Chapter 7 Endocrine System PDF

**[Chapter 7]** 1. Explain the four criteria that make a chemical signal a hormone. Chemicals secreted by a cell into the blood for transport to a distant target where, at very low concentrations, it affects growth, development, homeostasis, or metabolism 2. Compare endocrine cells'...

**[Chapter 7]** 1. Explain the four criteria that make a chemical signal a hormone. Chemicals secreted by a cell into the blood for transport to a distant target where, at very low concentrations, it affects growth, development, homeostasis, or metabolism 2. Compare endocrine cells' synthesis, storage, and release of peptide and steroid hormones. A diagram of a structure Description automatically generated - **Peptide Hormones**: - **Synthesis**: Made in advance as preprohormones; cleaved to active hormones. - **Storage**: Stored in secretory vesicles. - **Release**: Released by exocytosis when triggered (e.g., insulin). - **Steroid Hormones**: - **Synthesis**: Synthesized on demand from cholesterol. - **Storage**: Not stored; diffuse out of the cell immediately after synthesis. - **Release**: Diffuse through the cell membrane (e.g., cortisol). 3. Compare the location of hormone receptors and the cellular mechanisms of action of peptide and steroid hormones.  A diagram of a cell membrane Description automatically generated - **Peptide Hormones**: - **Receptors**: Located on the cell surface. - **Mechanism**: Activate second messenger pathways, leading to rapid responses (e.g., insulin). - **Steroid Hormones**: - **Receptors**: Located in the cytoplasm or nucleus. - **Mechanism**: Regulate gene expression, leading to slower but longer-lasting effects (e.g., testosterone). 4. Compare the three main groups of amine hormones. (**Amino-acid derived**) a. **Catecholamines**: i. Derived from single tyrosine. ii. Act like peptide hormones (e.g., epinephrine, norepinephrine). b. **Thyroid Hormones**: iii. Derived from two tyrosine molecules. iv. Act like steroid hormones (e.g., thyroxine \[T4\], triiodothyronine \[T3\]). c. **Melatonin**: v. Derived from tryptophan. vi. Regulates circadian rhythms. 5. Describe the role of the nervous system in endocrine reflexes. **(\*\*\*WEAK**) The nervous system integrates with the endocrine system through neurohormones and control pathways: - **Hypothalamus**: Produces neurohormones that regulate the pituitary gland. - **Neuroendocrine Reflexes**: Electrical signals trigger hormone release (e.g., oxytocin during childbirth). - **Feedback Loops**: Coordinates hormonal and neural responses for homeostasis. 6. List \[full spellings and abbreviations\] the six anterior pituitary hormones, the hormones that control their release, and their primary targets.  A screenshot of a medical form Description automatically generated \*\*\* These 6 are all peptide hormones 1. **Prolactin (PRL)**: - **Control**: Prolactin-releasing factors and dopamine. - **Target**: Mammary glands. 2. **Thyroid-Stimulating Hormone (TSH)**: - **Control**: Thyrotropin-releasing hormone (TRH). - **Target**: Thyroid gland. 3. **Adrenocorticotropic Hormone (ACTH)**: - **Control**: Corticotropin-releasing hormone (CRH). - **Target**: Adrenal cortex. 4. **Growth Hormone (GH)**: - **Control**: Growth hormone-releasing hormone (GHRH) and somatostatin. - **Target**: Liver and other tissues. 5. **Follicle-Stimulating Hormone (FSH)**: - **Control**: Gonadotropin-releasing hormone (GnRH). - **Target**: Gonads. 6. **Luteinizing Hormone (LH)**: - **Control**: Gonadotropin-releasing hormone (GnRH). - **Target**: Gonads. 7. Compare long-loop negative feedback for anterior pituitary hormones to the negative feedback loops for insulin and parathyroid hormone.  - **Long-Loop Negative Feedback**: - Hormones from target endocrine glands (e.g., cortisol) inhibit the anterior pituitary and hypothalamus. - **Insulin Feedback**: - High blood glucose stimulates insulin release, which lowers blood glucose, reducing the stimulus. - **Parathyroid Hormone Feedback**: - Low calcium levels stimulate parathyroid hormone release, which increases calcium, reducing further hormone release. - Long-loop negative feedback - Peripheral endocrine gland produces hormone that suppresses secretion of anterior pituitary and hypothalamic trophic hormones - Most dominant feedback mechanism - Short-loop negative feedback - Pituitary hormone suppresses hypothalamic trophic hormone production - Secondary feedback mechanism - Ultra-short-loop negative feedback (not depicted in figure above) - Occurs in hypothalamus and pituitary - Autocrine or paracrine signals to regulate secretion 8. Explain permissiveness, synergism, and functional antagonism as they apply to hormones. 9. Name the three most common types of endocrine pathologies. - **Hypersecretion**: Excess hormone production (e.g., hyperthyroidism); produces exaggerated effect - **Hyposecretion**: Deficient hormone production (e.g., hypothyroidism); absence of negative feedback leads to overproduction of trophic hormones - **Abnormal Target Response (Receptor/second messenger problems)** : Target cells fail to respond appropriately (e.g., type 2 diabetes). 10. Explain how negative feedback can be used to determine the location of a problem with one gland in a two- or three-gland pathway. (\*\*\* **NOT SURE)** Think above answers this as well