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[BIO 115] Anatomy & Physiology > Ch. 11 Endocrine System > Flashcards

Ch. 11 Endocrine System Flashcards

1
Q

The endocrine system works with the..

A

Nervous system to maintain homeostasis
[Homeostasis: Internal balance]

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2
Q

The endocrine system is made up of ..

A

Cells, tissues, and organs called endocrine glands, that secrete hormones into body fluids (blood)

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3
Q

Types of Glands:

A
  1. Endocrine glands— Ductless
    - They secrete hormones in body fluid
  2. Exocrine Glands- Containing ducts
    - Example: Sweat gland
    - Example: Salivary gland
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4
Q

Glands:

A
  • An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk
  • Endocrine glands release the substances directly into the bloodstream
  • Exocrine glands release the substances into a duct or opening to the inside or outside of the body
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5
Q

Introduction to the Endocrine System

A
  • Organs are not anatomically adjacent to each other
  • Hormones diffuse into the bloodstream to act on specific target cells some distance away
  • Certain glands secrete messenger molecules that never reach the bloodstream, so they are not true hormones; they are called “local hormones,” and include paracrine secretions (affect neighboring cells) and autocrine secretions (affect only the secretory cells)
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6
Q

There are specialized cells in various other organs that produce hormones, but are mainly part of other systems:

A
  • Liver— Erythropoietin
  • Heart
  • Gastrointestinal tract— Gastrin, secretin, cholecystokinin
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7
Q

The nervous and endocrine system:

A
  • There are similarities and differences in how the nervous and endocrine systems communicate with cells
  • Both the nervous and endocrine systems are precise in their action on specific target cells
  • The endocrine system communicates with cells using hormones; the nervous system uses neurotransmitters
  • Endocrine glands and their hormones regulate a number of metabolic processes within cells, and the whole body
    - [Metabolism: Sum of all chemical reactions in the body]
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8
Q

Control of Hormonal Secretions

A
  • Endocrine glands release hormones throughout the body but only have an effect on the cells or organs that have receptors
    - Endocrine gland (release) → Hormone (circulates in blood) → Acts only on the target organ
  • Hormone levels are very precisely regulated
  • Negative feedback control mechanisms:
    - Release of hormones from the hypothalamus controls secretions of the anterior pituitary, and anterior pituitary hormones affect the activity of other endocrine glands
    - The nervous system influences certain endocrine glands directly
    - Other glands respond directly to changes in the internal fluid composition
  • Negative feedback systems:
    - Commonly, negative feedback mechanisms control hormone release
    - In a negative feedback system, a gland is sensitive to the concentration of the substance it regulates
    - As hormone level rises, the hormone exerts its effects, further secretion is inhibited by negative feedback, and then hormone secretion decreases
    - When the concentration of the hormone then drops below its normal level, the inhibition is removed, and the gland begins secreting more hormone again
    - By this mechanism, hormone levels remain fairly constant, fluctuating within a normal average range
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9
Q

Endocrine glands release hormones throughout the body but..

A

only have an effect on the cells or organs that have receptors
- Endocrine gland (release) → Hormone (circulates in blood) → Acts only on the target organ

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10
Q

Negative feedback control mechanisms:

A
  • Release of hormones from the hypothalamus controls secretions of the anterior pituitary, and anterior pituitary hormones affect the activity of other endocrine glands
  • The nervous system influences certain endocrine glands directly
  • Other glands respond directly to changes in the internal fluid composition
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11
Q

Negative feedback systems:

A
  • Commonly, negative feedback mechanisms control hormone release
  • In a negative feedback system, a gland is sensitive to the concentration of the substance it regulates
  • As hormone level rises, the hormone exerts its effects, further secretion is inhibited by negative feedback, and then hormone secretion decreases
  • When the concentration of the hormone then drops below its normal level, the inhibition is removed, and the gland begins secreting more hormone again
  • By this mechanism, hormone levels remain fairly constant, fluctuating within a normal average range
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12
Q

The pituitary gland (hypophysis) is attached to

A

the hypothalamus by a stalk called the infundibulum

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13
Q

The pituitary glands is a size of a pea and is in the

A

depression/cup shape structure of the skull called: Sella Turcica

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14
Q

Anterior pituitary (anterior lobe):

A
  • Consists mostly of glandular epithelial tissue
  • Arranged around blood vessels and enclosed in a capsule of collagenous connective tissue
    - [AKA: Adenohypophysis— Attaches to the hypothalamus by blood vessels]
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15
Q

Posterior pituitary (posterior lobe):

A
  • Part of the nervous system
  • Consists of axons of neurons of the hypothalamus
    - [AKA: Neurohypophysis— Attaches to the hypothalamus by neurons]
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16
Q

