Human Biology Chapter 1-5 pt. 2
In the context of cell biology, what do we mean by form follows function? What are at least two?
"From follows function" refers to the idea that the function of a body part dictates the form of that body part. As an example, organisms like birds or fish that fly or swim quickly through the air or water have streamlined bodies that reduce drag. At the level of the cell, in tissues involved in scretory functions, such as the salivary glands, the cells have abundant Golgi.
For whom would an appreciation of the structural characteristics of the human heart come more easily: an alien who lands on Earth, abducts a human, and dissects his heart, or an anatomy and physiology student performing a dissection of the heart on her very first day of class? Why?
A student would more readily structures revealed in the dissection. Even though the student has not yet studied the workings of the heart and blood vessels in her class, she has experienced her heart beating every moment of her life, has probably felt her pulse, and likely has at least basic understanding of the role of the heart in pumping blood throughout her body. This understanding of the heart's function (physiology) would support her study of the hearts form (anatomy).
Once dietary fats are digested and absorbed, why can they not be released directly into the bloodstream?
All lipids are hydrophobic and unable to dissolve in watery blood and its environment. They are packaged into lipoproteins, whose outer protein enevelope enables them to transport fats in the bloodstream.
Why are negative feedback loops used to control body homeostasis?
An adjustment to a change in the internal or external environment requires a change in the direction of the stimulus. A negative feedback loop accomplished this, while a positive feedback loop would continue the stimulus and result in harm to the animal.
During the early years of space exploration our astronauts, who had been floating in space, would return to earth showing significant bone loss dependent on how long they were in space. Discuss how this might happen and what could be done to alleviate this condition.
Astonauts floating in space were not exerting significant pressure on their bones; they were "weightless". Without the force of gravity exerting pressure on the bones, bone mass was lost. To alleviate this condition, astronauts now do resistive exercise designed to apply forces to the bones and thus help keep them healthy.
At what level of organization would you place a grain of salt?
At the molecular or chemical level since a sodium ion Na+ and a chloride ion Cl- combine to make NaCl molecule
Which medical imaging technique is most dangerous to use repeatedly, and why?
CT scanning subjects patients to much higher levels of radiation than x-rays, and should not be performed repeatedly.
Name the six levels of organization of the human body.
Chemical, cellular, tissue, organ, organ system, organism
How is a condition such as diabetes a good example of the failure of a set point in humans?
Diabetes is often associated with a lack in production of insulin. Without insulin, blood glucose levels go up after a meal, but never go back down to normal levels.
If you put a drop of food coloring in a bowl full of water the food color will disperse. This is an example of __.
Diffusion
How does diffusion limit the size of an organism? How is this counteracted?
Diffusion is effective over a very short distance. If a cell exceeds this distance in its size, the center of the cell cannot get adequate nutrients nor can it expel enough waste to survive.
Which of the following tissues will have most mitochondria?
Heart Muscle
If the articular cartilage at the end of one of your long bones were to degenerate, what symptoms do you think you would experience? Why?
If the articular cartilage at the end of one of your long bones were to deterioate, which is actually what happens in osteoarthritis, you would experience joint pain at the end of that bone and limitation of motion at that joint because there would be no cartilage to reduce friction between adjacent bones and there would be no cartialge to act as a shock absorber.
When you open a bottle of sparkling water, the carbon dioxide gas in the bottle form bubbles. If the bottle is left open, the water will eventually "go flat". Explain these phenomena in terms of atmospheric pressure.
In a sealed bottle of sparkling water, carbon dioxide gas is kept dissolved in the water under a very high pressure. When you open the bottle, the pressure of the gas above the liquid changes from artificially high to normal atmospheric pressure. The dissolved carbon dioxide gas expands, and rises in bubbles to the surface. When a bottle of sparkling water is left open, it eventually goes flat because its gases continue to move out of solution until the pressure in the water is approximately equal to atmospheric pressure.
The skeletal system is composed of bone and cartilage and has many functions. Choose three of these functions and discuss what features of the skeletal system allow it to accomplish these functions.
It supports the body. The rigid, yet flexible skeleton acts as a framework to support the other organs of the body. It facilitates movement. The movable joints allow the skeleton to change shape and positions; that is, move. It protects internal organs. Parts of the skeleton enclose or partly enclose various organs of the body including our brain, ears, heart, and lungs. Any trauma to these organs has to be mediated through the skeletal system. It produces blood cells. The central cavity of long bones is filled with marrow. The red marrow is responsible for fomring red and white blood cells. It stores and releases minerals and fat. The mineral component of bone, in addition to providing hardness to bone, provides a mineral reservoir that can be tapped as needed. Additionally, the yellow marrow, which is found in the central cavity of long bones along with red marrow, serves as a storage site for fat.
Why is a fever a "good thing" during a bacterial infection?
Most bacteria have a narrow range of temperature they can survive?
