Normal Carbohydratic Feedback System
Bioscience 1 Assessment 2 (Part B)
Student Name: Leana Maria S. Ragaza
Student number: 18580538
Note: please ensure you have included in text references in the answers to show the source of all information
Answer the following questions:
Question 2: Normal carbohydrate digestion results in glucose being absorbed into the blood and elevating blood glucose levels. Why do body cells need glucose? Describe the homeostatic feedback system that would be activated in response to an elevated blood glucose level.
Answer:
Glucose is the most important fuel for cells as it is used for the synthesis of adenosine triphosphate (ATP), which is a form of energy all body cells can utilise (Marieb & Hoehn, 2015). Moreover, neurons and red blood cells are …show more content…
entirely dependent on glucose for energy (Marieb & Hoehn, 2015).
Despite the continuous changes in the internal and external environment, the body requires a relatively stable internal environment to be able to function properly.
The body's ability to maintain its optimal environment is called homeostasis and is maintained through feedback systems through the nervous and endocrine systems (Jenkins & Tortora, 2013). The negative feedback system is activated in response to elevated blood glucose level (BGLs) to reduce or reverse changes in the controlled condition through the endocrine system (Jenkins & Tortora, 2013). There are three main components to the negative feedback system - receptors, control centre, and effector (Jenkins & Tortora, 2013). When a controlled condition is altered by a stimulus, the change is detected by the receptor (Jenkins & Tortora, 2013). The receptor then sends this information as input to the control centre, which then compares this to the normal range (Jenkins & Tortora, 2013). If found to be above or beyond the set values, the control sends information as output to the effector, either as hormones or electrical signals, to reduce or reverse the change in the controlled condition (Jenkins & Tortora, 2013). In this case, the stimulus of the elevated BGLs (hyperglycaemia) is detected by the beta cells of the pancreatic islets (receptor) (Tortora & Derrickson, 2012). This input is then compared by the beta cells of the pancreatic islets in
the pancreas (control centre) located in the curve of the duodenum, to the normal range (Tortora & Derrickson, 2012). Hyperglycaemia stimulates the beta cells of the pancreatic islets to release insulin (effector), which then acts on body cells to increase glucose absorption to remove it from the bloodstream (Tortora & Derrickson, 2012). Insulin accelerates facilitated diffusion of glucose into cells, conversion of glucose into glycogen (glycogenesis), and the synthesis of fatty acids (lipogenesis) (Jenkins & Tortora, 2013). Additionally, insulin increases the uptake of amino acids and protein synthesis (Jenkins & Tortora, 2013). Insulin also decelerates the conversion of glycogen into glucose (glycogenolysis) and the synthesis of glucose from lactic acid and certain amino acids (Jenkins & Tortora, 2013). When BGLs return within the normal range, insulin release is inhibited (Tortora & Derrickson, 2012).
Question 3: Vitamins and minerals are important for body health. Name sources and describe the role of calcium ions and vitamin D in maintaining bone health. What would be the consequence to bone health if there was a lack of either calcium or vitamin D in the body?
Answer:
Some dietary sources of calcium are dark green vegetables, legumes, dairy products, and beverages with calcium such as fortified orange juice (Marieb & Hoehn, 2015; Health Link British Columbia, 2017). Vitamin D, on the other hand, is uncommon in most foods as it is made in the skin, can be found in dairy products, oily fish, cod liver oil, egg yolk, margarine, and other products fortified with vitamin D (Marieb & Hoehn, 2015; British Dietetic Association, 2016).
Vitamin D increases the absorption of calcium and phosphorus from foods in the gastrointestinal tract, which helps build osseous tissue (Jenkins & Tortora, 2013). Without vitamin D, calcium absorption is hindered and can lead to deficient skeletal health (Holick & Nieves, 2014; British Dietetic Association, 2016). Calcium is essential for the formation of strong teeth as well as bones because bones are constantly broken down and remodelled (Holick & Nieves, 2014). It is also important for physiological processes such as blood clotting (Marieb & Hoehn, 2015). Additionally, stable calcium ion levels in the surrounding extracellular fluid are required by nerve and muscle cells to function adequately (Jenkins & Tortora, 2013).
