Essentials of Anatomy & Physiology, Chapter 6, Skeletal System
The following are major steps in the process of endochondral ossification:
1. Chondrocytes enlarge and calcify. 2. Blood vessels invade the perichondrium. 3. The perichondrium is converted into periosteum, and the inner layer produces bone. 4. Osteoblasts replace calcified cartilage with spongy bone. 5. Osteoclasts create a marrow cavity.
Pubic angle on the female pelvis
100 degrees
In adults, what percentage of protein and mineral components are removed each year and replaced through remodeling?
18%
Intramembranous ossification is usually complete by _______ years of age, whereas endochondral ossification is usually complete by ________ years of age.
2 years and 25 years
Trabeculae
An irregular network of thin plates of bone and fuse to form spongy bone and Red Bone marrow sits atop trabeculae
Condylar joints
Angular motion in two planes Occur where an oval surface nests with a depression on the other bone Example: is the joint between the radius and the proximal carpal bones
Osteopenia
Inadequate ossification that naturally occurs as part of the aging process
Diarthroses, a freely movable joint
Includes the synovial joints, the articular cartilages, and the joint capsule
Extension, an angular movement
Increases the angle between two bones example is straightening your arm out
Function of calcitriol
Increases the level of calcium in the body by increasing the uptake of calcium in the gut. and Stimulates the absorption of phosphate ions in the digestive tract
Periosteum (Histology)
Intermingles with the fibers of the tendons. and Has two layers: A fibrous outer layer and a cellular inner layer
Two types of embryonic bone formation
Intramembranous ossification and Endochondral ossification
Why doesn't the cartilage become bone in the forth step of endochondral ossification?
New cartilage is formed faster that the osteoblasts can form the new bone.
Are all bones remodeled?
Not every bone is affected. Regional differences occur. For example: Spongy bone of the femur may be replaced 2 to 3 times a year but compact bone remains largely untouched.
Lateral Flextion
Occurs when your vertebral column bends to the side
Cartilage
Often occurs in thin plates and receives nutrients and oxygen by diffusion
Bone is also known as
Osseous Tissue
What is the process where cartilage is replaced by bone?
Ossification
Two types of arthritis
Osteoarthritis and Rheumatoid Arthritis
Responsible for the production of bone matrix.
Osteoblasts
Which cells produce the bone matrix during endochondral ossification?
Osteoblasts
What types of cells are located in the marrow cavity?
Osteoblasts and Ostoclasts
Why does growth of bones finally end?
Osteoblasts outpace the new cartilage formation
Giant bone cells with 50 or more nuclei.
Osteoclasts
Responsible for the breakdown of bone.
Osteoclasts
What cells break down the spongy bone?
Osteoclasts
What occurs during bone remodeling?
Osteoclasts and osteoblasts are still working together even after the epiphyseal plates are closed. Osteons are broken down and rebuild.
What happens during osteoporosis?
Osteoclasts outpace osteoblast activity. The hips, wrists, and vertebrae are more likely to fracture than other bones because of falls and the weight leads to compression of vertebrae
Cells of the bone
Osteocytes
Osteoblasts that have become surrounded by matrix are now
Osteocytes
Central Canal or Haversian Canal
Osteocytes are arranged in concentric layers around the central canal. and Contains one or more blood vessels
Functional unit of compact bone
Osteon or Haversian system
Storage
Valuable mineral reserves of calcium salts. Maintains normal concentrations of calcium and phosphate ions in body fluids. Lipids are stored in yellow marrow for energy reserves.
Important for bone growth and remodeling
Vitamin A
A deficiency of this results in scurvy
Vitamin C
Produced by epidermal cells in response to UV light.
Vitamin D
The kidneys convert this substance into its active form.
Vitamin D
Rickets
Vitamin D deficiancy
How do we get calcitriol?
Vitamin D gets processed in the liver, then goes to the kidney where it gets converted into calcitriol
A deficiency of this results in rickets.
Vitamin D3
Plays a role in the calcification of bone.
