long and slender, such as the femur. _____________ are small and boxy, such as the wrist bones (carpals). _____________ have thin, roughly parallel surfaces, such as the sternum and ribs. _____________ have complex shapes with short, flat-notched, or ridged surfaces, such as the spinal vertebrae. _____________, or wormian bones, are small, flat, irregularly shaped bones between the flat bones of the skull.

osteon, trabeculae, red bone marrow, yellow bone marrow

The basic functional unit of mature compact bone is the _____________, or haversian system. In spongy bone, the matrix forms struts and plates called _____________. Spongy bone contains _____________, which is responsible for blood cell formation. The _____________ in spongy bone serves as an important energy reserve.

marrow cavity, cancellous bone

The compact bone of the tubular shaft forms a protective layer that surrounds a central space called the _____________. The expanded areas at each end of the tubular shaft consist largely of spongy bone, or _____________.

osteocytes, lacunae, canaliculi, periosteum

The matrix of bone contains specialized cells called the _____________ within pockets called _____________. The branching network for the exchange of nutrients, waste products, and gases is the _____________ narrow passageway through the matrix. Except at the joints, the _____________ covers the outer surfaces of the bones.

ossification, endochondral ossification, intramembranous, remodeling

The process of replacing other tissues with bone is called _____________. When bone replaces existing cartilage it is called _____________, while in _____________, bone develops directly from mesenchyme or fibrous connective tissue. As a part of normal bone maintenance, the bone matrix is recycled and renewed through the process of _____________.

diaphysis, epiphysis, metaphysis

A representative long bone such as the tibia has an extended tubular shaft, or _____________, and an expanded area at each end known as the _____________. The narrow zone connecting the tubular shaft to the expanded area at each end is the _____________.

osteopenia, osteoporosis

As a normal part of the aging process, the bones become thinner and weaker, causing a reduction in bone mass called _____________. When the reduction in bone mass is sufficient to compromise normal functions, the condition is known as _____________.

short

Classify as long bone, short bone, flat bone, or irregular: calcaneus

long

Classify as long bone, short bone, flat bone, or irregular: humerus

flat

Classify as long bone, short bone, flat bone, or irregular: parietal (skull)

long

Classify as long bone, short bone, flat bone, or irregular: phalanx

flat bone

Classify as long bone, short bone, flat bone, or irregular: rib

long

Classify as long bone, short bone, flat bone, or irregular: ulna

irregular bone

Classify as long bone, short bone, flat bone, or irregular: vertebra

encircle inner and outer surface of bone surface of bone shaft-covered by periosteum and endosteum

Concerning compact/lamellar bone Explain circumferential lamellae

-hair like canals; connect lacunae to lacunae and lacunae to the central canal -osteoblasts maintain contact as matrix hardens -allows: nutrient and waste exchange between osteocytes

Concerning compact/lamellar bone explain canaliculi

-fill space between osteons

Concerning compact/lamellar bone explain interstitial lamellae

cavities where osteocytes live; between lamellae

Concerning compact/lamellar bone explain lacunae

-spider shaped; mature cells -functions-maintain bone/matrix

Concerning compact/lamellar bone explain osteocytes

strength, absorb stress on long axis of bone-allow femur to withstand 10-15X body weight

Concerning compact/lamellar bone explain the functions

-runs parallel to long axis -contains blood vessels and nerve fibers

Concerning compact/lamellar bone explain the haversian/central canal of the osteon

-spiraling collagen fibers reinforce layers -directions: alternate directions -resists twisting

Concerning compact/lamellar bone in terms of concentric lamellae

-microscopic; functional and structural unit of compact bone -series of cylinders -tiny weight bearing hollow pillars -runs: parallel to long axis

Concerning compact/lamellar bone in terms of the haversian system (osteon)

-runs perpendicular to long axis -connects periosteum to central canals -allows: blood vessels and nerves to penetrate lamellae

Concerning compact/lamellar bone in terms of volkmann's or perforating canals

-blood calcium decreases: PTH released -stimulated osteoclasts, Ca++ released -increases Ca++ interstitial absorption -decreases: Ca++ excretion by kidneys -Ca++ levels restored: PTH decreases

