A&P short answer repository

Explain 3 functions of hair as an accessory to the integumentary system of humans.

(Could use any three) Hair regulates body temp by creating a layer of trapped air around the body when arrector pili muscles contract and makes the hair stand erect. Hair also sense touch by being bent and alerting nerve cells in the dermis. They insulate heat on the body, protect from UV radiation and lubricate parts of the body with sebaceous oil (sebum) to prevent rubbing.

What is an example of negative feedback? Explain why.

An example of negative feedback is thermoregulation. When our body temperatures decrease, we have heating mechanisms that will activate(shivering) which leads to our body temperatures increasing. In addition when our body temperatures increase, we activate our cooling mechanisms (sweating) which leads to our body temperatures decreasing.

what type of epithelial composition is seen in transporting epithelia?

Cuboidal OR Columnar. movement and secretion of substances between lumen and the ECF requires large and tightly bound epithelial conposition. (THICC:))

The integument Includes the Cutaneous Membrane and the Accessory structures. Name and shortly summarize the 3 different accessory structures:

HAIR FOLLICLES: hair protects skull and provides delicate touch along with sensations on the general body surface. EXOCRINE GLANDS: assist in temperature regulation and waste excretion. NAILS: protect and support tips of fingers and toes.

What is the purpose of protective epithelial tissue? Name two examples of where this type of tissue is located on/in the body.

The main purpose of the protective epithelia is the protect you body from mechanical stresses such as sharp objects and chemicals. Two examples of this tissue are the skin and your esophagus.

Homeostasis can be defined as a stagnant, internal state of equilibrium. Is this definition correct? Why or why not? Provide evidence for your answer.

This answer is incorrect because homeostasis is not stagnant, it is actually quite dynamic. It involves a constant exchange of information and materials (ex. the sodium-potassium pump) within the body to maintain the most optimal conditions for biological processes. Though it does work to maintain a STABLE environment, it does not work towards maintaining one that is at equilibrium.

When eating spicy food, capsaicinoids trigger a protein, which usually detects heat on the surface of the tongue. When activated, the protein sends a message to the brain that it is burning. To combat this, the brain releases endorphins and dopamine in order to relieve the pain.A. Which type of control system is being described in the scenario above? Explain why.B. According to your answer to part A, which step of the control system's pathway would be associated with the brain? Explain why.

A. Reflex control because the scenario described activity from the nervous and endocrine systems. These systems were used when the tongue sent messages to the brain and when the brain released endorphins and dopamine. Furthermore, the location of change was at the tongue, but the evaluation and initiation of the response was processed from a distant site: the brain.B. The integrating center because the brain received the input signal — that the tongue is burning — through the nervous system, evaluated the change, and released endorphins and dopamine as output signals.

You are on a run. Your body heats up, consumes energy, produces wastes, etc. Name as many kinds of epithelial cells at work and what they are doing in this situation.

Exchange epithelium: lining blood vessels/heart, allowing Oxygen and C02 to move to and from erythrocytes to muscle tissues.Transporting epithelium: although digestion slows during exercise, transport epithelia from earlier in the day absorbed essential nutrients from your food to power your movement on this run.Ciliated epithelium: these cells in your respiratory tract continually move debris out of your airway so you can breathe better on your run.Protective epithelium: integument system protects entire outside body from friction and the elements on your run.Secretory epithelium: keeps you sweating to reduce body temperature (exocrine glands)

Explain what positive feedback is, and give an example.

Positive feedback is a cycle that increases the action that is going on. Unlike negative feedback, positive feedback requires an outside action stop the cycle. An example of positive feedback is blood clotting. When part of the body is injured chemicals that activate blood platelets are released. When platelets are activated, it in turn activates more platelets that combine to form a blood clot.

The inside of a cell and its surrounding solution have the same amount of particles on either side of the cell membrane. However, there is a higher concentration of a non-penetrating solute inside of the cell. What is the osmolarity of these environments? What is the tonicity of the surrounding solution? What will happen to the cell?

Since there is the same amount of particles in both environments, they are isosmotic. However, the low concentration of non-penetrating solute in the surrounding solution relative to the inside of the cell makes that solution hypotonic. Since the surrounding solution is hypotonic, osmotic pressure is going to push water into the cell, causing it to swell.

What are is the cell shape, function, and location of protective epithelia?

