What are found between C2-S1?
Discs - intervertebral discs that serve as shock absorbers foe the spine.
Explain a nerniation(when there is a herniation or bulged discs)....
The spinal nerves exiting the spinal cord can become impinged and inflammed; if this occurs in the L5-S1 area sciatica occurs (because it's the sciatic nerve) & pain can travel from lower back down to foot...
What occurs with in the mastoid process?
Sternocleidomastoid muscle inserts on them, flexes head if both sides contract and rotates head if one side contracts.
8 Carpul bones
1)Scaphoid 2)Lunate 3)Triquetral 4)Pisiform 5)Trapezium 6)Trapizoid 7)Capitate 8)Hamate
5 functions of the skeleton?
1)Supports the body 2)Protects soft body parts 3)Produces blood cells 4)Stores minerals and fats 5)Along with the muscles permits flexible body movement.
What is lined in the medullary cavity, and filoled with what?
lined with thin vascular memrane(the endosteum) and filled with yellow bone marrow, that stores fat..
What are the epiphyses composed of?
largely of spongy bone that contains red bone marrow, where blood cells are made.
The epiphyses are coated with a thin layer of hyaline cartilage, called?
Articular cartilage (because it occurs at a joint)
how many bones are in a skeleton?
a newborn has nearly 300, some of which fuse together as a child grows. The human skeleton has approximately 206 bones, numbers vary between individuals..Some people have extra that help to fuse skull bones together(called wormian bones)...Others may have additional small bones in the ankles and feet....
Except for the articular cartilage on its ends, a long bone is completely covered by a layer of fibrous connective tissue called?
other branches of blood vessels can be found with in the________, with in the bone tissue?
In a cross section of an osteon, bone cells called ________ lie in a lacunae, tiny chambers arranged in concentric circles around a central canal.
_____ nearest the center of an osteon exchange nutrients and waste with the blood vessels in the central canal.These cells then pass on nutrients and collect wastes from the other cells via gap junction..
Although spongy bone is lighter than compact bone, spongy bone is still ____________
designed for strength
The spaces of spongy bone are often filled with_________, a specialized tissue that produces all types of blood cells.
red bone marrow
_________ is not as strong as bone, but it is more flexible. Its matrix is gel-like and contains many collagenous and elastic fibers.
_________ has no nerves making it well suited for padding joints where the stresses of movement are intense.
________ also has no blood vessels and relies on neighboring tissues for nutrients and waste exchange. This makes it slow to heal.
Explain hyaline cartilage?
Firm and somewhat flexible.matrix appears uniform and glassy, but actually it contains a generous supply of collagen fibers. Hyaline cartilage is found at the end of long bones, in the nose, at the end of ribs,and in the larynx and trachea..
Stronger than hyaline catilage because the matrix contains wide rows of thick, collagen fibers. Fibrocartilage is able to withstand both tension and pressure and is found where support isf prime importance-in the disks located between the vertebrae and also in the cartilage of the knee.
Explain elastic carilage
More flexible than hyaline cartilage because the matrix contains mostly elastin fibers.This type of cartilage is found in the ear flaps and the epiglottis
_________ contains rows of cells called fibroblasts seperated by bundles of collagenous fibers. This tissue makes up ligaments and tendons.
fibrous connective tissue
In a sense bones can grow throughout a lifetime because they are able to respond to stress by changing size, shape and strength, this process is called
What different types of cell are involved in bone growth, remodeling, and repair?
1)osteoblasts 2)osteocytes 3)osteoclasts
bone forming cells. They secrete the organic matrix of bone and promote the deposition of calcium and salts into the matrix
bone absorbing cells. They breakdown bone and assist in returning calcium and phosphate to the blood
throughout life _______are removing the matrix of bone,and___________ are building it up. When_______are surrounded by calcified matrix, they become the __________within lucanae.
osteoclasts, osteoblasts, osteoblasts,osteocytes
describe intramembranous ossification?
Flat bones, such as the bones of the skull are examples of intramembranous ossification, in this way bones develope between sheets of fibrous connective tissue.Here cells derived from connective tissue cells become osteoblasts located in ossification centers.The osteoblasts secrete the organic matrix of bone.
Describe endochondral ossification?
Most of the bones of the human skeleton are formed by endochondral ossification. During which bone replaces the cartilaginous models of the bone . Gradually the cartilage is replaced by the calcified bone matrixthat makes these bones capable of bearing weight.* inside bone formation spreads from the center to the ends, and this accounts for the term used for this type of ossification..(Endochondral literally means"within cartilage")...the long bone such as the tibia is an example of this ossification....
