Anatomy & Physiology
Skeletal System
I.
Functions of the Skeletal System
A. ____________________ the body
B. ____________________ of vital organs
C. Provide ________________________for movement
D. ____________________ storage (calcium & phosphate)
E. ____________________ cell formation
II.
Bone Structure
A. Microscopic anatomy
1. _________________________________ – complex series of canals &
_________________________________ that run through the dense bone matrix and
supply _________________________ to the osteocytes (bone cells)
a. ___________________ (Haversian canal) – elongated cylinder that runs
_____________________to the long axis of the bone. Arteries, veins, & nerves run
through the osteons.
b. ______________________ – rings or layers of bone matrix.
c. _______________________– space in the bony matrix where the osteocyte
resides.
d. ______________________ – small channels that connect lacuna (and neighboring
osteocytes) to each other and provide a means for passing nutrients & wastes
between cells.
e. Matrix composition – ________________________ & ________________________
2. Types of bone tissue
a. _________________________ bone – relatively solid part of bone. Make bones
hard & strong. Usually found on the _________________________________ of the
bone.
b. _________________________ bone – network of bony struts that form a
“honeycomb” of flat bony pieces. Allows bones to be lightweight. Found on the
_______________________ of the bones.
1) ____________________________ – interlocking plates or struts.
2) ________________________ (red or yellow) - fills the spaces between the
trabeculae.
B. Gross anatomy
1. __________________________ – expanded ends. Compact bone on the exterior.
Spongy bone fills the interior. The joint surface of each epiphysis is covered with a
layer of ___________________________________________.
2. __________________________ – shaft of the bone. Composed of a thick layer of
compact bone.
a. _______________________________________ – hollow shaft of the diaphysis. It
is filled with marrow.
b. _____________________ on a bone is normally applied along the axis of the
diaphysis.
3. _______________________ – tissue that fills the spaces of spongy bone & medullary
canals.
a. ___________ – ____________________________ tissue (blood cell forming).
1) found in __________ the spongy bone & medullary canals of
___________________
2) found in the ____________ bones of ____________________.
b. __________________ – fat. Found in the medullary canals of the
_________________ bones of _____________________.
4. _________________________ cartilage – ______________________cartilage that
covers the ends of bones & provides a smooth articulating surface between the two
bones of a joint.
5. __________________________ – fibrous, tough, vascular layer that covers the outer
surface of a bone.
a. Actively involved in bone ___________________ & _____________________.
b. Allows attachment surface for tendons & ligaments.
6. _________________________ – covers the internal bone surface of the medullary
canal. Similar to periosteum.
C. Bone Development (__________________________)
1.
Formation of bones from the hardening of _______________________ cartilage
models of the future bones.
2.
____________________________ the process of bone formation. Has 2
phases.
a. _____________________ ossification
1) Begins at the center of the ___________________ of the hyaline “bone” around
the _______ month of development.
2) A bone collar forms around the diaphysis of the hyaline model.
3) Hyaline bone becomes ossified with ________________________.
4) Ossification proceeds from the center of the diaphysis toward the two epiphyses.
5) The hyaline bone continues to grow & elongate, thus preventing the ossification
from reaching the epiphyses for __________________ years.
b. __________________________ ossification
1) Around ___________________, both of the epiphyses begin calcifying the
cartilage from the inside outward.
2) Primary & secondary ossification usually finishes around _______ years of age.
3) The junction of P & S ossification forms a gagged line called the
_______________________________________.
c. Hyaline cartilage remains at the ends of the bones as
____________________________ cartilage.
D. Bone Remodeling
1. The continual breaking down of calcium salts by _____________________________
and the relaying of calcium salts by _________________________________.
2. We recycle _____% to _____% of our bones every week to repair and strengthen the
bones and to maintain calcium balance in our blood.
E. Hormonal effect on bone growth & remodeling
1. ____________________ gland – secretes the hormone ______________________,
which stimulates _________________________ & decreases blood calcium levels.
Makes bones stronger.
2. __________________________ – secretes the hormone _______________________,
which stimulates _________________________ activity & increases blood calcium
levels. This makes the bones weaker.
3. Anterior Pituitary – secretes ______________________________, which stimulates
bone growth & elongation.