The cell shape of protective epithelia is squamous near the apical surface as well as cuboidal and polygonal. The function of protective epithelia is to protect from chemical and mechanical stress. Lastly, protective epithelia can be found in the skin, mouth, pharynx, esophagus, urethra, and vagina.

Briefly explain what the integument is then list and explain 3 of its functions.

The integument is the bodies largest system. It is composed of two parts; the cutaneous membrane and the accessory structure. The integument has multiple functions including protection, maintenance of body temperature, and sensation. The integument protects the body by not only providing a physical barrier but also by its melanocytes which produce melanin. Melanin is responsible for protection against UV rays. The integument helps maintain body temperature by releasing excess body heat through sweat glands. Another way the integument maintains body temperature is through dilated or constricting blood vessels. Last, the integument allows us to feel sensations through a network of nerve endings and touch receptors.

Explain how surface area, the number of molecules, and temperature play a role in the rate of diffusion.

The more surface area there are for molecules to move around, the faster the rate of diffusion. This is why some parts of your body like the fingers shrivel up to create more surface area when you are in water for a long time.The greater number of molecules also increase the rate of diffusion because they want to spread out faster, going from a place of high concentration to low concentration.The higher the temperature, the more energy the molecules have, thus the faster rate of diffusion.

a.Why is homeostasis important for all organisms to maintain?b. Does positive feedback help maintain homeostasis? Explain why or why not.

a. Homeostasis is crucial for all organisms to keep their internal environment regulated and functioning, especially when there are changes to their external environment. Homeostasis helps to maintain a balance of things such as chemicals, temperature, and many other things, so that there is never too much or too little of a chemical and the temperature of the body is never too high or too low, so the body can remain at a comfortable, functioning level.b. Positive feedback is very unstable and does not help to maintain homeostasis. This is because when a stimulus occurs positive feedback creates a response that increases the stimulus, then increasing the response, and the process keeps moving in the same direction until an external factor interrupts and stops the process. An example of this is birth contractions. Oxytocin stimulates the muscle contractions that push the baby through the birth canal, and the release of that oxytocin results in stronger contractions, which then causes more oxytocin to be made in response, and the positive feedback loop keeps going until the baby is born. We can see how this type of process could be bad for maintaining homeostasis in the body, because the body could accidentally produce to much of a certain chemical or get too high in temperature because of the positive feedback loop.

Why is sweating during exercise beneficial?How does sweating show a negative feedback loop and not a positive feedback loop?

1) Sweating during exercise is beneficial for the body because as your muscles heat up your body attempts to counteract this affect by cooling the body down through releasing water through skin glands.2) Sweating shows a negative feedback loop because as the body (muscles) heat up the body tries to reverse this affect by sweating. This mechanism helps promote stability by keeping us from overheating, increases circulation through out vital organs and skin, and it also helps remove excess toxins and salt (which can lead to kidney stone formation). Sweating is not a positive feedback loop because as you heat up during exercise your body does not try to heat up more but decrease the effcet by cooling itself down to promote stability.

What are the 4 criteria that make a good study? Describe one of these criteria and why it makes for a good study.

1)Controls and Randomization, 2)Appropriate Methods, 3)Accurate Figures, 4)Peer-reviewed in reputable journal. 1)Controls account for hidden factors such as exercise, diet choices, age, background, etc. (other compounding factors) that may have an affect on the results of a study. These are in place to prevent the results of the study from being swayed or irrelevant.2)Having appropriate methods is important to make sure that the results of the study are not swayed or biased by incorrect testing or carrying-out of the study itself. This is to make sure that the study is conducted correctly and in a way that makes sense for the research question.3)Accurate Figures are easily readable with figure legends and the correct variables on the axes. The correct type of figure is also integral to a good study. Making sure that the x-axis is the independent variable with consistent y-axes and a baseline included. Figures help interpret data that is being relayed in writing so that results can be compiled and quantified for the reader.4)Making sure that a study is peer-reviewed in a reputable journal is very important to make sure that most if not all parts of a study are correct and foolproof. For example if a study is posted in the daily mail or in people magazine, those are not good science sources from which you should take studies. You also have to be careful for predatory journals which may not have very strict peer review policies, usually making the studies that they publish unreviewed and unrefined.

1. What is an emergent property?2. Name one way the human body maintains homeostasis, and explain why this is an example of homeostasis.3. What is the difference between a teleological approach and a mechanistic approach? Why is understanding this difference important?