Explain PTH negative feedback

-growth in diameter or width -osteoblasts of periosteum: add bone-osteoclasts of endosteum remove bone slower than new bone formed-result: stronger bone -ridges form parallel to blood vessels: form deep pockets-traps blood vessels and osteoblasts -osteoblasts->osteocytes -ridges meet and fuse->osteon -circumferential lamellae deposited and added

Explain appoistional growth of bone

-organ with 4 tx -osseous tx-primary type -nervous tissue-secondary type -connective tissue-linings -muscle and epithelial tissue: blood vessels

Explain bone in terms of tissues

pathway for blood vessels or nerves

Explain bone marking depressions, grooves or tunnels

tendon or ligament attachment, articulations

Explain bone marking elevations or projections

-projections: outward growths; heads, trochanters, spines -depressions or openings; fossa, sinuses, foramina, grooves

Explain bone marking fixed landmarks

-like concrete reinforced with rebar -inorganic and organic components -eg. ground substance and protein/cells

Explain bone matrix generally

-balance osteoblast and osteoclast activity - greater osteoblast activity->stronger bones -greater osteoclast activity-weaker bones -resistance(stress) training->stronger bones and muscles (wolfs law)

Explain bone remodeling

-red marrow: blood stem cells -adults: spongy bone of femur and humerus-diploe of flat bone and irregular bone such as sternum or hips -infants: like adults and diaphysis of long bones

Explain bone sites of hematopoietic tissue

-genetic disorder-> easily broken bones; severity varies -may be inherited or spontaneous mutation; 8 types-4 autosomal dominant (85-90%)-> too little or poor quality collagen-2 with unknown genetic source-2 recessive disorders: interfere with collagen production -symptoms-blue sclera: whites of eyes tinted blue-multiple fractures-deafness -severity varies: normal life span to death (fetus cannot survive birthing) -treatment: reduce pain and prevent breaking-drugs used in osteoporosis-low impact exercise such as swimming-may require rodding: insert metal rods in long bones for support-corrective surgery to maximize mobility

Explain brittle bone disease aka osteogenesis imperfecta in terms of what type of disorder, inheritance?, symptoms, severity, and treatment

-blood Ca++ increases: calcitonin released -inhibits osteoclasts -increases: Ca++ excretion by kidneys -stimulates: Ca++ deposition -Ca++ levels restored: calcitonin decreases

Explain calcitonin negative feedback

-growth at external surface in cell layer of perichondrium -fibroblasts differentiate->chondroblasts-->chondrocytes -make new matrix-->gradual increase in size at outer surface -adults may see due to-excess growth hormone or minor surface damage-or severe damage-->dense fibrous patch

Explain cartilage appositional growth

chondrocytes in lacunae and extracellular matrix with fibers

Explain cartilage generaly

-expands from within when chondrocytes make new matrix -most important in embryonic development -continues through adolescence -not seen in adults

Explain cartilage interstitial growth

-dense outer layer -fx-strength and protection

Explain compact bone

-osteoblasts catch up with chondrocytes and epiphyseal plate closes -epiphyseal plate ossifies->epiphyseal line visible in x-rays -end of epiphyseal growth=epiphyseal closure

Explain continued elongation of bone at puberty

-at growth plate aka epiphyseal plate -in metaphysis -chondrocytes add cartilage on epiphyseal side of growth plate

Explain continued elongation of bone in terms of where

break int more than two fragments

Explain different fractures: comminuted

broken through vs. not

Explain different fractures: complete vs. incomplete

bone crushed; osteoporosis

Explain different fractures: compression

spepreates end and shaft; stunts growth

Explain different fractures: epiphyseal

parallel vs. perpendicular

Explain different fractures: linear and transverse

ends in normal pos. vs. out of normal pos.