Vitamin D3 and Calcitriol
In adults, osteocytes in lacunae maintain the matrix, removing and replacing the surrounding __________.
calcium salts
Tiny, cytoplasmic extensions of osteocytes that form a network throughout bone
canaliculi
The atlas is classified as a ________ vertebra.
cervical
Most common fractured bone
clavicle
The organic component of the matrix, which makes up around one-third of the mass of bone, is dominated by
collagen fibers
organic complex of of bone matrix, 1/3 of mass
collagen fibers
Closed or simple Fracture
completely internal
Articular cartilages
covers the end of long bones because you do not want the bones to contact each other
The bony compartment that supports the brain is called the ________.
cranium
Which of the following types of joints permit angular movement in a single plane (such as occurs between the interphalangeal joints)?
hinge joints
The joints between the phalanges are classified as
hinges
In synovial joint, blood vessels and nerves do not enter
the articular cartilage or the joint cavity
Calcification
the deposit of calcium salts It occurs during ossification
Blood cells are produced in
the marrow of many bones
Ossification
the process of replacing cartilage and other connective tissues with bone.
What is the purpose of osteoclasts breaking down bone matrix?
to regulate calcium phosphate concentrates in body fluids
Spongy bone is made up of a network of bony rods or plates called
trabeculae
Secondary ossification centers are located
in the epiphysis of the bone
What causes osteoporosis?
inactivity and low dietary calcium and is more common in woman and accelerates after menapause due to decline in circulating estrogens
Which maxillary region feature serves as an opening for a major sensory nerve from the face?
infra-orbital foramen
Connects the fibula and tibia
interosseus membrane
Arthritis
is Damage to the articular cartilage and Can be cause by infection, injury, or severe physical stress
Where does ossification occur during intramembranous ossification?
ossification center
What happens during osteopenia?
osteoblast activity slows and osteoclasts activity increases. and woman lose 8 percent of their skeletal mass every decade, men lose 3 percent and Mostly affects epiphyses, vertebrae and jaws and Results in fragile limbs, reduction in height, and loss of teeth.
Immature, active bone cells that produce new bone matrix are termed
osteoblasts
Giant multi-nucleated cells
osteoclasts
Cell surrounded by a hardened matrix and connected via canaliculi
osteocytes
Mature bone cells
osteocytes
The mature bone cells that recycle calcium salts and assist in repair are called __________.
osteocytes
The term for inadequate ossification is ___________.
osteopenia
Cells that undergo mitotic division and differentiate into immature bone cells
osteoprogenitor cells
Immature bone cells
osteoprogenitor cells and osteoblasts
Intramembranous Ossification begins when
osteoprogenitor cells undergo mistosis and differenciate into osteoblasts
Two hormones that work together to elevate calcium levels in the body are ________ and ________.
parathyroid hormone and calcitriol
Glides over anterior surface, between the lateral and medial condyles
patella
Appendicular skeleton
pectorial girdle upper limbs pelvic girdle and lower limbs
In endochondral ossification, the perichondrium that surrounds the hyaline cartilage becomes
periosteum
The connective tissue covering the outer surface of a bone is the
periosteum
The outer layer of bone, composed of dense, irregular, collagenous connective tissue that contains blood vessels and nerves is called
periosteum
Open or compound fracture
projects through skin
In anatomical position, when the palm is moved to face posteriorly, the movement of the wrist and hand is called ________.
pronation
When one crosses his/her arms, which movement is performed by the clavicles?
protraction
The function of synovial fluid is to
provide lubrication
The lumbar curve develops
After birth
Ball-and-socket joints
All combinations of movement - angular, rotational, and circumduction they occur where the end of one bone is a round head that nests within the cup-shaped depression in the other bone they Allow for a wide range of motion Examples are: the hip and shoulder joints.
What is the function of the epiphyseal plates?
Allow for growth to occur lengthwise
Spongy Bone
Also called cancellous bone .... Network of rods or struts. separated by space .... Fills the epiphysis and lines the marrow cavity
Slightly movable joints
Amphiarthroses
Compact bone
Densely packed Forms Diaphysis
Downward movement of the body
Depression
Longest bone in the body
Femur
Skulls of infants and children
Fetal development of skull bones occurs around the developing brain. At birth, the cranial bones are connected with connective tissue called fontanels.
