HBS Unit 2.3 and 2.4 Assessment

Tapetum

(not in a human eye) functions as night vision

If someone eats a candy bar, will their glucose go down or up? Apply this knowledge to tell how the body will react to this. Use words such as glucose, insulin, beta cells, pancreas, and glucagon.

A candy bar contains a lot of sugar, and by extension contains a lot of glucose. Once someone eats a candy bar, the amount of glucose is released into the bloodstream. To be able to manage this, the pancreas secretes insulin through its beta cells. The pancreas is a part of the endocrine system. Insulin is a hormone that decreases glucose levels by using target cells which use glucose for ATP production. Insulin also stimulates the liver to store glucose as glycogen for future use.

Glands

A cell, group of cells, or organ of endothelial origin that selectively removes materials from the blood, concentrates or alters them, and secretes them for further use in the body or for elimination from the body.

What are negative feedback loops?

A demonstration of how the body maintains homeostasis.

Exocrine gland

A gland (as a sweat gland, a salivary gland, or a kidney) that releases a secretion external to or at the surface of an organ by means of a canal or duct.

Endocrine Gland

A gland (as the thyroid or the pituitary) that produces an endocrine secretion -- called also ductless gland, gland of internal secretion.

Glucagon

A protein hormone that is produced especially by the pancreatic islets of Langerhans and that promotes an increase in the sugar content of the blood by increasing the rate of breakdown of glycogen in the liver.

Insulin

A vertebrate hormone that lowers blood glucose levels by promoting the uptake of glucose by most body cells and the synthesis and storage of glycogen in the liver.

Outline what happens in the human body from an initial stimulus to a response in both voluntary and involuntary actions.

A voluntary action goes through the judgement process through the brain whereas an involuntary action goes through the reflex arc. A voluntary action has more reaction time than an involuntary reflex.

Does ADH relate to homeostasis? Why or why not?

ADH does relate to homeostasis because it has to do with the regulation of water, and ensuring the balance of water in the body.

Pituitary Gland

An endocrine gland at the base of the hypothalamus; consists of a posterior lobe, which stores and releases two hormones produced by the hypothalamus, and an anterior lobe, which produces and secretes many hormones that regulate diverse body functions.

Create and support an environment that fosters teamwork, emphasizes quality, and promotes learning.

An environment in which a team can put forward ideas can then collaborate to work towards a solution that has quality and is efficient.

Recall what astigmatism is.

An eye condition characterized by an oval shaped cornea and blurry vision. In rare cases astigmatism can be caused by a distorted lens shape.

Describe how imbalances in the body system can result in diseases.

An imbalance in hormones can result in disease. For example, and no insulin which is a type of hormone could lead to diabetes.

A patient with cataracts decides to get a surgery. Who should they go see?

An opthalmologist

A patient receives a prescription for glasses, who should they go see?

An optician

A patient goes to their annual eye exam. Who are they going to?

An optometrist

"Explain how solutions for complex problems can require interdisciplinary collaboration to incorporate a wide range of perspectives and skills." Apply this to opticians and optometrists.

An optometrist can perform eye exams, and if a patient needs glasses then the optometrist can refer them to an optician. This example demonstrates how two biomedical professionals can work together to help a patient.

Cone

Any of the conical photosensitive receptor cells of the vertebrate retina that function in color vision.

Rod

Any of the long rod-shaped photosensitive receptors in the retina responsive to faint light.

Hormone

Any one of the many circulating chemical signals found in all multicellular organisms that are formed in specialized cells, travel in body fluids, and coordinate the various parts of the organism by interacting with target cells.

A patient comes in with sensitivity to light, difficulty seeing the the dark, difficulty discerning colors, and differences in vision between both eyes. What might be the cause? What is the course of treatment?

Cataracts, there is a surgery that ophthalmologists do

Demonstrate the importance of punctuality and meeting deadlines.

