Chapter 6 - Bones & Bone Structure Flashcards
name the 3 sections of bone from outermost to innermost.
- Compact Bone
- Spongy bone
- Bone Marrow
bones are classified by their shape and structure. name the 6 shapes.
- Sutural
- Irregular
- Short
- Flat
- Long
- Sesamoid
what is a sutural bone? (Wormian bones)
- small, flat, oddly shaped bones found between the bones of the skull.
- they range in size from a grain of sand to a quarter
what is an irregular bone?
- the miscellaneous drawer of bones.
- anything that does not fit into the other categories: vertebrae, pelvis, some bones in the skull
what are short bones
- box-like: carpal (wrist) and tarsal (ankle) bones
what are flat bones?
- thin, parallel surface.
- roof of the skull, sternum, ribs, scapulae.
- provide protection for underlying soft tissue and offer surface area for muscle attachment
what are long bones?
- long and slender
- arm, forearm, thigh,
what are sesamoid bones?
- small, round, and flat
- found near the joints of the knees, hands, and feet: patellae
what are Projections? name the types of projections.
Projections for attaching muscles, tendons, or ligaments, at articulations with other bones
- *Process: like a bump
- *Condyle:
- *Ramus: kind of like a projection (eg. pubix and mandible
- Trochanter (only on femur)
- Crest (eg. outer pelvis)
- Spine (pointed process of pelvis)
- Line (low ridge, eg. inner pelvis)
- Tubercle (small rounded projection)
- Tuberosity (rough projection)
- Facet (small articular surface)
- Head
- Trochlea
Joint Projections: Process and Condyle - name and explain.
Process: a projection or prominence
Condyle: rounded articular projection of bone, articulates with a corresponding fossa
Ligament / Tendon Projections: Epicondyle, Trochanter, and Tuberosity. name and explain.
- Epicondyle: raised area on or above a condyle
- Trochanter: large projection on Femur
- Tuberosity: large rounded or roughened projection
what are openings? what are examples
- sinus - empty air chamber
- foramen - like a passage from one room to another, doorway.
- fissure - like a tunnel
- meatus - small fissure
- canal - very very very small fissure. passage of nerves.
what is a depression? name some examples
a valley or a dip, a groove. usually for nerves and muscles to pass along bone.
- sulcus - very small depression
- fossa - shallow depression
name the sections of long bones. what is the name of the line in between? what type of cartilage?
- epiphysis (most proximal and distal)
- metaphysis (sandwich the diaphysis)
- diaphysis (middle)
*epiphyseal line
*articular cartilage, or fibrous cartilage
just for fun… what is the name of the spongy bone in between compact bone layers of a flat bone?
- diploe
what is the bone matrix made of?
- calcium phosphate (almost 2/3 of bone mass, makes bones hard)
- collagen fibers (about 1/3 of bone mass)
- interacts with calcium hydroxide to form hydroxyapatite…
- incorporates other calcium salts, such as calcium carbonate and ions (like magnesium)
what are the cells of bone? describe each.
what are the branches or spider legs of mature cells called?
- osteogenic cell - mesenchymal stem cell > osteoblasts
- osteoblasts - immature cells that build bone (light color)
- osteocytes - mature cells that maintain matrix (dark color)
*canaliculi - osteoclasts - break down bone for recycling
ossification (or osteogenesis) vs. calcification
- ossification - bone formation
- calcification - deposition of calcium salts, during ossification
what is the open network of spongy bone called?
trabeculae.
spongy bone does not have osteons like compact bone.
what is the outer membrane layer of bone?
periosteum. allows for passage of blood
what is the inner membrane layer of bone?
endosteum. It’s a layer of flattened osteogenic cells. in-between compact and spongy bone.
***PTH (parathyroid hormone) and calcitonin
- bone, intestine, and kidneys (slides 88-90)
- increase and decrease of calcium ion level in blood
what are the 4 steps to repairing bone?
(watch a video on this)
- hematoma - large blood clot
- callus formation - joins the 2 bones that broke, fragment of new bone.
- spongy bone formation - osteoblasts replace cartilage
- compact bone formation - repaired bone may be thicker and stronger than normal
osteopenia vs. osteoporosis
osteopenia - inadequate ossification (reduction of bone mass)
osteoporosis - severe loss of bone mass
name the parts of compact bone
- Haversian Canal
- Lacuna
- Lamella
- periosteum
- Sharpey’s fibers
- Osteocytes
- Osteons
- Osteoblasts
- Endosteum
name the canals.
- Volkmann’s cannal
- Haversian cannal
know lamella, lacunae, and canaliculi
- lamellae is the solid matrix
- lacunae is the spaces within the lamellae
- canaliculi are the branches of the osteocytes
what are the 2 types of ossification?
- Endochondral - long bones
- How most bones form. Cartilage → bone
- Primary ossification center - begins in the center, grows outwards. Chondrocytes = the cells
- 7 main steps (do not need to know all the steps. Know that bone was originally cartilage, know the name of endochondral ossification)
- creates an Epiphyseal line with Articular cartilage - Intramembranous - eg. skull and clavicle
No center, no steps of ossification
Osteoblasts build bone. Osteoblasts are everywhere in bone, where the bone originates
know where the bone cells are located…
- osteoblasts near periosteum
- osteocytes in compact bone
- osteocytes and osteogenic (mesenchymal) cells in near endosteum
explain how the Parathyroid Gland, kidneys, intestines, and bones maintain calcium levels if they are too low.
A. low levels of calcium in blood trigger the parathyroid gland to release the parathyroid hormone (PTH)
B. calcitriol is useable vitamin D made in the kidneys from the sun and food.
C. together, PTH + Calcitriol do 3 things to bring calcium levels up:
- increase activity of osteoclasts to release calcium from bones.
- tell kidneys to stop peeing out so much calcium
- tells the intestines to increase their absorption of calcium from food