Explain cartilage model
In the embryo chondrocytes lay down hyaline cartilage which is shaped like the future bones.As the cartilage models calcify, the chondrocytes die off...
Explian the bone collar
osteoblasts are derived from the newly formed periosteum. Osteoblasts secrete the organic bone matrix,and the matrix undergoes calcification.The result is a bone collar which covers the diaphysis.The bone collar is composed of compact bone.In time the bon e collar thickens
Explain primary ossification center
Blood vessels bring osteoblasts to the interior, and they begin to lay down spongy bone.This region is calleda primary ossification cente rbecause it is the first center for bone formation.
Explain the medullary cavity and secondary ossification sites?
The spongy bone of the diaphysis is absorbed by osteclasts, and the cavity created becomed the medullary cavity. Shortly after birth secondary ossification centers form in the epiphysis. Spongy bone persists in the epiphysis and they contain red bone marrow for quie some time.Cartilage is present at two locations: the epiphyseal(growth) plate and articular cartilage which covers the ends of long bones..
Explain the epiphyseal (growth) plate?
A band of cartilagge called a growth plate remains between the primary ossification center and each secondary center. The limbs keep increasing in length as long as the growth plates are still present.
Name the 4 zones of the epiphyseal plate
1)resting zone-where cartilage remains 2)proliferaing zone-in which chondrocytes are producing new cartilage cells 3)degenerating zone-the cartilage cells are dying off 4)ossification zone-bone is forming.bone formation here causes the length of the bone to increase. the inside layer of articular cartilage also undergoes ossification in the manner described.
_______ are chemical messengers secreted by the endocrine glands and distributed about the body by the blood stream. These also control the activity of the epiphyseal plate
A ______ is a chemical messenger produced by one part of the body, which acts on a different part of the body.
Children can develope what from the lack of vitamin D?
Rickets, a condition marked by bone deformities including bowed long bones.
What directly stimulates growth of the epiphyseal plate, as well as bone growth in general?
Growth Hormone (GH)
what will too much growth hormone during childhood result in?
(prior to epiphyseal fusion)can produce excessive growth and even gigantism.
_______ results from excess GH in adult following epiphyseal fusion.This condition produces excessive growth of bones in the hands and the face.
Adolescents usually experience a dramatic increase in height, called a growth spurt, due to an increased level of? These hormones apparently stimulate osteblast activity.
Rapid growth causes epiphyseal plates to?
Become "paved over" by the faster growing bone tissue, within one or two years of the onset of puberty.
Bone is constantly being?
Broken down by osteoclasts and and reformed by osteblasts in the adult.As much as 18% of bone is recycled each year.
In what disease is new bone generated at a faster-than-normal rate. This rapid remodeling produces bone that's softer and weaker than normal bone and can cause bone pain, deformities and fractures
To illustrate that the ____________ is critical,recall that calcium is required for blood to clot.
blood calcium level
If the ______________is too high, neurons and muscle cells no longer function.
Blood calcium concentration
the _______are the storage sites for calcium, if the blood calcium rises above normal, at least some of the excess is deposited here..
If the ________dips to low calcium is removed from the bones to bring it back up to the normal level..
2 hormones in particular are involved in regulating the blood calcium level
parathyroid hormone (PTH) and Calcitonin
What happens to a particular bone when it is called apon to engage in an activity in which the particular bone will be used?
Enlarge in diameter at the region most affected by the activity.
Increasing the size of the______ prevents the bones from getting to heavy and thick..
Bone repair takes place over a span of several months in a series of 4 steps:
1)Hematoma 2)Fibrocartilaginous callus 3)Bony callus 4)remodeling
What occurs during a hematoma?
After a fracture blood escapes from ruptured blood vesselsand forms a hematoma(mass of clotted blood) in the space between the broken bones..forms within 6 to 8 hours
What occurs during a fibrocartilageinous callus?
Tissue repair begins and a fibrocartliaginous callus fills the space between the ends of the broken bone for about three weeks.
What occurs during a bony callus ?
Osteoblasts produce trabeculae of spongy bone and convert the fibrocartilage callus to a bony callus that joins the broken bones together. This lasts for about three to four months..
What occurs during remolding?
Osteoblasts build new compact bone at the periphery. Osteoclasts absorb the spongy bone, creating a new medullary cavity.
In some ways bone repair parallels the developement of a bone except which steps?
the first step hematoma indicates injury has occured and fibrocartilaginous callus precedes the production of compact bone.
