Clinical scenario: Homeostatic Imbalance in Blood Pressure
Dinird as year old woman decided she wotha het/a bilke/90a.paricubany/hokand suny day she
feeling lightheaded and had a rapid heartbeat.
Wailrestinated the amount of walenshfalted b crop -ad, the our balfway throughherty davine
unders anyarated. her blood valumertated to drop. ty the time Maria reunedto hera? Were. Using the information above, describe the situation in terms of homeostasis. Start with what variable is being sensed then describe the sensor/integrator/effector and negative feedback
Essay Question B:
Answer a. or b. below. (If you answer both, I will only grade the first one I see. I won't look at the other.)
3pts
a. Your metabolism is low, and you want to bring it back up to homeostasis. Explain the endocrine pathway
of the thyroid gland to achieve this. Be sure to include all the endocrine glands, hormones, target cells and
effects, and negative feedback control. What could happen if there is a primary failure of the thyroid
gland?
b. Your plasma glucose levels are low. Describe the pathway of adrenal gland stimulation of cortisol to increase plasma glucose levels. Include the endocrine glands, hormones, target cells and effects, and the negative feedback control. What could happen if the adrenal cortex is over stimulated in this case?
Answer c. or d. below. Only answer one (4pts):
In class, we learned that not all control systems in the Endocrine System utilizes the hypothalamus as the
integrator. Please explain the negative feedback control of
c. Describe the endocrine function of the pancreas in regulating glucose levels.
or d. Describe how the Parathyroid glands control calcium levels.
Using the numbers on the graph above, answer the following questions:
Essay Question A: Thyroid Gland and Metabolism
Endocrine Pathway:
- Hypothalamus: The hypothalamus detects low thyroid hormone levels.
- Pituitary Gland: The hypothalamus releases thyroid-releasing hormone (TRH), which stimulates the anterior pituitary gland to release thyroid-stimulating hormone (TSH).
- Thyroid Gland: TSH stimulates the thyroid gland to produce and release thyroid hormones (T3 and T4).
- Target Cells: Thyroid hormones increase metabolism, heart rate, and body temperature.
- Negative Feedback: When thyroid hormone levels rise to normal, they provide negative feedback to the hypothalamus and pituitary gland, reducing the release of TRH and TSH.
- Hypothalamus: The hypothalamus detects low blood glucose levels.
- Pituitary Gland: The hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the anterior pituitary gland to release adrenocorticotropic hormone (ACTH).
- Adrenal Cortex: ACTH stimulates the adrenal cortex to produce cortisol.
- Target Cells: Cortisol increases blood glucose levels by stimulating the breakdown of glycogen in the liver and muscles.
- Negative Feedback: When blood glucose levels return to normal, they provide negative feedback to the hypothalamus and pituitary gland, reducing the release of CRH and ACTH.
- Glucagon: Glucagon increases blood glucose levels by stimulating the breakdown of glycogen in the liver and the release of glucose into the bloodstream.
- Insulin: Insulin lowers blood glucose levels by promoting glucose uptake by cells in the liver, muscle, and fat tissues.
Homeostasis and Negative Feedback
In this scenario, Dinird's body is attempting to maintain homeostasis, a state of internal equilibrium. When she reduces her water intake, her blood volume decreases, leading to a drop in blood pressure. This triggers a series of physiological responses to restore homeostasis:
- Sensor: The body's baroreceptors, located in the carotid arteries and aortic arch, detect the decrease in blood pressure.
- Integrator: The brain's cardiovascular control center processes the information from the baroreceptors and initiates a response.
- Effector: The effector organs, such as the heart, blood vessels, and kidneys, work together to increase blood pressure. The heart rate increases to pump more blood, the blood vessels constrict to increase blood pressure, and the kidneys conserve water to increase blood volume.