Three types of joints
Fibrous, cartilaginous, and synovial
What is the function of the hyaline cartilage located between the epiphyses and diaphysis?
Responsible for growth in the lengthwise direction
To pull a projected part of the body backward
Retraction
Diaphysis
Shaft of bone Filled with bone marrow (long bone)
Where does bone formation first occur during endochondral ossification?
Shaft surface
Axial skeleton
Skill, thoracic cage, including ribs and sternum and the vertebral column.
Canaliculi
Small channels that run through the matrix. and Connect to the lacunae and blood vessels
Lacunae
Small pockets where bone cells are located
What type of bone is located at the end of long bones?
Spongy Bone
Bone where no osteons are present
Spongy bone
Composed of trabeculae.
Spongy bone
Found where bones are not heavily stressed or where stress arrives from many directions.
Spongy bone
Microscopic spaces are present between the hardened matrix of bone.
Spongy bone
What do osteoblasts form at the primary ossification center?
Spongy bone
When does osteopenia occur?
Starting between the ages of 30 and 40
Five steps of Endochondral Ossification
Step 1 - Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calcifies. Step 2 - Newly derived osteoblasts cover the shaft of the cartilage in a thin layer of bone Step 3 - Blood vessels penetrate the cartilage. New osteoblasts form a primary ossification center. Step 4 - The bone of the shaft thickens, and the cartilage near each epiphyses is replaced by shafts of bone. Step 5 - Blood vessels invade the epiphyses and osteoblasts form a secondary centers of ossification.
Supination
Turning the palm forward
Inversion
Twisting the sole of the foot inward. This is a common way to sprain your ankle
Eversion
Twists the foot outward
Bones encased within the temporal bone that are involved in sound detection are called
auditory ossicles
Embryonic development of bone
begins 6 weeks after fertilization as a cartilaginous formations ..... they are like miniature models of future bones
Which of the following primary functions of the skeletal system applies to the role of bone marrow?
blood cell production
Bones can heal after severe damage, as long as the __________ remains and the cellular components of the periosteum and endosteum survive.
blood supply
Compound fracture
bone projecting through skin
A compound fracture results in
bone projecting through the skin.
Saddle joints
bones fit together like rider in a saddle Angular in two planes, and circumduction They have two bones that each have a concave face on one axis and convex on the other Allowing for circumduction, but not rotation Example is: twiddling your thumbs
a thin fibrous cartilage between the surfaces of some joints, like the knee.
meniscus
Bone matrix hardens after the addition of these
mineral salts
Abduction
moves a limb away from the body example is swinging your arms to the side or separating the fingers
Which cell populations are particularly sensitive to changes in calcium ion concentration?
neurons and muscle cells
Pott's Fracture
occurs at the ankle and affects bones of the leg
The point of the elbow is called the
olecranon
The special movement of the thumb that allows it to grasp an object and hold onto it is called
opposition
Immovable joints
synarthrosis
The term for a functionally immovable joint is
synarthrosis
When does the bony skeleton begin to form?
6 weeks after fertilization
When does the bony skeleton start to form?
6 weeks after fertilization
Osteoprogenitor
A stem cell that can undergo mitotic division and They differentiates into an osteoblast. and are located in the inner cellular layer of the periosteum, the endosteum and lining osteonic canals.
Depression
A structure moves in an inferior direction example is opening your mouth
Elevation
A structure that moves in a superior direction example is closing your mouth
Calcium Reserve
A typical human body contains 2.2 to 4.4 pounds of calcium. Nintey-nine percent is stored in skeleton and Balance calcium in the body and essential for many physiological mechanisms.
Meniscus
Additional padding in synovial joints and acts like shock absorbers and is found in the knee
Movement away from the midline of the body
Abduction
Movement to the midline of the body
Adduction
What covers the ends of the epiphyses?
