HUMAN ANATOMY AND PHYSIOLOGY The Skeletal System Notes

1. HUMAN ANATOMY AND PHYSIOLOGYThe Skeletal System Notes Chapter 5

2. 2 divisions: • ____________________________bones that form longitudinal axis • _______________________________bones of the limbs and girdles Axial skeleton Appendicular skeleton

4. The system includes joints ,cartilage and ligaments. I. Bones:An Overview • Functions-besides giving body shape and Form: • 1)Support-supports body and cradles soft organs • 2)Protection-protect soft organs-eg. Protects brain/vertebrae-spine and ribs for organs of the thoracic cavity

5. Functions cont’d • 3)Movement-Skeletal muscles attach to bones by _______________and bones work as levers tendons

6. Functions cont’d Fat • 4)Storage- • ______in internal cavities of bones • Storehouse for minerals-esp.Ca and P….A small amount of Ca must be in blood at all times to reach the nerve tissue for transmission,so muscles contract and help clot blood.Ca in bones as salts go to provide Ca 2+ ions for blood • Hormones control the movement of Ca to and from blood according to body need…..too much Ca can be a problem 5)Blood Cell Formation or ________________________ in the marrow cavities of certain bones hematopoiesis

7. B.Classification of Bones*(all 206 of them) • There are 2 main types of osseous tissue • ____________________________dense and looks smooth and homogeneous • ___________________________ made of needlelike pieces of bone and lots of open space Spongy bone Compact bone

9. wrist • Many sizes and shapes:-eg. Tiny pisiform bone of __________________-size of a pea and at the other extreme-the ________________-thigh bone is ~ 2’ long and has large,ball shaped head femur

10. Shape grouping: • _____________________-longer than they are wide;shaft with heads at both ends;mostly compact bone; bones of limbs • _________________________-generally cube shaped and mostly spongy bone ;bones of wrist and ankle;____________________bones-within tendons-special type of short bone-patella Short bones Long bones sesamoid

11. Shape cont’d • ____________________-thin,flattened and usually curved-2 thin layers of compact bone sandwiching spongy bone-skull,ribs,sternum • __________________________don’t fit other categories-vertebrae and hip Flat bones Irregular bones

13. C. Structure of a long bone • GROSS ANATOMY • __________________-shaft-makes most of bone length and is __________________bone • Diaphysis is covered by fibrous connective tissue membrane-_________________________-Hundreds of connective tissue fibers,called perforating or Sharpey’s fibers secure periosteum to underlying bone compact diaphysis periosteum

14. _______________at the ends of each long bone…consists of thin compact layer of bone filled with spongy bone…._____________cartilage covers the external surface(glassy hyaline cartilage gives smoothness to decrease friction at joint surfaces) • Adult bones have a thin line of bony tissue at epiphysis-called ____________________-a remnant of epiphyseal plate of hyaline cartilage in young ,growing bones • epiphyseal plates cause lengthwise growth of bones epiphysis Articular cartilage Epiphyseal line

15. At end of puberty,hormones inhibit long bone growth and the epiphyseal plate is completetly replaced w/bone • Cavity of shaft stores adipose tissue--________________________,or medullary cavity …In infants this area forms RBC’s-red marrow is there as well • For adults ___________________is in cavities of spongy bone of flat bones and epiphyses of some long bones • Surfaces have bumps holes and ridges=__________________________-show where muscles,tendons,and ligaments were attached and where blood vessels and nerves pass Red marrow Yellow marrow Bone markings

16. Bone markings • 1.projections or processes • -grow out from bone surface---goes w/terms beginning w/T • 2.depressions or ________________________-indentations in bone---goes w/terms starting w/F(except facet cavities

20. Long Bones-MICROSCOPIC ANATOMY • ______________________-mature bones cells found in matrix in lacunae cavities • Lacunae arranged in concentric circles called____________________around central(Haversian) canals • _________________is a complex of central canal and matrix rings—Haversian system • Central canals run lengthwise through bony matrix to carry blood vessels and nerves to all of bone osteocytes lamellae oteon

21. Microscopic anatomy cont’d • _____________________-tiny canals that radiate outward from central canals to all lacunae-form a transportation system that connects all bone cells to nutrients in matrix --therefore well nourished • _____________run into compact bone at right angles to shaft and communicate from outside to interior • Bone light in weight,but strong canaliculi Perforating(Volkmann’s) canals

23. Bone Formation,Growth and Remodeling • 2 most strong and supportive tissue-bone and cartilage • Except for flat bones,most bones develop using hyaline cartilage as model

24. Bone formation cont’d • ____________________-bone formation in 2 phases: • 1)Hyaline cartilage model is completely covered by bone matrix(a “collar”) by bone forming _________________________.For a while,fetus has cartilage enclosed by bony bones.Enclosed hyaline cartilage model is digested away,forming a medullary cavity osteoblasts ossification

25. 2)By birth most hyaline converted to bone.except articular cartilage on ____________________and epiphyseal plates • New cartilage is continually on the face of articular cartilages(covering bone ends) and epiphyseal plate surface that faces bone ends.At the same time,old cartlage abutting internal face of articular cartlage and the medullary cavity is BROKEN down and replaced by bony matrix Bone ends

26. Growing bones must widen as they lengthen---osteoblasts in _____________add bone tissue to external face of diaphysis as osteoclasts in endosteum remove bone from inner face of diaphysis wall---both occur at same rate circumference of long bone expands and bone widens….>__________________growth.This is controlled by hormones –esp. growth hormones and ,during puberty , sex hormones • Overall growth ends at puberty ,when ____________are converted to bone periosteum Appositional growth Epiphyseal plates

