skeletal system

texture of compact and spongy bone

compact- smooth and hard spongy- rough and porous

what is bone stronger than?

concrete

comminuted

multiple bone fragments -high impact trauma

when do bones break?

when under extreme pressure or stress

irregular bone examples

-pelvis -vertebral column

transverse

-piece of broken bone is at a 90 degree angle to the bone axis, -break across the bone direct blow

bone trabeculae.

- bone full of holes -connected to each other by thin rods and plates of bone tissue .

hematoma formation

-Blood vessels that are ruptured during the break swell to form a mass called a hematoma -forms between the broken bones

Fibrocartilage Callus Formation

-New capillaries begin to form into the clotted blood in the damaged area. -Connective tissues cells form a mass of repair tissue called a fibrocartilage callus (contains some cartilage - some bone and collagen fibers and the combined mass closes the gap between the broken bones

Bone Remodeling

-Over the weeks and months to come, the callus is remodeled with the help of osteoclasts and osteoblasts. -The shape of the bones will gradually return to normal and there will eventually be little evidence of the fracture.

Bony Callus Formation

-The fibrocartilage callus is gradually replaced by one made of spongy bone. -This new mass is referred to as the bony callus. -Osteoclasts and osteoblasts move to the area and multiply.

Describe at least two ways bone functions in protection of the human body.

-The skull is a bone that protects the brain. It covers over the brain so that it won't get damaged. Without the skull, the brain will be moving around all the time, disrupting thoughts, and will be much more vulnerable to concussions, hemorrhages, and other severe brain damages. -The ribs protect the lungs and the heart. The ribs keep the lungs in place and also protects it from damage. It also protects the heart from outside damage. -The spine/vertebrae not only serves as a support for the whole body, but it also encases nerves in the spinal column that bring messages to the brain from the peripheral nerves.

cartilage

-articular cartilage coats bones at joints - reduces friction -sturdy connective tissue

long bone examples

-bones of arms and legs -humerus -femur -tibia -radius -unla

spiral

-break curves -rotating force applied to axis of bone when one extremity is planted and the body rotates

compact bone

-cortical bone -forms hard outer layer -strongest and densest form of bone in the body -contains tiny openings for blood vessels and nerves -houses cells that can repair and maintain bone tissue -made of connective tissue

compression

-crack by pressure (spine) weakening of bone

medullary cavity

-cylinder at the center of compact bone -surrounds and protects spongy bone marrow -central cavity of bone tissue -where yellow bone marrow is produced and stored

how long does does bone healing take

-depends on fracture step 1= 1-3 hours after the fracture occurred step 2= 2-3 weeks after injury step 3= 6-12 weeks step 4= can occur for years

oblique

-diagonal break across the bone fall, longer bones affected more often

be able to label picture of a long bone

-epiphysis -diaphysis -articular cartilage -periosteum -compact bone -spongy bone -medullary cavity -red bone marrow -yellow bone marrow

epiphysis

-extended portion of long bone -forms joint -mostly composed of spongy bone -coated with articular cartilage

functions of calcium in the body

-helps blood clot -maintains normal heart rate (the circulatory system would not circulate blood efficiently leaving to a deprivation of oxygen affecting all body systems) -helps action potentials travel down neurons (nervous system needs calcium on order for singles to be sent) -needed for muscle contraction (muscle contraction is facilitated by calcium, without it our muscle can't contract)

how to regulate high levels of calcium

-high levels -detected by parathyroid gland -the thyroid gland secretes more calcitonin -decreases reabsorption of calcium in kidney -stimulates a decrease in osteoclast(no calcium released into the blood) -calcium levels in the blood decrease

x-ray

-imaging technique that allows doctors to view internal injury and diagnose a variety of illnesses. - high-energy form of radiation is passed through the body and projected onto a film. -Hard tissues such as bone absorb the X-rays and appear white. -X-rays pass through softer tissues, such as muscle, and show up in black and gray. -first step in identifying a broken bone

diaphysis

-lengthy portion of long bone

what happens to bones in space?