Certain situations are time-sensitive, such as medical conditions requiring treatments and help immediately, so by being punctual it is helping the process move more efficiently.

Compare and contrast chemical and electrical modes of communication.

Chemical modes of communication can be hormones and electrical modes can be synapses. Both are forms of communication with a similar purpose of having to send messages and contribute to the functions of the body.

Viterious Humor

Clear viscous substance that fills the eyeball behind the lens

Retina

Converts what is seen by the eye into what is sent as neural signals to the brain to interpret

Which eye disease can cause blindness and has the death of cells in the macula and surrounding retina tissue?

Dry Macular Degeneration

Write a biomedical professional who could work with the endocrine system.

Endocrinologist A doctor who specializes in the endocrine system, such as hormone related diseases and conditions.

"Solutions for complex problems can require interdisciplinary collaboration to incorporate a wide range of perspectives and skills." Apply this knowledge to endocrinologists and another biomedical professional.

Endocrinologists can often collaborate and work with neurologists. The endocrine system and the nervous system both work together when sending signals and messages throughout the body. Therefore often, when diagnosing or relative duties, endocrinologists and neurologists which are interdisciplinary can collaborate. Each can bring perspective of their own knowledge as well.

True or false: Insulin and glucagon are neurotransmitters.

False, insulin and glucagon are hormones

True or false: Light enters the eye through the pupil

False, light first enters through the cornea, which refracts light

Aqueous humor

Fluid which fills the space between the lens and cornea

Describe medical interventions that improve human health.

Glasses, cataract surgery, LASIK surgery

Name three of the body's functions that hormones regulate

Growth and development, metabolism, and reproduction

Essential Question: How do hormones and feedback mechanisms maintain homeostasis in the human body?

Hormones and feedback mechanisms maintain homeostasis in various ways. Negative feedback loops can involve hormones which have a role to counterbalance the variable which is shifting homeostasis.

What are positive feedback loops?

How the body reacts and adds to a variable that might affect it to be out of homeostasis.

A patient comes in unable to see nearby, and experience blurry vision. What might be the cause? What is the course of treatment?

Hyperopia, and can be treated by glasses or sometimes surgery

Apply knowledge about the pituitary gland, hypothalamus, and hormones to write out a feedback loop for the regulation of metabolism in the body.

If the thyroid levels decrease, then the hypothalamus releases more TRH which is sent to the pituitary gland. Then the TRH signals the pituitary gland to release TSH. The TSH causes the thyroid to make more hormones, thereby regulating the metabolism in the body. If the thyroid levels increase, then the hypothalamus releases less TRH which is sent to the pituitary gland. Afterwards, the TRH releases TSH (less is produced) and then less TSH means that there are less thyroid hormones overall. This also regulates the metabolism of the body.

Describe two problems in the loop which can produce an imbalance of sugar in the blood and lead to diabetes.

If there is no insulin present then that can lead to diabetes because there would be no regulation of glucose and sugars in the body, If there is insulin, but the insulin receptors cannot respond and communicate with the glucose in order to regulate the levels.

Explain how light is processed differently in a person with proper vision versus a person with myopia or hyperopia.

In myopia the eyeball is either elongated or the cornea curves too sharply, so the light rays focus in front of the retina and therefore cause blurry vision. In hyperopia a shortened eyeball or a flat cornea results in light being focused behind the retina, blurring everything nearby. Eyesight should be taken in and refracted by the cornea to point to the retina at the proper angle.

What roles do these muscles play?

In other words, the muscles allow for more flexibility in a sense, where the eye can move in more directions.

Explain how events can cause organ system dysfunction and lead to disease.

Infections or injuries are events that can cause multiple system organ failure due to sepsis. When many organs fail, that can lead to disease as there is a loss of communication meaning that the organs aren't doing their job, thus homeostasis is interrupted in addition to the daily activities and tasks of the body not being preformed.

