Chapter 6

1. Chapter 6 Osseous Tissue & Bone Structure

2. Objectives • Describe the primary functions to the skeletal system • Classify bones according to shape and internal organization • Be able to give examples of each type, and explain the functional significance of each of the major type of bone markings • Identify cell types in bone, and list their major functions. • Compare the structures and functions of compact bone and spongy bone • Describe the remodeling and homeostatic mechansims of the skeletal system • Explain the role of calcium as it relates to the skeletal system

3. Introduction to the Skeletal System • Functions - _____________ - _____________ of Minerals and Lipids - Blood Cell _______________ - _____________ - Leverage

4. Bone Classifications - a bone may be classified by its general __________ or by its internal tissue organization. • Shapes • typical adult skeleton contains 206 major bones - divided into ________ broad categories according to their individual shapes _________ Bones: - relatively ________ and ____________ - located in the ________, forearms, __________, leg, ____________, soles, ____________, and toes

5. Bone Classification Cont. ___________ Bones: - have ___________ roughly ____________ surfaces - provide ______________ for underlying soft tissues - offer an extensive surface area for attachment of skeletal muscles ex. ______________ Bones: - small, _______, __________________ shaped bones - vary in _________, shape, __________, and position - located between the _________ bones of the skull

6. Bone Classification Cont. Irregular: - have complex shapes with short, _______, notched, or ridged surfaces ex. ____________ Bones: - _________ and boxy ex. ____________ Bones: - general small, flat, and shaped somewhat like a sesame seed - develop inside ________, most commonly located near joints at the knees, hands, and feet - individuals vary in the location and abundance (form in at least 26 locations)

7. Bone Classification Cont.

8. Bone Markings/Surface Features • external and internal ___________________ - ______________ or ______________ form where tendons and ligaments attach - _____________, ______________, and ____________ in bone indicate cites where blood vessels or nerves lie alongside/penetrate bone Uses - determine __________, _________, sex and general appearance

9. Anatomical Terms: Bone Surfaces Elevations and Projections - ___________: projection or bump - Ramus: __________ of a bone making an angle with the rest of the structure Processes formed where tendons or ligaments attach - ______________: large, rough projection - Tuberosity: smaller, _______________ projection - Tubercle: small, rounded projection - _____________: prominent ridge - Line: low ___________ - __________: pointed or narrow process

10. Anatomical Terms: Bone Surfaces Processes formed for articulation with adjacent bones - _________: expanded articular end of an epiphysis, separated from the shaft by a neck - Neck: narrow connection between the _____________ and the _____________ - ___________: smooth, rounded articular process - Trochlea: smooth, grooved articular process shaped like a pulley - Facet: small, flat articular surface Depressions: - Fossa: shallow _____________ - Sulcus: narrow groove

11. Anatomical Terms: Bone Surfaces Openings - Foramen: rounded passageway for blood vessels or nerves - Canal: passageway through the substance of a bone - Fissure: elongated cleft - Sinus: chamber within a bone, normally filled with air

12. Bone Structure (marco) • Diaphysis: _________, makes up up of the bone’s length - wall consists of a layer of __________ bone (dense bone) - relatively solid, forms a sturdy protective layer that surrounds a central space, _______________ cavity - covered and protected by a fibrous connective tissue membrane called the _______________, attached to bone by ____________ fibers • Epiphysis: at each _________ of the long bone - thin layer of compact bone composed largely of _____________ bone - open network of struts and plates, like a lattice - glassy hyaline cartilage known as an ____________ cartilage covers external surface providing a slippery surface that decreases friction - ___________ line : remnant of epiphyseal plate when growth occurs

13. Bone Structure Cont. • _______________: narrow zone connecting the epiphysis and diaphysis • Medullary cavity: central space in bone primarily a __________ area for adipose tissue - in infants formation of blood cells and red marrow occurs here

15. Structure of Compact Bone • ____________ (Haversian system) - basic unit of mature compact bone - _______________ are arranged in concentric layers around a central canal - canal contain blood vessels that carry blood to and from the osteon - central canals generally ___________ to the surface of the bone - perforating canals extend _____________ to the surface - ____________ of each osteon form a series of nestled cylinders around the central canal (target/bullseye) - _____________ radiating through the lamellae interconnect the lacunae with one another and the central canal