1. An emergent property is a characteristic of an organism that could not be predicted by simply looking at the components that make it up, i.e. if you took apart a clock, you would not know just by looking at the gears that it was a time telling device.2. There are many examples applicable. One might be temperature, which is an example of the body maintaining homeostasis because even if the external environment changes temperature, the human body cam respond to this external stimulus to keep its internal temperature relatively stable through responses like sweating or shivering.3. A teleological approach looks to answer why a specific process or component of the body exists as it does. The mechanistic approach looks to answer how the component does this. The difference between the two is important because without fully understanding what the question is looking for (whether in the classroom or the laboratory), you will not be able to answer it.

What is a control system?What are the two control systems, and describe each of them.

A control system regulate the variables that are maintained at a setpoint (preferred value.) The two different control systems are local control and reflex control.Local control also known as auto-regulation is restricted to the tissue or the cell involved and adjusts in response to nearby change such as dilating blood vessels when oxygen levels are low in the tissue.Reflex control or extrinsic regulation maintains homeostasis widespread throughout the body. It could also be considered as long-distance control where it uses the nervous and endocrine systems to regulate body. An example could be when you're exercising, blood flow increases to working muscles.

How does a negative feedback loop help maintain homeostasis?

A negative feedback loop helps maintain homeostasis through a regulation process. This one, in comparison to a positive feedback loop, promotes stability of the system by decreasing or negating the effect of the stimulus on the action of that system. This shuts off the response, keeping the system in a steady state by shutting off the response loop.

What is a reflex loop? Give an example of a reflex loop that happens in the body. List the steps and describe what happens at each step.

A reflex loop is a reflex control response that is a type of control system that regulates variables in the body to maintain homeostasis. It is initiated by cells at a distant site that controls the response, making it extrinsic regulation and activities of the nervous or endocrine system. An example of a reflex loop that takes place in the body is when an individual has low blood pressure. The steps and order that occur in a reflex loop include the stimulus, sensor, input signal, integrating center, output signal, target, and response. In the case of someone having low blood pressure, the stimulus is the decrease in blood pressure because that is the issue that is stimulating the reflex loop. The sensors are the baroreceptors in the blood vessels because that is what is detecting the decreasing blood pressure. The input signal is the afferent nerve impulse which is sending the signal to the brain, which makes the medulla oblongata in the brain the integrating center since that is what is processing the signal. The output signal is then the different nerve impulses and the target is the heart because that is where the response needs to take place to improve the blood pressure. Lastly, the response is the heart rate slowing because that is the result of the reflex loop reacting to the decreasing blood pressure.

A)What are the two types of regulation processes? Give an example of each.B) Consider these steps: blood glucose level rises, receptors send signal to pancreas, blood glucose level decreases, blood, pancreas, receptors in body sense a change, secretion of insulin into the blood.Match these steps with the following words: stimulus, sensor, input signal, integrating center, output signal, target, response.C) What type of feedback loop was shown in part B?

A) The two types of regulation processes are positive feedback and negative feedback. Positive feedback is shown in childbirth, since the response (delivery of baby) reinforces the stimulus (cervical stretch) instead of decreasing it. Negative feedback is shown in maintaining homeostasis. An example of this is related to maintaining body temperature. The stimulus (an increase in body temperature) is decreased or removed by the response (sweating, which is a cooling mechanism).B) The stimulus is blood glucose level rises because it sets the other steps into motion. The sensor is receptors in body sense a change because the receptors are what recognize that there has been a change in blood glucose levels. The input signal is receptors send signal to pancreas because the receptors are what sensed the change and the message needs to be sent to the pancreas so that a change will be made. The integrating center is the pancreas because the pancreas produces what is necessary to make the correct response. The output signal is the secretion of insulin into the blood because this is the change that was made by the integrating center. The target is the blood because that is where the output signal is heading towards. The response is blood glucose level decreases because this was the change needed to be made for the body to maintain homeostasis.C) A negative feedback loop was shown in part B because the response (blood glucose level decreases) decreased the stimulus (blood glucose level rises)

A. Choose an Integument accessory. B. What is the accessory's function? C. What are the cells in the accessory?

A. For this question, I chose Raif as the accessory. B. The function of hair is to maintain body temperature, insulation, used for sensation, defense (not as much in humans), UV protection, and lubricates skin. C. Hair uses nerve fibers as the cells. An example of this are pressure/touch centers.

If someone wants to get rid of excess fat on their body, one may work out more often and change their diet. What type of tissue are they aiming to reduce?