What is the function of the hypothalamus in regards to the endocrine system?

Influences energy balance and glucose metabolism (for example, pancreatic secretion)

Demonstrate the importance of honesty, integrity, and accountability for biomedical professionals.

It is important for biomedical professionals to maintain honesty, integrity and accountability in their professions. Honesty and integrity allow for people to place trust in the findings and conclusions of the data. Additionally, having integrity and honesty demonstrates that the conclusions are in fact truthful. Accountability is important as it teaches valuing the work as well as being responsible.

Explain the value of diverse perspectives in the problem-solving process.

It provides many potential solutions with many approaches to a problem, and can help with efficiency.

Seeing the state of the retina after removing the fluid, what would happen to the retina if this fluid was not present? How would this affect vision?

Light would not be able to pass through to the blind spot which is a location on the retina. This would affect vision because then one would not be able to see.

How is the exocrine system related to homeostasis?

Maintaining the body temperature is apart of homeostasis. The exocrine system is relevant because the sweat glands are apart of the exocrine system. When the body overheats, these glands are met with hormones and signals to release sweat. This lowers the body temperature, which means homeostasis is maintained.

What is the function of myelin?

Myelin allows electrical impulses to travel in order to send signals to the brain.

A patient comes in unable to see at a distance, and experience blurry vision. What might be the cause? What is the course of treatment?

Myopia, and can be treated by glasses or sometimes surgery

Explain how the body uses feedback mechanisms to maintain proper levels of hormones for homeostasis.

Negative feedback mechanisms are used to maintain levels of hormones such as thyroid metabolism.

Model the structures and describe the functions of the nervous and endocrine systems, as well as sensory organs such as the eye.

Nervous system CNS, PNS (Brain, Spinal cord, Nerves) Sensory input, integration, motor output, communication Endocrine system Pituitary gland, Thyroid gland, Adrenal gland, Pancreas Secretion of hormones that coordinate and direct target cells and organs Eye Orbicularis Oculi - A ringlike band of muscle, called a sphincter muscle, surrounding the eye. Lies in the eyelid tissue so the eye can close or blink. Helps a tear flow over the surface of the eye. Corneas, retina, eye socket Vision

What system does the endocrine system work with to regulate and control all the actions of the human body?

Nervous system, specifically the hypothalamus

We have already talked about another class of chemicals that helps send signals in the body—neurotransmitters. How are neurotransmitters and hormones similar and how are they different?

Neurotransmitters and hormones have similarities between them. Both are released with a function, and have to attach to receptors in order to be activated. Neurotransmitters are released and have to attach to a receptor on the receiving neuron. Hormones are released from a gland and need to meet with a connecting receptor in order to perform their functions. Furthermore, both help in the response of the body and communication. Both can also play a role in the emotional responses of the body. Neurotransmitters and hormones can also have differences. For example, neurotransmitters are found within neurons whereas hormones have a more cellular structure. Neurotransmitters are communicated through synapses between neurons, and hormones are communicated through the bloodstream.

Essential Question: How can new technology improve human vision?

New technology such as LASIK surgery can improve vision. This is because a laser is used to change the shape of the tissue in front of the cornea in order to improve vision. This would cause the cornea to refract the light precisely to the retina. In myopia, the light is taken in however isn't refracted properly to the retina, and therefore the vision is blurry. Glasses can also help with vision, because they can refract the light.

What shape is the pupil in a cow's eye?

Oval

Describe how persistence is a key mindset when identifying problems and/or pursuing solutions.

Persistence is a key mindset when identifying problems and pursuing solutions because it demonstrates that despite errors there is determination towards finding the solution. It shows determination and the fact that one is unwilling to give up. Furthermore, this mindset is a positive one which is a good motivator.

Lens

Refracts light to focus on the retina and works with the cornea

Which eye disease has damage to the retina?

Retinitis Pigmentosa

Explain how scientists use calculated risks to increase scientific knowledge.