A_________is complete if the bone is broken clear through and incomplete if the bone is not seperated in two parts.
The 206 bones of the skeleton are classified according to whether they occur in the __________or the___________?
axial skeleton and appendicular skeleton
Which lies in the midline of the body and consists of the skull,hyoid bone, vertebral column, and the rib cage.
What is formed by the cranium (braincase) and the facial bones. However, some cranial bones contribute to the face.
In adults what is composed of eight bones fitted tightly together and in newborns certain bones are not completely formed
bones joined by membranous regions. Usually closed by the age of 16 months by the process of intramembranous ossification.
Some of the bones of the cranium contain the sinuses which are?
Air spaces lined by mucous membrane. The sinuses reduce the weight of the skull and give a resonant sound to the voice.
The major bones of the cranium have the same name as the lobes of the brain?
frontal,parietal,occipatal, and temporal..
________extend to the side, and the ______curves to form the base of the skull.
parietal bone, occipital bone
Below the much larger parietal bones, each______has an opening (external auditory canal) that leads to the middle ear
There is a large opening, the __________, through which the spinal cord passes and becomes the brain stem.
The ________ shaped like a bat with outstretched wings, extended across the floor of the cranium from one side to the other.This is the keystone of the cranial bones because all the other bones articulate with it.
the sphenoid completes the sides of the skull and also contributes to forming what?
The orbits(eye sockets)
________which lies in front of the sphenoid also helps form the orbits and the nasal septum
What is the most prominant of the facial bones are the?
mandible, maxillae,zygomatic bones, and the nasal bones.
The__________, or the lower jaw is the only movable portion of the skull,and it also forms the chin
Other bones the __________and__________are a part of the nasal septum, which divides the interior of the noseinto two nasal cavities..
ethmoid and volmer
The ________contains the opening for the nasolacrimal canal, which drains tears from the eyes to the nose.
The ________ and the wings of the _______account for the flattened areas we call the temples.
temporal bone, sphenoid bone
The __________ forms the forehead and has supraorbital ridges, where the eyebrows are located.
__________completes the tip of the nose, and fibrous ____________forms the flared sides of the nose.
cartilage, connective tissue
The___have numerous functions..They assist in the formation of the eye sockets and the nasal cavity.They form the upper jaw and contain sockets for the upper teeth.
The________is the lover jaw with sockets for the lower teeth and the projection we call the chin.
Although the _________is not part of the skull,it is mentioned here because it is part of the axial skeleton.
The __________is attached to the temporal bones by muscles and ligamentsand to larynx by a membrane.
The________anchors the tongue and serves as the site for the attachment of muscles associated with swallowing.Due to the position this bone is not easily fractured in most situations. In cases of suspicious death, this could be a strong sign of manual strangulation..
The_______consists of 33 vertebrae. Normally this column has four curvatures that provide more resilience and strength for an upright posture than a straight column could provide.
2 other well-known abnormal curvatures
1)kyphosis an abnormal posterior curvature that often results in a"hunch-back" 2)An abnormal anterior curvature results in lordosis or "sway-back"
The ___________ is in the center of the column,and the spinal cord passes through this canal
The______________(foramen,a hole or opening)are found on either side of the column.
_______ branch from the spinal cord and travel through the intravertebral foramina to location throughout the body, and function to control skeletal muscle contraction,among other functions.
If a _________is compressed or slips out of position the spinal cord and spinal nerves might be injured.The resukt can be paralasis or even death.
Movement of the atlas permits the"_____" motion of the head.It also allows the head to tilt from side to side...
The second cervical vertebra is called the _____because it allows a degree of rotation,as we shake the head"no"..
How are the thoracic vertebre,ribs,and sternum joined to form the rib cage?
A) the thoracic vertebrae articulate with one another and also with the ribs at articular facets.A thoracic vertebra has two facets for articulation with a rib;one is on the body and the other is on the transverse process, B) The rib cage consists of the 12 thoracic vertebra,the 12 pairs of ribs,the costal cartilages,and the sternum.The rib cage protects the lungs and the hearts.
The_______have long,thin,spinous processes and articular facets for the attachment of the ribs.
between the vertebrae are_______composed of fibrocartilage that acts as padding.They prevent the vertebrae from grinding together.
The presence of the ______allows the vertebrae to move as we bend forward,backward, and from side to side.
Pain results if a disk presses against the __________, surgical removal of the disk may relieve the pain
spinal cord or spinal nerves