Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
11 Cards in this Set
- Front
- Back
|
What are hormones?
|
Hormones are chemical messengers secreted by endocrine glands into the blood and transported by the blood to specific targets.
|
|
|
What chemical substances are used as hormones in humans?
|
1. Steroids. ex. estrogen.
2. Peptides. ex. insulin. 3. Tyrosine. ex. thyroxin. |
|
|
How do steroid hormones work?
|
Steroid hormones enter the cells and affect genes directly.
|
|
|
How do steroid hormone affect cell activity?
|
They bind to receptor proteins in the cytoplasm to form a hormoe-receptor complex that acts as a regulator of gene transcription by binding to specific genes to promote or inhibit them.
|
|
|
How do peptide hormones work?
|
Peptide hormones bing to receptors in the plasma membrane, which causes the release of a secondary messenger inside the cell.
|
|
|
How do secondary messengers affect cell activity?
|
The secondary messengers cause a change to cell activity usually by activating or inhibiting an enzyme.
|
|
|
What is the hypothalamus?
|
They hypothalamus is a small part of the brain that links the nervous and endocrine systems. It controls hormone secretion by the pituitary gland located below it.
|
|
|
What is the pituitary gland?
|
The anterior and posterior lobes of the pituitary gland are controlled in a different way by the hypothalamus. The hormones released by the pituitary gland control hormone secretion by other endocrine glands.
|
|
|
Draw a diagram of the hypothalamus and the pituitary gland.
|
Include the portal vein connecting the hypothalamus and the anterior pituitary gland and the neurosecretory cells connecting the hypothalamus and posterior pituitary gland.
|
|
|
Explain the control of thyroxin secretion by negative feedback.
|
Include the secretion of TRH, transport to anterior pituitary in portal vein, secretion of TSH, and secretion of thyroxin. Negative feedback to the hypothalamus involves thyroxin level, TSH level, and body temperature.
|
|
|
Explain the control of ADH secretion by negative feedback.
|
Include neurosecretory cells in the hypothalamus, transport of ADH to the posterior pituitary for storage and release under stimulus by osmoreceptors in the hypothalamus.
|