Control of the pituitary by the hypothalamus:

A
  • The hypothalamus controls the activity of the pituitary gland
  • The hypothalamus stimulates the anterior pituitary gland and posterior pituitary gland when hormones are needed
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17
Q

Anterior pituitary control:

A
  • Releasing and inhibiting hormones from the hypothalamus control the secretion from the anterior pituitary
  • These hormones are carried in the bloodstream directly to the anterior
    pituitary by hypophyseal portal veins
  • Specific anterior pituitary cells are then stimulated to release or stop releasing their hormone
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18
Q

Posterior pituitary control:

A
  • The posterior pituitary stores hormones made by the hypothalamus
  • The posterior pituitary releases these hormones into the blood in response to nerve impulses from the hypothalamus
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19
Q

Anterior pituitary hormones:

A
  • (1) Growth Hormone (GH):
    - Stimulates body cells to grow and reproduce
    - Speeds the rate at which cells use carbohydrates and fats
    - [Rate: Time]
    - Growth hormone-releasing hormone (GHRH) from the hypothalamus increases the amount of GH secreted, GH inhibiting hormone (GHIH, somatostatin) inhibits its secretion
    - Nutritional status also affects the release of GH; more is released when glucose is low, or when certain amino acids increase
      - GH imbalances:
      - Hyposecretion—
          - Dwarfism: Due to GH deficiency during childhood (Small body but proportional)
          - Achondroplastic dwarf (Head is normal with a small body)
      - Hypersecretion—
          - Gigantism: Due to GH oversecretion during childhood (Hypersecretion in childhood)
          - Acromegaly: Due to GH oversecretion in adulthood (Hypersecretion in adulthood)
    • (2) Prolactin (PRL)
      • Only in females (Lactating mothers)
      • Promotes milk production following the birth of an infant
      • Controlled by prolactin releasing factor (PRF) and prolactin inhibiting hormone (PIH) from the hypothalamus
      • There is no known normal physiological role in males
      • Overview of the Production of Milk in Lactating Mothers
        • Sucking nipple (stimulate) → Hypothalamus (to release) → Prolactin releasing factor (PRF) (to stimulate) → Anterior pituitary gland (to produce) → Prolactin (target organ) → Mammary gland
    • (3) Thyroid stimulating hormone (TSH)
      • Controls the secretion of hormones from the thyroid gland
      • Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the release of TSH
      • As blood concentration of thyroid hormones increases (and reaches its threshold → negative feedback), secretions of TRH and TSH decrease
    • (4) Adrenocorticotropic hormone (ACTH)
      • Controls the secretion of certain hormones from the adrenal cortex
      • Regulated by corticotropin-releasing hormone (CRH) from the hypothalamus
      • Stress can also increase release of CRH, which increases ACTH secretion
    • Gonadotropin-releasing hormone— Gonadotropins (FSH and LH):
      • (5) Follicle-stimulating hormone (FSH)
      • (6) Luteinizing hormone (LH)
        • Follicle-stimulating hormone (FSH) function: Stimulates the testes to produce sperm
        • Luteinizing hormone (LH) function: Stimulate the cells in the testes to produce testosterone
      • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) affect the male (testes) and female (ovaries) gonads
      • In males, LH is also known as interstitial-cell stimulating hormone (ICSH)
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20
Q

GH

A

Growth Hormone

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21
Q

Growth Hormone (GH):

A
  • Stimulates body cells to grow and reproduce
  • Speeds the rate at which cells use carbohydrates and fats
    - [Rate: Time]
  • Growth hormone-releasing hormone (GHRH) from the hypothalamus increases the amount of GH secreted, GH inhibiting hormone (GHIH, somatostatin) inhibits its secretion
  • Nutritional status also affects the release of GH; more is released when glucose is low, or when certain amino acids increase
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22
Q

GH imbalances:

A
  • Hyposecretion—
    - Dwarfism: Due to GH deficiency during childhood (Small body but proportional)
    - Achondroplastic dwarf (Head is normal with a small body)
  • Hypersecretion—
    - Gigantism: Due to GH oversecretion during childhood (Hypersecretion in childhood)
    - Acromegaly: Due to GH oversecretion in adulthood (Hypersecretion in adulthood)
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23
Q

Hyposecretion of GH—

A
  • Dwarfism: Due to GH deficiency during childhood (Small body and proportional)
  • Achondroplastic dwarf (Head is normal with a small body)
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24
Q

Hypersecretion of GH—

A
  • Gigantism: Due to GH over secretion during childhood (Hypersecretion in childhood)
  • Acromegaly: Due to GH over secretion in adulthood (Hypersecretion in adulthood)
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25
Q

