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WorksheetsAnatomy Chapter 2: Bone Structure
Total questions: 92
Worksheet time: 2hrs 56mins
Hematopoiesis: the formation of (a) cells
Occurs in the ______ ________ ________, mostly in flat bones but also vertebrae
(a)
Triglyceride storage: ________ marrow, mostly in ________ bones
(a)
Ca²⁺ functions:
Unfortunately, bone also will concentrate other metals not normally found in the body, e.g. Pb, Ra, ⁹⁰Sr: when ingested are concentrated in bone - may cause problems; e.g. _______________
Periosteum: the tough covering of dense irregular CT and osteogenic (stem) cells (below)
Covers the entire bone except at articulations / joints
Continuous with the tendons, ligaments & the joint capsule
Epiphysis (pl. epiphyses) the expanded ends of a long bone
Articulates with another bone
Composed of spongy bone & a thin outer layer of compact bone
The articulating portion is covered with articular (= ________) cartilage
Diaphysis: the shaft
Composed mainly compact bone, forms a rigid tube
Strong, solid and bend resistant
Epiphyseal Line: the line between the diaphysis and the epiphysis
Forms from the epiphyseal / growth plate: an area of cartilage that allows bone to grow in length
Once this is bone (the epiphyseal line) the bone no longer can grow in length
Medullary Cavity: the hollow area continuous with areas of spongy bone
Lined with a cell layer called endosteum, which is mostly osteoblasts
Contains bone marrow
red marrow: produces RBC, some WBCs & platelets - found mostly in spongy bone (and mainly flat bones)
yellow marrow: composed of adipose and is located mostly in diaphyses; bone is considered an area of fat storage
Osteogenic (Progenitor) Cell / OPC: bone "stem cell" - derived from (a)
Osteoblast: a cell which ________ bone tissue
Becomes an osteocyte once enclosed in a lacuna
Vital to development, remodeling & repair
Osteocyte: a mature bone cell located in a lacuna; maintains matrix
Large multinucleate bone cell that is rich in phosphatase activity
Important to development & remodeling and in mobilizing Ca²⁺ to the ECF
Osteoclast: breaks down and resorbs bone; is considered a phagocyte of bone
Large multinucleate bone cell that is rich in phosphatase activity
Important to development & remodeling and in mobilizing Ca²⁺ to the ECF
A note on the traditional bone histology nomenclature: Lamellar Bone: mature compact bone and spongy bone; named because it is formed into _______ or lamella.
sheets
fibers
cells
A note on the traditional bone histology nomenclature: Woven / Embryonic Bone: immature bone - contains an irregular arrangement of collagen; is formed during development, repair and remodeling.
True
False
Compact bone is composed of groups of _______ or Haversian Systems.
osteons
trabeculae
osteocytes
The osteocytes are in chambers called (a) .
The matrix is composed of hydroxyapatite & collagen, etc. and organized into rings or _______.
lamellae
osteons
canaliculi
Hydroxyapatite: calcium phosphate crystals that are hard and brittle.
True
False
Collagen imparts strength and some "bendability".
True
False
Osteonic / Haversian Canal: Run the entire length of the bone.
True
False
Osteonic / Haversian Canal: Contains BVs, nerve, areolar CT - bone is highly vascularized.
True
False
Canaliculi: the "canals" connecting osteocytes in each ring.
True
False
Osteocytes are linked by gap junctions.
True
False
Perforating / Volkmann's / Communicating Canals: The roughly "perpendicular" canals connecting adjacent osteons.
True
False
Perforating / Volkmann's / Communicating Canals: Contain large blood vessels that connect osteons.
True
False
Blood supply to bone: Nutrient arteries enter bone via small nutrient foramina (foramina = holes).
True
False
Blood supply to bone: The BVs enter the medullary cavity, Volkmann's canal, osteonic canal, etc. & small BVs that supply osteocytes.
True
False
Blood supply to bone: Note that the red marrow is the source of all newly formed RBCs.
True
False
The osteocytes are in trabeculae: the branching bony plates.
True
False
This is found on the inner regions of and keeps the weight of the bone minimal but still allows for strength.
True
False
There are no osteonic canals.