Articular Cartilage
Bone that allows for "nodding yes"
Atlas
Allows for rotation "shaking your head no"
Axis
Intramembranous Ossification
Bone develops within sheets of connective tissue and Results in the formation of flat bones of the skull including frontal, parietal, occipital, temporal bones also includes the clavicles and the mandible
The inorganic, structural material of bone
Bone matrix
Colles fracture
Break in the distal portion of the radius
What is the process called where deposits of Calcium are laid down?
Calcification
What causes the chondrocytes to die during endochondral ossification?
Calcified matrix slows the diffusion of nutrients
Plays a role in the absorption of calcium and phosphate ions from the intestinal tract.
Calcitriol
Hormones that raise calcium levels in body fluids
Calcitriol and parathyroid
What is calcitriol?
Calcitriol is the hormonally active metabolite of Vitamin D
Bones are largely composed of
Calcium Phosphate - A salt deposited into the matrix and accounts for 2/3 of the bone weight. Remaining 1/3 is collagen fibers.
The most important mineral required for bone growth?
Calcium salts
Synarthrosis or immovable joints
Can be fibrous or cartilaginous examples are Sutures of the skull interlocked with dense connective tissue and Gomphoses, a ligament binding each tooth in the socket and Synchondrosis, a rigid cartilaginous connection. For example between the first pair of ribs and the sternum
Transports nutrients and respiratory gasses from nearby blood vessels to neighboring osteocytes.
Canaliculi
What is the skeleton made of initially
Cartilage
What is the skeleton made of initially?
Cartilage
Haversian canal
Central canal that contains one or more blood cells
Which of the following curves helps a baby hold it's head up?
Cervical Curve
Appositional growth of cartilage
Chondroblasts in the perichondruim lay down new matrix
Endochondral ossification starts with the
Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calcifies.
Forms the external layer of all bones; it may be a thin or thick layer.
Compact bone
Important for protection and support of the body and functions to withstand forces applied at either end of a bone
Compact bone
Osteons are the function units of this type of bone.
Compact bone
What type of bone comprises the shaft of a long bone?
Compact bone
Bone
Contains an abundant intercellular matrix, and has widely dispersed cells
Characteristics of compact done
Covers all bone surfaces except for articular surfaces. And Can tolerate a lot of stress applied to either end of a long bone. (Limb bones) And Cannot tolerate moderate stress applied to the side of the shaft.
Secondary curves of the spine
Develop several months after birth and project anteriorly and include the cervical curve, which keeps the head up and the lumbar curve which develops with the ability to stand
What is the shaft of long bones called?
Diaphysis
Freely movable joints
Diarthroses
Why are astronauts concerned about their bones?
Due to the lack of gravity there isn't any stress put on their bones. Degeneration occurs even after a brief period of inactivity. After a few weeks an unstressed leg can lose up to a third of it's bone mass. This is also a concern when people have to use crutches after an injury.
Dorsiflexion
Elevates the sole at the ankle. Example is putting the heel down and toes up
Upward movement of the body
Elevation
What is the lining of the marrow cavity called?
Endosteum, the cellular lining of the medullary cavity.
Epiphysis
Ends of long bone House red bone marrow Covered with articular cartilage
What cells manufacture Vitamin D after UV exposure?
Epidermal cells
What is located between the epiphyses and diaphysis?
Epiphyseal Plate or Growth Plate
What remains of the epiphyseal cartilage in the adult?
Epiphyseal line
What are the ends of long bones called?
Epiphyses
Physiological mechanisms of calcium in the body
Essential for nerves and muscles and an increase in calcium by 30 percent or more causes neurons and muscles to become unresponsive and a decrease in calcium by 35% or more causes neurons and muscles to become excitable and convulsions may occur
Movement of the soles of the feet outward
Eversion
To increase the angle between articulating bones
Extension
Four steps of intramembranous ossification
First, osteoprogenitor cells undergo mistosis and differenciate into osteoblasts ................... Second, Osteoblasts secrete the matrix of bone and become osteocytes when they are fully surrounded by matrix. Then, mineral salts are added. .................... Third, as bone matrix forms it develops trabeculae that fuse together and form spongy bone. .................... Fourth, The periostium forms on the external surface of the bone and Remodeling of some of the spongy bone produces osteons of compact bone. Some of the spongy one remains in the center.