PRL

A

Prolactin

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26
Q

Prolactin (PRL)

A
  • Only in females (Lactating mothers)
  • Promotes milk production following the birth of an infant
  • Controlled by prolactin releasing factor (PRF) and prolactin inhibiting hormone (PIH) from the hypothalamus
  • There is no known normal physiological role in males
  • Overview of the Production of Milk in Lactating Mothers
    - Sucking nipple (stimulate) → Hypothalamus (to release) → Prolactin releasing factor (PRF) (to stimulate) → Anterior pituitary gland (to produce) → Prolactin (target organ) → Mammary gland
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27
Q

Overview of the Production of Milk in Lactating Mothers

A
  • Sucking nipple (stimulate) → Hypothalamus (to release) → Prolactin releasing factor (PRF) (to stimulate) → Anterior pituitary gland (to produce) → Prolactin (target organ) → Mammary gland
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28
Q

TSH

A

Thyroid stimulating hormone

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29
Q

Thyroid stimulating hormone (TSH)

A
  • Controls the secretion of hormones from the thyroid gland
  • Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the release of TSH
  • As blood concentration of thyroid hormones increases (and reaches its threshold → negative feedback), secretions of TRH and TSH decrease
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30
Q

ACTH

A

Adrenocorticotropic hormone

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31
Q

Adrenocorticotropic hormone (ACTH)

A
  • Controls the secretion of certain hormones from the adrenal cortex
  • Regulated by corticotropin-releasing hormone (CRH) from the hypothalamus
  • Stress can also increase release of CRH, which increases ACTH secretion
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32
Q

Gonadotropin-releasing hormone— Gonadotropins

A
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) affect the male (testes) and female (ovaries) gonads
  • In males, LH is also known as interstitial-cell stimulating hormone (ICSH)
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33
Q

FSH

A

Follicle-stimulating hormone

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34
Q

LH

A

Luteinizing hormone

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35
Q

Posterior pituitary hormones:

A
  • Neurons in the hypothalamus produce antidiuretic hormone (ADH) and oxytocin (OT), which are stored in the posterior pituitary
  • Impulses from the hypothalamus release the hormones from the posterior pituitary gland
  • These hormones travel down the axons of the hypothalamus to their storage area in the posterior pituitary gland
  • Even though these 2 hormones are synthesized in the hypothalamus, they are called posterior pituitary hormones, because they are released into the blood there
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36
Q

ADH or vasopressin

A

Antidiuretic hormone

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37
Q

Antidiuretic hormone (ADH or vasopressin)

A
  • Causes the kidneys to conserve water, and reduces amount of water excreted in the urine
  • The hypothalamus regulates the secretion of ADH, based on the amount of water in body fluids
  • Osmoreceptors detect changes in osmotic pressure in body fluids, and adjust amount of ADH secretion
  • At high level, also causes vasoconstriction of blood vessels, which helps to maintain blood pressure in conditions of dehydration
  • Diabetes insipidus is a condition resulting from insufficient ADH
38
Q

OT

39
Q

Oxytocin (OT)

A
  • Target organs:
    • Uterus
    • Breast
  • Plays a role in childbirth by contracting muscles in the uterine wall, and in milk-letdown by forcing milk into ducts from the milk glands
  • Stretching of the uterus in the latter stages of pregnancy stimulates release of oxytocin
  • Suckling of an infant at the breast stimulates release of oxytocin after childbirth
  • Release is controlled through positive feedback
40
Q

Thyroid Gland

A
  • The thyroid gland is located below the larynx and consists of 2 broad lobes connected by an isthmus
  • 2 hormones of the thyroid gland help control caloric intake, and 1 helps regulate blood calcium level and bone growth
41
Q

Parenchyma of thyroid gland contains 2 types of cells:

A
  • (1) Follicular cell (produce 2 hormones:) → T3 + T4 (stores in) → Colloid
    - Function of T3 + T4— Maintains metabolic rate
  • (2) Parafollicular cell (releases) → Calcitonin (which maintains) → Blood calcium level
42
Q

Overview of the Release of Calcitonin:

A
  • Hypercalcemia (will stimulate) → Parafollicular cells of thyroid gland (to release) → Calcitonin (which will take the calcium to the bones; bones become storage) → (this will lower the blood calcium level) Hypocalcemia (will stimulate) → Parathyroid gland (to release) → Parathyroid Hormone (PTH)
    - [Hypercalcemia: Calcium level in your blood is above normal]
    - [Hypocalcemia: Levels of calcium in your blood are too low]
43
Q

Structure of the thyroid gland:

A
  • The thyroid consists of secretory units called follicles, filled with hormone-storing colloid
  • Follicular cells secrete hormones that can be stored in the colloid or released into the blood
44
Q

