Chapter 18 - The Endocrine System Flashcards
The endocrine system acts with what other system to control all body systems?
Nervous system
Compared to the nervous system, the endocrine takes longer to? The effects, however, last _______ and influence what?
Cause a response / longer, a broader area of the body
The endocrine system releases these chemical substances that enter the bloodstream and travel to target cells where they exert effects by binding to receptor sites.
Hormones
The endocrine system consists of these ductless glands that release hormones.
Endocrine glands
The endocrine system consists of? (2)
Endocrine glands & several other organs and tissues that contains cells that secrete hormones.
Name the endocrine glands (5)
Pituitary, pineal, thyroid, parathyroid, adrenal glands
Glands that are not classified as endocrine glands, but they still secrete hormones (13)
Hypothalamus, ovaries, testes, kidneys, stomach, liver, pancreas, small intestine, thymus, heart, skin, adipose tissue, placenta
Hormones help to regulate? (5)
CHEMICAL composition and VOLUME of body fluids, metabolism and energy BALANCE, CONTRACTION of smooth and cardiac muscle fibers, SECRETION of glands, some IMMUNE system activities
Name 3 functions of hormones.
CONTROL growth and development, REGULATE operation of the reproductive system, help establish CIRCADIAN rhythms
How do hormones influence their target cells?
By binding to their receptors (typically protein)
Most target cells have how many receptors for a specific hormone?
2,000 - 100,000
If a hormone is prevented from binding with a receptor, what happens?
It cannot carry out its normal function.
What eventually happens to most hormones?
They are inactivated by the liver and excreted by the kidneys.
Most of these types of hormones are attached to transport proteins which make the hormones water-soluble long enough to circulate to the target cells.
Lipid-soluble hormones
Where are the receptors for lipid-soluble hormones located?
Inside of the target cells
These types of hormones circulate freely in the blood plasma.
Water-soluble
Example of a water soluble hormone.
Insulin
Where are receptors for water-soluble hormones located?
In the plasma membrane of target cells
Hormone secretion is regulated by what 3 things?
SIGNALS from the nervous system, CHEMICAL CHANGES in the blood, OTHER hormones
What is the main link between the nervous and endocrine systems?
The hypothalamus
What is the master endocrine gland?
The pituitary gland
What is the pituitary gland attached to?
The hypothalamus
The pituitary gland secretes hormones that do what?
Regulate other endocrine glands.
The pituitary gland consists of two of these? They are called?
Lobes / a large anterior and smaller posterior
The hypothalamus produces and releases these two types of hormones?
Releasing and inhibiting hormones
Releasing hormones cause the pituitary gland to?
Release hormones
Inhibiting hormones does what to the pituitary gland?
Suppresses the release of pituitary hormones
This hormone stimulates growth of body tissues.
Human growth hormone (hGH)
This hormone stimulates the synthesis and secretion of thyroid hormones.
Thyroid-stimulating hormone (TSH)
These hormone stimulates the ovaries and testes.
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
This hormone helps stimulate milk secretion by the mammary glands in females and has an unknown function in males.
Prolactin (PRL)
This hormone influences the production and secretion of certain hormones of the adrenal cortex.
Adrenocorticotropic hormone (ACTH).
This hormone may cause darkening of the skin; its exact role in humans is unknown.
Melanocyte-stimulating hormone
While the posterior pituitary gland does not synthesize hormones, it does store and release what two hormones?
Oxytocin (OT) & antidiuretic hormone (ADH)
This hormone that is produced in the hypothalamus and stored and released by the posterior pituitary gland stimulates contractions of the uterus in pregnant females and the ejection of milk.
Oxytocin (OT)
The synthetic form of this hormone is sometimes given to induce labor.
Synthetic OT (Pitocin)
This hormone is stored in the posterior pituitary gland and conserves body water, decreases urine volume and perspiration, and increases blood pressure.
Antidiuretic hormone (ADH)
Endocrine system disorders often involve?
Inadequate release of a hormone (hyposecretion) or excessive release of a hormone (hypersecretion)
This is the inadequate release of a hormone.
Hyposecretion
This is the excessive release of a hormone.
Hypersecretion
When there is an endocrine system disorder, sometimes the problem involves?
The hormone receptors
This hormone indirectly causes body cells to grow and multiply. For example, increased growth of bones and muscles during childhood and teenage years, maintenance of bones and muscles and healing/repair of tissues during adulthood.
Human growth hormone (hGH)
This hormone causes a decrease in the breakdown of proteins for energy, but an increase in the breakdown of lipids.
Human growth hormone (hGH)
This hormone helps to keep blood glucose levels at a proper level.
Human growth hormone (hGH)
This is caused by the secretion of too little hGH. The body fails to grow to an adult size.
Pituitary dwarfism
This is caused by the secretion of too much hGH during childhood. The long bones increase in length so the individual grows to be very tall.
Giantism
In giantism, body proportions are?
Normal
This is a butterfly-shaped gland located below the larynx (voice box) on the anterior portion of the trachea (windpipe).
Thyroid gland
These gland is highly vascularized.
Thyroid & adrenal glands
The thyroid gland produces what 3 hormones?
Thyroxine (T4), triiodothyronine (T3), calcitonin (CT)
This hormone produced by the thyroid gland contains 4 atoms of iodine and is lipid soluble.