Bone deformities (rickets) in children and bone softening (osteomalacia) in adults are consequences of Vitamin D deficiency (Marieb & Hoehn, 2015. The repercussions of calcium deficiency are growth retardation, potential bone mass loss, and increased risks of fractures (Holick & Nieves, 2014; Marieb & Hoehn, 2015). The vitamin D and calcium deficiency can also result in the inability to gain the maximum peak bone mineral density prescribed genetically (Holick & Nieves, 2014). Furthermore, vitamin D and calcium deficiency could precipitate accelerated bone loss that can cause and exacerbate osteoporosis, potentially reducing quality of life (Holick & Nieves, 2014).
References
British Dietetic Association. (2016). Food fact sheet. Retrieved from https://www.bda.uk.com/foodfacts/VitaminD.pdf
Health Link British Columbia. (2017). Food sources of calcium and vitamin D. Retrieved from https://www.healthlinkbc.ca/healthlinkbc-files/sources-calcium-vitamin-d
Holick, M.F., & Nieves, J.W. (Eds.). (2014). Nutrition and bone health (2nd ed.). Retrieved from https://ebookcentral.proquest.com/lib/uwsau/reader.action? docID =1968115
Jenkins, G.W., & Tortora, G.J. (2013). Anatomy and physiology: from science to life (3rd ed.). Hoboken, NJ: John Wiley & Sons.
Marieb, E.N., & Hoehn, K.N. (2015). Human anatomy and physiology, global edition (10th ed.). Essex, England: Pearson Education Limited.
Tortora, G.J., & Derrickson, B. (2012). Principles of anatomy & physiology (13th ed.). Hoboken, NJ: John Wiley & Sons
Page 2 of 2
Student Name: Leana Maria S. Ragaza
Student number: 18580538
Note: please ensure you have included in text references in the answers to show the source of all information
Answer the following questions:
Question 2: Normal carbohydrate digestion results in glucose being absorbed into the blood and elevating blood glucose levels. Why do body cells need glucose? Describe the homeostatic feedback system that would be activated in response to an elevated blood glucose level.
Answer:
Glucose is the most important fuel for cells as it is used for the synthesis of adenosine triphosphate (ATP), which is a form of energy all body cells can utilise (Marieb & Hoehn, 2015). Moreover, neurons and red blood cells are …show more content…
entirely dependent on glucose for energy (Marieb & Hoehn, 2015).
Despite the continuous changes in the internal and external environment, the body requires a relatively stable internal environment to be able to function properly.
The body's ability to maintain its optimal environment is called homeostasis and is maintained through feedback systems through the nervous and endocrine systems (Jenkins & Tortora, 2013). The negative feedback system is activated in response to elevated blood glucose level (BGLs) to reduce or reverse changes in the controlled condition through the endocrine system (Jenkins & Tortora, 2013). There are three main components to the negative feedback system - receptors, control centre, and effector (Jenkins & Tortora, 2013). When a controlled condition is altered by a stimulus, the change is detected by the receptor (Jenkins & Tortora, 2013). The receptor then sends this information as input to the control centre, which then compares this to the normal range (Jenkins & Tortora, 2013). If found to be above or beyond the set values, the control sends information as output to the effector, either as hormones or electrical signals, to reduce or reverse the change in the controlled condition (Jenkins & Tortora, 2013). In this case, the stimulus of the elevated BGLs (hyperglycaemia) is detected by the beta cells of the pancreatic islets (receptor) (Tortora & Derrickson, 2012). This input is then compared by the beta cells of the pancreatic islets in
the pancreas (control centre) located in the curve of the duodenum, to the normal range (Tortora & Derrickson, 2012). Hyperglycaemia stimulates the beta cells of the pancreatic islets to release insulin (effector), which then acts on body cells to increase glucose absorption to remove it from the bloodstream (Tortora & Derrickson, 2012). Insulin accelerates facilitated diffusion of glucose into cells, conversion of glucose into glycogen (glycogenesis), and the synthesis of fatty acids (lipogenesis) (Jenkins & Tortora, 2013). Additionally, insulin increases the uptake of amino acids and protein synthesis (Jenkins & Tortora, 2013). Insulin also decelerates the conversion of glycogen into glucose (glycogenolysis) and the synthesis of glucose from lactic acid and certain amino acids (Jenkins & Tortora, 2013). When BGLs return within the normal range, insulin release is inhibited (Tortora & Derrickson, 2012).
