Chapter 13 Readings PDF

Why do nervous system responses tend to be more rapid than endocrine system responses? Neural transmission in the nervous system can happen at a quicker rate because of its complex, interconnected branches that produce quick, short term responses to changes in the external environment. However hormo...

Why do nervous system responses tend to be more rapid than endocrine system responses? Neural transmission in the nervous system can happen at a quicker rate because of its complex, interconnected branches that produce quick, short term responses to changes in the external environment. However hormones in the endocrine system must travel through the bloodstream to produce a longer lasting response. Define the term hormone using a specific example. Hormones are chemical messengers that stimulate a gland or cells to perform a specific function. The endocrine system transmits hormones to ductless glands, making it easier for them to find receptor sites to bind to. An example of a hormone is ADH. ADH is a hormone that regulates water reabsorption from the kidneys into the blood. When your body is dehydrated, ADH will be secreted to tell the distal tubules in the kidneys to reabsorb water to the blood, resulting in highly concentrated urine. Provide four reasons why the distinction between the nervous and endocrine systems is sometimes blurred. Both the endocrine and nervous system send chemical signals towards parts of the body to initiate a given response, Both systems are heavily involved and influenced by the hypothalamus, They both involve the parasympathetic and sympathetic NS, and they both work to achieve homeostasis within the body How did Adolph Berthold’s experiment with roosters demonstrate the function of an endocrine gland? What are some of the challenges for researchers studying the endocrine system? The complexity of the endocrine system makes it difficult for researchers to understand the many pathways of a hormone. Briefly describe two technologies used to study hormones and endocrine glands What are the two major groups of hormones? How do they interact with their target cells? Protein hormones are water soluble hormones that cannot pass through the cell membrane therefore they must go to receptor sites located on the surface of the membrane through a secondary messenger. Steroid hormones are lipid soluble and have receptor sites located at the nucleus of the cell. (direct gene activation) How does a hormone stimulate a response in a target cell? Hormones stimulate responses by binding to receptor sites on the target cells. Identify which glands secrete the following hormones: thyroxine, human growth hormone, cortisol, insulin, glucagon The thyroid gland secretes thyroxine when the hypothalamus produces thyroid releasing hormone to the anterior pituitary which secretes thyroid stimulating hormone, therefore releasing T3 and T4 (thyroxine). The anterior pituitary gland secretes hGH as small pumps of doses throughout the day. This happens when the hypothalamus sends chemical signals to the anterior pituitary to release hGH. The adrenal glands secrete cortisol when the hypothalamus produces cortisol releasing hormone (CRH) towards the anterior pituitary which then secrets ACTH to the adrenal glands which therefore produce cortisol. When blood sugar levels rise, The pancreas secretes insulin to regulate and lower BS levels. When blood sugar levels are low, The pancreas releases glucagon which raises BS levels. Describe how the secretion of ADH is regulated by negative feedback. ADH maintains negative feedback by ensuring that the body does not become over dehydrated. When dehydration occurs, ADH works to make the distal tubules in the kidneys to reabsorb water into the bloodstream, thus creating high concentrations of urine. What is a tropic hormone? A tropic hormone is a hormone produced by the anterior pituitary, that stimulates target glands to produce their own hormones. How is the secretion of tropic hormones from the pituitary gland regulated The hypothalamus regulates the anterior pituitary by producing “releasing hormones” such as the gonadotropin releasing hormone. Compare the anterior and posterior pituitary. The posterior pituitary stores hormones produced by the hypothalamus, the anterior pituitary stimulates the production of hormones in the target glands. List three effects of hGH on the body -​ Gigantism- too much hGH as a kid -​ Dwarfism- too little hGH -​ Acromegaly- too much hGH as an adult Explain how the thyroid gland is like a metabolic thermostat. The thyroid hormones (t3 and t4) regulate metabolism by speeding up heart rate and energy consumption Explain the role of thyroxine. Thyroxine provides functions in metabolism, heart rate, brain development, etc. Why does hypothyroidism cause a goiter to develop Hypothyroidism occurs by a lack of thyroid hormone within ones body. Iodine is an essential component in the production of thyroxine. When there is a lack of iodine is ones diet, the thyroid gland works in attempt to over secret thyroxine, however because of the lack of iodine, thyroxine cannot be secreted. This increased need for function leads to the thyroid gland increasing in size, therefore developing a goiter. Describe what is meant by the fight-or-flight response. Fight or flight response refers to the increase in energy during acute stress which allows an individual to seek survival through protective action or to have increased stamina if needing to flee. How is the hypothalamus involved in the release of epinephrine and norepinephrine in the stress response? When stressed, the hypothalamus will produce CRH (cortisol releasing hormone) towards the anterior pituitary which will respond by secreting ACTH to the adrenal glands, therefore releasing cortisol.. Compare and contrast the major physiological changes that occur in the short-term and long-term stress responses. Short term stress symptoms include increased heart rate, nausea, butterflies, dilated blood vessels, increased blood pressure. Lasts a short amount of time​ Long term stress symptoms include a constant elevated heart rate, blood pressure, cortisol, etc, therefore weakens the immune system. Lasts long periods of time How does cortisol make more glucose available to cells? Cortisol converts proteins into amino acids to produce increased glucose levels that can then be used to produce more energy. How does cortisol affect the immune system? Chronic amounts of cortisol can weaken the immune system by causing a constant elevation in blood pressure, blood sugar, etc, therefore increasing risks of health issues. Describe how aldosterone increases blood pressure. Aldosterone causes the reabsorption of water into the bloodstream, increasing blood volume, therefore increasing the blood pressure. Describe how Addison’s disease affects the body Addison's disease causes fatigue, hyperpigmentation, abdominal pain, etc. Identify two cell types of the islets of Langerhans and explain their functions. Alpha cells aka glucagon works to raise blood sugar when levels are too low. Beta cells aka insulin work to lower blood sugar when levels reach too high. Describe the roles of insulin and glucagon in maintaining homeostasis Insulin maintains homeostasis by lowering blood sugar levels back to normal, which glycogen maintains homeostasis by raising blood sugar levels back to normal. What are the symptoms of diabetes mellitus? Increased urine, low or no insulin production, increased thirst, blurred vision, etc. What is hyperglycemia? Occurs when there is increased amounts of glucose in the blood What are the effects of untreated diabetes mellitus on the body Developing type 1 or 2 diabetes, blindness, kidney issues, stroke, pain in feet, etc. What interferes with the secretion of insulin in type 1 diabetes? Type 1 diabetes is autoimmune, meaning it was most likely genetically inherited therefore affecting the pancreases ability to secrete insulin (little or none) What risk factors are associated with developing type 2 diabetes? Stroke, kidney failure, blindness, etc What was Banting and Best’s contribution to the treatment of diabetes? They discovered insulin and ways to treat it How can people with diabetes monitor their blood glucose levels? Insulin injections, frequent checking blood glucose levels, eating healthy, exercising, arm monitor, belt moniter, etc.