16. Structure of Spongy Bone • Matrix - forms struts and plates called ______________ - branch to create an _____________ network - no capillaries or venules - nutrients reach the osteocytes by _____________ along the canaliculi • Characteristics - ____________ than compact bone - able to withstand stress from multiple directions • Locations - _________ bones (carpal of wrist) - inner layer of _________ bones - sesamoid

17. Bone Composition • Specialized cells ex. • Matrix consisting of extracellular protein fibers and ground substance - very dense and contains _____________ deposits - bone cells (ostecytes) inside of lacunae - canaliculi

18. Cells of the Bone • 4 types of cells - ______________ - ______________ - ______________ - ______________

19. Cells of Bone Cont. • Osteocytes - ______________ bone cells, cannot divide - most abundant - occupies a ___________ (tiny cavities) arranged in concentric circles called lamellae around central (Haversian) canals - a central canal, and matrix rings is called an ___________ or Haversian system - lamellae are penetrated by _________________ (narrow passageways) radiating through matrix connecting lacunae and sources of nutrients, such as a central canal • Functions: - ____________ the protein and mineral content of the surrounding matrix - participate in the _____________ of damaged bone

20. Cells of Bone Cont. • Osteoblasts - produce new bone matrix by _______________ - __________ and ___________ proteins and other organic components of the matrix before calcium salts are deposits - assist in elevating local concentrations of calcium phosphate above its solubility limit triggering the deposition of calcium salts in the organic matrix converting matrix to bone - become ______________ once completely surrounded by bone matrix

21. Cells of Bone Cont. • Osteoprogenitor - small numbers of _______________ cells - squamous stem cells that divide to produce daughter cells that differentiate into osteoblasts - maintain populations of ________________ - important in the role of _______________ - located in the ______________

22. Cells of Bone Cont. • Osteoclasts - giant cells with more than 50 nuclei - ___________ and _____________ bone matrix by secreting enzymes that dissolve and release stored minerals (osteolysis)

23. Bone Formation, Growth • Two Ways • ______________________ bones originate between sheetlike layers of connective tissues ex. • _______________ bones begin as masses of cartilage that are later replaced by bone tissue ex.

24. Intramembranous Bones • broad, flat bones of the skull • membranelike layers of unspecialized, or relatively undifferentiated, connective tissue appear at sites of the future bones • some of the partially differentiated ____________ cells enlarge and further differentiate into bone-forming cells, ____________ • osteoblasts ___________ bony matrix around themselves • as a result _________ bone tissue forms in all directions with the layers of connective tissue • when extracellular matrix completely surrounds osteoblasts, they become __________ • formation of bone is known as _____________

25. Endochondral Bones • most all bones of the skeleton • develop in the fetus from masses of ___________ ____________ - in long bones, change occurs from center of ____________ - _____________ slowly breaks down and disappears - a ___________ forms from connective tissue that encircles the developing diaphysis - blood vessels and osteoblasts from periosteum invade the disintegrating cartilage, and spongy bone forms in its place - this region is called the _______________________ - bone growth occurs from it towards the ends of the cartilaginous structure - osteoblasts from the periosteum deposit a thin layer of compact bone around the primary ossification center

26. Endochondral Bones Cont. - epiphyses remain cartilaginous and continue to grow - secondary ossification centers appears, epiphyses fill with ______________ bone, except at the center where calcification occurs - a band of cartilage remains between the two ossification sites, called the _____________ _____________

27. Bone growth in Length Cont. - cartilagenous tissue of the epiphyseal plate includes layers of young cells that are undergoing mitosis and producing new cells - cells enlarge, and extracellular matrix form around them, thickening the cartilagenous plate, and lengthening the bone - calcium salts accumulate in the extracellular matrix adjacent to the oldest cartilaginous cells, and as the matrix calcifies the cells begin to die - _________ remove matrix as _________ deposit new bone - epiphyses remain throughout life as __________ ________ - growth ends when the two ___________ _________ meet - at puberty rising levels of sex, growth, and thyroid hormones stimulate bone growth; osteoblasts produce bone faster than chondrocytes at producing new cartilage