What bones are formed from intramembranous ossification?
Flat bones of the skull, mandible, and clavicles
Movement of hips and shoulders
Flex by moving forward and extend by moving backward
Fontanelles
Flexible soft spots that allow for easier delivery of the head. They disappear by age 4 and skull growth is finished.
Decrease the angle between articulating bones
Flexion
Fat pads
Found in synovial joints and acts as a cushion
Functions of the Axial skeleton
Framework for support and protection of the brain, spinal cord, and organs of the ventral body cavity. and Provides surface area for attachment of muscles that move the head neck and trunk muscles that perform respiration and muscles that stabilize elements of the appendicular skeleton.
How long does bone formation and growth last?
From 6 weeks after fertilization - the embryo is about .5" long at this time. It lasts until the end of adolescence. Some portions of bone do not stop until the age of 25
Types of synovial joint movement
Gliding, angular movements, rotation, and special movements
Hormones required for normal bone growth?
Growth hormone Sex hormone Thyroid hormone and the Calcium balancing hormones
Synovial joint, a freely movable joint
Has a wide range of motion and is usually found at the ends of long bones
A vertical canal that transports blood vessels and nerves into bone
Haversian canal
Blood Cell Production
Hematopoiesis Red blood cells, White blood cells, and platelets are produced in red bone marrow.
skull
Houses brain and sense organs for sight, smell, taste, and balance. Has 22 bones, 8 are cranial, and 14 are facial Skull bones are joined by tight connections called sutures.
What type of cartilage composes the epiphyseal plate?
Hyaline Cartilage
The only bone that does not articulate with another bone.
Hyoid
Define and describe the process of intramembranous ossification.
Intramembranous ossification is the process by which bone develops within sheets or membranes of connective tissue. This process begins when osteoblasts differentiate within embryonic or fetal fibrous connective tissue. This type of ossification normally occurs in the deeper layers of the dermis. The osteoblasts differentiate from connective tissue stem cells after the organic components of the matrix --- secreted by the stem cells-- and become calcified.
Movement of the soles of the feet inward
Inversion
Vitamin D3
Involved in calcium metabolism and Needed to prevent diseases such as Rickets. Rickets is a Vitamin D3 deficiency which softens the bones. Children with rickets have bending of the bones.
Rotational joint movements
Involves turning around the longitudinal axis of the body or limb. Example of this is turning your head from side to side.
Osteoarthritis
Is a degenerative arthritis that results from wear and tear or can be genetic and Affects older people usually 60 years old and up
Syndesmosis, a slightly movable joint
Is a fibrous joint that is connected by a ligament and found between the tibia and fibula
Rheumatoid Arthritis
Is an inflammatory condition Some cases are due to autoimmune attack on the joints
Calcitonin
Is from the thyroid gland lowers calcium levels in body by putting it back into bone.
Symphysis, a slightly movable joint
It is cartilaginous, connected by a fibrocartilage pad and found between the right and left halves of the pelvis also found between adjacent vertebrae
Why is regular exercise important for the bones?
It is the key to maintaining normal bone structure and strength by promoting remodeling. Making bones thicker and stronger.
Ligaments
Join bone to bone
Joint capsule
Joint is surrounded with a fibrous joint capsule The inner surfaces are lined with the synovial membrane and filled with synovial fluid to reduce friction
Open areas that surround osteocytes
Lacunae
Spongy bone
Lamella forms rods or plates called trabeculae. And. Has no osteons. Is Found in the epiphysis of long bones where the stress is handled by joints. Is much lighter than compact bone reducing the amount of work for the muscle.
Concentric layers of calcified matrix
Lamellae
Osteoclasts
Large, multinucleated cells that secrete acid and enzymes to break down the matrix
Endosteum
Lines the marrow cavity in spongy bone
Osteocytes (bone cells) are located where in bone?
Located in the lacunae. and Found between the sheets of matrix called lamellae
Osteoporosis
Loss of bone mass that impairs normal function and can lead to more fractures.