Hormones of the thyroid gland:

A
  • Follicular cells produce 2 iodine-containing hormones, thyroxine (T4 or tetraiodothyronine), and triiodothyronine (T3)
    - Production of T3 and T4:
    - T3 needs 3 molecules of Iodine
    - T4 needs 4 molecules of Iodine
    • T3 is the more potent hormone
    • These two hormones have similar actions; they regulate metabolism of carbohydrates, lipids and proteins
    • They also increase the rate at which cells release energy from carbohydrates, enhance protein synthesis, and stimulate the breakdown and mobilization of lipids
      • Increase the production of ATP
    • Thyroid hormone level is the major factor in determining the basal metabolic rate (BMR), the caloric intake necessary to maintain life
      • [Basal metabolic rate (BMR)— When is person is at rest; ATP is still being produced]
    • These hormones are essential for normal growth and development and nervous system maturation
    • The hypothalamus and pituitary gland control release of thyroid hormones
    • Iodine is needed by the follicular cells to make thyroid hormones (T3 and T4)
    • Extrafollicular cells of the thyroid secrete calcitonin, a hormone which lowers blood levels of calcium and phosphate ions when they are too high
    • Calcitonin increases calcium deposition in bones, by inhibiting osteoclasts and stimulating osteoblasts
    • It also increases calcium excretion by the kidneys into urine
    • Calcitonin secretion is regulated by the blood concentration of calcium; when calcium is high, calcitonin is secreted
45
Q

Thyroid stimulating hormone (TSH):

A
  • Controls the secretion of hormones from the thyroid gland
  • Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the release of TSH
  • As blood concentration of thyroid hormones increases (and reaches its threshold → negative feedback), secretions of TRH and TSH decrease
46
Q

Overview of the TRH-TSH- Thyroid Hormone Pathway

A
  • BMR decreases (stimulate) → Hypothalamus (release TRH which stimulates) → Anterior pituitary gland (secrete) → TSH (stimulates) → Thyroid gland (releases) → T3 and T4 (increases) BMR
47
Q

Thyroid gland— Relational anatomy:

A
  • Lateral border: CCA and Jugular vein
  • Posterior border: Longus Colli Muscle and Parathyroid gland
  • Medial border: Trachea and Esophagus
  • Anterolateral border: Sternocleidomastoid muscle
  • Anterior: Strap muscles
48
Q

Thyroid disorders:

A
  • Hypothyroidism:
    - Underactivity of the thyroid gland
    - Causes low metabolic rate, fatigue and weight gain in adults
    - In infants, causes cretinism: poor growth and bone formation, abnormal mental development, sluggishness
    - [Cretinism— In newborn]
    - [Myxedema— In adult]
  • Hyperthyroidism:
    - Overactivity of the thyroid gland
    - Causes high metabolic rate, restlessness, overeating in adults
    - May lead to eye protrusion (exophthalmia)
  • Depending on cause of disease, either hypothyroidism or hyperthyroidism may lead to formation of a goiter, an enlarged thyroid that appears as a bulge in the neck
    • Goiter— Enlarged thyroid gland
      • Symptom of thyroid disorders
      • Dietary iodine intake is inadaquet
      • Leads to low level of T3 and T4
        • BMR decreases (stimulate) → Hypothalamus (release TRH which stimulates) → Anterior pituitary gland (secrete) → TSH (stimulates) → Thyroid gland (releases) → T3 and T4 (increases) BMR
49
Q

Hypothyroidism:

A
  • Underactivity of the thyroid gland
  • Causes low metabolic rate, fatigue and weight gain in adults
  • In infants, causes cretinism: poor growth and bone formation, abnormal mental development, sluggishness
    • [Cretinism— In newborn]
    • [Myxedema— In adult]
50
Q

Hyperthyroidism:

A
  • Overactivity of the thyroid gland
  • Causes high metabolic rate, restlessness, overeating in adults
  • May lead to eye protrusion (exophthalmia)
51
Q

Goiter—

A

Enlarged thyroid gland
- Symptom of thyroid disorders
- Dietary iodine intake is inadequate
- Leads to low level of T3 and T4
- BMR decreases (stimulate) → Hypothalamus (release TRH which stimulates) → Anterior pituitary gland (secrete) → TSH (stimulates) → Thyroid gland (releases) → T3 and T4 (increases) BMR

52
Q

Parathyroid Glands

A
  • 4 tiny parathyroids are located on posterior of thyroid gland (2 on the superior thyroid gland and 2 on the inferior thyroid gland)
53
Q

Structure of the parathyroid glands:

A
  • Parathyroid glands consist of tightly packed secretory cells covered by a thin capsule of connective tissue; secretory cells are associated with capillaries
54
Q