-less mechanical strain -decreased bone mass -increased calcium (kidney stones) bc of osteoclast activity and decreased osteoblast activity - osteoclast works normally -increase in fracture risk

4 types of bones

-long -short -irregular -flat

spongy bone

-majority of the interior of bones -soft and spongy texture -pourus -cancellous

composition of spongy bone

-network of irregularly shaped bone (osteocytes) -provides framework -spaces in between contain yellow or red bone marrow

what happens at age 35 (and after)

-new bone formation cannot keep up with the destruction of bone -bone mass begins to decrease

composition of compact bone

-osteocytes (known as bone cells) -surrounded by solid intracellular matrix of mineral salts protein fibers -rich in calcium and hydroxyapatite (a mineral containing phosphorus- very hard and brittle) -collagen protein fibers give it flexibility and more resistant to stress

low levels of calcium

-parathyroid gland sense low levels -parathyroid gland secretes more PTH -triggers activity of osteoclasts and suppresses of osteoblast -increases calcium absorption in intestines -reabsorption of calcium kidney

red bone marrow

-produces red blood cells, white blood cells, and platelets -usually found in flat bones -highly vascular -red because of hemoglobin

flat bones

-protect internal organs -somewhat flat -provides large area of attachment for muscles -broad surfaces -usually thin

short bones

-provide stability -provide some movement -cube shaped

function of skeletal system

-shape -support -movement (mostly musclar though, joints) -protection -blood cell production

flat bone examples

-skull -rib cage -sternum

canaliculi

-small channel or duct -provide nutrients in osteocytes

yellow bone marrow

-stores fat -can be converted to red bone marrow -in medullary cavity

long bones

-support the weight of the body -long (not wide) -facilitate movement -appendicular skeleton - tubular shaft and articular surface at each end

periosteum

-thin though layer surrounding bones -made of collagen fibers -acts like skin of bones -connects bones of ligaments and tendons -does not cover joints -helps in bone growth and maintenance (osteoblast cells)

irregular bones

-vary in shape and structure -complex shape -helps guard internal organs

Why did a decrease in bone mass lead to increased calcium levels in the blood?

A decrease in bone mass leads to increased calcium levels in the blood because the bones no longer need so much calcium to function as their is less of the. This excess calcium is moved to the blood, causing an overall increase in the levels. Also if a person is not consuming enough calcium in their diet, the body will begin to extract calcium from the bones, as many vital processes within the body require this nutrient. By doing this the bones are weakening and decreasing in mass, which can lead to osteoporosis.

Why do you think a runner will most likely develop bigger leg bones than a swimmer? How does this happen?

A runner's legs is under much more pressure from gravity and impact than those of a swimmer. This increase in work makes the leg bones stronger and their density to be greater than the swimmer counterparts, who's legs are stil under some force, but significantly less. If the runners leg bones didn't become stronger with activity, eventually they would become brittle and break under the increased force of gravity.

Describe at least three bones that function to protect a particular internal organ.

A set bones that serves the purpose of protecting organs is the ribs. They shield the heart and lungs from harm, which are two very vital organs. The skull is very important because it protects one of the most important organs in the body, the brain. If the head impacts with something hard, the brain will hit the side of the skull and create a bruise (concussion will occur). Finally the pelvis protects the very sensitive reproductive organs in the lower region of our body.

Which do you think would have a greater impact on the body's homeostasis, an open or a closed fracture? Explain your reasoning.

An open fracture would have a greater impact on the body's homeostasis because almost always it is a worse injury. This is because an open fracture will breach the skin and the bone will be outside the body. This throughs the body into mayhem as it is more prone to infection and the white blood cells are sent to the sight to fight the invaders. The bodies equilibrium is out of balance and is only returned when an operation is performed to return the bone to its normal place inside the body.

How does weight-bearing exercise actually help bone?

By putting the bone under the stress of weight during physical activity, it actually helps the bone. This allows for the bone to become denser and stronger as it is forced to work harder against gravity. Also the bones are at less of a risk to getting osteoporosis (when the bone becomes weak and brittle).

Explain how damage to a bone could affect other body systems.