Explain different fractures: nondisplaced vs. displaced

one small/break

Explain different fractures: oblique

skin broken vs. no skin breaks

Explain different fractures: open/compound and closed/simple

ragged due to twisting; sports and abuse

Explain different fractures: spiral

-appears similar to hyaline but yellowish, rarest -chondrocytes: size and shape varies -fibers: collagen and elastic -4 locations: external ear and epiglottis, auditory canal, and cuneiform cuticle of larynx -functions: support, distort and returns to original shape

Explain elastic cartilage in terms of what it looks like, chondrocytes, fibers, locations, and functions

-result: all bones except clavicle, mandible, and skill -embryonic skeleton: fibrous connective tissue and hyaline cartilage model-cartilage growth interstitial and appositional

Explain endochondral ossification in terms of result and embryonic skeleton

-general-stress determines "where"-hormones determine "when"

Explain factors that affect remodeling generally

-chondrocytes: in rows alternating with fiber packs -fibers: rows of collagen, densely packed -locations: intervertebral discs, knee meniscus, and pubic symphysis

Explain fibrocartilage in terms of chondrocytes, fibers, locations, and functions

-thing, flat, slight curve -fx. protect, provides SA for skeletal muscle attachment -ex. sternum, scapula, ribs and most of skull

Explain flat bones

-around 206 in adults (some extra vertebrae_ -more or equal to 300 in baby-->fusion with growth-->around 206 -for upright movement -long legs vs arms unique -few organisms with grasping hand

Explain general facts about the bones (how many etc.)

-stress affects bone shape-greater muscle mass leads to more bone mass at attachment-less stress->less bone-wolff's law -inactivity->weaker bone within weeks

Explain how exercise and gravity affect remodeling

-calcitriol source: kidneys-functions: Ca++ and Po43- absorption from digestive tract -growth hormone source: anterior pituitary gland-function: stimulates epiphyseal plate activity -thyroxine source: thyroid gland-function: ensure proportional growth and growth plate activity thru puberty -sex hormones-estrogen and testosterone promote: adolescent growth spurt-development of gender specific characteristics-epiphyseal plate closure is narrow -calcitonin (thyroid gland) and Parathyroid Hormone (PTH)-control: Ca2+ and PO43- in blood levels

Explain how hormones affect remodeling: calcitriol, growth hormone, thyroxine, sex hormones, calcitonin and parathyroid hormone

-Ca++ and Pi->forms hydroxyapatite (cement) -vitamin C: collagen synthesis and osteoblast differentiation -Vitamin A: stimulates osteoblasts

Explain how nutrition affects remodeling

-frosted glass appearance, most abundant -chondrocytes: spherical -fibers are collagen only -4 locations-movable joint: articular-thoracic cage: costal-respiratory tract: larynx-nose: passage ways, internal support -functions-reduce frictions (bone to bone)

Explain hyaline cartilage in terms of its look, cells, fibers, locations, and functions

-complicated shapes -vertebrae, hip (coxal) bones

Explain irregular bones

-length>width -shaft (diaphysis) and 2 ends (diaphysis) -ex. most limb bones

Explain long bones

-overuse disorder -symptoms: painful swelling on anterior, proximal tibia -seen in: 10-15 year olds involved in basketball, soccer, volleyball, gymnastics, etc. -treatment: ice, rest, ibuprofen-like drugs -healing: 6-8 wks

Explain osgood schlatter/osteochondrosis

-bone building cells; responsible for osteogenesis -make osteoid: protein-sugar complex and collagen fibers -concentrates salts and triggers deposition in osteoid-bone -once enclosed in matrix-->osteocytes-secrete matrix

Explain osteoblasts in terms of what they are, what they make, etc.

-bone destroying cells -giant multinucleated cells related to WBCs; macrophage and monocytes -causes: osteolysis or resorption via acids and proteolytic enzymes -function: maintain blood Ca++ levels

Explain osteoclasts

-mature, maintenance cells of bone -location: lacunae between lamellae (layers) -cell extensions: penetrate lamellae via canaliculi (canals)n and connect cells -2 major fxs-maintain protein and minerals in matrix-repair damage

Explain osteocytes in terms of what they are, locations, extensions, and functions

-bone tissue formation: 3 functions -formation of bony skeleton in embryos -bone growth: increase size until early adulthood -remodeling and repair: bone homeostasis in adult

Explain osteogenesis/ossification

-groups of disorders in older adults: calcium salts not deposited -effect: soft weak bones -symptoms: pain with weight -cause: calcium or vitamin D deficiency

Explain osteomalacia

-inadequate ossification: normal aging -30-40 yrs: bone mass reduction begins-osteoblasts activity slows but not osteoclast -site of bone loss: greater effect on epiphysis, vertebrae and mandible-women lose around 8% every 10 years-men: lose around 3% every 10 years