Parathyroid Hormone (PTH):

A
  • PTH increases blood calcium ion concentration and decreases phosphate ion concentration
  • PTH stimulates bone resorption by osteoclasts, which releases calcium into the blood
  • PTH also stimulates the kidneys to conserve calcium (not filter calcium)
  • PTH causes activation of vitamin D by kidneys, which causes increased absorption of calcium in the intestines
  • A negative feedback mechanism involving blood calcium level regulates release of PTH
55
Q

Calcium regulation and parathyroid disorders:

A
  • Calcitonin and PTH maintain proper blood calcium concentration
  • Calcitonin and PTH exert opposite effects in regulating calcium ion levels in the blood
  • Calcitonin decreases blood calcium when it is too high
  • PTH increases blood calcium when it is too low
  • Parathyroid hormone disorders:
    - Hypoparathyroidism: Deficiency of PTH, due to surgical removal or injury to glands, which results in a decrease in blood calcium
    - Hyperparathyroidism: Excess of PTH, perhaps due to parathyroid tumor, which results in an increase in blood calcium
56
Q

Parathyroid hormone disorders:

A
  • Hypoparathyroidism: Deficiency of PTH, due to surgical removal or injury to glands, which results in a decrease in blood calcium
  • Hyperparathyroidism: Excess of PTH, perhaps due to parathyroid tumor, which results in an increase in blood calcium
57
Q

Hypoparathyroidism:

A

Deficiency of PTH, due to surgical removal or injury to glands, which results in a decrease in blood calcium

58
Q

Hypoparathyroidism:

A

Deficiency of PTH, due to surgical removal or injury to glands, which results in a decrease in blood calcium

59
Q

Hyperparathyroidism:

A

Excess of PTH, perhaps due to parathyroid tumor, which results in an increase in blood calcium

60
Q

Overview of the effects of parathyroid hormone:

A
  • When the blood calcium level decreases, it will stimulate the parathyroid gland to produce parathyroid hormone (PTH)
  • The functions of PTH:
    - (1) Take calcium from the bone
    - (2) Ask the kidneys to not filter calcium
    - (3) Absorb calcium from the small intestine from whatever you are eating
  • When blood calcium increases
    - (4) It stimulates the parafollicular cells of the thyroid gland to release calcitonin, which takes excess calcium and deposit on the bones to make the bones stronger
    - (Homeostasis of calcium in the blood)
61
Q

Adrenal Glands

A
  • The adrenal glands sit on top (superior pole) of the kidneys, enclosed in a layer of adipose and connective tissues
    - Covered by fatty tissue
62
Q

Structure of the adrenal glands:

A
  • The pyramid-shaped glands consist of an inner adrenal medulla and an outer adrenal cortex
  • The adrenal medulla is made up of modified postganglionic
    neurons that are connected to the sympathetic nervous system
  • The adrenal cortex makes up most of the adrenal glands, and consists of epithelial cells in three layers: an outer (glomerulosa), middle (fasciculata), and an inner (reticularis) zone
63
Q

Hormones of the adrenal medulla:

A
  • The adrenal medulla secretes epinephrine and norepinephrine into the bloodstream
  • These two hormones are similar in structure and function
  • Effects resemble those of the sympathetic neurotransmitters of the same name, except that they last up to 10 times longer when they are secreted as hormones
  • They are used in times of stress and for “fight-or-flight” responses
  • Effects: Increase heart rate, blood pressure and blood glucose, dilate airways, (decrease digestive activities—decrease peristalsis)
  • Release of medullary hormones is regulated by nerve impulses from the central nervous system through the sympathetic division of the autonomic nervous system
64
Q

Hormones of the adrenal cortex:

A
  • The cells of the adrenal cortex produce over 30 steroids, some of which are hormones that are vital to survival
    • Most important hormones are aldosterone, cortisol, and the sex hormones
  • (1) Aldosterone/Mineralocorticoid
    - Aldosterone, a mineralocorticoid, is secreted by cells of the outer layer; helps regulate mineral/electrolyte balance (sodium and water)
    • Causes the kidneys to conserve sodium ions and thus water, and to excrete potassium ions
      • Aldosterone is secreted in response to decreasing blood volume and blood pressure; these changes are detected by the kidney
        • Decreased blood volume—
          • Donating blood
          • Hemorrhage
          • Sweating/dehydration
        • [Blood pressure— The pressure of the circulating blood on the wall of arteries]
      • Overview of the Release of Aldosterone (Mineralocorticoid):
        • Decrease blood volume + Decrease blood pressure (stimulate) → Adrenal cortex (releases) → Aldosterone/Mineralocorticoid (acts on kidney to) → Conserve sodium/water to maintain blood volume and pressure
  • (2) Cortisol/Glucocorticoid
    - Cortisol is a glucocorticoid; regulates glucose metabolism
    - Produced by cells of the middle layer of the adrenal cortex
      - Functions of cortisol:
      - Inhibits protein synthesis, which increases blood amino acids
          - Protein ****— The building block of protein is amino acid
      - Promotes fatty acid release from adipose tissue, increasing use of fatty acids for energy and decreasing use of glucose
          - Lipids — The building block of fat (lipid) is a fatty acid
      - Causes liver cells to produce glucose from noncarbohydrates, to increase blood glucose
        
