Bio 5: The Endocrine System

Front 1

Endocrine signaling involves the secretion of ______ directly into the bloodstream. The hormones travel to distant target tissues, where they bind to receptors and induce a change in gene expression or cell function.

Back 1

Endocrine signaling involves the secretion of hormones directly into the bloodstream. The hormones travel to distant target tissues, where they bind to receptors and induce a change in gene expression or cell function.

Front 2

______ hormones are composed of amino acids. They are polar and cannot pass through the plasma membrane. They travel freely (don't require carrier) in blood. Have rapid onset and are short-lived

Back 2

Peptide hormones are composed of amino acids. They are polar and cannot pass through the plasma membrane.

Front 3

Peptide hormones bind to extracellular receptors, where they trigger the transmission of a _____ messenger. Each step of the signaling cascade can demonstrate ________ of the signal.

Back 3

Peptide hormones bind to extracellular receptors, where they trigger the transmission of a second messenger. Each step of the signaling cascade can demonstrate amplification of the signal.

Front 4

-Steroid hormones are derived from ______.

-They are _____; thus pass through the plasma membrane.

-They bind to a receptor, which binds to DNA in the nucleus, which affects Tx of a gene.

-They need a carrier to by transported in the blood. Examples: _____

-Steroid hormones are longer lasting

Back 4

-Steroid hormones are derived from cholesterol.

-They are nonpolar; thus pass through the plasma membrane.

-They bind to a receptor, which binds to DNA in the nucleus, which affects Tx of a gene.

-They need a carrier to by transported in the blood. Examples: hormone-binding-globulin or albumin

Front 5

The peptide hormone is considered the first messenger. Some common second messengers are:

Back 5

cAMP, Inosital triphosphate (IP3) and Calcium

Front 6

Amino acid-derivative hormones are modified amino acids.

Examples:

-Estrogen and testosterone are examples of:

Back 6

Amino acid-derivative hormones are modified amino acids.Examples: epinephrine, and norepinephrine.

-Estrogen and testosterone are examples of: steroid hormones.

Front 7

Hormones can be classified by their target tissues:

Direct vs. Tropic hormones

Back 7

-Direct: secreted into the bloodstream and travel to target tissue. (Ex. prolactin, endorphins, growth hormone (GH))

-Tropic: cause secretion of another hormone which then travels to target tissue. (Ex. follicle-stimulating hormone (FSH), LH, adrenocorticotropic hormone (ACTH), and thyroid-stimulating hormone (TSH)).

Front 8

In ___ ___, the final hormone (or product) of a pathway inhibits hormones (or enzymes) earlier in the pathway, maintaining homeostasis.

Back 8

In negative feedback, the final hormone (or product) of a pathway inhibits hormones (or enzymes) earlier in the pathway, maintaining homeostasis.

Front 9

The _________ stimulates the anterior pituitary gland through paracrine release of hormones into the hypophyseal portal system, which directly connects the two organs.

Back 9

The hypothalamus stimulates the anterior pituitary gland through paracrine release of hormones into the hypophyseal portal system, which directly connects the two organs.

Front 10

-Hormones released from the hypothalamus travel directly to the anterior pituitary and are not found in systemic circulation. Hind receptors on the pituitary stimulates the release of other hormones (antidiuretic ADH and oxytocin)

Back 10

Whereas most of the hormones in the anterior pituitary require a factor from the hypothalamus to be released, prolactin is an exception. As long as the hypothalamus releases dopamine (PIF), no prolactin will be released. It is the absence of dopamine that allows the prolactin to be released.

Front 11

Hormones from hypothalamus:

-Gondadotropin-releasing hormone

-Growth hormone-releasing hormone

-Thyroid-releasing hormone

-Corticotropin-releasing factor

-Prolactin-inhibiting factor

Back 11

Hormones released from anterior pituitary

-Follicle-stimulating hormone

-Luteinizing hormone

-Adrenocorticotropic hormone

-Thyroid-stimulating hormone

-Prolactin (milk production)

-Endorphins (decrease pain)

-Growth hormone

Front 12

Hormones from posterior pituitary:

Antidiuretic hormone (ADH):

Oxytocin:

!!These are produced in the hypothalamus and released in the posterior pituitary.

Back 12

Antidiuretic hormone: when you have low blood volume or higher blood osmolarity. It recreases water reabsorption to increase volume and decrease osmolarity.

Oxytocin: Promotes uterine contractions during birth. Promotes milk ejection. Has a positive feedback not negative.