Which of the following curves as the child begins to stand or walk?
Lumbar Curve
Osteon
Made of concentric circles of lamella. And Surrounds a central canal the contains blood vessels.
Why are bones remodeled?
Maintains the integrity of the skeletal system. Bones not regularly stressed become thin and brittle.
Movement
Many bones function as levers that change the magnitude and direction of the forces generated by skeletal muscles.
Protection
Many soft tissues and organs are surrounded by the skeleton. Examples are: The ribs protect the heart and lungs. The skull encloses the brain. The vertebrae shields the spinal cord. The pelvis cradles digestive and reproductive organs.
What is the open area surrounded by diaphysis called?
Marrow Cavity
What do osteoclasts create during endochondral ossification?
Marrow cavity
Bone tissue
Matrix consists of extracellular protein fibers and a ground substance
Osteocyte
Mature bone cells, The main bone cells in bone tissue
Bone matrix hardens after the addition of these.
Mineral Salts
Endochondral Ossification
Most bones are formed this way ............. The cartilage develops first .................. They are formed through ossification of existing hyaline cartilage ..................
Protraction
Move part of the body anteriorly such as grasping your upper lip with your lower teeth. Retraction is the opposite of this.
Adduction
Moves limbs toward the body example is bringing your fingers back together
Circumduction
Moves the limbs in a loop Think sparklers on the forth of July
Opposition
Moving the thumb toward the palm or fingertips to grasp
Lamellae
Narrow sheets of calcified matrix Lacunae are found in Lamellae
How do osteoporosis and osteopenia differ?
Osteoporosis is a condition that produces a reduction in bone mass great enough to compromise normal function. The difference between the "normal" osteopenia or inadequate ossification of aging and the clinical condition of osteoporosis is a matter of degree
Stem cells that have the ability to become osteoblasts or chondroblasts
Osteoprogenitor Cells
Periosteum
Outer covering of bone. and Supports and protects
What roles do the hormones, parathyroid hormone (PTH), calcitonin, and calcitriol, play in maintaining calcium homeostasis?
PTH - from the parathyroid glands and calcitriol -- from the kidneys work together to elevate calcium levels in body fluids. Their actions are opposed by calcitonin, a thyroid gland hormone that depresses calcium levels in body fluids.
Parathyroid hormone
PTH from the parathyroid gland and calcitriol from kidneys work together to elevate calcium levels in body fluids.
PTH is secreted from the ________, whereas calcitonin is secreted from the _________.
PTH is from the parathyroid gland and Calcitonin is from the thyroid gland
What is the function of articular cartilage on the end of long bones?
Pads the surfaces between two bones in the joint.
Hormones that raise calcium in blood
Parathyroid hormone and calcitriol
What covers the outer surface of the diaphysis?
Periosteum, a tough connective tissue sheet that functions to support and protect the bone.
Hinge joints
Permit angular movement in one plane are Like opening and closing a door Examples: joints at the elbow, knee and ankle
Pivot joints
Permit rotation only, in a single plane an Example: is the joint between the atlas and axis Like turning the head or supinating and pronating the palm
Osteoblasts
Produce new bone through ossification and promote deposition of calcium salts into the matrix
What is the function of red marrow?
Production of red and white blood cells
Primary curves of the spine
Project posterior and include the thoracic and sacral curves.
Movement of the mandible or shoulder girdle forward
Protraction
Perforating canal
Provides passageways for blood vessels in the central canal to be linked to other vessels
Vitamin A and Vitamin C
Provides support for osteoblasts and Vitamin C deficiency can cause scurvy. Scurvy is a reduction of osteoblasts that leads to brittle bones.
Support
Provides support to the entire body. Individual bones or groups of bones provide framework for the attachment of soft tissues and organs.
Synovial fluid
Reduces friction in a synovial joint
Four steps of fracture repair
Step 1) Fractures result in broken blood vessels that cause a blood clot called fracture hematoma. The blood clot closes off blood supply and Kills osteocytes and Results in dead bone on either side of the fracture
Four steps of fracture repair
Step 2) Cells of periosteum develop into an external callus and cells of the endosteum collect at the fracture and form an internal callus
Four steps of fracture repair
Step 3) Osteoblasts replace new cartilage with spongy bone
Four steps of fracture repair
Step 4) Spongy bone is replace by compact bone. It will leave a slightly thicker spot at the fracture site.