  - A negative feedback mechanism involving corticotropin-releasing hormone (CRH) from the hypothalamus and adrenocorticotropic (ACTH) from the anterior pituitary controls the release of cortisol
  - Stress, injury, or disease can also trigger increased release of cortisol
    
  - Overview of the Release of Cortisol/Glucocorticoid
      - The hypothalamus will release corticotropin-releasing hormone (CRH) then stimulate the anterior pituitary gland to release adrenocorticotropic hormone (ACTH), adrenocorticotropic hormone (ACTH) will then circulate in the blood and will stimulate the adrenal cortex to release cortisol/glucocorticoid
      - The effects of cortisol/glucocorticoid will inhibit protein synthesis, promote fatty acid, and stimulate glucose formation
      - When it reaches the threshold, cortisol/glucocorticoid will inhibit the secretion of corticotropin-releasing hormone (CRH)  and adrenocorticotropic hormone (ACTH)
  • (3) Adrenal sex hormones/Adrenal androgen
    - Sex hormones, produced in the inner zone, are mostly male hormones (adrenal androgens), but can be converted to female hormones (estrogen, progesterone) in the skin, liver, and adipose tissues
    - ( In females) Androgen- At puberty, helps estrogen and progesterone for the production of secondary sex characteristics— Development of the breast growth pubic hair, and deposition of fat
    - (In male) Androgen- Help testosterone for the production of secondary sex characteristics— Facial hair, pubic hair, development of stronger bones and muscles
    - These hormones supplement those released by the gonads and may stimulate early development of reproductive organs
    - [Gonads: Reproductive organs (Testes and ovaries)
      - Disorders of adrenal hormones:
      - Addison disease: Hyposecretion of glucocorticoids and mineralocorticoids
      - Cushing syndrome: Hypersecretion of adrenal cortical hormones
65
Q

Aldosterone/Mineralocorticoid

A
  • Aldosterone, a mineralocorticoid, is secreted by cells of the outer layer; helps regulate mineral/electrolyte balance (sodium and water)
  • Causes the kidneys to conserve sodium ions and thus water, and to excrete potassium ions
  • Aldosterone is secreted in response to decreasing blood volume and blood pressure; these changes are detected by the kidney
    • Decreased blood volume—
      • Donating blood
      • Hemorrhage
      • Sweating/dehydration
    • [Blood pressure— The pressure of the circulating blood on the wall of arteries]
66
Q

Overview of the Release of Aldosterone (Mineralocorticoid):

A
  • Decrease blood volume + Decrease blood pressure (stimulate) → Adrenal cortex (releases) → Aldosterone/Mineralocorticoid (acts on kidney to) → Conserve sodium/water to maintain blood volume and pressure
67
Q

Cortisol/Glucocorticoid

A
  • Cortisol is a glucocorticoid; regulates glucose metabolism
  • Produced by cells of the middle layer of the adrenal cortex
68
Q

Functions of cortisol/glucocorticoid:

A
  • Inhibits protein synthesis, which increases blood amino acids
    - Protein— The building block of protein is amino acid
  • Promotes fatty acid release from adipose tissue, increasing use of fatty acids for energy and decreasing use of glucose
    - Lipids — The building block of fat (lipid) is a fatty acid
  • Causes liver cells to produce glucose from noncarbohydrates, to increase blood glucose
69
Q

Overview of the Release of Cortisol/Glucocorticoid

A
  • The hypothalamus will release corticotropin-releasing hormone (CRH) then stimulate the anterior pituitary gland to release adrenocorticotropic hormone (ACTH), adrenocorticotropic hormone (ACTH) will then circulate in the blood and will stimulate the adrenal cortex to release cortisol/glucocorticoid
  • The effects of cortisol/glucocorticoid will inhibit protein synthesis, promote fatty acid, and stimulate glucose formation
  • When it reaches the threshold, cortisol/glucocorticoid will inhibit the secretion of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH)
70
Q