Explain osteopenia

-group of disorders: resorption>deposition -composition normal: mass reduced->lighter, more porous -most vulnerable sites: spongy bone of vertebrae and femur neck -contributing factors: estrogen deficient postmenopausal women and smokers-insufficient exercise and immobility-diet deficiency of calcium proteins or vitamin D-steroids, hyperthyroidism, diabetes

Explain osteoporosis in terms of groups of disorders, composition, most vulnerable sites, contributing factors, and treatments

-bone stem cells; divide-->osteoblasts -important in bone repairs -location: cellular layer of periosteum and endosteum

Explain osteoprogenitor cells

-greater turnover of bone with less mineralization -more woven bone made than normal -causes: spotty weakening -seen in: spine, pelvis, femur and skull -stats: > 40 yrs old; 3% North American affected -trigger: may be virus -treatment: long-term didronate, calcitonin, Fosamax

Explain paget's disease

-reshaping related to stresses during lifetime -maintains or changes shape and mineral content -remodeling units: osteocytes and osteoblasts and osteoclasts

Explain remodeling

-childhood equivalent of osteomalacia -effect: bowed legs, axial skeleton deformities -cause: deficiency of calcium or vitamin D

Explain rickets

-like sesame seed -functions:within tendon; may alter direction of tendon pull -ex. patella -vary in # between people; around 26 sites; function not always obvious

Explain seasmoid bones

-length about equal to width -wrist and ankle bones

Explain short bones

-high water content allows: compression and recoil -matrix: chondroitin SO4 and proteins=proteoglycans -avascular due to anti-angiogenesis factor: prevents blood vessel formation -outer protective covering-perichondrium w 2 layers-outer layer=dense irregular connective tissue girdle that covers and gives structural support-inter cellular layer-feeds chondrocytes by diffusion

Explain skeletal cartilage structure in terms of water content, matrix, vascularity, and outer protective covering

-Ca++ required for neurons, skeletal muscles -Ca++ levels restored: PTH lowers

Explain skeleton as a calcium reservoir

-inner light weight layer -function: storage and strength -honeycomb or trabeculae (little beam) -red or yellow marrow fills spaces -aka. cancellous bone or trabecular bone

Explain spongy bone

-no osteons, lamellae irregular -trabeculae: struts and plates form open, spongy bone matrix-contains red marrow (produce WBC and RBC)-osteocytes connected by canaliculi-strut arrangement:lightweight strength -endosteum-surrounds trabeculae-source of capillaries

Explain spongy bone in terms of trabeculae and endosteum

-small, irregular shape; between flat bones of skull -# and locations vary between people

Explain sutural or wormian bones

-endochondral-bone replacing cartilage -intramembranous-bone from fibrous connective tissue

Explain the 2 general forms of bony skeleton formation

-making bone from a sheet-like template of fibrous connective tissue -step 1-bone stem cells cluster and form ossification center-osteoid secreted, mineralization occurs-stem cells->osteoblasts-bone expands as series of spicules -step 2-blood vessels invade area, trabeculae are formed-osteoid laid down between blood vessels-trabeculae formed-trapped osteoblasts->osteocytes -step 3-periosteum and compact bone plate forms-periosteum forms from connective tissue membrane-compact bone plate forms below periosteum, surround spongy bone-internal spongy bone remains and red marrow invades -result-flat bones of skill, mandible, and clavicle

Explain the 3 steps and results of intramembranous ossification

-step 1-hematoma formation-blood leaks from vessels-fracture hematoma forms: isolates area-deprived osteocytes die-tissue swells, hurts, inflamed -step 2-callus formation-external callus: periosteum forms enlarged collar of cartilage and bone-internal callus: spongy bone bridge forms -step 3: external callus replaced with spongy bone -step 4: area of external callus remodeled-internal medullary cavity-converts to bony/hard callus-starts 3-4 weeks after injury-completed 4-12 months

Explain the 4 steps of fracture repair

-126 bones -forms: upper and lower limbs, pectoral and pelvic girdles -hang from acial skeleton

Explain the appendicular system

-80 bones -function: protect and support -forms: long axis of body; skull, vertebral column, rib cage

Explain the axial system

-inner lining, delicate connective tissue -incomplete cellular lining of medullary cavity, etc. -contains osteoblast and osteoclasts -exposed bone: site of matrix +/-

