Unit III Compendium review 2
• Muscle Cells, Contraction and Calcium
• Movement Across Joints
• Bones, Bone Tissue and Calcium
Muscle cells, contraction and calcium:
We have three kinds of muscles skeletal, smooth and cardiac. Muscle cells are like bands; so for this reason they are called muscle fibers. Smooth muscle cells are involuntary meaning they contract and perform their task without us telling them to. Examples would be the walls of internal organs. Cardiac muscle is the muscle that makes up the walls of the heart, it is also involuntary. Skeletal muscle is usually attached to the skeleton; we control its movement. Unlike the other two kinds of muscle fibers, skeletal muscles are multinucleated; meaning they have multiple nucleuses. Skeletal muscles help keep our body temperature regulated. They keep us warm in the winter. Muscles along with bones help us to stay up right. The fibers in our muscles are surrounded by connective tissue that holds them all together. Muscles are attached to bones by tendons. When we move our muscle it in turn pulls the tendon causing our bone to move as well. When we bend our arms the muscles contract and shorten. Our nerves send a message to an axon to contract. The axon can tell several muscle fibers to contract. For a muscle to move all of the muscle fibers that make up that particular muscle must contract. Muscle fibers shorten by actin filaments sliding past myosin filaments. Calcium ions are released when this happens. Muscles require ATP for contraction. ATP is broken down to ADP for an energy source. Muscle cells also use plasma fatty acids and blood glucose as energy sources.
• Muscle Cells, Contraction and Calcium
• Movement Across Joints
• Bones, Bone Tissue and Calcium
Muscle cells, contraction and calcium:
We have three kinds of muscles skeletal, smooth and cardiac. Muscle cells are like bands; so for this reason they are called muscle fibers. Smooth muscle cells are involuntary meaning they contract and perform their task without us telling them to. Examples would be the walls of internal organs. Cardiac muscle is the muscle that makes up the walls of the heart, it is also involuntary. Skeletal muscle is usually attached to the skeleton; we control its movement. Unlike the other two kinds of muscle fibers, skeletal muscles are multinucleated; meaning they have multiple nucleuses. Skeletal muscles help keep our body temperature regulated. They keep us warm in the winter. Muscles along with bones help us to stay up right. The fibers in our muscles are surrounded by connective tissue that holds them all together. Muscles are attached to bones by tendons. When we move our muscle it in turn pulls the tendon causing our bone to move as well. When we bend our arms the muscles contract and shorten. Our nerves send a message to an axon to contract. The axon can tell several muscle fibers to contract. For a muscle to move all of the muscle fibers that make up that particular muscle must contract. Muscle fibers shorten by actin filaments sliding past myosin filaments. Calcium ions are released when this happens. Muscles require ATP for contraction. ATP is broken down to ADP for an energy source. Muscle cells also use plasma fatty acids and blood glucose as energy sources.
This is a picture of muscles in the human body.
Movement across joints:
There are three kinds of joints, fibrous joints, cartilaginous joints and synovial joints. Fibrous joints are not mobile; an example is the bones of the skull are attached by sutures of the cranium that do not move. Cartilaginous joints like
in our ribs and sternum move slightly. Synovial joints are filled with synovial fluid as a lubricant. This helps bones move against each other with out pain. Joints can be like the elbow hinge joints that move mainly in one direction and back. They can be like our hip; ball and socket joints that allow movement in almost all direction.
There are three kinds of joints, fibrous joints, cartilaginous joints and synovial joints. Fibrous joints are not mobile; an example is the bones of the skull are attached by sutures of the cranium that do not move. Cartilaginous joints like
in our ribs and sternum move slightly. Synovial joints are filled with synovial fluid as a lubricant. This helps bones move against each other with out pain. Joints can be like the elbow hinge joints that move mainly in one direction and back. They can be like our hip; ball and socket joints that allow movement in almost all direction. This is a knee joint. Notice the cartlige pading the two bones.