28. Bones dynamic and active tissue and continuously remodeled in response to : • 1)Ca levels in blood-When blood Ca levels drop below homeostatic levels,the _________________in throat stimulated to release parathyroid hormones-______-into blood.PTH activates ____________-giant bone destroying cells in bones to break down bone matrix and release Ca into blood. • If blood Ca levels are too high,Ca is deposited into bone matrix as Ca salts osteoclasts PTH Parathyroid glands

29. 2.In response to gravity and muscle mass-long bones retain normal proportions and strength and bones become thicker and form large projections to increase their strength where muscle is bulky….here ________________lay down new matrix and become trapped w/in it….now,trapped,they become osteocytes-mature bone cells osteoblasts

31. Those that are bedridden and /or weakened lose mass • Rickets-look up p.142______________________________________________________________

32. E.Bone Fractures • Bones amazingly strong • _____________________= breaks---in young due to activity level and in older people due to thin and weakened bones_ • 1)Closed fracture-clean break that does not penetrate skin • 2)__________________is when the broken bone breaks the skin Open-compound fractures

34. A fracture is treated by ________________-where the realignment of break happens.In closed breaks,the ends are coaxed back into their position by M.D..For OPEN breaks,surgery is performed and pins or wires are used.After reduction it is _________________________by cast or traction • Simple fracture takes 6-8 weeks to heal….bot longer for large bones and bones of older people(due to their poor circulation) reduction immobilized

35. 4 Events for bone repair: • _________________________forms and blood cells deprived of nutrition die • The break is splinted by a __________________-growth of new capillaries(granulation tissue) into hematoma at site of damage.as this happens,connective tissue of various types form a mass called fibrocartilage callus containing some cartilage matrix,some bony matrix,collagen and acts to splint the bone Fibrocartilage callus hematoma

36. bony callus forms-more osteoblasts and osteoclasts come to area-the fibrocartilage callus is relaced by one made of spongy bone • Bone remodeling occurs-weeks to months-forms strong,permanenet bone patch at site

38. Axial SkeletonForms longitudinal axis of body

39. Skull • Formed by cranium –protects brain and ____________________-hold eyes in anterior position and allow facial muscles to show expression • All but one bone of skull is joined by ____________-interlocking , immovable joints(mandible has a freely movable joint) Facial bones sutures

40. Cranium-8 large ,flat bones • ___________________________forms forehead,bony projections under eyebrows,and superior portion of orbit • ____________________________paired,forms superior and lateral walls of cranium;include _________________________and ____________suture • Temporal Bones(pair) lie inferior to parietal and join at ___________________________________ Parietal bones Sagittal suture Frontal bone coronal Squamous sutures

41. Temporal bone markings: • a-External acoustic meatus-leads to eardrum and middle ear-here sound enters ear • b-Styloid process-sharp/attachment for many neck muscles • c-__________________-process bridge of bone that joins with cheek bone(zygomatic bone) anteriorly • d-Mastoid process-full of air cavities(mastoid sinuses)-rough projection posterior and inferior to external acoustic meatus-some neck muscles attach here---The proximity to middle ear makes these sinuses a hot spot for infections- -__________________________---also could spread to the brain Zygomatic process Mastoiditis

42. d-______________foramen allows passage of jugular vein(largest vein of head-drains the brain)-anterior to this is the e-____________________-transmits cranial nerves VII and VIII-facial and vestibulocochlear nerves…. f- anterior to foramen is carotid canal that carotid artery brings most of the blood to the brain Internal acoustic meatus Jugular foramen

43. Occipital bone-most posterior of cranium-floor and back wall of skull • a._________________________suture joins this bone with parietals • b. ______________________magnum allows spinal cord to connect to brain • c._____________________________________rest on 1st vertebra Lambdoid suture Foramen magnum Occipital condyles

44. Sphenoid bone-butterfly shaped-spans width of skull and is some of floor of cranial cavity • ________________________”Turk’s saddle”-encloses pituitary gland • Foramen ovale allows cranial nerve v(trigeminal)to pass to chewing muscles of mandible. • Parts form part of eye orbit • Have 2 important openings- • 1-______________________allows optic nerve to pass and • 2-_____________________through which cranial nerves III,IV,VI pass to control eye movement • Many air cavities--_________________________________ Sella turcica Optic canal Superior optical fissure sphenoid sinuses

45. Ethmoid Bone-anterior to sphenoid • __________________________”cocks comb”outermost covering of brain attaches here • Small holes on each side of crista galli-_____________________-for olafactory nerves • Extensions form superior and _______________________-lateral walls of nasal cavity-and increase turbulence of air here middle nasal conchae Crista galli Cribiform plates

46. facial bones-14 bones-12 are paired plus mandible and vomer • Maxillae(maxillary)-2 fuse to form upper jaw-main –or keystone bones of the face-carry upper teeth in a)alveolar margin • b)palatine processes-form anterior part of hard palate of __________________- • c) ________________________sinuses drain into nasal cavity,lighten skull bones and amplify sound we make….mucosa continue into nose and throat and is a source of __________________________-infection of sinuses which is an infection of sinuses Paranasal sinuses sinusitis mouth

47. ______________________paired-posterior part of hard plate-failure to fuse medially is called ___________________________________ Cleft palate Palatine bones

49. Zygomatic bones • __________________________________cheekbones-also border of eye sockets • Lacrimal bones-finger-sized bones-part of medial wall of each orbit-each has a groove for tears

50. Nasal bones • ________________________-small rectangular making bridge of nose—lower part is cartilage • Vomer bone-single bone in median of nasal cavity-most of nasal septum • Inferior nasal conchae-thin,curved-lateral walls of nasal cavity • _____________________-lower jaw-largest and strongest bone of face….meets temporal bone and is only freely movable joint of face • ---lower teeth lie in ______________________ mandible Alveolar margin