F. Classification of bones
1. ____________________ – almost all bones of appendages
2. ____________________ – carpals & tarsals
3. ____________________ – ribs, scapula, cranial bones, sternum
4. ____________________ – vertebrae, coxal, facial
5. ____________________ – small bones with no bony attachments (E.g. patella)
III.
Skeletal System Disorders
A. Bone Fractures
1. _____________________ – bone breaks cleanly, but does not penetrate the skin.
2. _____________________ – broken ends of the bone penetrate through the skin.
3. _____________________ – bone broken into many pieces & fragments.
4. _____________________ – bone is crushed inward.
5. _____________________ – broken bone ends forced into each other.
6. _____________________ – ragged break occurs when excessive twisting is applied to
the bone.
7. __________________________ – bone breaks incompletely much like a green twig.
B. Skeletal Disorders
1. _________________________ – decreased osteoblast activity due to the body’s
inability to absorb calcium. Usually seen in the __________________ although
exercise & proper calcium intake in middle years can delay the onset of this disorder.
Factors that speed up the effects of osteoporosis are:
_____________________________________________________________________
_______________________________________________________________. More
often seen in ________________________.
2. ___________________ – Vit. _____ deficiency causes soft bones due to a reduction in
calcium. Causes __________________ legs and other skeletal disformities.
3. ___________________ – excessive GH secretion ___________________closure of
the epiphyseal plates. Results in a
_________________________________________.
4. ___________________ – excessive GH secretion ___________________ closure of
the epiphyseal plates. Results in
___________________________________________.
IV.
Joints / Articulations
A. General info
1. Joints are __________________________________________________________.
2. Three functional types: ______movable (synarthrosis); ______________________
moveable (amphiarthrosis);
_____________________ moveable (diarthrosis)
B. Synarthroses (________movable joints)
1. Occur between bones that come in close contact with each other.
2. A thin layer of fibrous connective tissue separates the bones.
3. Examples are:
C. Amphiarthroses (____________________ moveable joints)
1. Joints are limited to a few degrees of movement.
2. Occur in areas where the bones are connected by disks of fibrocartilage or by thick
ligaments.
3. Examples are:
D. Diarthroses (______________________ moveable joints)
1. Joints are able to move in ________________ directions and with ______________
degrees of movement.
2. Bones have a layer of ___________________ (hyaline) cartilage at the ends & are held
together by ligaments.
3. Articulating bones are separated by a fluid filled joint cavity – the
___________________ cavity – that allows for substantial freedom of movement.
4. The articular capsule is a double layers capsule that surrounds the ends of the bones
with a protective fibrous layer and a inner synovial membrane.
5. _____________________ fluid is a slippery lubricant that fills the synovial joint.
6. Synovial joints that bear greater weight (E.g. knee) contain
__________________________ pads & fluid filled sacs (__________________) also
help to pad the joints from extrinsic wear.
E. Types of freely moveable joints
1. _______________________________ – most freely moveable type. Able to move in 3
planes. Ex: ___________________________________________
2. ________________________________ - nearly flat surfaces are able to glide over one
another in 2 planes. Ex: ________________________________________.
3. _________________________ - oval surface of one bone fits on the complementary
concave surface of the other bone.
Ex:_______________________________________________.
4. __________________________ – convex surface of one bone fits into the concave
surface of the other bone thus limiting them to 1 plane of movement.
Ex: _____________________________________________________.
5. __________________________ – cylindrical surface of one bone rotates within a ring
formed by the other bone. Movement limited to rotation.
Ex: _____________________________________________.
6. __________________________ – cones with both concave & convex shaped articular
surfaces. Allows for a wide variety of movements. Only one example –
V.
Joint Disorders
A. _________________________ – chronic joint disorder due to the wearing down of the
articular cartilage due to age. Often called “_________________________” arthritis.
Accounts for _______% of all arthritis.
B. ________________________ arthritis – autoimmune disease whereby the immune
system attacks its own tissues and destroys the articular cartilage. Onset usually begins in
the _______’s and can eventually lead to disfigurement and crippling.
C. _____________________________ – the build up of ___________________ crystals in
the joints. The crystals are painful and can wear away at the articular cartilage.
D. ________________________ – inflammation of a bursa due to injury or excessive friction
in a joint.
E. ________________________ – inflammation of the tendon sheaths of a joint due to
overuse.