Growth hormone (GH) is released by the cerebellum in small amounts while sleeping. What does it do?
Stimulates bone and skeletal muscle growth and Binds to chondrocytes and stimulates mitosis
Functions of the Skeletal Sytem
Support Storage Hematopoiesis - Blood cell production Protection Movement
Amphiarthroses or slightly movable joints
Symphysis and Syndesmosis
Appositional growth
The enlargement of bones in diameter, occurs at they grow longer and Periosteum cells develop into osteoblasts and produce more matrix on the outer surface of the bone and Osteoclasts erode the inner surface enlarging the marrow cavity
Bursa
The packet of connective tissue containing synovial fluid. It also acts to reduce friction and absorb shock
Pronation
The palm is facing the front and is then rotated to the back
What causes growth spurts occur during puberty?
The release of sex hormones such as testosterone and estrogen stimulates an increase of osteoblasts activity
Ostolysis
The releasing of material from broken down bone matrix or reabsorbtion
Bone remodeling
The skeleton is recycled and replaced. The turnover rate for bone in young adults is almost one-fifth of the skeleton each year.
Discuss the importance of vitamin D3 in normal calcium metabolism.
Vitamin D3 can be obtained from dietary supplements or manufactured by epidermal cells exposed to UV radiation. After it has been processed in the liver, the kidneys convert a derivative of this vitamin into calcitriol, a hormone that stimulates the absorption of calcium and phosphate ions in the digestive tract.
Synovial movement of gliding
When two opposing surfaces slide past each other and movement in any direction, but it is slight examples are carpals and tarsal bones
Depressions, grooves, and openings
Where blood vessels and nerves pass through the bone.
projections
Where tendons and ligaments attach and where bones articulate. Meaning the joining of two bones.
An immovable joint is known as?
a synarthrosis
Slightly movable joints
amphiarthrosis
The presence of ________ strongly indicates that the long bone is still growing.
an epiphyseal plate
Flexion, an angular movement
decreases the angle between two bones example is bending your arm or bending at the waist
The hormone calcitonin functions to
depress calcium levels in body fluids
Freely movable joints
diarthrosis
The skeletal system is largely under the physiological control of the ____________.
endocrine system
The surface of the medullary cavity of long bones is lined with a connective tissue membrane called
endosteum
The presence of an epiphyseal line indicates
epiphyseal growth has ended
Hyperextension
extension beyond anatomical position such as looking up at the sky also think whiplash
A small, flattened articular surface is a
facet
Movement in the anterior-posterior plane that decreases the angle between articulating bones is which movement?
flexion
The general term for a depression in a bone is
fossa
Which structural feature of the scapula articulates with the humerus?
glenoid cavity or glenoid fossa
Plantar Flexion
is to point the toes common position for ballet dancers
A point where two joints meet
joint
The bones of the limbs are classified as
long bones
Hormone calcitonin functions to
lower calcium levels in body fluids
Considering the bony structure of the palate, a cleft palate is a malformation of which bone?
maxillary
Fibrous cartilage discs that act as shock absorbers in joints are called ________.
menisci
Reposition
returns the thumb form opposition
Which bone acts like a bridge that unites the cranial and facial bones?
sphenoid bone
The vertebral arches contribute structurally to surround and protect the
spinal cord
Skull bones are joined by tight connections called
sutures
Amphiarthrotic joints that are connected by a fibrocartilaginous pad are called __________.
symphyses
The typical vertebra's ________, projecting laterally or dorsolaterally from the pedicles, serves as a site for muscle attachment.
transverse process
Ribs that are connected to the sternum by separate cartilaginous extensions are called ________ ribs.
true
Rickets is a condition marked by a softening and bending of bones that occurs in growing children, as a result of ________ deficiency.
vitamin D3
The most inferior portion of the sternum is called the
xiphoid process