Damaging the bones means damage to bone marrow and ability to support the structure of the whole body. If a bone such as the pelvis were to be damaged, the red bone marrow will also be affected in a way that there will be less of it, causing a lower RBC count in the blood stream. If not enough red blood cells are produced, there's also not enough hemoglobin leading to a insufficiency in oxygen transport. If the amount of oxygen is lower than the norm, muscles will become a little bit weaker (not much assuming not all the bones in the body are damaged, only the pelvis). But if a bone in the vertebrae or a rib had been damaged, that can result in much more severe consequences. If a rib was to be damaged, the lungs, heart and liver are at risk of being penetrated with the broken rib, and if one of the vertebral bones were to be damaged, that would severely affect the protection of nerves that travel up the spinal cord-influencing the nervous system- and can also affect the overall structure of the body itself.

Explain how a dislocation relates to joints and movement.

Dislocation is when the bone moves away from the normal position at the joint. This happens to someone when a violent jerking force occurs tearing at the ligaments that hold the bone in place. To fix this the bone has to be forced into place and allowed to heal with rest for a while before returning to any activity.

greenstick

Occurs in soft and young bones, breaks on the outside, usually happens in infants and children when the bones are fragile and still developing -more vulnerable to surface breaks

What lifestyle choices help a person maintain healthy, strong bones and prevent bone loss? Explain.

One lifestyle choice that helps a person maintain healthy and strong bones is by including an appropriate amount of calcium in the diet. Calcium helps to make the bones strong by maintaining the bone mass necessary for them to function well. If the body doesn't have this mineral, which is necessary for many other processes throughout the body, it will remove some from the bones, overall making them weaker. Another smart choice is to do some sort of physical activity that will put the bones under force. This will cause the bones to become stronger and increase in density. By doing this the bones will be better protected from bone loss and osteoporosis.

What type of fibers or minerals do you find in the extracellular matrix of bone? How does this composition relate to the properties of bone?

One type of fiber found in the extracellular matrix of the bone is collagen. This type of fiber is extremely strong and makes of 90% of the bone (this is the most abundant protein in the body, not all in the matrix). Another important aspect is the different minerals of calcium salts. The most common salt is calcium phosphate and some calcium carbonate. This composition is made of strong materials which give the bones the rigid property.

What is osteoporosis? How can a study of what is happening to bones in space potentially help prevent and treat this condition?

Osteoporosis is a condition in which the bones become brittle and weak normally as one ages and weight bearing decreases. Bones in space often times lose their density and become weak, much like those of someone with osteoporosis. If we can observe the effects of zero g on the bones in space, we can look for ways to help treat both astronauts and people with this condition. Studies have already shown that physical excessive while in space such as biking can help with the strength of the bones, and this applies to victims of osteoporosis. A way to prevent osteoporosis is to maintain physical activity of some sort even as we age, this will ensure the bones remain strong and do not become brittle. With advancing technology and increased observation of space bones, it should not be long until there is a way to treat/cure this disease.

How do red bone marrow and yellow bone marrow differ in function?

Red bone marrow produces red blood cells, white blood cells and platelets. The cells get their red color from the hemoglobin present in the cells. Yellow bone marrow produces and stores fat (mainly stores the fat) which is why the yellow bone marrow appears yellow in color.

What aspects of bone's structure make it stronger than concrete? Think about the engineering design of bone. Use the terms tensile strength and compressional strength in your answer.

The bone is made up mostly of calcium. This mineral along with the framework made up of collagen helps to make bones very strong, like concrete. Bones have a very high tensile strength, which is why we can put the pressure of our body weight on them without the bones being fractured immediately. The structure of the bone also helps as well because the shaft or diaphysis is made up of compact bone which is very good at resisting tension. To help with the compressional strength of the bones, the ends or extremities are made of cancellous material which is very good at fighting compression. Overall the material and engineering of the bone allow for it to be very rigid, yet flexible, making them hard to break and good at their function of support and protection.

What properties of bone prevented Matt from breaks and damage to internal organs?

