How images form in the eye
“How exactly do we see things with our eyes?”
Everything that we perceive in this world is formed through our eyes. However, have you ever wondered how images can physically form in these biological objects? Well, let’s analyze this question scientifically to find out. If one were to take an eyeball and cut it in half through the midpoint of the pupil, they will find a lens just behind the cornea. If you were to then shine parallel light beams through this lens, then you would find that all of the light would focus on to the backside of the eye. The back of the eye will then transmit information to the brain, which will invert the image “in the mind’s eye” enabling us to see!
“What happens when bones weaken as they get older?”
The human body changes throughout it’s lifetime. And as one approaches an older age, the bone structure in the body begin to weaken. Specifically, the holes in cancellous bones will become exacerbated and largen, causing a loss in bone density. This loss in bone density reduces the strength of human bones. This brittleness could lead to bone fracture in case of an unforseen accident, such as a falling event. Doctors have termed this condition osteoporosis. To prevent the onset of osteoporosis, one should commit to a weight-bearing exercise and a diet full of vitamin-D and calcium
“What holds all of the different parts of a skeleton together?”
Skeletons are quite complex structures. The average adult human skeleton holds around 206 individual bones in it’s composition! However, how what connects these bones all together, and what allows for their range of movement? Well, much like a mechanical machine, these bones are connected to each other through the use of elements called bone joints. Bone joints come in three different types of varieties: Fibrous (allowing for no movement between the connections,), cartilaginous (allowing for limited movement), and synovial (allowing for full movement). Fibrous joints are utilized in skull connections, cartilaginous joints in back vertebrae, and synovial joints are used in the knees.
“What is the tissue that fills the center of bones?”
Bones are quite sturdy structures. A cubic inch of this material can sustain the weight of five pickup trucks. However, what exactly is at the center of bones and what functions do they perform? Well, it turns out that a quite peculiar bone marrow is what fills the interior of bones. Bone marrow is a soft and spongy in nature, and it contains stem cells. Stem cells are analogous to workers that have not yet been given a function. These cells are nascent and have no use, but they can be specialized to perform become cells that create new parts of the body such as cartilage, muscles, blood cells, and even other bones! Bone marrow is vital for the health of a human body.
“How can something as rigid as bones allow for flexibility?”
Bones are one of the most fundamental aspects of human physiology. Without them, the human body would just be a pool of flesh, tissue, and organs! However, this rigid quality of bones has potential drawbacks, such as inflexibility and weakness to sudden stresses, and as a result, the body will require some form of flexibility from these structures. However, how does the body solve this problem? Well, luckily for us, human physiology have evolved past this problem through the use of cancellous bones. Cancellous bones are bones that contain sponge-like holes through throughout their structure. These holes not only allow for blood vessels to be transported through them, but most importantly allow for structural flexibility. These holes can be likened to a biological shock absorber, absorbing and damping incoming shocks to prevent the breakdown of the structure. These cancellous types make up 20 percent of the human bones, the other 80 percent being the standard solid compact bones. What is most interesting is that to maximize both flexibility and cohesion, cancellous bones are sometimes enveloped by a shell of compact bones!
“What are Kidney stones?”
You have probably heard of Kidney stones, those mysterious solid objects that cause major pain to everyone. But what are they and how do they form? Well, it turns out that kidney stones is caused by simple chemistry, insoluble compounds. When your urine contains too many insoluble components such as calcium, they begin to build up and cause kidney stones to form. In order to avoid Kidney stones, you should commit to regular exercise and avoid diets that are too high in protein, sugar, and sodium.
“What is blood pressure?”
When you go for a medical checkup, you will often hear a lot of talk about your “blood pressure”. But what exactly is this phenomena? Well, believe it or not, blood pressure is actually a very simple concept. Your body is able to maintain it’s operations because the heart pumps blood (which carries oxygen) to all of it’s vital systems. This pumping motion causes blood to be pushed against the walls of your blood vessels, and we can quantify this force as blood pressure. Your blood pressure is usually measured in “millimeters of mercury” (or mmHg), and is given two values (for example, a stable blood pressure is considered to be 120/80 mmHg). But why on Earth will your blood pressure be given two values? Well, let’s think about it. When your heart pumps blood, it does not do so in a constant fashion. Instead, it acts like a piston, with a force changing in a beating nature. So your blood pressure will be the highest at the peak force (termed the systolic blood pressure), and lowest at the bottom (termed the diastolic blood pressure). The higher your blood pressure is, the higher you will have a risk of developing heart heart problems. For example, someone with a blood pressure reading of 135/85 mmHg is twice as likely to receive a heart attack as someone with a blood pressure of 115/75
Diastolic heart failure 05/07/16
Diastolic heart failure is when the heart’s lower left muscle becomes to stiff and weakened and to compensate the the heart increases the pressure in the ventricle to properly fill the vesicle. Resultant the lower left chamber is unable to be filled with blood, and much of the blood spills over in to the lungs. The effect is most often caused by aging of the heart.