Explain the endosteum

-step 1-near center of shaft (diaphysis), cartilage calcifies and chondrocytes die-chondrocytes enlarge and triggers matrix calcification-death because no diffusion -step 2-blood vessels form and bony collar forms around diaphysis-perichondrium vascularizes-cells differentiate into osteoblasts-osteoblasts form bony collar-perichondrium now periosteum -step 3-primary ossification center forms-blood vessels penetrate to center of cartilage-fibroblasts follow-calcified matrix (B1) breaks down-fibroblasts-->osteoblasts; makes spongy-primary ossification center expands toward epiphysis

Explain the first 3 steps of endochondral ossification

-14% body weight; weight for weight 5X as strong as steel -support: framework for body, supports organs -storage: minerals and lipids-mineral: needs for strong bones, Calcium for muscle contractions nerve impulse conductions blood clotting membrane transport systems and enzyme co-factors-PO4 for ATP, Enzyme activations and nucleic acids-lipids: yellow bone marrow is an energy source -blood cell formation: hematopoiesis in red bone marrow from RBC and WBC -protections: skull, vertebra and rib cage for central nervous system, heart, etc. -movement: levers for skeletal muscle-design of articulations (joints) determine movement-range of motion=gross to fine

Explain the functions of the skeletal system in terms of body weight percentage, support, storage, blood cells, protection, and movement

-concrete: hydroxaplaties or mineral salts of calcium; like concrete-around 2/3 of bone mass -tightly packed crystals of extracellular matrix-Ca3(pO4)2 +Ca(OH)2-->Ca10(PO4)6(OH)2 -withstands compression (wolfs law) -cannot tolerate twisting, bending, impact

Explain the inorganics of the bone matrix

-step 4-osteoclasts form medullary cavity -step 5-secondary ossification center forms in epiphysis-capillaries and osteoblasts migrate to epiphyses-centers of epiphysis calcifies-trabeculae form-occurs before birth through adolescence -step 6-epiphyses fills with spongy bone; 2 area of hyaline cartilage remain-articular layer remains protect surfaces-epiphyseal cartilage remain in metaphysis: site of bone elongation -fetal growth: bone lengthened by cartilage formation, then ossification occurs

Explain the last 3 steps of endochondral ossification

-rebar: collagen fibers; like rabr; 1/3 of bone mass-withstands tension, twists and bends-cannot tolerate compression -cells: around 2% of bone mass-osteocytes, osteoblasts, osteoprogenitor cells and osteoclasts

Explain the organics of bone matrix

-contains blood vessels, nerves, lymphatic vessels -sharpey's (perforating) fibers: collage fibers-attach periosteum to the bone-locations: where tendons and ligaments attach -functions-isolates bone, route for blood vessels and nerves, bone growth and repair

Explain the periosteum in terms of what it contains, sharpey's fibers, and functions

-outer bone covering -fibrous layer-outer dense irregular ctx-continuous with ligaments, tendons, and articular capsules -osteogenic layer-inner, contacts vone-contains: osteoblasts=bone building cells and osteoclasts=bone destroying, clash with bone

Explain the periosteum in terms of what it is, layers, and layer cells

-on diaphysis side of growth plate -growth zone-mitotic cartilage cells form stacks of cells-push: epiphysis away from diaphysis (shaft) -transformation zone-chondrocytes enlarge, lacunae enlarge and erode-matrix: calcifies and chondrocytes die-spicules remain -osteogenic zone-marrow elements invade and spongy bone forms-spicules digested->medullary cavity -summary: osteoblasts chase new cartilage, making bone and extending length

Explain the three zones and osteoblasts converting cartilage into bone

-shaft; cylinder of compact bone -external connective tissue covering: periosteum -hollow area: medullary or marrow cavity-partial lining: endosteum-infant/children: red marrow-adults: yellow marrow or red marrow with several anemia

Explain the typical long bone in terms of the diaphysis

-expanded ends -exterior layer: compact bone -spongy bone that contains red marrow -hyaline cartilage cover: articular cartilage

Explain the typical long bone in terms of the epiphysis

-neck, connects diaphysis and epiphysis -includes sight of bone elongation: epiphyseal plate -adults: epiphyseal line