Adipose tissue.The answer is adipose tissue, because it is composed of adipose (fat) cells, which provides extra cushioning in places all around the body. While some adipose tissue is necessary for regulating homeostasis and bodily functions, one can build an excess of adipose tissue, or excess fat. One of the best ways to reduce adipose tissue in the body is to exercise often and eat healthier meals.

What is the difference between an input and an output signal and how do they work together in a reflex pathway?

An input signal is the signal sent to the integrating center to be analyzed and then initiate the output signal. The output signal directs the target to carry out a response. Both signals play a major part in a reflex pathway. The input signal helps to initiate the output signal which plays a big role in the response.

What is a control system? Tissues releasing chemicals in order to increase the flow of blood to cells is an example of what type of control system? Explain.

Control systems are regulated variable that are maintained at a set point through local control and long-distance reflex control. Control systems have three basic components. 1. an input signal. 2. an integrating center which integrates incoming information and reacts with an appropriate response. 3. an output signal which creates a response.A tissue releasing chemicals in order to increase the flow of blood to the cells is an example of local/intrinsic/auto-regulation. This control system is restricted to tissues and cells involved. When an isolated change in a tissue occurs a nearby cell group of cell senses the change and responds typically by releasing a chemical. Because there seem to be a low flow of blood to the cells the tissues respond to this by releasing chemicals.

What is the difference between dense regular and dense irregular?

Dense regular connective tissue collagen fibers line up a parallel manner (the same direction) which tears when stressed in the incorrect direction. While dense irregular connective tissue collagen fibers are thicker and arranged in different directions, which allows for tension in many different direction.

Diffusion is a method of what type of transport across membranes? What are the characteristics of diffusion? Name all four.

Diffusion is a form of passive transport. The characteristics of diffusion include using the kinetic energy of molecules to bump around and go in different directions, going from high concentration to low concentration, continuation of diffusion even after equilibrium because it is dynamic, and the ability to diffuse both in an open system and across a partition, like a semi-permeable membrane.

What is Fick's Law of Diffusion? Describe the factors and how they affect the rate of diffusion.

Fick's Law of Diffusion states that the rate of diffusion is affected by the surface area, concentration gradient, and membrane permeability. Diffusion is a passive process and the rate of diffusion is based on the ability of the molecule to dissolve in the lipid layer of the membrane. Diffusion is proportional to the surface area of a membrane which means that as the surface area increases, the rate of diffusion increases because more molecules can diffuse across at the same time. The concentration gradient is also proportional to diffusion. This is because when there are more molecules, there is more diffusion since molecules move from high concentration to low concentration. Membrane permeability also affects the rate of diffusion and is dependent on the size of the diffusing molecule and lipid solubility of the molecule. It is inversely related to the weight and size of the molecule. This is because smaller molecules do not require as much energy to move. As the lipid layers composition changes, the membrane permeability can increase or decrease. When the membrane is thin, there is a shorter distance to travel, which increases diffusion to reach equilibrium. But when the membrane is thick, discussion is slower over the long distances. Temperature is also a factor that directly affects diffusion. When there are higher temperatures, there is more molecular movement and more energy which results in increasing diffusion.

Is homeostasis the same thing as equilibrium? Why or why not?

Homeostasis does not mean equilibrium. The term equilibrium implies that the composition of all compartments are identical.Homeostasis is maintaining an environment for cells so they are the most productive.

Your friend says that homeostasis is about maintaining equilibrium and that positive feedback helps maintain homeostasis. How do you respond?

Homeostasis is not maintaining equilibrium but is disequilibrium, specifically dynamic disequilibrium. Homeostasis is dynamic because materials are constantly moving back and forth because the body is adjusting to changes and trying to keep the variables at normal ranges. There is also no net movement. This means that there is no change because whenever there is input there is always the same amount as output. Homeostasis does not mean that things have to be exactly equal. Next, positive feedback does the opposite of homeostasis because the stimulus triggers the increased response. Positive feedback starts the pattern of increasing the response until an outside event stops the response. Since homeostasis is returning the body back to stability despite any external changes positive feedback does the opposite and tends to amplify the response, straying away from a safe range.

What is homeostasis and what is its importance in the human body? List at least four factors that are regulated.

Homeostasis is the regulation of the internal environment in the human body, it is the way in which organisms cope with variable conditions in their external environment. It is a dynamic steady state where materials are moving constantly but there is little net movement overall, remaining relatively stable. If the human body fails to maintain homeostasis then a pathological condition can occur. Four regulated factors include: body temp., pH, hormones, water.