Scientists use calculates risks to increase scientific knowledge, so that they can understand the risks so that they can choose which route to take. For example, a scenario with a larger calculated risk would be avoided and not taken.

Is the sclera designed for strength or clarity?

Strength because the external layer is protecting the eyeball. The sclera is additional protection from the external environment, and possible dangers to the eye.

What tests is the letters chart used? What is it called? In this test, what structure of the eye is tested along with what function?

The Snellen chart is used. This is called the visual acuity test. In this test the visual perception of the eye is checked by examining the iris which controls the amount of light that enters the eye, thereby adjusting the pupil size.

What differences are present between the aqueous and vitreous humors?

The aqueous humor is the fluid between the lens and the cornea, whereas the vitreous humor is the clear substance behind the lens which fills the eyeball. The vitreous humor is a jelly like substance which is a mixture of protein and water, whereas the aqueous humor is more water like. The vitreous humor is clear so that light can pass through it.

Applying knowledge about insulin and glucose, what would happen if the hormone insulin stopped doing its job?

The body has trouble controlling blood sugar and maintaining homeostasis. There is a possibility of diabetes as well.

Note that the cornea does not have any blood vessels. Given the function of the cornea, why is it important that the cornea is clear and free of blood vessels?

The cornea doesn't have any blood vessels because they would obstruct vision. Since the cornea is circling the lens of the eye, in order to see it is important there not be any blood vessels there, otherwise one would be unable to see.

Describe two ways in which the cow eye and the human eye differ. How are these differences linked to function?

The cow eye is different from the human eye because it has five muscles. The human eye has seven muscles. This impacts the function because the cows' eyes move more up, down, and side to side. The human eye moves more freely according to the video. Another difference between the human eye and the cow eye is that cows have the tapetum and humans don't. Therefore, cows have night vision, and humans don't.

How do you think the endocrine system and the nervous system work together to control communication in the body?

The endocrine system and the nervous system works together to control communication in the body. For example, the hypothalamus which is a part of the nervous system plays an important role in the endocrine system. The hypothalamus is located in the brain, and the function of the hypothalamus is to influence the energy balance and the glucose metabolism. For example, the pancreatic secretion of the hormone insulin is controlled by the hypothalamus. Furthemore, the pituitary gland also works to control the chemical balances and hormones in the body. Thus, the endocrine system and nervous system work together to communicate throughout the body.

How does the endocrine and nervous system work together to communicate throughout the body?Draw a connection between both systems towards the pancreas.

The endocrine system and the nervous system works together to control communication in the body. For example, the hypothalamus which is a part of the nervous system plays an important role in the endocrine system. The hypothalamus is located in the brain, and the function of the hypothalamus is to influence the energy balance and the glucose metabolism. They work together in terms of the pancreas, because that is the organ of the body that is involved with insulin. For example, the pancreatic secretion of the hormone insulin is controlled by the hypothalamus. Furthermore, the pituitary gland also works to control the chemical balances and hormones in the body. Thus, the endocrine system and nervous system work together to communicate throughout the body.

Essential Question: How does an error in the structure or function of the eye relate to disease or dysfunction?

The error in structure or function of the eye can relate to disease and dysfunction. For example, if the retina's structure is impaired or unable to do its job, then it can cause Retinitis Pigmentosa. If the optic nerve doesn't do its job then it can cause glaucoma.

Elaborate on the difference between the exocrine and endocrine system.

The exocrine system secretes hormones externally whereas the endocrine system secretes hormones internally.

How does sweat relate to the exocrine system?

The exocrine system secretes hormones externally. Therefore the sweat glands are apart of the exocrine system, and the hormones involved would lead to the release of sweat. Therefore, sweat is thereby related to the exocrine system.

Essential Question: How do the eye and the brain work together to process what we see?

