Skeletal System Flashcards
Skeletal System Function
Support
Protection
Movement
Storage
Blood cell production (hematopoiesis)
Rigid strong bones – for bearing weight and is the major supporting tissue of the body. Cartilage – provides a firm yet flexible support within certain structures (ex. nose and
external ears).
Ligaments – are strong bands of fibrous connective tissue that attach to bone and hold them together.
Support
for bearing weight and is the major supporting tissue of the body.
Rigid strong bones
– are strong bands of fibrous connective tissue that attach to bone and hold them together.
Ligaments
The hardness of the bone contributes to its ability to protect the vital organs of the body from injury (ex.cranial bones protect the brain).
Protection
Skeletal muscles attach to bones by tendons. When muscles contract, they pull on bones and together they produce movement.
Movement
When muscles —- , they pull on bones and together they produce movement.
contract
Fat is stored in the internal cavities of bones.
Stores several minerals especially calcium and phosphorus.
Important in maintaining homeostasis of minerals in the blood with minerals stored in the
bone are released in response to body’s demand.
Storage
is stored in the internal cavities of bones.
Fat
Many bones contain cavities filled with bone marrow that gives rise to blood cells and platelets.
Blood cell production (hematopoiesis)
Many bones contain cavities filled with —- that gives rise to blood cells and platelets.
bone marrow
Skeletal System Functions
Protects internal organs
Stores and releases fat
Produces blood cells
Stores and releases minerals
Facilitates movement
Support the body
The study of bone structure and treatment of bone disorder.
OSTEOLOGY
It refers to the formation of bone by osteoblast.
BONE OSSIFICATION (OSTEOGENESIS)
BONE OSSIFICATION
(OSTEOGENESIS)
TWO TYPES BONE OSSIFICATION (OSTEOGENESIS)
Intramembranous Ossification
Endochondral Ossification
A process of bone development from fibrous membrane.
It is involved in the formation of the flat bones of the skull, the mandible and clavicles.
Intramembranous Ossification
Bones involved in Intramembranous Ossification
flat bones of the skull, the mandible and clavicles.
A process of bone development from hyaline cartilage.
All of the bones of the body, except for the flat bones of the skull, mandible and clavicles
are formed.
Endochondral Ossification
is secreted within the fibrous membrane.
Bone matrix (osteoid)
• begin to secrete osteold, which is mineralized within a few days.
Osteoblasts
• Trapped osteoblasts become —.
osteocytes
An — appears in the fibrous connective tissue membrane.
• Selected centraily located mesenchymal cells cluster and differentiate into osteoblasts, forming an —-.
ossification center
Accumulating osteoid is laid down between embryonic blood vessels, which form a random network. The result is a —-.
network (instead of lamellae) of trabeculae
• Vascularized mesenchyme condenses on the external face of the —- and becomes the ——.
woven bone, periosteum
just deep to the periosteum thicken, forming a woven bone collar that is later replaced with mature lamellar bone.
Trabeculae
• consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow.
Spongy bone (diploë),
Bone growth occur by:
Appositional Growth
Endochondral Growth
It refers to the formation of new bone on the surface of existing bone.
Appositional Growth
results as osteoblasts deposit new bone matrix on the surface of bones between the periosteum and the existing bone matrix.
Responsible for the increase in width or diameter of long bones and most growth of other
bones.
Appositional growth
Osteoblasts beneath the periosteum secrete bone matrix, forming ridges that follow the course of periosteal blood vessels.
As the bony ridges enlarge and meet, the groove containing the blood vessel becomes a tunnel.
The periosteum lining the tunnel is transformed into an endosteum and the osteoblasts just deep to the tunnel endosteum secrete bone matrix, narrowing the canal.
As the osteoblasts beneath the endosteum form new lamellae, a new osteon is created.
Meanwhile new circumferential lamellae are elaborated beneath the periosteum and the process is repeated, continuing to enlarge bone diameter.
Appositional Growth
It refers to the growth of cartilage in the epiphyseal plate and its eventual replacement by bone.
Endochondral Growth
Responsible for the increase in the length of the bone.
Bones continue to grow in length until early childhood, the rate of growth is controlled by
hormones.
Endochondral Growth
Bones continue to grow in length until early childhood, the rate of growth is controlled by
hormones
Growth
Bone grows in length because:
1. Cartilage
Grows here
2. Cartilage replaced by bone here
3. Cartilage grows here
4. Cartilage replaced by bone here
Remodelling
Growing shaft is remodeled by :
1. Bone resorbed here
2. Bone added by appositional growth here
3. Bone resorbed here
Endochondral Growth
It involves the removal of old bone by cells called osteoclast and the deposition of new bone by osteoblast.
It occurs in all bone.
Bone Remodeling
Remodeling is responsible for:
Bone growth
Changes in bone shape
Adjustment of bone to stress
Bone repair
Calcium ion regulation
Bone remodeling involves the removal of old bone by cells called —— and the deposition of new bone by —-.
osteoclast, osteoblast
Bone remodeling Consists of three consecutive phases:
Resorption
Reversal
Formation
– during which osteoclasts digest old bone.
Resorption
when mononuclear cells appear on the bone surface.
