Chapter 6-7 Flashcards
Function of bones
Support Protection Movement Mineral homeostasis Blood production
What bones protect
Cranial bones
Vertebrae
Pelvic girdle
How do bones help with movement
Muscles attached to the bones
How are bones involved in homeostasis
Through minerals Ca++ and PO-4 storage
What do bones produce
Blood cells hematopoiesis in red bone marrow
Spinal abnormalities
Scoliosis
Kyphosis
Lordosis
Scoliosis
Twisted disease
Abnormal rotation of the spine. Results in a lateral curvature. Most often in the thoracic region.
Kyphosis
Hunchback. Is a dorsally exaggerated curvature. Common in elderly people, because of osteoporosis.
Lordosis
Sway back. Accentuated lumbar curvature. Can result from spinal tuberculosis, or osteomalacia.
What does temporary lordosis come from
Those carrying a large load up front. Potbellys pregnancy.
Curvature of the cervical and lumbar
Concave posteriorly
Curvature of the thoracic and sacral
Convex posteriorly
The spine is made up of what sections of bones
Cervical Thoracic Lumbar Sacral Coccyx
How many vertebrae are in the cervical, thoracic and lumbar.
7, 12, 5
Where do the vertebrae become larger and smaller. Why?
Become progressively larger from the cervical to lumbar. They must support greater weight as you go down
Sacrum
Inferior to the lumbar.
Articulates the hip bones
What is the terminus vertebrae column
Coccyx
How do the curvatures of the spine develop?
Cervical and lumbar curvature develop first. Then thoracic and sacrum.
Is your sacrum a few vertebrae?
No, it’s one
What does your sacrum hold
Your coxal bones together
What’s the remnant of our tail bone
Coccyx
What are the names of the first and second vertebrae? C1, C2?
Atlas
Axis
C1
Atlas
C2
Axis
C1 and C2 together.
Collectively give us the ability to rotate our head.
Which sexes skull is heavier
Male
Which sex has a squarer chin
Male
Which sex has a larger brow ridge and sloping forehead
Male
Which sex has a developed ridge where neck muscles attach
Male
Which sex has a more pointed chin and wider angle of jaw
Female
Which sex has sharp upper margins on the superior of the Orbital cavity
Female
Which sex has a more massive and heavier skull
Male
Which sex has a low sloped frontal lobe and which has a higher more rounded lobe
Male, female
Who has a squarer chin
Male
Who has a v shaped chin
Female
Who has smoother facial bones
Female
Who has square eye orbits
Male
Who has rounded eye orbits
Female
Who has a larger mastoid process
Male
Who has a larger occipital condyle
Males
Who has a parabola palate
Female
Who has Sharper suborbital margins
Females
Who has thicker pelvic bone
Male
Who has a tilted forward, broad, shallow, and greater capacity pelvic bone?
Female
Who has a smaller and farther apart acetabula
Female
Who’s pubic arch is broader and more round (80 to 90 degrees)
Female
Who has a 50-60 degree pubic arch
Male
Who has a wider shorter sacrum and more accentuated sacral curvature
Female
Whose coccyx is more movable and projects inferiorly
Female
Who has a wide and shallow sciatic notch
Female
Who has a more oval wider pelvic inlet
Females
Who has a more heart shaped narrow inlet
Males
Who has a wider further apart and every pelvic outlet
Female
Who has a more narrow and sharper point more medially pelvic outlet
Male
Who has a less movable and projects more anteriorly coccyx
Male
Who has a narrow and deep sciatic notch
Male
The angle of the spinous process
Is the bony projection off the posterior of each vertebrae. Ridges that can be felt through the skin on the back of the spine.