Why does homeostasis not apply that the body is always at an equilibrium? Explain why and give an example for your reasoning.

Homeostasis is the stability of the body's internal environment. The composition of the body is regulated by several factors (temperature, pH, electrolytes) that create a stable environment within the body. Homeostasis does not imply equilibrium because this would suggest that the composition of the body is the same throughout all body compartments. For example, the sodium and chloride concentrations are higher in the extracellular fluid (ECF) of a cell, and there are higher concentrations of potassium in the intracellular fluid. This steady state of disequilibrium plays a key role for maintaining cell function.

The epithelia is the largest organ in the body, and has many different types. How are you able to distinguish between different types of epithelia.

How many layers it has, the shapes of the cells, and the function. For layers you can either have simple or stratified. Simple means one layer, and stratified means multiple layers. The shape of the cell is determined by the shapes of the cells on the top layer. You can have cells that are squamous, cuboidal or columnar in shape. And the function of the cell can be exchange, transport, ciliated, protective or secretory. All these factors combined can help you determine the type of epithelia.

What does it mean when a protective epithelia is 'keratinized', and where would you you find keratinized epithelia?

Keratinized means that the protective epithelia is extra tough to help protect from mechanical damage and keeps in moisture. Places where you find this epithelia do not have to be constantly kept wet. You can find it in the skin.

When compartments of the body maintain homeostasis, are they at equilibrium? Explain your answer.

No, they are not at equilibrium because that implies that the concentration of substances in each compartment are equal to each other. However, in homeostasis, the compartments have materials that are constantly moving between each other so there is not net movement, but the compartments themselves do not have equal concentrations of the material. Therefore the compartments are in dynamic disequilibrium rather than equilibrium.

The coral reefs are dying due to external factors in the environment. These factors cause the reefs to bleach and eventually die. Name one possible factor that is causing the reefs to die since they cannot regulate them and maintain a homeostatic environment. Explain how either positive or negative feedback could save the reefs from your listed factor.

One factors I would talk about would be a possible temperature increase. (others could be a change in pH, maybe how oil spills and pollutants increase gases or changes the entire composition of the water around them). An increase in temperature would cause the coral to have an internal environment that is not homeostatic. This would cause a disequilibrium that would cause a cascade of effects since the coral cannot maintain balance. Without a healthy and steady balance, the coral cannot function and thus causes the bleaching and ultimately death. Negative feedback could save the coral because it would be able to moderate and maintain their internal temperature. When the sea temperature rises, the coral itself would use negative feedback to maintain homeostasis and keep itself at the right temperature for it to function and live.

Define the two feedback loops.

One feedback loop would be the positive feedback loop. This is when the effect of the initial stimulus leads to further action from the body, increasing the effect. This process will come to a natural endpoint provided from an outside factor that will end the loop. Another feedback loop would be the negative feedback loop and this is when the effect from the initial stimulus leads to further action from the body that instead, decreases the effect. Negative feedback promotes stability and can be more commonly used in the body.

What does it mean for an epithelial cell to have polarity?

Polarity of the epithelia can be loosely defined as the cell having two different ends: the apical surface and the basolateral surface. The apical surface contains either microvilli that aid in absorption and secretion or cilia that help move fluid. The basolateral surface forms a barrier between the cell and other cells and acts as a good structure for epithelial cells to multiply.

What is positive feedback? Give an example and explain it.

Positive feedback, or a positive feedback loop, is a cyclic process that continues to amplify your body's response to a stimulus until an external stimulus causes it to stop. This simply means that the body is moving further away from homeostasis. An example of a positive feedback is child birth. When labor begins, the baby's head is pushed downwards, putting pressure on the cervix to stretch. This stimulates receptor cells to send a chemical signal to the brain to release oxytocin. The oxytocin diffuses to the cervix through the blood, which causes uterine contractions to occur. These contractions stimulate further oxytocin release until the baby is born and pushed out. Once the baby is born, the contractions will stop and the release of oxytocin will also stop. The body then will return to homeostasis.

List two regions of the body that undergo constant chemical and mechanical stress. What type of epithelial tissue is present in these areas?

Possible regions may include: skin, mouth, pharynx, esophagus, urethra, and the vagina. This is a protective epithelia with stratified squamous cells near the apical region and cuboidal underneath. The stratified aspect helps to maintain the integrity of the tissue as it undergoes various levels of chemical and mechanical stress.