28. Appostional Growth Appositional Bone growth (________________) - ___________ in periosteum add bone tissue to the ___________ face of the _______________ - ____________ in the endosteum remove bone from the ______ face of the ____________ wall - forms the a space resulting in a __________ ____________ which later fills with ___________

29. Bone Remodeling • Remodeling - components of bone continuously recycle and renew occurring throughout life - older minerals deposits are removed from bone and released in to the circulation at the same time that circulating minerals are being absorbed and deposited - “game” between osetocytes, blasts, and clasts - osteocyts create ________, at the same rate osteoclasts remove one by ______________ - _______ of the adult skeleton is replaced every year - femur spongy bone replaced 2-3 times a year

30. Factors Affecting Bone Growth, Remodel & Repair • Nutrition ex. • ____________ ex. • Physical Exercise ex. • ____________ ex.

31. Bone Fractures • General Categories - _________ (simple) - _________ (compound) • Closed - completely ______________ - no break of the skin, so they can only be seen in x-rays - usually easy to treat • Open - project through the ___________ - more dangerous due to possibility of infection

32. Types of fractures • Pott - occurs at the ___________ and affects both bones of the leg • Comminuted - ____________ bone into multiple fragments • _______________ - break bone shaft across its axis • Spiral - ____________ up/down the length of the bone • Displaced/Nondisplaced - produce new and abnormal bone arrangements - retain normal ______________

33. Type of Fractures • Colles - break in the distal portion of the radius • Greenstick - only one side of the shaft is ____________, and the other is bent • Epiphyseal - occur where bone matrix is undergoing calcification - can permanently stop growth • Compression - occur in the ____________ • Avulsion - tendon or ligament is injured in such a manner that it pulls off a piece of ________

34. Fractures

35. Repair of a Fracture • Step 1 - blood vessel rupture, ____________ tears (usually) - blood escapes spreading through damaged area leading to a ___________ or large blood clot - vessels in surrounding tissue __________, swelling and inflaming tissue • Step2 - ___________ and new blood vessels from the periosteum invade the hematoma, create __________ bone • Step 3 - __________ fills in the gaps of broken bone, called a _______________ ________ (later be replaced by bone tissue very similar to endochondral bone) • Step 4 - ___________ appear and reabsorb fragments or dead bone is removed - ___________ cells begin to remove blood clot and damaged cells

36. Skeleton • 2 parts - ___________ - _____________ • Appendicular - forms the longitudinal axis of the body - ________ bones - 40% of the bones in human body - Includes - ________________ & _______________ - _______________ column - ________________ ____________ • provide framework that supports and protects the brain, spinal cord, and organs in the ventral cavities • extensive surface areas for attachment of muscles • joints have limited movement

37. Skull - composed of the cranium, and facial bones - encloses the cranial cavity, a ___________ filled _____________ that cushions and supports the brain - occipital, parietal, and frontal bones form the _____________ - blood vessels, nerves, and membranes that stabilize the position of the brain are attached to the inner surface of the cranium - outer surface provides areas of attachment for muscles of the eyes, jaws, and head - joint between occipital bone and 1st vertebrae of neck stabilize the positions of the brain and spinal cord

38. Skull Cont. • Contains 22 bones - __ form the cranium - __________ - ethmoid - ___________ - frontal - _________ - temporal (2) - 14 facial - maxilla (2) - ___________ - palatine (2) - _________ - nasal (2) - ___________ - vomer - inferior nasal concha (2)

39. Skull (Facial) - superficial bones - - provide areas for the attachment of muscles that control facial features and assist in the manipulating of food - deep bones - - separate the __________ and __________ cavities - increase surface area of cavities - help form the nasal septum which divides the ____________ _____________

40. Skull Cont. • Sinuses - ______________ chambers - two major functions - make bone ______________ - mucous membrane lining produces mucus that moistens and cleans air • Joints or Articulations - form where two bones ________________ - exception between mandible and cranium contact - sutures are located between ______________ joints of the skull bones in adults - bones are tied together via dense fibrous connective tissue - ___ major sutures