Explain the typical long bone in terms of the metaphysis

-thin exterior plates of compact bone: cortex or cervical bone -surface cover: periosteum -spongy bone: between cortex layers, filled with bone marrow-diploe=spongy bone or flat bone-lining=endosteum -no shaft or epiphysis

Explain the typical short, flat or irregular bone (parietal bone) in terms of compact and spongy bone

-closed reduction: without surgery -open reduction: with surgery, uses pins, wires, plates -immobilization by cast or traction -healing: 6-8 weeks for simple fracture; longer in longer bone or elderly

Explain treatment of fractures

-each week: 5-7% recycled -daily: .5g Ca++ enter/leave -spongy bone: 3-4 years -distal femur: 5-6 months -compact bone: around 10 years

Explain turn over rates of bones

femur, spongy, stress, RBC, red bone marrow

Journey 1-5 For this journey you are miniaturized and injected into the interior of the largest bone of your host's body, the ___________. Once inside this bone, you look around and find yourself examining the stalagmite and stalactite like structures that surround you. Although you feel as if you are in an underground cavern, you know that it has to be bone. Since the texture is so full of holes, it is obviously ___________ bone. Although the arrangement of these bony spars seems to haphazard, as if someone randomly had dropped straws, they are precisely arranged to resist points of ___________. All about you is frantic, hurried activity. Cells are dividing rapidly, nuclei are being ejected, and disclike cells are appearing. You decide that these disclike cells are ___________ and that this it the ___________ cavity.

matrix, osteoclast

Journey 11-12 You decide to investigate one of these tiny openings and begin to swing on your cord, trying to get a foothold on one of the openings. After managing to anchor yourself, and squeezing into an opening, you use a flashlight to illuminate the passageway in front of you. You are startled by a giant cell with many dark nuclei that appears to be plastered around the entire lumen directly ahead of you. As you watch this cell, the bony material beneath it, the ___________, begins to liquefy. The cell apparently is a bone-digesting cell, or ___________, and since you are unsure whether or not its enzymes can also liquefy you, you slither backward hurriedly and begin your trek to your retrieval site.

nerve, haversian, compact

Journey 6-8 As you explore further, strolling along the edge of the cavity, you spot many tunnels leading into the solid bony area on which you are walking. Walking into one of these drainpipe-like openings, you notice that is contains a glistening rope-like structure, a ___________, and blood vessels running the length of the tube. You eventually come to a point in the channel where the horizontal passageway joins with a vertical passage that runs with the longitudinal axis of the bone. This is obviously a ___________ canal. Since you would like to see how nutrients are brought into ___________ bone, you decide to follow this channel.

perforating/volkmann, osteon

Journey 9-10 Reasoning that these is no way you can possibly scale the slick walls of this channel, you leap up and grab onto a white cord hanging down its length. Since it is easier to slide down than to try to climb up the cord, you begin to lower yourself, hand over hand. During you descent, you notice small openings in the wall, which are barely large enough for you to wiggle through. You conclude that these are the ___________ that connect all the ___________ to the nutrient supply in the central canal.

sinus

Match the bone marking with the following: air-filled cavity

ramus

Match the bone marking with the following: arm like-projection, takes part in joint formation

meatus

Match the bone marking with the following: canal-like structure, a passageway for nerves or blood vessels

tuberosity

Match the bone marking with the following: large rounded projection, a site of muscle attachment

trochanter

Match the bone marking with the following: large, irregularly shaped projection, a site of muscle attachment

fissure

Match the bone marking with the following: narrow depression or opening, that is a passageway for nerves or blood vessels

crest

Match the bone marking with the following: narrow ridges of bone, a site of muscle attachment

foramen

Match the bone marking with the following: opening through a bone, a passageway for nerves or blood vessels

process

Match the bone marking with the following: projection or prominence

epicondyle

Match the bone marking with the following: raised area of a condyle, a site of muscle attachment

condyle

Match the bone marking with the following: rounded, convex projection

fossa

Match the bone marking with the following: shallow depression, takes part in joint formation

spine

Match the bone marking with the following: sharp slender process, a site of muscle attachment

tubercle

Match the bone marking with the following: small rounded projections, a site of muscle attachment

head

Match the bone marking with the following: structure supported on neck, takes part in joint formation

skeleton=bone (support) and cartilage (flexibility)

skeletal tissue