Describe what polarity of epithelia means. In addition, what are the two surfaces of an epithelial cell?

Saying that an epithelia cell has polarity means that it has two distinctly different surfaces on each side of the cell. The first surface is called the apical surface and is the side that's open to the outside environment. It usually contains some cilia or microvilli, depending on what type of epithelia the cell is. The microvilli is able to increase absorption and secretion, and the cilia is there to move fluids along the surface of the cell. The second surface is called the basolateral surface which is also called the basal lamina (or basement membrane). It if the flooring for all epithelium and allows the cells attach to a solid surface containing collage and laminin fibers.

What are the steps in a reflex pathway?

Stimulus, sensor, inout signal, integrating center, output signal, target and response.

What is the difference between a first degree burn and third degree burn in regards to regeneration?

The basement layer is what provides a good structure for epithelial cells to multiply. A first degree burn is superficial to the skin, so tissues still have cells the will continue to multiply into adulthood as well as having the basement layer as a layer of support to help tissue regain its normal function. Third degree burns are when the basement membrane is damaged, so it can't regenerate to its normal look and function because there is no longer a good structure to build on.

There are three types of muscle tissue, skeletal, cardiac, and smooth muscle tissue. Each one has its own structure and function that is designed for a specific purpose. Of the muscles, cardiac muscle tissue is responsible for pumping heart. Knowing this could it be possible to have skeletal muscle replace cardiac muscle tissue?

The correct answer to this question is no. It is not possible because skeletal muscle tissue is voluntary meaning we do have to think about it to move the muscle. Because we have to think about it to move. It would virtually impossible to think of each movement one by one in the heart. Making the answer no in that skeletal muscle tissue could not replace cardiac muscle tissue.

Describe how the function of the hypodermis might differ from the epidermis due to composition.

The epidermis, having keratinocytes, will act as a protective layer. The hypodermis, being mostly composed of adipose tissues and adipocytes, will be involved in nutrient and energy storage.

List the three type of cell junctions and their functions

The first type of junction is communicating junction, or gap junction. The communicating junction allows direct cell to cell communication. The second type of junction is occluding junction, or tight junction. The occluding junction blocks movement of materials between cells. The third type of junction is anchoring junction, or desmosome junction. The anchoring junction holds cells to one another and to the extracellular matrix

One of the accessories of the integument is your glands. Explain the functions of the ceruminous gland.

The function of this integumentary gland is to produce cerumen, which can also be referred to as earwax. The another important function of this gland is to prevent foreign particles from reaching the eardrum.

List the functions of the integumentary system, include as many functions as possible

The integumentary system serves as a physical barrier against external damage (physical, thermal, chemical), a UV radiation buffer, an important layer of the immune system, and as a moisture and temperature regulator for the rest of the body.Skin is filled with strong elastic proteins and melanin that make it resilient to most types of damage. The skin has immune functions like preventing cancer from reproducing, killing bacteria, and neutralizing dangerous chemicals. Sebaceous glands and hair follicles add an extra layer of moisture and protection from the elements.

Why is protective epithelia stratified?

The multiple layers of cells found in stratified, protective epithelia protect against chemical and mechanical stress in locations of the body such as the mouth, skin, pharynx, esophagus, urethra, and vagina. The layer of squamous cells on the apical surface along with the numerous layers of cuboidal/polygonal cells below are there to replace the cells that have been damaged.

Explain the two steps of reflex control to maintain homeostasis.

The reflex control can be broken down into response look and feedback loop, it begins with the response loop. The response loop can be further broken down into seven stages: stimulus, sensor, input signal, integrating center, output signal, target and response. A stimulus will be picked up by a specialized sensor and convey the input signal to the integrating center. The integrating center will analyse the input signal and respond with an output signal for a target tissue or organ. When the output signal reaches the target the target tissue or organ will respond based on the signal it received. The feedback loop senses the change created by the target tissue or organ and ends the reflex response.

Explain how homeostasis is maintained through the reflex control.

The reflex control can be broken into two parts the response loop and the feedback loop. The response look senses the initial stimuli and responds to it, while the feedback loop sense the response loop response and ends the reflex control. The response loop can be broken down into seven parts: stimuli, sensor, input signal, integrating center, output signal, target, and respond. The stimuli is sensed by a specialized sensor that sends an input signal to the integrating center. At the integrating center the the input signal is interpreted and a output signal is sent to a target tissue or organ. The target tissue or organ then responds based off of the output signal and creates a response.