Question 3: Vitamins and minerals are important for body health. Name sources and describe the role of calcium ions and vitamin D in maintaining bone health. What would be the consequence to bone health if there was a lack of either calcium or vitamin D in the body?
Answer:
Some dietary sources of calcium are dark green vegetables, legumes, dairy products, and beverages with calcium such as fortified orange juice (Marieb & Hoehn, 2015; Health Link British Columbia, 2017). Vitamin D, on the other hand, is uncommon in most foods as it is made in the skin, can be found in dairy products, oily fish, cod liver oil, egg yolk, margarine, and other products fortified with vitamin D (Marieb & Hoehn, 2015; British Dietetic Association, 2016).
Vitamin D increases the absorption of calcium and phosphorus from foods in the gastrointestinal tract, which helps build osseous tissue (Jenkins & Tortora, 2013). Without vitamin D, calcium absorption is hindered and can lead to deficient skeletal health (Holick & Nieves, 2014; British Dietetic Association, 2016). Calcium is essential for the formation of strong teeth as well as bones because bones are constantly broken down and remodelled (Holick & Nieves, 2014). It is also important for physiological processes such as blood clotting (Marieb & Hoehn, 2015). Additionally, stable calcium ion levels in the surrounding extracellular fluid are required by nerve and muscle cells to function adequately (Jenkins & Tortora, 2013).
Bone deformities (rickets) in children and bone softening (osteomalacia) in adults are consequences of Vitamin D deficiency (Marieb & Hoehn, 2015. The repercussions of calcium deficiency are growth retardation, potential bone mass loss, and increased risks of fractures (Holick & Nieves, 2014; Marieb & Hoehn, 2015). The vitamin D and calcium deficiency can also result in the inability to gain the maximum peak bone mineral density prescribed genetically (Holick & Nieves, 2014). Furthermore, vitamin D and calcium deficiency could precipitate accelerated bone loss that can cause and exacerbate osteoporosis, potentially reducing quality of life (Holick & Nieves, 2014).
References
British Dietetic Association. (2016). Food fact sheet. Retrieved from https://www.bda.uk.com/foodfacts/VitaminD.pdf
Health Link British Columbia. (2017). Food sources of calcium and vitamin D. Retrieved from https://www.healthlinkbc.ca/healthlinkbc-files/sources-calcium-vitamin-d
Holick, M.F., & Nieves, J.W. (Eds.). (2014). Nutrition and bone health (2nd ed.). Retrieved from https://ebookcentral.proquest.com/lib/uwsau/reader.action? docID =1968115
Jenkins, G.W., & Tortora, G.J. (2013). Anatomy and physiology: from science to life (3rd ed.). Hoboken, NJ: John Wiley & Sons.
Marieb, E.N., & Hoehn, K.N. (2015). Human anatomy and physiology, global edition (10th ed.). Essex, England: Pearson Education Limited.
Tortora, G.J., & Derrickson, B. (2012). Principles of anatomy & physiology (13th ed.). Hoboken, NJ: John Wiley & Sons
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