The eye takes in the image by the cornea. Then proceeds to the lens, when focus or refract the light to the retina, which then convert the light to electrochemical impulses which are transferred to the optic nerve which can be neural signals delivered to the brain.

What is the function of the eyelid and eyelashes?

The function of the eyelashes is to protect the eye from debris, and to also reflexively close the eye in case of any impending danger to it, such as dust. The eyelid is the layer of skin which protects the eye, meaning if there is a sense of danger to the eye, the eyelid will close in order to act as a layer of protection towards the eye.

Endocrine System

The glands and parts of glands that produce endocrine secretions, help to integrate and control bodily metabolic activity, and include especially the pituitary, thyroid, parathyroid, adrenals, islets of Langerhans, ovaries, and testes.

Essential Question: How can improper levels of a hormone lead to disease or dysfunction in the human body?

The hormone would not be present to counterbalance the variable and return the body back to homeostasis. Since homeostasis would not be achieved, then the body may fall ill. For example, if there is no insulin to regulate the variable that is glucose, then diabetes could occur.

Based on the function of this structure, why doesn't the human eye have a tapetum?

The human eye doesn't have a tapetum because humans don't have night vision.

Why is the human eye is surrounded by seven different muscles?

The human eye is surrounded by seven different muscles to allow the eye to move more freely.

Describe an example that illustrates this statement: "Some hormones control the release of other hormones."

The hypothalamus is a hormone that releases TRH which then travels to the pituitary gland, thereby releasing TSH. The hormone TRH controls the release of the hormone TSH.

Explain the role the hypothalamus plays in regulating hormone action.

The hypothalamus is to influence the energy balance and the glucose metabolism. Since glucose metabolism and the energy balance is affected also by the hormones released by the pituitary gland, the hypothalamus and pituitary gland work together to regulate hormone action. Another example is when the regulation of thyroid hormones, the hypothalamus sends TRH to the pituitary gland to release TSH which controls the thyroid regulation. The hypothalamus sends signals that release hormones which play a role in regulating hormone action.

Essential Question: How does information received through sight initiate a response in other body systems?

The information received through sight can initiate a response in other body systems. External stimuli can affect some of the other body systems. For example, if one saw a car in the road, then the nervous system would signal to the muscle and skeletal system to move out of the way. Or if one was at the beach and saw a wave, then this would signal to the respiratory system to hold one's breath. Therefore, vision can impact a response of the other body systems.

Homeostasis

The maintenance of relatively stable internal physiological conditions (as body temperature or the pH of blood) in higher animals under fluctuating environmental conditions.

Describe how the membrane looks in the cow's eye dissection video and compare it to the 3D model.

The membrane in the cow's eye dissection video is similar to the cornea of the 3D model. Both are acting as a protective layer to the eye.

The optic nerve takes messages back to the brain which then interprets the signal projected on the retina. Which area(s) of the brain is (are) responsible for processing these signals?

The occipital lobe is responsible for vision and visual perception in the brain.

Match regions of the brain with their primary function in the human body.

The occipital lobe is the part of the brain that helps with vision.

Iris

The opaque muscular contractile diaphragm that is suspended in the aqueous humor in front of the lens of the eye, is perforated by the pupil and is continuous peripherally with the ciliary body, has a deeply pigmented posterior surface which excludes the entrance of light except through the pupil and a colored anterior surface which determines the color of the eyes.

Pupil

The opening of the iris which allows light to enter the eye

An optometrist has to test a patient for glaucoma. What test will they perform? Elaborate further on the structure and function of the eye.

The optometrist would perform an eye pressure check. This would check the intraocular pressure, where a puff of air is blown into the eye to test for pressure. This also examines the optic nerve, which sends signals to the brain.

Analyze physical symptoms of a patient and relate these symptoms to errors in hormonal levels.

The physical symptoms of fatigue, and ketones in the urine and relative to the errors in the insulin levels. Ketones form because they are a breakdown of muscle and fat which occurs because there isn't enough insulin to regulate the glucose. Fatigue occurs because glucose intake means that there isn't much energy supplied to the body.