Front 13

Thyroid hormones:

-Triiodothyronine or thyroxine:

-Calcitonin:

Back 13

-Triiodothyronine or thyroxine: Increase metabolic rate

-Calcitonin: decrease calcium concentrations by promoting excretion, decrease absorbtion in gut, promoting storage in bone.

Front 14

Parathyroid gland releases ______ ______, which increases blood calcium concentration.

Back 14

Parathyroid gland releases parathyroid hormone, which increases blood calcium concentration.

Front 15

Adrenal cortex produces three classes of steroid hormones (corticosteroids)

-Glucocorticoids:

-Mineralocorticoids:

-Cortical sex hormones:

Back 15

-Glucocorticoids: cortisol, increase blood glucose concentration

-Mineralocorticoids: aldosterone, increase water reabsorption, blood pressure increase.

-Cortical sex hormones: androgens, testosterone and estrogens.

Front 16

Adrenal medulla secretes catecholamines into blood.

Examples:

Back 16

epinephrine and norepinephrine

(promote glycolysis, increase metabolic rate, increase heart rate, dilate bronchi, alter blood flow)

Front 17

Pancreas

α-cells:

β-cells:

Back 17

α-cells: produces glucagon; raises blood glucose levels by stimulating protein and fat degradation, glycolysis, and gluconeogenesis

β-cells: produces insulin; stimulates glucose uptake by cells and anabolic processes, like glycogen, fat and protein synthesis.

Front 18

Type 1 diabetes: immune system destroys _____ and can't secrete insulin.

Type 2 diabetes: insulin receptors are ______. High carb diet and obesity adds to situation.

Back 18

Type 1 diabetes: immune system destroys β-cells and can't secrete insulin.

Type 2 diabetes: insulin receptors are resistant. High carb diet and obesity adds to situation.

Front 19

-Insulin is antagonistic to glucagon.

-Excess insulin=low blood glucose=hypoglycemia

-Insufficient insulin=high blood glucose=hyperglycemia

Back 19

Key Concept: Insulin decreases plasma glucose. Glucagon increases plasma glucose. Growth hormone, glucocorticoids, and epinephrine are also capable of increasing plasma glucose. These hormones that raise blood glucose are commonly called counter regulatory hormones.

Front 20

Pineal gland releases ______, which helps to regulate circadian rhythms.

Back 20

melatonin.

Front 21

Characteristics of Growth Hormone (GH)

Back 21

-GH is a direct hormone secreted by the anterior pituitary.

-GH promotes bone and muscle growth.

-Overproduction of GH in children results in gantism, childhood deficiency results in dwarfism.

-Overproduction of GH in adults results in acromegaly (enlargement of small bones in the extremities and of certain facial bones, such as the jaw)

Front 22

Inflammation of the thyroid or iodine deficiency can cause _____, in which the thyroid hormones are under-secreted or not secreted at all.

Back 22

Inflammation of the thyroid or iodine deficiency can cause hypothyroidism, in which the thyroid hormones are under-secreted or not secreted at all.

Front 23

Hypothyroidism in newborn infants cause _____, which is characterized by poor neurological and physical development (including mental retardation, short stature, and coarse facial features).

-Iodine deficiency can result in a swelling of the thyroid gland (called a _____).

Back 23

Hypothyroidism in newborn infants cause cretinism, which is characterized by poor neurological and physical development (including mental retardation, short stature, and coarse facial features).

-Iodine deficiency can result in a swelling of the thyroid gland (called a goiter).

Front 24

Thyroid-stimulating hormone (TSH) from the anterior pituitary stimulates the secretion of _________ (T3) and ________ (T4) from the thyroid.

Back 24

Thyroid-stimulating hormone (TSH) from the anterior pituitary stimulates the secretion of triiodothyronine (T3) and thyroxine (T4) from the thyroid.

Front 25

Pancreatic somatostatin secretion is increased by high blood ___ or amino-acid levels, leading to both decreased insulin and glucagon secretion. Thus, it is always an ____ hormone.

Back 25

Pancreatic somatostatin secretion is increased by high blood glucose or amino-acid levels, leading to both decreased insulin and glucagon secretion. Thus, it is always an inhibitory hormone.

Front 26

Aldosterone signals the reuptake of ____ in the kidneys. It is synthesized in the adrenal _____.

Back 26

Aldosterone signals the reuptake of sodium in the kidneys. It is synthesized in the adrenal cortex.