41. Skull Cont. • ________________ - arches across the posterior surface of the skull - seperates the occipital bone from the two parietal bones • Coronal - attaches the ___________ bone to the _________ bones of either side • _______________ - extends from lambdoid suture to the coronal suture, between the parietal bones • Squamous - one each side of the skull forms the boundary between the ____________ bone and the ______________ bone of that side

42. Orbital Complexes • __________ bones and ___________ bones which surrounds each eye, and the nasal complex surrounding the cavities • protect and support openings of the digestive and respiratory systems and sense organs responsible for vision and smell • Orbits - __________ recesses that contain the eyes - each orbit is formed by ___ bones of the orbital complex

43. Nasal Complexes • bones that enclose the nasal cavities and the paranasal sinuses • Paranasal Sinuses - sphenoid - ethmoid - frontal bone - maxillia - palantine bone - lighten the skull bones and provide an extensive area of ____________ epithelium - as mucous secretions are released ciliated epithelium pass it back toward the throat to be swallowed or expelled by coughing - incoming air is _______________ and warmed - foreign particles are trapped swallowed or expelled by coughing

44. Fontanelles - fibrous membranes connecting cranial bones • _________ fontanelle (exists about 2 years after birth) - largest - located at the intersection of the frontal, sagittal, and coronal sutures in the anterior portion of the skull - often referred to as the “soft spot” • Occiptial fontanelle (disappear 1-2 months after birth) - junction between the lambdoid and ___________ sutures • ____________ fontanelles - junctions between the squamous and coronal sutures • Mastoid fontanelles (disappear 1-2 months after birth) - junctions between the ____________ and lambdoid suture

45. Vertebral Column • consists of ____ bones - vertebrae (___) – _________ - __________ • provides a column of support • bears the weight of the head, neck, and trunk • protects the ____________ __________ • helps maintain an upright body position • averages 71 cm or 28 in in adults • several __________

46. Spinal Curvature • ___ curves • ____________ - neck • ____________ - upper back • ____________ - lower back • ____________ - gluteal reigon

47. Vertebral Anatomy • 3 basic parts - vertebral ___________ - vertebral ___________ - ____________ process • Vertebral Body - transfers _______ along the axis of the vertebral column - interconnected by ____________ - separated by fibrous cartilage (_______________ discs) • Vertebral Arch - forms the posterior margin of each vertebral _________ - ____________ (walls) arise along the posterior and lateral margins of body - roof called ___________, extend dorsally and medially - successive vertebrae form the vertebral __________, enclosing spinal cord

48. Vertebral Anatomy Cont. - intervertebral discs separate adjacent vertebral bodies - intervertibral __________ (gaps) separate successive pedicles, permitting passage of ___________ - ___________ process projects ____________ where vertebral laminae fuse to complete arch (feel through skin when back is flexed) - _____________ processes project ___________ on both sides where laminae join pedicles - sites for muscle attachments - some articulate with ribs • Articular processes - arise at the junction between the pedicles and the laminae - superior articulate with inferior on each side - each articulation has a smooth concave surface called an articular ___________

49. Vertebral Regions • Cervical - _______, create the neck - extend from ____________ bone to the thorax - _________ of the vertebral column - small body compared to foramen - support only the _________________ of the head • General Characteristics __________ - superior surface of body is ___________ side to side - slopes with the anterior edge inferior to posterior edge - stumpy spinous process, __________ than the diameter of foramen, with prominent __________ (bifid) - laterally transverse processes are fused to ____________ processes - encircle round transverse ______________ - provide more flexibility than other regions

50. Vertebral Regions Cont. • Atlas: __(after Atlas who holds the world on his shoulders) - holds up the ________ - articulates superiorly with occipital _________, allowing us to nod yes - articulates with the ____, allowing us rotation for no - no ___________ ____________ - ________, _______ vertebral foramen bounded by anterior and posterior arches • Axis: ___ - during development fuses with atlas creating the prominent ________ (adontoid) - a __________ ligament binds the dens to the inner surface of the atlas - strong spinous process for muscle attachment - incomplete in children