Between the three different types of muscular tissue, which one(s) move(s) voluntarily and which one(s) move(s) involuntarily?

The smooth muscle tissue and the cardiac muscle tissue both move involuntarily. Humans already have enough to think about with their body movements and their brains constantly preoccupied which is why it is so nice that our body supports us by making their own decision when the heart pumps and when to dilate our blood vessels. It is something we do not have to think about because it is "done for us." On the contrary, skeletal muscle tissue is only moved when we decide to move it, it is completely voluntary.

Give an example of a negative feedback loop found in the body. Name the steps of a negative feedback loop and match them to the part of the body related in the example.

The steps of a negative feedback loop are (1) a stimulus, (2) a sensor, (3) an input signal, (4) an integrating signal, (5) an output signal, (6) a target, (7) a response which stops the stimulus. One possible example is temperature control (Sweating). In this example the stimulus is a warmer temperature, the sensor would thermoreceptors in the skin, the input signal would be the neural pathways from the receptors to the hypothalamus as it translates the signal to cool the body from the receptor , the integrating signal in this example is the hypothalamus as it receives the input signal and properly addresses this issue, sending out a output signal to address the issue , the output signal is the neural pathways between the hypothalamus and the skin, as it sends a response signal from the integrating center to the target, the target would be the skin, as it is the thing that creates the response, and the response would be to lower the body temperature by sweating. This would stop the input signal of a high body temperature, therefore completing the negative feedback loop.

When getting a tattoo what is the deepest the layer of skin it will penetrate? and why does it become permanent?

The tattoo will go through your first layer of skin; the epidermis. Then continue to inject into the deeper part of your dermis where we have more permanent cells, nerve endings, blood vessels, and a mesh of collagen fibers; which means the ink will not fade. Opposed to temporary tattoos that are just on the epidermis which is dead and will come off.

What are the functions of the integumentary system and explain how the system carries out those functions?

There are 6 functions: protection, waste removal, thermoregulation, vitamin D3 synthesis, fat storage, and sensation. The integumentary system offers protection as a physical barrier. The system removes waste through the excretion of sweat. These waste products include urea, ammonia, salts and sugars. In cases of overheating, thermoregulation is also carried out by the excretion of sweat. Sweat is released from sweat glands and evaporates to dissipate body heat. In cases of low temperatures, core body temperature is conserved by the constricting of arterioles to reduce circulation. Vitamin D3 is synthesized from cholesterol by the exposure of the epidural layer of skin to UV radiation. D3 is then converted to vitamin D by the kidneys. Excess energy is stored as fat through the process of lipogenesis. Fat also aids in protection and thermoregulation as an insulating layer. Sensation is carried out though the sensory nerve structures that detect temperature, touch, and pain.

When a person gets a cut or a scrape, the process of sealing the wound is required quickly in order to limit pathogens entering the bloodstream as well as limit the loss of blood. Is this an example of a Positive or Negative feedback system? Describe the process in general terms.

This is an example of positive feedback. When skin is ruptured, the body receives the signal that there is an opening and responds by sending more blood to the cut. This causes platelets to begin sticking together and closing the wound, thus releasing chemicals that attract more platelets to the clot. This process continues and more and more platelets are sent to the area until the clot is large enough to stop the bleeding altogether. The process ends when chemicals are released to stop the increased platelet activity.

Your friend is running down a hill, trips, and falls scraping her knee. In the cut, a chemical is released by her body to produce platelets in order to stop the bleeding. Is this a positive or negative feedback?

This is positive because there is an increase of reaction causing her to move farther away from the target of equilibrium. It would not be negative because there is nothing that is decreasing the reaction.

During their clinical shift, this nursing student came across a male patient with burn injuries across both of his arms. The student took note that the patient had some hair present under the blisters on his arm. The injuries penetrated the epidermis layer and the upper layer of the dermis. How does this injury affect the patient's skin and other potential loss of functions?

This second degree burn affects the ability of the epidermis layer of the arm to allow nutrients and oxygen to diffuse from the capillaries in the dermis. The structures of the epidermis, such as the keratinocytes, basal cells, melanocytes, Langerhans cells, and Merkel cells to be affected. This causes the loss of function to the protection of the skin from UV radiations, the lost of first line of defense, and exposure to the lower layers of the dermis. Since it's mentioned that the patient's arm has hair, this may cause a lack of protection from UV radiations, lubrications, sensation, insulation, and body temperature from the injuried hair follicles.