Reversal
when osteoblasts lay down new bone until the resorbed bone is completely replaced.
Formation
A process in which a bone repairs itself following a bone fracture.
When a bone is broken, a clot forms in the damaged area.
Callus forms, the zone of tissue repair between the two bone fragments.
Osteoblasts enter the callus and form cancellous bone.
The cancellous bone is slowly remodeled to form compact bone and the repair is complete.
Bone Repair (Healing)
When a bone is broken, a —- forms in the damaged area.
clot
the zone of tissue repair between the two bone fragments.
Callus
Osteoblasts enter the callus and form —-.
cancellous bone
The cancellous bone is slowly remodeled to form —- and the repair is complete.
compact bone
Bone repair (healing)
Hematoma formation
Callus formation
Callus ossification
Bone remodeling
serves as the major storage site for calcium.
Bone
The movement of calcium in and out of bone helps determine.
blood calcium levels
Calcium moves — bone as —- build new bone.
Calcium move — of bone as —- break down bone.
into, osteoblasts
out, osteoclasts
Calcium homeostasis is maintained by —— and ——.
parathyroid hormone, calcitonin
is maintained by parathyroid hormone and calcitonin.
Calcium homeostasis
Osteoclasts break down bone and release calcium into the blood, and osteoblasts remove
calcium from the blood to make bone. PTH regulates blood calcium levels by indirectly stimulating osteoclast activity, resulting in increased calcium release into the blood. Calcitonin plays a minor role in calcium maintenance by inhibiting osteoclast activity.
In the kidneys, PTH increases calcium reabsorption from the urine
In the kidneys, PTH also promotes the formation of active vitamin D, which increases calcium
absorption from the small intestine.
Bone and Calcium Homeostasis
A form of short-limbed dwarfism.
literally means “without cartilage formation”.
the problem is not in forming cartilage but in converting it to bone.
ACHONDROPLASIA
Achondroplasia literally means
“without cartilage formation”.
Also known as brittle bone disease. A genetic disorder that results from a lack of protein collagen producing very brittle bones that are easily fractured.
OSTEOGENESIS IMPERFECTA
OSTEOGENESIS IMPERFECTA Also known as.
brittle bone disease
Bones of children are inadequately mineralized causing softened, weakened bones. Bowed legs and deformities of the pelvis, skull, and rib cage are common.
Caused by insufficient calcium in the diet, or by vitamin D deficiency.
RICKETS
Bones are inadequately mineralized causing softened, weakened bones. Main symptom is pain when weight is put on the affected bone.
Caused by insufficient calcium in the diet, or by vitamin D deficiency.
OSTEOMALACIA
Infection in bone caused by Staphylococcus bacteria.
The bacteria can enter a bone by : the bloodstream, injuries and surgery.
OSTEOMYELITIS
Osteomyelitis caused by
Staphylococcus bacteria.
Group of diseases in which bone reabsorption outpaces bone deposit.
Spongy bone of the spine is most vulnerable.
Occurs most often in postmenopausal women.
Bones become so fragile that sneezing or stepping off a curb can cause fractures.
OSTEOPOROSIS
OSTEOPOROSIS occurs most often in
Postmenopausal women
Lateral curvature of the central part of the spine.
SCOLIOSIS
The condition, scoliosis is brought on by:
- congenitally malformed vertebra
- chronic sciatica
- paralysis of muscles on one side of the backbone
- poor posture
It refers to a break in a bone.
Common types of fractures include simple, compound, compression, comminuted and greenstick
Fracture
Bone breaks into many fragments.
Particularly common in the aged, whose bones are more brittle.
Comminuted
Bone is crushed. (i.e., osteoporotic bones).
Common in porous bones
Compression
Broken bone portion is pressed inward.
Typical of skull fracture.
Depressed
Broken bone ends are forced into each other.
Commonly occurs when one attempts to break a fall with outstretched arms
impacted
Ragged break occurs when excessive twisting forces are applied to a bone.
Common sports fracture.
Spiral
Bone breaks incompletely, much in the way a green adults.
Common in children, whose bones are more flexible than those of
Greenstick
Common types of fractures include
simple
compound
compression
comminuted
greenstick
It literally means “joint inflammation”, however some forms could affect the skin and internal organs.
It is marked by pain, stiffness and swelling of the affected joint. It may include one or several joints.
ARTHRITIS
Arthritis literally means
joint inflammation”
Commonly known as “wear and tear” arthritis
A degenerative joint disease in which the cartilage that covers the ends of the bones in the joint deteriorates.
Symptoms include: pain, restriction of movement, formation of hard nobs.
OSTEOARTHRITIS
Osteoarthritis Commonly known as
“wear and tear” arthritis
An active chronic inflammatory autoimmune disease affecting synovial membrane.
RHEUMATOID ARTHRITIS
RHEUMATOID ARTHRITIS affects?
Synovial membrane
A disease associated with an inborn error of uric acid metabolism.
GOUTY ARTHRITIS
An acute or chronic inflammation of the bursa (a small sac filled with fluid and located at friction points).
BURSITIS
(a small sac filled with fluid and located at friction points).
bursa