The angle of the thoracic point
Inferior
Why can you feel your lumbar spineous process more than your thoracic
Because lumbar are superior to the back
What sections of the spine curvature develop first
Cervical and lumbar
What part of the spines curvature develop 2nd
Thoracic and sacrum
What bone doesn’t bear weight in the lower extremity. does it help with muscle movement
Lateral leg, fibula. Yes
What area is not protected by bones
Abdominal pelvic region
Ca++, PO-4
Calcium salts
Makes bones hard
Hematopoesis
Creation of new red blood cells in red bone barrow
Where are our baby blood cells born or stem cells
In red bone marrow through hematopoiesis
Stem cells don’t have a
Function yet
Diaphysis
Shaft of a long bone
What does the diaphysis contain
Medullary cavity or marrow cavity
Do infants of adults have more red bone marrow
Infants
What is red marrow gradually replaced by
Yellow fatty bone marrow
Epiphysis
Ends of long bones
Epiphyseal plate
Growth plate made of cartilage
What is the nutrient foramen
Site of blood vessel entry into the bone
Periosteum
Outer bone
Protects the bone
Articular cartilage
Hyaline cartilage (fish eggs) covering epiphysis
Why is cartilage only on the ends of bone
To protect the bones from hitting each other
The epiphysis is made up of what kind of bone
Spongy bone
What kind of bone in the diaphysis made up of
Compact
Why is spongy bone where it is
Because it doesn’t need to withstand a lot of forces because it is capped with cartilage
Cavity Inside the of the bone
Medullary cavity
Medulla
Inside
Cortex
Outside
What’s inside the medullary cavity of the diaphysis
Bone marrow
Why are our bones pouros.
Arteries, veins, nerves
Two types of bone marrow
Red and yellow
Why do infants have more red bone marrow than adults
They are developing at a faster rate
Red bone marrow gets replaced with
Yellow bone marrow, fatty bone marrow or adipose tissue
What surrounds the bone
Two layers of connective tissue
What are the two layers of connective tissue around the bone
Fibrous layer
Osteogenic layer
What is the fibrous layer of connective tissue around the bone
Outer layer. Dense irregular connective tissue.
What is the osteogenic layer of connective tissue around the bone
Inner layer. Made up of osteoblasts and osteoclasts.
Osteoblasts
Bone forming cells
Osteoclasts
Bone remodeling cells
What anchors the periosteum to the bone
Perforating fibers
What do perforating fibers look like and made of
Sharpies and are made of collagen
The periosteum is there to do what?
Protect the bone
Protective strong tissue
Fibrous connective tissue
Osteon
Smallest functional unit of bone
What is the site of ligament and tendon attachment
Periosteum- Two layers of connective tissue around the bone. Fibrous and osteogenic layer
What is the large supply of nerves and blood vessels on the bone
Periosteum
What lines the medullary cavity
The endosteum
Endosteum
Inner layer
Where on the bone has an osteogenic layer
The endosteum
What layer of the bone contain osteoblasts and osteoclasts
The periosteum and endosteum
What do the concentric rings surround
Are where we give nutrients to in the bone
Three main components that make up osteons
Osteoblasts
Osteocytes
osteoclasts
Osteoblasts
Build new bone. Lays down the cement
Osteoclast
Break down, resorb or remodel bone
As osteoblastic activities increase
Two much growth hormone or something breaks
Osteoclast and osteoblasts are always
In homeostasis
Increased osteoclast activity
Brittle bones, osteoporosis
Spongy bone has a particular orientation know as
Trabeculae
Trabeculae
Network of bony projections that are porous
Why is the bone trabeculae
To supply nutrients to the bone
Bone tissues matrix mineralized is
25% water
25% protein (collagen)
50% hydroxyapatites (calcium phosphate or salts)
Why is Ca+PO4- or calcium phosphate a salt
Because they are ionic compounds
Lamella
Rings on osteon
Osteoblasts
Bone forming cells
What do osteoblasts secrete and where are they found
secrete collagen and other organic compounds for bone synthesis. Found on any bone surface
Osteocytes are found
Embedded in matrix in lacunae with canaliculi
What do osteocytes maintain
Daily activities of bone tissue, nutrient, waste exchange
Osteocytes
Are mature bone cells- hard cement
How do osteoclast build bone
By secreting collagen- protein fiber found in all bone
Matrix synthesizing cell responsible for bone growth
Osteoblasts
Mature bone cell that maintains bone matrix
Osteocytes
Harden bone is a
Osteocytes
Bone resorbing cell
Osteoclast
Osteoclasts are found
Settled on the bones surface
Osteoclast function
Bone resorption, matrix destruction for growth, development, maintenance, repair.