What is the structure of the pituitary gland?

The pituitary gland in humans is the size of almost a pea, and is located between the hypothalamus and the pineal gland.

Discuss three hormones that the pituitary gland produces.

The pituitary gland produces hormones such as TSH which stimulates the thyroid and metabolism in tissues. Another hormone produced by the pituitary gland is ACTH which controls the production of cortisol, which is present in small glands above the kidneys. The pituitary gland can also produce hormones which are known as GH hormones which are known as growth hormones. Their target organ is all tissues.

What is the function of the pituitary gland?

The pituitary gland secretes nine hormones, which cause other endocrine glands to secrete their own type of hormones. The pituitary gland monitors body function and delivers signals to other organs and glands to maintain homeostasis.

Sclera

The white external layer of the eyeball

An optometrist has to check for Retinitis Pigmentosa. What test will they perform? Elaborate on the structure and function of the eye.

They might perform a retinoscopy, which is when a retinoscopy light is shined into the eye, and a series of lenses is flipped to test the retina's ability to refract light.

Is your body's response an example of positive or negative feedback? (relating to the regulation of sugar in the body)

This is a negative feedback loop, because the body is countering the variable. In this case, the variable is the blood sugar levels either decreasing or increasing. The body doesn't add to this, meaning it doesn't promote more of the blood sugar levels decreasing or increasing, and that would be a positive feedback loop. The body instead counteracts these variables through insulin or glycogen and glucagon. Therefore, it is a negative feedback loop.

Is the pupil's response an involuntary reflex or a voluntary action? How is this response controlled by the nervous system?

This is an involuntary reflex because it is a natural reflex. This response is controlled by the nervous system because this reflex when the autonomic nervous system's sympathetic branch is stimulated and then the pupil dilates.

Where are hormones secreted from?

Tissues in the body referred to as glands

What is the function of the hormone ADH?

To help the kidneys maintain water balance.

Cornea

Transparent coat of the eyeball, protecting the iris and pupil

True or false: The retina is the sensory layer of the eyeball which contains receptors for sight, called rods and cones. The eye uses light coming in to make an image, a picture which lands on the retina.

True

True or false: Hormones are proteins.

True, hormones are proteins

True or false: There is a correlation between glaucoma and eye pressure.

True, there is a correlation between glaucoma and eye pressure

Recall who an optometrist is. Name 3 exams they may do in order to examine someone's vision.

Visual Acuity Test Eye pressure check Retinoscopy

Describe how what you see can impact other human body systems. Provide at least five specific examples of how your communication with the outside world through your eyes initiates a response in another body system.

What the eyes see can impact other human body systems. For example, if the eyes see a danger, then the nervous system will respond by providing a reflex. While at the beach, the eyes can see a wave and that would signal the respiratory system to hold one's breath. While riding a bike, the eyes can see the red light which would indicate the muscular system to press the brakes on the bike. If one cannot see a paper cut on their finger then they won't know to put a bandage on it which would impact the integumentary system. Another example is if someone was standing in a line and couldn't see they might not know when to move.

Draw a connection between insulin and glucagon towards homeostasis.

When the blood sugar, or glucose levels rise in the body then the pancreas secretes insulin, releasing it into the bloodstream. Insulin is a hormone that decreases glucose levels by using target cells which use glucose for ATP production. Insulin also stimulates the liver to store glucose as glycogen for future use. Insulin continues to decrease the amount of glucose (sugar) in the blood stream through absorption. Homeostasis is then maintained. If blood sugar decreases then glucagon is released to meet the target organ: the liver. The liver releases glycogen which has stored glucose in it. Glucose (sugar) is released into the bloodstream. This maintains homeostasis.

Optic nerve

Where all the nerves exit to go to the brain

Blind spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there, and light is not stimulated here