The bone is very strong yet flexible which allows for Matts injuries to be very minimal. The bone is made up of collagen as a framework and calcium. Both of these materials contribute to the hardness and flexibility properties that allow for them to be very hard to break and protect the internal organs.

What do you think happens to the fracture rate of bones as we age? Explain.

The fracture rate of bones as we age will increase because as we get older and older, the bones in our body become worn out and fragile. They will also become brittle over the time, therefore they are at a much higher risk of breaking than they are when they are at a younger age.

Explain why a person who has been in a leg cast for two months will notice a significant change in size and function of the leg. How do you think muscle would be affected?

The leg will have a significant decrease in size and strength after two months of being in a cast. This occurs because the leg is completely inactive for this time, and without the force of gravity and body weight the bones density will decrease and be weaker. This will also affect the muscle because it is also not being used so it will decrease in muscle mass.

Describe at least three types of medical interventions that can be used to treat and repair broken bones. Explain the theory behind each intervention.

The most common medical intervention to fix broken bones is to place a cast on the area to stabilize the bone and keep it in place. From the here the bodies amazing ability to heal itself will fix the bone and rejoin the broke area. Another way is using a form of surgery to implant rods, screws or plates to hold the bones in place and allow them to do their normal function. A final way to treat broken bones is by using physical therapy to return function to the area as disuse makes the muscles weak and more prone to injury when return to activity. This normally occurs after the bone has been mostly or fully healed, and will help to return the body to normal quicker.

Explain how the body will use bone remodeling to repair a fracture.

The osteoclasts in the broken section of the bone will disassemble and shred so that the osteoblasts can generate and fix the area. This is easier task because the bone is smooth rather than jagged so the osteoblasts will fix the matrix quickly. This process is known as bone remodeling.

Explain how the structure of spongy bone helps reduce the overall weight of bone.

The spongy bone is structurally very porous and it weighs a lot less than the compact bones surrounding it -the compact bones are much denser- which is why it helps reduce the overall weight of the bone.

The fetal skeletal is made of cartilage and eventually turns to bone in a process called ossification. Given what you know about bone cells, how do you think this occurs?

This occurs because in babies they have more of the osteoblasts bone cells. Osteoblasts will lay down new bone material creating the hard bone rather than the cartilage in the fetal skeleton in order to allow for good support for the body and allow them to grow up to be a strong individual.

What role did Matt being knocked unconscious play in his body's ability to resist damage?

When Matt was knocked completely unconscious this allowed for his body to resist damage better. At this point his body was completely relaxed, with all of his muscles no contracting. This allowed for the muscles to absorb the shock from the fall easier and allow for the bones to remain unharmed.

Explain why bone mass is "lost in space." Make sure to mention specific bone cells in your response. Do you think there is any way to fight this loss?

When in space the body is under significantly less pressure with the zero gravity. As time goes on the bones begin to weaken as their is no force upon them and therefore no reason for them to be strong and dense like they would on earth. During this time the osteoclasts are far more active, causing the bone to weaken as the digestive enzymes break down bone tissue. The osteoblasts are less active so minerals such as calcium are not being placed in the matrix. Overall the bone tissues and cells are diminishing during the time in space.

Haversian canal

any of the tubes throughout bone in which blood vessels (and nerves can) travel

bone remodeling

bone is constantly being recycled and rebuilt

short bone examples

bones in carpals and tarsals

lacuna

cavity or depression in bone

name the types of fractures

comminuted, depression, compression, transverse, oblique, spiral, greenstick, open and closed

depression

curved inward (skull) -something hits the skull hard

closed fracture

does not penetrate the skin

where is red bone marrow found?

flat bones

steps of bone fracture healing

hematoma formation Fibrocartilage Callus Formation Bony Callus Formation Bone Remodeling

what are characteristics of bone structure?

lightness, flexibility, and strength

osteoclasts

make and secrete digestive enzymes that break or dissolve bone tissue

osteocyte

mature bones cell

open fracture

penetrates the skin

osteoblast

produce and secrete matrix proteins and transport minerals into the matrix

what does bone provide?

tough and flexible frame for human body