If we have a broken bone what comes in to repair it
Osteoclasts
As bone is hardened it becomes more and more deposited with
Minerals and collagen fibers
Matrix secretes in bone tissue
Ground substance and collagen
Calcification
Mineralization
Osephication
Hardening of bone
The matrix in the bone is not continuous because
It’s where all the vascular passageways penetrate is
What determines if a bone is spongy or compact when it matures
Size and distribution of vascular channels
Mineralization is
Crystallization develops around collagen fibers
Stronger than egg shells, which have no collagen
Mineralization
Maturing of bone
Crystallization = calcification = mineralization
Most of the bone mass in the body
Compact
Bone that appears very dense
Compact
Small struts of bone (trabeculae)
Spongy
Spongy bone may appear randomly organized but is actually
Oriented in the direction of stresses
Only spongy bone to have dipole and surrounded by compact bone
Skull bone
Blood vessels run through
(Volkmans) Perforating canals to the (haversian) central canals
Canaliculi
Can I lick your eye
move blood from each ring
The central canals of bone tissue characteristics
Center of osteon, is where the blood supply goes in and out
Osteocyte lacunae
Look like eyes on the rings (lamella) of the osteon.
From the central canals to the canaliculi to the lacunae what is happening
Blood is being drained
Canaliculi
House cytoplasmic extensions from the osteocytes so they are in contact for transportation and communication
Interstitial lamellae are found
In older bone
What happens to osteons during the remodeling process
Gradually broken down and replaced during the remodeling process
What tissue is not alive that is around the bone. Why
Cartilage, because it’s avascular
Is bone alive, why
Yes, because it’s highly vascularized
Does spongy bone have a true osteon system. Why?
No, because osteoblasts produce an irregular strutwork of trabuculae
How do osteocytes receive nutrients
By diffusion through canaliculi
Red marrow does what
Fills the spaces between the trabeculae and then creates new blood cells through hematopoietic marrow
Do blood vessels move through compact and spongy bone
Yes
Do blood vessels pass through yellow marrow cavities, which open to become red marrow cavities
Yes
The early embryonic skeleton (4weeks) is composed of
Fibrous connective tissue membranes and hyaline cartilage
Hyaline cartilage is fully formed
At four weeks
Fish eggs
What does hyaline cartilage form into during bone formation
Harden bone
What bone formations happen at week 4 of development
Ossification and osteogenesis
Spongy bone and compact bone formation
Hyaline cartilage model to endochondral ossification
Initial cartilage is transformed to become endochondral bones
Intramembranous ossification
Causes us to have spongy bone. At the site of bone development. Results in the formation of cranial bones and the clavicles (all are flat bones)
Ossification begins
In fibrous connective tissue membranes formed by mesenchymal cells
Osteoprogenitor cells are
Osteoblasts- clusters of embryonic cells
Osteoprogenitor cells become
Centers of ossification, secrete matrix until they are surrounded.
First step of intramembranous ossification
In the messenchymal cell/region or meisoderm. Around week four come up with a center in that hyaline cartilage. That production center has a bunch of osteoblasts
intramembranous Ossification center appears where?
The fibrous connective tissue membrane aka hyaline tissue.
Step two if intramembranous ossification
Osteoblasts start laying down (liquid cement) bone matrix Aka osteoid within the fiburous membrane.
Osteoid
Bone matrix
Trapped osteoblasts during intramembranous ossification becomes
Osteocytes
intramembranous Ossification step three
Woven bone is created (spongy bone) and periosteum form. So blood vessels can weave around it. What
Ossification step four
Form a bone collar. An area that surrounds or outline where the bone should stop. Then bone marrow appears.
Endochondral ossification
Inside cartilage hardening.
Making of compact bone
When does endochondral ossification start
Second month or 8 weeks
Which happens first endochondral ossification or intramembranous ossification
Intramembranous Ossification
What stage of ossification forms all of the bones below the base of the skull (except clavicle)
Endochondral ossification
What uses hyaline cartilage model for bone development
Endochondral ossification
What requires hyaline cartilage prior to ossification
Endochondral ossification
What bone development begins in the primary ossification center
Endochondral ossification
Stages of endochondral ossification
Formation of bone collar.