Homeostasis can be defined as a stagnant, internal state of equilibrium. Is this statement correct? Why or why not? Provide evidence for your reasoning.

This statement is not correct because homeostasis is not at all stagnant, in fact it is very dynamic. Homeostasis involves the constant movement of information and materials within and among the body and its many parts all in an attempt to maintain the most IDEAL internal environment, NOT one that is at equilibrium.

What's two ways the Integumentary System protects your body throughout the day or your lifetime?

Two ways the Integumentary System protects your body is through protection and maintenance of body temperature. The skin protects the inside of your body by providing a physical barrier between the inside of the body and the outside world. It can protect the body from things like impact and chemicals. The Integumentary system also maintains body temperature. It helps your body so you don't get too hot or cold and stay at a temperature that is healthy. These two things would count as an answer for this question because protection and temperature regulation are functions of the Integumentary System and help protect the body.

Explain the term 'selectively permeable', applied to a cell membrane, and list several solutes or molecules that can cross a cell membrane with and without transport protein

When cell membranes are selectively permeable it means that some molecules can cross them but others cannot. Some molecules, such as oxygen, carbon dioxide, and lipids, move easily across most cell membranes. On the other hand, ions, most polar molecules, and very large molecules (such as proteins, amino acids), enter cells with more difficulty or may not enter at all.

Integumentary system (6 pts)a) What are 4 functions of the integumentary system and name the two major parts. (2 pts)b) What Major part of the integumentary system is the Dermis apart of? And what are the two layers of the Dermis and their functions? (3 pts)c) What is the function of nails? (1 pt)

a) FUNCTIONS: Protection, excretion, maintenance of body temp, vitamin D3 synthesis, general sensation, lipid storage. MAJOR PARTS: Cutaneous Membrane and Accessory Structures.b) MAJOR PART: The cutaneous membrane. TWO LAYERS: papillary layer- nourishes and supports epidermis, reticular layer- has sensory receptors to detect pain, temp, pressure, vibration, touch... has blood vessels that assist in thermoregulation.c) FUNCTION: protect and support tips of fingers and toes.

a. Why is it important for all organisms to maintain homeostasis?b. Does Positive Feedback help to maintain homeostasis? Explain why or why not.

a. Homeostasis regulates many things such as temperature, chemicals, hormones, and many other processes in the body, and helps to keep internal environments regulated even when external environments change. It is important to have so that the body does not get too hot or cold, or have too many or too little chemicals in the body.b. Positive Feedback does not help maintain homeostasis. In positive feedback the stimulus creates a response that produces an even bigger stimulus, and the loop keeps moving and growing in the same direction until an external factor interrupts and stops the process. This is very unstable and does not help to regulate systems in the body but rather can cause them to go out of control if an external factor does not stop or regulate the process.

There are 3 different degrees of burns. Some heal more rapidly than others, while some rarely heal at all.i. Which degree of burn usually cannot be healed or has the hardest time healing?ii. What important part of the tissue is damaged, contributing to theslowed/nonexistent healing process associated with this type of burn?iii. Why does the damage of this portion of the tissue lead to a slowed/nonexistenthealing process in accordance with this type of burn?

i. A third (3rd) degree burn usually cannot be healed or has the hardest time healing.ii. The important part of the tissue that is damaged, contributing to the slowed/nonexistent healing process associated with a 3rd degree burn is the basal lamina/basement membrane.iii. The damage of the basal lamina/basement membrane leads to a slowed/nonexistent healing process in accordance with a 3rd degree burn because the basement membrane is a very thick and secure matrix of collagen and laminin. It is primarily responsible for holding the tissue together and also serves as the platform for which the repair of damaged tissue occurs upon. The basal lamina rarely is able to be repaired on its own and therefore, if this layer is damaged , the tissue cannot be repaired.

What are the two different types of feedback loops and give an example for each.

there are positive feedback loops, this is when the product of the reaction leads to more, this leads to getting further away from homeostasis until the final result is achieved, an example of this is child birth. There are also negative feedback loops which is a reaction that is trying to get the product back to homeostasis, if its body temperature and someone is too hot the body will sweat and use other mechanisms to cool down until the optimum temperature is achieved. If body temperature was a positive feedback loop the body wouldn't stop the cooling process and the cooler the body became the more cooling mechanisms it would use.