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Sunday, June 26, 2016

Coursera Introduction to Physiology - Week 1 - Endocrine Concepts

1. Cells may communicate with one another by_____

A. transfering signal molecules to adjacent cells through gap junctions.

B. local-acting chemicals, called paracrines and autocrines

C. long-distance means, which rely on combinations of electrical and chemical signals.

D. A, B, and C

2. Which of the following statements is TRUE?

A. Autocrine and paracrine control use chemicals (ligands) to regulate cell activity.

B. Paracrine control is when a cell regulates its neighbor (local).

C. Target cells have receptors that recognize and bind the specific chemical (paracrine, autocrine or hormone).

D. A, B and C

3. Peptide hormones regulate their target cells by:

A. binding to cell surface receptors which activate intracellular signaling pathways

B. binding to DNA to change gene (DNA) expression.

C. binding to ion channels

D. B and C

One way to remember this is that peptide hormone are not ions, and there are not membrane permeable, so they have to do that on the cell surface receptors.

4. Which of the following statements correctly describes the mechanisms used by the tyrosine derivative hormones, epinephrine and thyroid hormone, to trigger their target cell’s response?

A. Thyroid hormone (TH) binds intracellular receptors to increase gene expression.

B. Thyroid hormone (TH) binds cell surface receptors triggering a rapid change in metabolism

C. Thyroid hormone and epinephrine binds intracellular receptors to increase gene expression

D. Thyroid hormone and epinephrine bind cell surface receptors triggering a rapid change in metabolism

Thyroid hormone is an amino acid derivative and is plasma membrane permeable. I have to remember this.

5. When steroid hormones bind to their receptors:

A. a second messenger pathway is activated.

B. G protein second messengers are inhibited.

C. gene transcription is activated

D. protein kinases are activated

6. Joanne presents to her physician with elevated plasma cortisol levels. She is administered dexamethasone, a drug used to suppress the secretion of ACTH from the pituitary gland. Her plasma cortisol levels fall to normal 60 minutes after the dexamethasone treatment. Joanne's condition is which of the following?

A. Primary pathology because the adrenal hormone, cortisol, was suppressed by the dexamethasone.

B. Secondary pathology because suppression of the pituitary hormone, ACTH, corrected the secretion of cortisol from the adrenal gland.

C. Tertiary pathology because the pituitary hormone ACTH was low in this patient.

The problem is that Joanne should not have high level of ACTH. The adrenal gland is functioning normally, but the Anterior Pituitary is not.

7. Which of the following statements is TRUE for steroid hormones?

A. They enter target cells by active transport.

B. They require carrier proteins for delivery to target tissues.

C. They are stored in secretory vesicles.

D. A, B and C

Steroid hormones are not plasma soluble and therefore requires carrier protein

8. The single most important factor that determines whether a specific gene in a given cell can be regulated by growth hormone is the presence in this cell of:

A. heat shock proteins

B. specific growth hormone receptors.

C. active transporters for growth hormone.

D. G proteins.

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