Cavitation of hyaline cartilage.
Internal cavities form by periosteal bud and spongy bone formation.
Formation of medullary cavity.
Second ossification centers in the epiphysis.
Ossification of epiphysis. Hyaline cartilage remains in epiphyseal plates.
Endochondral ossification stage 1- week 9
Formation of bone collar
Formation of primary ossification center within the diaphysis of long bone or cartilage.
Endochondral ossification stage 2
Cavitation of the hyaline cartilage. Osteoblasts start laying down that material (deterioration cartilage matrix) and spread toward that primary center toward the epiphysis.
Endochondral ossification stage 2
Diaphysis turns into the spongy bone. Hardening the shaft, create two ends of spongy bone that migrates. Blood vessels in diaphysis.Invasion of the internal cavities by the periosteal bud and spongy bone formation.
At 3 months of age.
Endochondral ossification step 4
Diaphysis elongated, medullary cavity formed, appearance of secondary ossification centers in epiphysis. Blood vessels in epiphysis.
Endochondral ossification step 5
Ossification of the epiphysis and hyaline cartilage only remaining in the epiphyseal plates. Outer edge of the bones still have cartilage, not ossified.
Allows for us to have fluid movement in all our joints
Articular cartilage
Gap in our bones. Where epiphysis and diaphysis meet
Epiphyseal plate cartilage
Growth plate
Post natal bone growth determined by
hGH and sex hormones
What happens if you do have a fracture in the epiphyseal plate
Growth is stunted. Bone will show epiphyseal line fractures in that region
When do you completely stop growing or ossifying
25
What is the last bone to stop growing
Clavicle
Growth in length is determined
By the epiphyseal plate and how much cartilage is left in there
Longitudinal or appendicular growth stops and the epiphysis and diaphysis fuse when?
Females 18
Males 21
What happens at the end of adolescence to long bone growth
Epiphyseal plate chondrocytes divide less often and the remains hyaline cartilage of the epiphyseal plates is replaced by bone tissue
Appositional bone growth
After it stops growing in length it grows in width.
Where does appositional bone growth occur
Weight bearing areas
Coxal egion
Femur head in the asitabulum
How does appositional bone growth grow
Inside out
What happens to the compact bone lining the medullary cavity during appositional growth
It’s destroyed
What do osteoblasts do during appositional bone growth
Osteoblasts from periosteum continue to add more bone to outer surface.
The forces of stress over time on a bone can cause
A thicker periosteum- Appositional bone growth
Wolfs law
Forces put on a bone over a period of time can cause bone growth
Bone homeostasis remodeling
Replacement of old bone with new
What hormones are used and where are they from in Bone homeostasis remodeling.
Calcitonin- thyroid gland
Parathyroid hormone- parathyroid gland
What regulates how much calcium is in our blood at all times
Parathyroid hormones and calcitonin hormone
What increases osteoblastic activity in bone homeostasis
Calcitonin from the thyroid.
What increases osteoclastic activity during bone homeostasis
Parathyroid hormone in the parathyroid gland
What does the parathyroid monitor and secrete and where does it pull the nutrients from
Secretes calcium and pulls it from the bone by breaking it down
If we have too much calcium (hypercalcium) in the blood stream what happens
Calcitonin is released from the thyroid. It takes extra calcium and moves it to the bones and increases osteoblastic activity
Which hormone is the most important regulator of blood calcium levels
Parathyroid hormone
What is a very metabolically active tissue
Bone
How often is the distal head of the femur replaced
Every four months
How often is bone replaced
Every 3-10 years
What happens if there is too much mineral in the bone
Causes bumps or spurs in the joints interferes with motion
What happens if there is too much bone tissue
Bones become thick and heavy
Too much Ca++ loss or crystallization makes bones
Brittle and breakable
When is bone remodeled
When going from old to new. Or when remodeling due to mechanical stress
When is parathyroid secreted
When your blood calcium levels drop
Why is it always important to monitor blood calcium
Because we need it for muscle contractions. The heart
Stages of bone remodeling
Bone is resorbed and added by appositional growth.