Bones, bone tissue and calcium:
Our bodies have over 200 bones in them. They are there for many different reasons. They support our body so that we can stand up right. Our spine is made up of bones that protect our spinal chord and help us stand up. Bones help protect our vital organs. For example our heart is hidden behind our rib cage. So if you were hit in the chest your ribs would protect your heart from damage. Bones can repair themselves when broken or fractured. Bones have many functions. They produce blood cells. They also store minerals, fat and most importantly calcium. Perhaps one of the most noticeable things that bones do is movement. We have joints in our bodies
so that we can function and move. Another important part of movement is cartilage. The ends of our bones are padded with cartilage so that the joints aren’t rubbing bone to bone. Other parts of our body contain cartilage too. Our ears are made of cartilage and so is part of our nose. Cartilage is more flexible than bone. Unlike bone cartilage does not contain blood vessels; this causes it to be slow to heal. Ligaments and tendons are fibrous connective tissues. They help connect bone to bone and muscle to bone at the joints. Bones are constantly being broken down and regenerated on the inside. They are broken down by osteoclasts. Osteoclasts help put calcium and phosphate into our blood stream. Osteoblasts are the cells that form new bone. “As much as 18% of bone is recycled each year.” (Mader 212) This is done by the constant processes of cells breaking down bone and other cells regenerating. This process also allows the body to maintain calcium levels in the blood. Our bodies need calcium for many reasons besides our bones needing them; we also need it for our blood to clot. Calcium has to be kept at a curtain level if it is too high or too low problems occur.
Osteoporosis is a condition where bones are weak and brittle because of decreased bone mass. After ages 40-50 years old bones begin to break down more than they rebuild. This leads to weaker bones and easily broken bones. This is a big problem in older women. Men’s bones are denser than women to begin with and they don’t break done as much as women’s do. Older women especially seniors often suffer from hip fractions from the smallest fall. Doctors recommend eating a diet high in calcium your entire life to help prevent this. Calcium helps keep your bones denser, exercise also helps with this.
Our bodies have over 200 bones in them. They are there for many different reasons. They support our body so that we can stand up right. Our spine is made up of bones that protect our spinal chord and help us stand up. Bones help protect our vital organs. For example our heart is hidden behind our rib cage. So if you were hit in the chest your ribs would protect your heart from damage. Bones can repair themselves when broken or fractured. Bones have many functions. They produce blood cells. They also store minerals, fat and most importantly calcium. Perhaps one of the most noticeable things that bones do is movement. We have joints in our bodies
so that we can function and move. Another important part of movement is cartilage. The ends of our bones are padded with cartilage so that the joints aren’t rubbing bone to bone. Other parts of our body contain cartilage too. Our ears are made of cartilage and so is part of our nose. Cartilage is more flexible than bone. Unlike bone cartilage does not contain blood vessels; this causes it to be slow to heal. Ligaments and tendons are fibrous connective tissues. They help connect bone to bone and muscle to bone at the joints. Bones are constantly being broken down and regenerated on the inside. They are broken down by osteoclasts. Osteoclasts help put calcium and phosphate into our blood stream. Osteoblasts are the cells that form new bone. “As much as 18% of bone is recycled each year.” (Mader 212) This is done by the constant processes of cells breaking down bone and other cells regenerating. This process also allows the body to maintain calcium levels in the blood. Our bodies need calcium for many reasons besides our bones needing them; we also need it for our blood to clot. Calcium has to be kept at a curtain level if it is too high or too low problems occur.Osteoporosis is a condition where bones are weak and brittle because of decreased bone mass. After ages 40-50 years old bones begin to break down more than they rebuild. This leads to weaker bones and easily broken bones. This is a big problem in older women. Men’s bones are denser than women to begin with and they don’t break done as much as women’s do. Older women especially seniors often suffer from hip fractions from the smallest fall. Doctors recommend eating a diet high in calcium your entire life to help prevent this. Calcium helps keep your bones denser, exercise also helps with this.
Work Cited:
Madder, Sylvia S. “Human Biology” 10th ed. New York: McGraw-Hill, 2007.
Madder, Sylvia S. “Human Biology” 10th ed. New York: McGraw-Hill, 2007.
Skeleton http://www.bio.psu.edu/people/faculty/strauss/anatomy/skel/skeletal.htm
Skull http://www.bio.psu.edu/people/faculty/strauss/anatomy/skel/anterior.htm
Skull http://www.bio.psu.edu/people/faculty/strauss/anatomy/skel/anterior.htm
Knee jointhttp://www.bio.psu.edu/people/faculty/strauss/anatomy/skel/knee.htm
Muscle anatomy http://www.abs-exercise-advice.com/images/Muscle-anatomy.jpg
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