Thursday, January 8, 2009
Thurs-Day 1
AP Chem- we had our test on most of the colligative properties as well as metal-ligand complex naming and Born-Haber Hess Diagrams; quite a potpourri!
Bio 6/7- we discussed the life process of regulation as directed by the nervous system (shorter term coordination) and the endocrine system (longer term coordination). We discussed the function of each of the major glands and the important mechanism of hormonal "feedback" loops.
The endocrine system is a system of 9 glands: hypothalamus, pituitary, pineal, thymus, thyroid, parathyroid, adrenal, islets of Langerhans (of the pancreas), testes (male), ovaries (female).
These glands secrete substances DIRECTLY into the bloodstream for quick circulation throughout the body, HOWEVER, only one SPECIFIC group of "target cells" can bind to a given specific hormone. The target cells will then produce a substance or substances that will help the body maintain homeostasis. The glands are then signalled to stop secreting the hormone once homeostasis is reached (this is known as a negative feedback loop).
Specifically, we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.
Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.
We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.
We then finished our discussion of the salivary amylase enzyme lab.
Bio 8- we discussed the life process of regulation as directed by the nervous system (shorter term coordination) and the endocrine system (longer term coordination). We discussed the function of each of the major glands and the important mechanism of hormonal "feedback" loops.
The endocrine system is mainly a system of 9 glands: hypothalamus, pituitary, pineal, thymus, thyroid, parathyroid, adrenal, islets of Langerhans (of the pancreas), testes (male), ovaries (female).
These glands secrete substances DIRECTLY into the bloodstream for quick circulation throughout the body, HOWEVER, only one SPECIFIC group of "target cells" can bind to a given specific hormone. The target cells will then produce a substance or substances that will help the body maintain homeostasis. The glands are then signalled to stop secreting the hormone once homeostasis is reached (this is known as a negative feedback loop).
Specifically, we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.
Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.
We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.
Bio 6/7- we discussed the life process of regulation as directed by the nervous system (shorter term coordination) and the endocrine system (longer term coordination). We discussed the function of each of the major glands and the important mechanism of hormonal "feedback" loops.
The endocrine system is a system of 9 glands: hypothalamus, pituitary, pineal, thymus, thyroid, parathyroid, adrenal, islets of Langerhans (of the pancreas), testes (male), ovaries (female).
These glands secrete substances DIRECTLY into the bloodstream for quick circulation throughout the body, HOWEVER, only one SPECIFIC group of "target cells" can bind to a given specific hormone. The target cells will then produce a substance or substances that will help the body maintain homeostasis. The glands are then signalled to stop secreting the hormone once homeostasis is reached (this is known as a negative feedback loop).
Specifically, we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.
Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.
We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.
We then finished our discussion of the salivary amylase enzyme lab.
Bio 8- we discussed the life process of regulation as directed by the nervous system (shorter term coordination) and the endocrine system (longer term coordination). We discussed the function of each of the major glands and the important mechanism of hormonal "feedback" loops.
The endocrine system is mainly a system of 9 glands: hypothalamus, pituitary, pineal, thymus, thyroid, parathyroid, adrenal, islets of Langerhans (of the pancreas), testes (male), ovaries (female).
These glands secrete substances DIRECTLY into the bloodstream for quick circulation throughout the body, HOWEVER, only one SPECIFIC group of "target cells" can bind to a given specific hormone. The target cells will then produce a substance or substances that will help the body maintain homeostasis. The glands are then signalled to stop secreting the hormone once homeostasis is reached (this is known as a negative feedback loop).
Specifically, we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.
Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.
We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.
# posted by C @ 7:07 PM 
