ENDOCRINE SYSTEM Flashcards
True or false. Endocrine and nervous system compliment each other
True
The endocrine system relies on the production and release of hormones from various glands transport of hormones via the ___
Bloodstream
the scientific study of hormones and endocrine organs
Endocrinology
Hormones are classified chemically as: (3)
Amino-acid based, steroids, prostaglandins
Hormones that are proteins, peptides, and amines
Amino-acid based
Hormones made from cholesterol
Steroids
Hormones made from highly active lipids that act as local hormones
Prostaglandins
How do specific hormones only affect certain tissues or organs?
Presence of target cells that have specific protein receptors
Hormone levels in the blood are maintained mostly by?
negative feedback
What triggers the release of more hormone?
A stimulus or low hormone levels in the blood
Most common category of stimulus. Endocrine organs are activated by other hormones
Hormonal stimuli
Changing blood levels of certain ions and nutrients stimulate hormone release
Humoral stimuli
What are produced in response to changing levels of blood calcium levels?
parathyroid hormone and calcitonin
What is produced in response to changing levels of blood glucose levels?
Insulin
Nerve fibers stimulate hormone release. Most are under the control of the sympathetic nervous system
Neural stimuli
All glands have purely endocrine functions except?
Pancreas and gonads (they both have endocrine and exocrine)
Pea-sized glands that hangs by a stalk from the hypothalamus in the brain
Pituitary gland
Protects the pituitary gland
sella turcica of the sphenoid bone
Glandular tissue that produces a total of 6 pituitary hormones
Anterior pituitary
general metabolic hormone ; major effects are directed to growth of skeletal muscles & long bones
Growth hormone
usually result from tumors of the affected gland; hypersecretion of GH during childhood
Gigantism
due to hyposecretion of GH during childhood; maximum adult height is 4 feet
Dwarfism
stimulates and maintains milk production following childbirth
Prolactin
stimulates follicle development in ovaries (for estrogen production and preparation for ovulation) ; stimulates sperm development in testes
Follicle-stimulating hormone
triggers ovulation of an egg in females (for progesterone production & some estrogen); stimulates testosterone production by the interstitial cells in males
Luteinizing hormone
Hyposecretion of FSH and LH
Sterility
influences growth and activity of the thyroid gland
thyroid-stimulating / thyrotropic hormone
regulates endocrine activity of the adrenal cortex
adrenocorticotropic hormone
Does not make the hormones it releases and stores hormones made by the hypothalamus
Posterior pituitary
stimulates contractions of the uterus during labor, sexual relations, and breastfeedings
Oxytocin
causes milk ejection in a breastfeeding woman and stops poast-partum bleeding
Oxytocin
inhibits urine production (diuresis) by promoting water reabsorption by the kidneys, urine volume decreases while blood pressure increases
Antidiuretic
Large amounts of antidiuretic causes ___, leading to increased blood pressure
Constriction of arterioles
Often called the master endocrine gland
Pituitary gland
produces releasing hormones and inhibiting hormones
Hypothalamus
oxytocin and antidiuretic hormone are carried to posterior pituitary via ___ for storage, they are later released into the blood in response from nerve impulses from the hypothalamus
Neurosecretory cells
small, o-shaped gland that hangs from the roof of the third ventricle of the brain
Pineal gland
believed to trigger the body’s sleep/wake cycle, known as sleep trigger, and believed to coordinate the hormones of fertility in humans and to inhibit the reproductive system until maturity occurs
Melatonin
found at the base of the throat, inferior to the adam’s apple. fairly large gland that consists of two lobes and a connecting isthmus
Thyroid gland
major metabolic hormone; controls rate of oxidation of glucose to supply body heat and chemical energy ( form of ATP); needed for tissue growth and development (specially in reproductive and nervous system)
Thyroid hormone
major hormone secreted by thyroid follicles
Thyroxine (t4)
formed at target tissues; conversion of T4 at target tissues
Triiodothyronine (t3)
is the enlargement of the thyroid gland which results from the deficiency of iodine from an individual’s diet
Goiter
Hyposecretion of thyroxine may cause lack of stimulation of thyroid stimulating hormone, if it occurs in early childhood, what will occur?
