Functional Anatomy of Endocrine Glands Comparison

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Functional Anatomy of the Endocrine Glands

Gross Anatomy and Basic Function of the Endocrine Glands:

1. Both the endocrine and nervous systems are major regulating systems of the body. However, the nervous system has been compared to an airmail delivery system, while the endocrine system has been compared to the pony express.
2. The comparison is due to their different modes of operation. The nervous system employs electrochemical impulses to bring about rapid control, while the endocrine system is more slowly acting with hormones.

1. What is a hormone? A substance secreted by the endocrine tissues into the blood that acts to target specific tissues to produce a defined response.

2. Define hormone. Hormones are chemical messengers secreted by endocrine glands that travel through the bloodstream and affect specific target organs or tissues.

3. Chemically, hormones belong chiefly to two molecular groups: steroids and amino acid-based compounds.

4. What do all hormones have in common? They are all chemical messengers that regulate various physiological processes in the body.

5. Define target organ. Target organs are specific organs or tissues that respond to a particular hormone, based on their ability to bind with specific receptors on cells’ plasma membrane or within the cell.

6. If hormones travel in the bloodstream, why don’t all tissues respond to all hormones? The ability of the target tissue to respond depends on its ability to bind with specific receptors on cells’ plasma membrane or within the cell, which varies among different types of cells and tissues.

Identify the endocrine organ described by each of the following statements:

1. Located in the throat; bilobed gland connected by an isthmus – thyroid
2. Found close to the kidney – adrenal
3. A mixed gland, located close to the stomach and small intestine – pancreas
4. Paired glands suspended in the scrotum – testes
5. Ride “horseback” on the thyroid gland – parathyroid gland
6. Found in the pelvic cavity of the female, concerned with ova and female hormone production – ovary
7. Found in the upper thorax overlying the heart; large during youth – thymus
8. Fund inthe roof ofthe third ventricle- pineal gland

179.

8. For each statement describing hormonal effects, identify the hormone(s) involved by choosing a number from key A, and note the hormone’s site of production with a letter from key B. More than one hormone may be involved in some cases. For example: Key A: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. ACTH ADH aldosterone calcitonin cortisone epinephrine estrogens FSH glucagon insulin 11. 12. 13. 14. 15. 16. 17. LH oxytocin progesterone prolactin PTH T4 /T3 testosterone 16 , L basal metabolism hormone Key B: a. b. c. d. e. f. g. h. i. j. k. l.

The endocrine system consists of several glands, including the adrenal cortex, adrenal medulla, anterior pituitary, hypothalamus, ovaries, pancreas, parathyroid glands, pineal gland, posterior pituitary, testes, thymus and thyroid gland. These glands produce hormones that regulate various bodily functions. Some of the hormones produced by these glands include:

• Thymosin (programming of T lymphocytes)
• TSH (regulation of another endocrine gland)
• PTH (regulation of blood calcium levels)
• Cortisol (released in response to stressors)
• Testosterone and estrogen (drive development of secondary sexual characteristics)
• Norepinephrine and epinephrine (mimic the sympathetic nervous system)

The pituitary gland is responsible for several important functions in the body, including the regulation of blood glucose levels. It is a mixed” gland that produces hormones involved in various bodily processes. One of its functions is the direct regulation of the menstrual cycle. Additionally, it helps to maintain salt and water balance in the extracellular fluid and plays a role in milk production and ejection.

Although often referred to as the master gland, the pituitary gland is influenced by the hypothalamus. The hypothalamus controls both anterior and posterior pituitary functioning through neurosecretions.

These hormones are liberated into hypophyseal portal system and carried to cells of the anterior pituitar where they control the release of anterior pituitary hormones. and controls posterior pituitary functioning by storing the ones transported by the axons of neurons in the 180 Review Sheet 27 10. Indicate whether the release of the hormones listed below is stimulated by (A) another hormone; (B) the nervous system (neurotransmitters, or neurosecretions); or (C) humoral factors (the concentration of specific nonhormonal substances in the blood or extracellular fluid).

Below is a list of hormones and their corresponding numbers:

1. ADH
2. Aldosterone
3. Estrogens
4. Insulin
5. Norepinephrine
6. Parathyroid hormone
7. T4/T3
8. Testosterone
9. TSH, FSH

Please name the hormone(s) that are produced in inadequate amounts resulting in the following conditions:

1. Low amount of PTH:
   The hormone produced in inadequate amounts resulting in tetany is parathyroid hormone (PTH).
   The hormone produced in inadequate amounts resulting in excessive diuresis without high blood glucose levels is aldosterone.
   The hormone produced in inadequate amounts resulting in loss of glucose in the urine is insulin.
   The hormone produced in inadequate amounts resulting abnormally small stature with normal proportions is growth hormone.
   The hormones produced inadequately leading to low BMR, mental and physical sluggishness are T4/T3.
2. Low ADH:
   The condition caused by low ADH production is diabetes insipidus.
3. Low insulin:
   The condition caused by low insulin production or impaired insulin function is diabetes mellitus.
4. Low growth hormone:
   Inadequate production of growth hormones can result to dwarfism or stunted growth.
5. Low amounts of thyroid gland:
   Inadequate production of thyroid hormones can result in hypothyroidism.

Name the hormone(s) produced in excessive amounts that directly result in the following conditions. (Use your textbook as necessary. ) to much growth hormone 1. 2. 3. large hands and feet in the adult, large facial bones nervousness, irregular pulse rate, sweating demineralization of bones, spontaneous fractures to much thyroid hormone to much PTH Microscopic Anatomy of Selected Endocrine Glands 13. Choose a response from the key below to name the hormone(s) produced by the cell types listed. Key: a. b. c. A calcitonin GH, prolactin glucagon 1. 2. 3. 4. 5.

The following are hormones produced by various endocrine glands:

• Glucocorticoids
• Insulin
• Mineralocorticoids
• PTH
• T4/T3
• TSH, ACTH, FSH, LH

The cells that produce these hormones are:

• Parafollicular cells of the thyroid follicular epithelial cells of the thyroid beta cells of the pancreatic islets (islets of Langerhans) alpha cells of the pancreatic islets (islets of Langerhans) basophil cells of the anterior pituitary
• Zona fasciculata cells
• Zona glomerulosa cells
• Chief Cells
• Acidophil Cells Of The Anterior Pituitary H E F G B C I Review Sheet 27.

• Six diagrams representing microscopic structures of endocrine glands are presented below.

  Identify and name all structures indicated by a leader line or bracket:

  • Thyroid gland
    • Basophils
    • Chromophobe ant. pituitar acidophil follicle cells (d)
    • Blood cells
    • Colloid-filled follicles / thyroid gland
    • Connective tissue capsule
    • Zona blomerulosa
    • Zona fasciculata
    • Zona reticularis

  • MEDULLA (b)
  • Nerve fibers (e)
  • Pituicytes adrenal gland posterior pituitary Anterior pituitary exocrine tissue of pancreas cells beta (c) alpha cells chief cells (f) oxyphil cells pancreatic islet parathyroid gland 182 Review Sheet 27