Adrenal sex hormones/Adrenal androgen

A
  • Sex hormones, produced in the inner zone, are mostly male hormones (adrenal androgens), but can be converted to female hormones (estrogen, progesterone) in the skin, liver, and adipose tissues
    - ( In females) Androgen- At puberty, helps estrogen and progesterone for the production of secondary sex characteristics— Development of the breast growth pubic hair, and deposition of fat
    - (In male) Androgen- Help testosterone for the production of secondary sex characteristics— Facial hair, pubic hair, development of stronger bones and muscles
    • These hormones supplement those released by the gonads and may stimulate early development of reproductive organs
      • [Gonads: Reproductive organs (Testes and ovaries)
71
Q

Disorders of adrenal hormones:

A
  • Addison disease: Hyposecretion of glucocorticoids and mineralocorticoids
  • Cushing syndrome: Hypersecretion of adrenal cortical hormones
72
Q

Pancreas

A
  • The pancreas secretes hormones as an endocrine gland, and digestive juice into the digestive tract as an exocrine gland
  • Pancreatic hormones control level of blood glucose
73
Q

Structure of the pancreatic gland:

A
  • The pancreas is an elongated organ posterior to the stomach
  • Its endocrine portions are the pancreatic islets (islets of Langerhans), that include 3 cell types:
    • (1) Alpha cells that secrete alpha glucagon
    • (2) Beta cells that secrete beta insulin
      • [Function of insulin— Takes sugar and puts into the cell for cellular respiration]
      • [Cellular respiration: A chemical process in which oxygen is used to make energy from carbohydrates (sugars)]
    • (3) Delta cells that secret delta somatostatin
  • Pancreatic duct joins the pancreas to the duodenum, for digestive juice to enter duodenum of the small intestine
74
Q

Hormones of the pancreatic islets:

A
  • Glucagon:
    - Increases the blood level of glucose, by stimulating the breakdown of glycogen and the conversion of non-carbohydrates into glucose by the liver
    - [Glycogen- Store form of sugar]
    - The release of glucagon is controlled by negative feedback
    - Low blood glucose level stimulates the secretion of glucagon
  • Insulin:
    - Decreases the blood level of glucose by stimulating the liver to form glycogen, promotes facilitated diffusion of glucose into cells, increases protein synthesis, & stimulates adipose cells to store fat
    - The release of insulin is controlled by negative feedback
    - High blood glucose stimulates the release of insulin
    - Insulin and glucagon coordinate to maintain a relatively stable blood glucose concentration
  • Overview of the Control of Blood Glucose by Glucagon
    - Fasting → Blood sugar level decreases (stimulates) → Alpha cells of islet of langerhans (release) → Glucagon (to take) → Stored glucose-glycogen from the liver to maintain blood sugar level
  • Overview of the Control of Blood Glucose by Insulin
    - After intake of food → Blood sugar level increases (stimulates) → Beta cells of islet of langerhan (release) → Insulin (takes sugar into the cell for cellular respiration to produce) → Glucose
75
Q

Alpha Glucagon:

A
  • Increases the blood level of glucose, by stimulating the breakdown of glycogen and the conversion of non-carbohydrates into glucose by the liver
    - [Glycogen- Store form of sugar]
  • The release of glucagon is controlled by negative feedback
  • Low blood glucose level stimulates the secretion of glucagon
76
Q

Insulin:

A
  • Decreases the blood level of glucose by stimulating the liver to form glycogen, promotes facilitated diffusion of glucose into cells, increases protein synthesis, & stimulates adipose cells to store fat
  • The release of insulin is controlled by negative feedback
  • High blood glucose stimulates the release of insulin
  • Insulin and glucagon coordinate to maintain a relatively stable blood glucose concentration
77
Q

Overview of the Control of Blood Glucose by Glucagon

A
  • Fasting → Blood sugar level decreases (stimulates) → Alpha cells of islet of langerhans (release) → Glucagon (to take) → Stored glucose-glycogen from the liver to maintain blood sugar level
78
Q

Overview of the Control of Blood Glucose by Insulin

A
  • After intake of food → Blood sugar level increases (stimulates) → Beta cells of islet of langerhan (release) → Insulin (takes sugar into the cell for cellular respiration to produce) → Glucose
79
Q

Diabetes mellitus:

A
  • A metabolic disease due to lack of insulin or the inability of cells to recognize insulin
  • High blood glucose harms eyes, heart, kidneys, peripheral nerves
  • Causes disturbances in metabolism of carbohydrates, fats, proteins
  • Glucose entry into body cells is impaired
    • Symptoms: Hyperglycemia, glycosuria, polydipsia, polyphagia, acidosis
80
Q

Pineal gland:

A
  • Located near the upper portion of the thalamus
  • Secretes melatonin, which is involved in the regulation of
    circadian rhythms of the body
  • It is released at night, but is suppressed during the day
81
Q