True
False
Osteocytes are in lacunae, surrounded by bony matrix and connected via canaliculi.
True
False
Osteoblasts and osteoclasts are also present.
True
False
Nutrients are obtained via diffusion into the canaliculi.
True
False
The fetal sites of future flat bones are occupied by membranous sheets of (a) .
Mesenchyme differentiates into _______ ___________ ____ (OPCs) and then __________.
(a)
Ossification centers (areas of bone formation) form as osteoblasts secrete ________: matrix of collagen that __________.
(a)
Woven (embryonic) bone develops & osteoblasts differentiate into osteocytes.
Spaces between trabeculae fill with red marrow.
Woven bone is remodeled into spongy / cancellous bone and (a) bone (note these are mature / lamellar bone).
Mesenchyme forms the periosteum.
Periosteal OPCs differentiate into osteoblasts and form ore bone from the outside.
Areas of the neonate skull remain as fontanels (soft spots) and ossify later in development (see lab).
Fetal (a) occupies areas of future bone.
Mesenchyme forms __________ and a model of __________ cartilage forms.
(a)
The cartilage model enlarges via mitosis.
OPCs in the perichondrium form (a) .
Bone forms on the outer diaphysis, beginning at mid-diaphysis.
Chondrocytes & lacunae hypertrophy.
The matrix becomes calcified & chondrocytes die.
Nutrient arteries invade at mid-diaphysis bringing more nutrients etc.
Osteoblasts invade - from the periosteal OPCs and use the calcified matrix to form.
Woven / embryonic bone & the 1° ossification center enlarges towards the epiphyses.
Woven bone is remodeled into compact bone.
(a) form the medullary cavity.
2° ossification centers are located in the epiphyses.
The events are similar to the 1° ossification center.
Form inner spongy & outer compact bone.
A layer of cartilage remains in the epiphyses: = (a) : allows the bone to grow in length.
Cells are temporarily in (a) of the cell cycle.
Forms the (a) .
Osteoblasts develop from (a) in the periosteum.
Osteoblasts form the (a) form bone from the inside.
(a) enlarge the medullary cavity.
Adult bone is continually remodeled gradually but in defined zones / (a) .
Linked to Ca2+ (a) .
The effect of mechanical stress on bone is sometimes referred to as Wolf's Law: states that bone growth is promoted by stress on bone.
Mechanical stress creates an anionic charge on hydroxyapatite.
This stimulates osteoblasts (via calcitonin) and results in hypertrophy & strengthening of bone.
Applications of Wolf's Law:
Physical therapy in injury recovery
Weight bearing exercise to prevent/treat osteoporosis
Explains the formation of 'bony processes'
Differences between processes in the ♂ and ♀ skeleton
Ca2+ and (PO4)3- are essential for bony matrix.
Deficiencies: 1) rickets: bending & weakness of bone in children 2) osteomalacia: similar condition in adults
GH is secreted by the anterior pituitary and acts to promote release of IGF / somatomedin from the liver.
Stimulate mitosis of chondroblasts & osteoblasts, etc.
Disorders: A. Hypopituitary dwarfism: GH deficiency in children – small but normally proportioned body
B. Giantism: GH overproduction in children
C. Acromegaly: GH increase in adults; hands, feet & jaw enlarge but height is normal
Androgens (mainly (a) ) & estrogens
Secreted (from the thyroid) during hypercalcemia ( (a) blood Ca²⁺)
Secreted during hypocalcemia ( (a) blood Ca²⁺)
Stimulates (a) , etc.
Fractures: A break in the bone; may involve cartilage; two basic causes
Traumatic fracture: due to injury
Spontaneous / pathologic fracture: due to disease
Two General Types of Fractures
Simple or closed: protected by uninjured skin
Compound or open: bone protrudes through broken skin
Physical therapy – remember (a) law
Result: demineralization and (a) of bone mass
Diet: ensure proper (a) intake and eat a healthy diet
Exercise: especially weight bearing exercise; again remember (a) law
menopause: OP is much more common in females because of the decrease in (a) following menopause
Bone marrow sample is taken from -------------space of sternum.
2nd
3rd
4th
5th
Hematopoiesis is the function of the:
integumentary system
nervous system
endocrine system
skeletal system