Oxygen, whose atomic number is eight, has three stable isotypes: ^16O, ^17O, and ^18O. Explain what this means in terms of the number of protons and neutrons.
Oxygen has eight protons. In its most abundant stable form, it has eight neutrons, too, for a mass number of 16. In contrast, 170 has nine neutrons, and 180 has 10 neutrons.
Describe the structures that are characteristic of a prokaryotic cell.
Prokaryotic cells are surrounded by a plasma membrane and have DNA, cytoplasm, and ribosomes, like eukaryotic cells. They also have cell walls and may have a cell capsule. Prokaryotes have a single large chromosome that is not surrounded by a nuclear membrane. Prokaryotes may have flagella or motility, pili for conjugation, and fimbria for adhesion to surfaces.
When you do a load of laundry, why do you not just drop a bar of soap into the washing machine? In other words, why is laundry detergent sold as a liquid or powder?
Recall that the greater the surface area of the reactants, the more quickly and easily they will interact. It takes energy to separate particles of a substance. Powder and liquid laundry detergents, with relatively more surface area per unit, can quickly dissolve into their reactive components when added to the water.
If you were a dietician who had a young female patient with a family history of osteoporosis, what foods would you suggest she include in her diet? Why?
Since maximum bone mass is achieved by age 30, I would want this patient to have adequate calcium and vitamin D in her diet. To do this, I would recommend ingesting milk and other dairy foods, green leafy vegetables, and intact canned sardines so she receives sufficient calcium. Intact salmon would be a good source for calcium and vitamin D. Other fatty fish would also be a good vitamin D. source.
What are the advantages and disadvantages of light, transmission, and scanning electron microscopes?
The advantages of light microscopes are that they are easily obtained and the light beam does not kill the cells. However, typical light microscopes are somewhat limited in the amount of detail they can reveal. Electron microscopes are ideal because you can view intricate details, but they are bulky and costly, and preparation for the microscopic examination kills the specimen. Transmission electron microscopes are designed to examine the internal structures of a cell, where as a scanning electron microscope only allows visualizaton of the surface of a structure.
Where does the cell get energy for active cell processes?
The cell harvests energy from ATP produced by its own metabolism to power active transport processes, such as pumps.
In what ways is the structural makeup of compact and spongy bonewell suited to their respective functions?
The densely packed concentric rings of matrix in compact bone are ideal for resisting compressive forces, which is the function of compact bone. The open spaces of the trabeculated network of spongy bone allow spongy bone to support shifts in weight distribution, which is the function of spongy bone.
The female ovaries and the male testes are a part of which body system? Can these organs be members of more than one organ system? Why or why not?
The female ovariesand the male testes are parts of the reproductive system. But they also secrete hormones, as does the endocrine system, therefore ovaries and testes function within both the endocrine and reproductive systems.
Why is it advantageous for the cell membrane to be fluid in nature?
The fluidity of the cell membrane is necessary for the operation of some enzymes and transport mechanisms within the membrane.
On his midsummer trek through the desert, Josh ran out of water. Why is this particularly dangerous?
The primary way that the body responds to high environmental heat is by sweating; however, sweating requires water, which comes from body fluids, including blood plasms. If Josh becomes hydrated, he will be unable to sweat adequately to cool his body, and he will be at risk for heat stroke as his blood pressure drops too much from the loss of water from the blood plasma.
The most abundant elements in the foods and beverages you consume are oxygen, carbon, hydrogen, and nitrogen. Why might having these elements in consumables be useful?
These four elements - oxygen, carbon, hydrogen, and nitrogen - together make up more than 95% of the mass of human body, and the body cannot make elements, so it is helpful to have them in consumables.
Explain why ultrasound imaging is the technique of choice for studying fetal growth and development.
Ultrasonography does not expose a mother or fetus to radiation, to radiopharmaceuticals, or to magnetic fields. At this time, there are no known medical risks to ultrasonography.
An Individual with very low levels of vitamin D presents themselves to you complaining of seemingly fragile bones. Explain how these might be connected.
Vitamin D is required for calcium absorption by the gut. Low vitamin D could lead to insufficient levels of calcium in the blood so the calcium is being released from the bones. The reduction of calcium from the bones can make them weak and subject to fracture.
In a hurry one day, you merely rinse your lunch dishes with water. As you are drying your salad bowl, you notice that it still has an oily film. Why was the water alone not effective in cleaning the bowl?
Water is a polar molecule. It has a region of weakly positive charge and a region of weakly negative charge. These regions are attracted to ions as well as to other polar molecules. Oils are nonpolar, and are repelled by water.
Name at least three reasons to study anatomy and phsyiology?
an understanding of anatomy and physiology is essential for any career in the health professions. It can also help you make choices that promote your health, respond appropiately to signs of illness, make sense of health-related news, and help you in your roles as a parent, spouse, partner, friends, colleague, and caregiver.