Thymus gland:

A
  • Lies between the lungs, behind the sternum: Mediastinum
  • Secretes thymosins, that affect production and differentiation of T lymphocytes (which are important in immunity)
  • The gland is largest in children, and shrinks with age
82
Q

Reproductive Glands:

A
  • The ovaries produce estrogen and progesterone
  • The placenta produces estrogen, progesterone, and gonadotropin
  • The testes produce testosterone
83
Q

Digestive Glands:

A
  • The digestive glands secrete hormones associated with the stomach and small intestine for the processes of digestion
    (Gastrin, cholecystokinin, and secretin)
84
Q

Heart:

A
  • Secretes atrial natriuretic peptide, which affects sodium and water excretion by the kidneys
85
Q

Kidneys:

A
  • Secrete erythropoietin for blood cell production
86
Q

Gonadotropin-Releasing Hormone

A
  • Gonadotropin-releasing hormone— Gonadotropins (FSH and LH):
    - Follicle-stimulating hormone (FSH)
    - Luteinizing hormone (LH)
  • Follicle-stimulating hormone (FSH) function: Stimulates the testes to produce sperm
  • Luteinizing hormone (LH) function: Stimulate the cells in the testes to produce testosterone
  • Females:
    - Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are not released until puberty
    - At puberty, the hypothalamus releases gonadotropin-releasing hormone (GnRH) which stimulates the anterior pituitary gland to release follicle-stimulating hormone (FSH) first , and then the luteinizing hormone (LH)
    - Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) acts on the ovaries to release estrogen and progesterone
    - Help develop secondary sex characteristics
    - Every month, menstruation occurs
    - 4-5 Follicles increase in size and release estrogen
    - 1 of 5 follicles grows in size to reach ~2cm
    - On the 14th day (Different for everyone— Different cycle)
    - The luteinizing hormone is released and ruptures the follicle
    - The follicle is split into the egg and the corpus luteum
    - The egg needs to be fertilized
    - The corpus luteum releases a large amount of progesterone and a smaller amount estrogen causing a thickened inner lining of the uterus (to arranged red carpet for the fertilized egg)
    - If the egg is fertilized by the sperm, it will be receive and nutrition will be given to the baby
    - If the egg is not fertilized, menstrual cycle will occur and the lining of the uterus sheds
  • Males:
    - At puberty, the hypothalamus releases gonadotropin-releasing hormone (GnRH) which stimulates the anterior pituitary gland to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
    - Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) circulate in the blood and act on the testes to release androgens (primarily testosterone)
    - Help develop secondary sex characteristics and increase the production of sperm
  • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) affect the male (testes) and female (ovaries) gonads
  • In males, LH is also known as interstitial-cell stimulating hormone (ICSH)
87
Q
  • Gonadotropin-releasing hormone— Gonadotropins (FSH and LH):
A
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
88
Q
  • Follicle-stimulating hormone (FSH) function:
  • Luteinizing hormone (LH) function:
A
  • Follicle-stimulating hormone (FSH) function: Stimulates the testes to produce sperm
  • Luteinizing hormone (LH) function: Stimulate the cells in the testes to produce testosterone
89
Q

Gonadotropin-releasing hormone: Females

A
  • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are not released until puberty
    - At puberty, the hypothalamus releases gonadotropin-releasing hormone (GnRH) which stimulates the anterior pituitary gland to release follicle-stimulating hormone (FSH) first , and then the luteinizing hormone (LH)
    - Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) acts on the ovaries to release estrogen and progesterone
    - Help develop secondary sex characteristics
    - Every month, menstruation occurs
    - 4-5 Follicles increase in size and release estrogen
    - 1 of 5 follicles grows in size to reach ~2cm
    - On the 14th day (Different for everyone— Different cycle)
    - The luteinizing hormone is released and ruptures the follicle
    - The follicle is split into the egg and the corpus luteum
    - The egg needs to be fertilized
    - The corpus luteum releases a large amount of progesterone and a smaller amount estrogen causing a thickened inner lining of the uterus (to arranged red carpet for the fertilized egg)
    - If the egg is fertilized by the sperm, it will be receive and nutrition will be given to the baby
    - If the egg is not fertilized, menstrual cycle will occur and the lining of the uterus sheds
90
Q

Gonadotropin-releasing hormone: Males

A
  • At puberty, the hypothalamus releases gonadotropin-releasing hormone (GnRH) which stimulates the anterior pituitary gland to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
    - Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) circulate in the blood and act on the testes to release androgens (primarily testosterone)
    - Help develop secondary sex characteristics and increase the production of sperm

[BIO 115] Anatomy & Physiology (16 decks)

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