Cretinism
in adults, this results in myxedema (characterized by both physical and mental sluggishness; mental impairment does not occur); other signs are puffiness of the face, fatigue, poor muscle tone, no body temp. (always cold), obesity, and dry skin
Hypothyroidism
generally results from a tumor of a thyroid gland; may be treated surgically by removing the part of the thyroid or chemically with thyroid-blocking drugs or radioactive iodine which destroys some of the thyroid cells
Hyperthyroidism
is a condition wherein the eyes bulges or protrude anteriorly
Exophthalmos
one form of hyperthyroidism, overproduction of thyroid hormone
Grave’s disease
hypocalcemic hormone; decreases blood calcium ion levels by causing calcium deposition on bone
Calcitonin
Found between the follicles that produces calcitonin
Parafollicular cells
True or false. Calcitonin stops when you reach adulthood
True
located in the upper thorax, posterior to the sternum. largest in infants and children and decreases in size throughout adulthood
Thymus
Thymus produces what hormone?
Thymosin
sit on top of the kidneys (like triangular hats) and has parts made of glandular (in the cortex) and neural tissue (in the medulla)
Adrenal gland
outer glandular region that has 3 layers that produce corticosteroids: mineralocorticoids, glucocorticoids, and sex hormones
Adrenal cortex
regulates mineral (salt) content in blood, particularly sodium and potassium ions. also regulates water and electrolyte balance with kidney as the target organ
Mineralocorticoids
promote normal cell metabolism, operate during resistance stage of the stress response, help resist long-term stressors by increasing blood glucose levels
Glucocorticoids
these are prescribed as drugs to suppress inflammation for patients with rheumatoid arthritis
Glucocorticoids
small amounts are made throughout life and are secreted by innermost layer of the adrenal cortex
Sex hormones
Produced in the middle layer of the adrenal cortex
Glucocorticoids
Produced in outer adrenal cortex
Mineralocorticoids
hyposecretion of adrenal cortex hormones leads to a condition called ___, characterized by a peculiar bronze-tone of the skin which resembles a sun tan
Addison’s Disease
Can be a symptom of Addison’s Disease; a lessened ability to cope with stress/burnout and suppression of immune system thereby increasing susceptibility to infection
Hypoglycemia
hypersecretion of adrenal cortex hormone results to
Cusning’s syndrome
hypersecretion of sex hormones lead to ___ regardless of sex
Masculinization
produces 2 similar hormones: catecholamines
Adrenal medulla
these hormones prepare the body to deal with short-term stress (“fight or flight”) by increasing heart rate, blood pressure, blood glucose levels and dilating small passageways of lungs
Catecholamines
Give some symptoms of hypersecretion of catecholamines
Rapid heart beat, high blood pressure, and perspiration
located in the abdomen, close to stomach. called a mixed gland, with both endocrine and exocrine functions
Pancreas
also called as islets of Langerhans, scattered among the exocrine tissue of the pancreas
Pancreatic islets
these hormones are antagonists that maintain blood sugar homeostasis
Insulin and glucagon
unables the body to maintain homeostasis of blood glucose levels
Diabetes mellitus
beta cells of the pancreas are destroyed by the immune system, and so no insulin is produced
Type 1 diabetes
the pancreas produces insulin but target cells do not take up glucose
Type 2 diabetes
increases the rate of glucose uptake and metabolism by body cells
Insulin
True or false. Insulin is produced by alpha cells
False. They are produced by beta cells
Name the sign of diabetes mellitus: excessive urination to flush out glucose and ketones
Polyuria
Name the sign of diabetes mellitus: excessive thirst
Polydipsia
Name the sign of diabetes mellitus: hunger due to inability to use sugars and the loss of fat and protein in the body
polyphagia
stimulates the liver to release glucose to blood, thus increasing blood glucose levels
Glucagon
Produce sex cells and sex hormones
Gonads
testosterone production is specifically stimulated by
Luteinizing hormone
female gonads located in the pelvic cavity that produce eggs
Ovaries
The 2 steroid hormones that ovaries produce
Estrogen and progesterone
stimulate the development of secondary female characteristics ; mature the female reproductive organs
Estrogen
acts with estrogen to bring about the menstrual cycle ; helps in the implantation of an embryo in the uterus ; helps prepare breasts for lactation
Progesterone
male gonads suspended outside the pelvic cavity that produces sperm
Testes
the most important androgen responsible for adult male secondary sex characteristics and promoting growth and maturation of male reproductive system
Testosterone