Endocrine System Flashcards
The Endocrine System: Hormones
Chemical Messengers secreted into the blood or extracellular fluid by one cell that affect the functioning of other cells
The Endocrine System: Definition
That system that broadcasts its hormonal message to essentially all cells by secretion into blood and extracellular fluid…cells must bear a receptor for the hormone being broadcast in order to respond
Types of Actions: Endocrine
The hormone is distributed in blood and binds to distant target cells
Types of Actions: Paracrine
The hormone acts locally by diffusing from its source to target cells in the area
Types of Actions: Autocrine
The hormone acts on the same cell that produced it
The Pituitary Gland
A roundish organ that lies immediately beneath the hypothalamus, resting in depression of the base of the skull called the sella turcica
Pituitary Gland: 3 parts
Anterior Pituitary: composed of cells that secrete protein hormones
Posterior Pituitary: composed largely of axons of hypothalamic neurons, which extend downward as a large bundle behind anterior pituitary
Stalk: portion of the posterior pituitary that suspends the anterior gland from the hypothalamus
Anterior Pituitary: Growth Hormone
target: liver, adipose tissue
Promotes growth, control of protein, lipid, and carbohydrate metabolism
Anterior Pituitary: Thyroid-stimulating hormone
Target: thyroid gland
Stimulates secretion of thyroid hormones
Anterior Pituitary: Adrenocorticotropic Hormone
Target: adrenal gland
Stimulates secretion of glucocorticoids
Anterior Pituitary: Prolactin
Target: Mammary a Gland
Milk production
Anterior Pituitary: Luteinizing Hormone
Target: ovary and testies
Control of repro function
Anterior Pituitary: Follicle Stimulating Hormone
Target: Ovary and testies
Control of repro function
Posterior Pituitary: Antidiuretic Hormone
Target: kidney
Conservation of body water
Posterior Pituitary:Oxytocin
Target: ovary and testies
Stimulates milk ejection and uterine contractions
Pineal Body
Melatonin: aids night activity in reptiles and amphibians
The Thyroid Gland
Thyroxin and triiodothyronine: growth, metabolism and cellular differentiation
Calcitonin: minor role in decreasing blood calcium levels
The Parathyroid Gland
Parathyroid Hormone: maintains blood calcium levels
The Thymus Tissue
May control stem cell production of lymphocytes
The Adrenal Glands
Glucocorticoids: promote gluconeogenesis, decrease inflammatory reaction, affect muscle tone, and excitability of nerves, affect fat and water metabolism, inherit cartilage growth and development
Aldosterone: maintains proper levels of blood sodium and phosphorus
Epinephrine: fight or flight reaction
The Pancreas
Insulin: promotes movement of glucose into the cells
Glucagon: promotes the breakdown of glycogen to glucose
Other glands
Testis Ovaries Uterus Stomach Small intestines Kidney Liver
Cell Surface Receptors
Proteins and peptides
Generation of second messengers which alter activity of other molecules usually enzymes within the cell
Intracellular Receptors
Steroids and thyroid Hormones
Alter transcriptional activity of responsive genes
Epinephrine
Flight or fight
In adrenal glands
Aldosterone
Maintains proper levels of blood sodium and phosphorus
Vasculature
Total circulation…blood leaves one organ and is directed to another
Hypothalamic-Pituitary Relationship
Regulates balance of the nervous system
Melatonin
Aids night activity for reptiles and amphibians
PINEAL BODY
Calcitonin
Minor role in decreasing blood calcium levels