Where does remodeling of bone occur
At periosteum and endosteum
What cells are used to coordinate remodeling
Osteoblasts and osteoclasts
Falling blood ca levels signal?
Parathyroid gland to release PTH
What does PTH stimulate
Osteoclasts to degrade bone matrix which releases ca into the blood
Rising blood Ca levels trigger
The thyroid to release calcitonin
Calcitonin stimulates what
Calcium phosphate deposition in bone
If you have low calcium and your bones are always secreting PTH how are your bones going to look
Brittle
A bone grows or remodels in response to the forces or demands placed upon it is what law
Wolfs law
What observations support wolfs law
Long bones are thickest along the shaft (where bending stress is greatest).
Curved bones are the thickest where they are most likely to buckle
What happens to the trabeculae in response to mechanical stress
It forms along the lines of stress. Large bony projections form where strong active muscles attach.
What minerals are needed for remodeling
Ca2+
PO4-
Magnesium
Meaganese
Why is magnesium needed for remodeling
It is needed for osteoblast functions
Why is manganese needed for remodeling
Needed for lamellae formation
What vitamins are needed for remodeling
D, C, A, B12 D- absorbs Ca+ C- matrix/collagen A- controls how well osteoblasts and osteoclasts work. B12- for osteoblast metabolism
Too much blood Ca is and causes?
Hyperclacium
Heart stops
Too little blood Ca is called and causes?
Hypocalcemia and breathing stops
Bone serves as what to prevent sudden changes in Ca levels
A buffer
What is the main reservoir for Ca ions
Bone tissue
Blood levels are regulated very tightly by?
The endocrine system
How do phosophate levels tend to move in relation to blood calcium levels
Opposite direction
Antagonist
Thyrocalcitonin
Bone fractures are classified by four things
Position of the bone after fractures.
Completeness of the break.
Orientation of the bone to the long axis.
If the bone penetrates the skin or not.
Comminuted fracture
Bone fragments into three or more pieces
Spiral fracture
Ragged break occurs when excessive twisting forces are applied to the bone
Depressed fracture
Broken bone portion is pressed inward
Compression fracture
Bone is crushed
Epiphyseal fracture
Epiphysis separates from the diaphysis along the epiphyseal plate
Greenstick fracture
Bone breaks incompletely, much in the way a green twig breaks. Only one side of the shaft breaks the other bends.
Any break in the bone
Fracture
Surgical repair of a fracture
Closed reduction
Open reduction
Closed reduction
No incision during surgery
Open reduction
Incision during surgery
Stages of healing in a bone fracture
- Hematoma forms
- Fibrocartilaginous callus forms
- Bony callus forms
- Bone remodeling occurs
Hematoma formation
Stage one, healing a bone fracture. Torn blood vessels hemorrhage. A mass of clotted blood forms. Site becomes swollen, painful and inflamed. Cells in area die. Osteoclast breakdown damaged portion.
Fibrocartilaginous callus
Stage two, healing a bone fracture. Soft granulation tissue forms. Fibroblasts secrete collagen. New blood vessels form
Bony callus forms
Stage three healing a bone fracture. Bone callus- fibrocartilaginous callus, spongy bone which forms into hard callus. Bony callus is very similar to scar tissue.
Bone remodeling occurs
Stage 4 bone fracture healing. Replacing spongy bone with compact bone where.m needed.
How can remodeling be accelerated.
Through electrical stimuli increase osteoblast activity
Rickets
Caused by insufficient calcium in the diet or by vitamin D deficiency. Bones are softened or weakened.
Osteoporosis
Group of disease in which bone resorption outpaces bone deposit. Increase osteoclastic activity.
Osteoporosis occurs mostly in
Postmenapausal skinny white women
What bone is the most vulnerable to osteoporosis
Spongy bone
Osteoporosis treatment
Calcium and vitamin d supplements. Increased weight bearing exercise. Hormone replacement therapy.