Thyroxine (T4)
This hormone produced by the thyroid gland contains 3 atoms of iodine and is lipid-soluble.
Triiodothyronine (T3)
T3 and T4 exert effects where in the body? H is this made possible?
Throughout the body / most body cells have receptors for these hormones
T3 and T4 hormones regulate what 3 things?
BASAL metabolic rate, CELLULAR metabolism, and GROWTH and development
Calcitonin does what to blood calcium levels? It achieves this?
Lowers / decreases bone breakdown by increasing bone building by inhibiting osteoclasts and stimulating osteoblasts.
These disorders are among the most common endocrine disorders
Thyroid gland
Symptoms of this thyroid disorder include edema, a slow metabolism (slow heart rate and low body temperature), a tendency to gain weight easily, sensitivity to cold, dry hair and skin, muscular weakness and lethargy
Hypothyroidism
Symptoms of this thyroid disorder may include enlarged thyroid gland, bulging eyes, increased heart rate, increased blood pressure, agitation, and weight loss.
Hyperthyroidism
True or False: hypothyroidism is more common in males than females?
False
True or False: hyperthyroidism is more common in females than males?
True
The parathyroid glands consist of how many glands?
4
The parathyroid glands are attached where?
To the posterior surface of the thyroid gland
Parathyroid glands produce what hormone?
Parathyroid hormone (PTH)
Parathyroid hormone (PTH) works opposite of?
Calcitonin
How does parathyroid hormone work opposite of calcitonin?
It increase blood calcium levels, decreases bone building, and increases bone breakdown. It inhibits osteoblasts and stimulates osteoclasts.
The glands are paired and are superior to each kidney.
Adrenal glands
This is the outermost portion of the adrenal glands. This is the inner portion.
Adrenal cortex / adrenal medulla
The adrenal medulla secretes what hormones?
Epinephrine & nonrepinephrine
The adrenal cortex secretes what hormones?
Mineralocorticoids, glucocorticoids, androgens
This hormone secreted by the adrenal cortex affects mineral homeostasis
Mineralocorticoids
This hormone secreted by the adrenal cortex effects glucose homeostasis.
Glucocorticoids
An example of mineralocorticoids is?
Aldosterone
An example of glucocorticoids is?
Cortisol
This hormone secreted by the adrenal cortex is a steroid hormone that has masculinizing effects
Androgens
When are epinephrine and norepinephrine secreted?
When the adrenal medulla is stimulated by the sympathetic division of the ANS
Epinephrine and norepinephrine enhance?
The “fight or flight” responses (increase heart rate, blood pressure, respiration rate, etc).
This hormone secreted by the adrenal glands help in fluid and electrolyte balance. Mainly sodium (Na+) and potassium (K+) ions and water.
Aldosterone
This hormone secreted by the adrenal glands helpsto reduce inflammation and the body’s immune responses.
Cortisol
This hormone secreted by the adrenal glands stimulates glucogenesis n increases the breakdown of proteins and lipids.
Cortisol
This process involves the conversion of non-carbohydrate substances (substances other than glycogen or another monosaccharide) into glucose which can be used for energy.
Glucogenesis
Androgens are secreted by the adrenal cortex in which sex?
Both male and female
This is an androgen produced within the testes in males
Testosterone
What does androgens contribute to in females?
Sex drive
This is a flattened organ that measure about 4-5.6 inches in length and is located in the curve of the duodenum.
Pancreas
Most of the cells of the pancreas produce these which are carried by ducts to the gastrointestinal tract.
Digestive enzymes
These are clusters of cells that produce hormones n the pancreas.
Pancreatic islets/Islets of Langerhans
This portion of the pancreas is considered a part of the endocrine system.
Pancreatic islets/Islets of Langerhans
The primary hormones secreted by the pancreas are?
Insulin and glucagon
This hormone raises blood glucose levels.
Glucagon
This hormone lowers blood glucose levels.
Insulin
Glucagon targets the cells of the liver causing them to convert glycogen into?
Glucose
After glycogen is converted into glucose, it is released where? This causes?
Blood / glucose levels to rise
This is low blood glucose levels
Hypoglycemia
Hypoglycemia stimulates?
Secretion of glucagon
High blood glucose levels.
Hyperglycemia
High blood glucose levels do what?
They inhibit the release of glucagon and stimulates the release of insulin.
Insulin acts on various body cells which causes?
An increase in the rate at which glucose moves into cells by facilitated diffusion
Most glucose that enters the liver is converted into?
Glycogen
After glucose enters the liver and is converted into glycogen, what happens?
Blood glucose levels decrease
The primary hormone produced by the ovaries are the steroid hormones?
Estrogen & progesterone
Examples of lipid-soluble hormones
Steroid and thyroid hormones
These hormones regulate the menstrual cycle, control development of feminine secondary sex characteristic, maintain pregnancy, and prepare the mammary glands for milk production and secretion.
Estrogen, progesterone, FSH, and LH
This is the main hormone produced and secreted by the testes.
testosteron
This hormone regulates the production of sperm and controls development of masculine secondary sex characteristic.
testosterone
This is a small endocrine gland attached to the roof of the third ventricle of the brain.
Pineal gland
The pineal gland secretes what hormone?
melatonin
Melatonin is derived from?
Serotonin
More melatonin is released when?
During sleep and in darkness
Melatonin is thought to contribute to?
setting the body’s biological clock.
This is a type of depression that affects some individuals during the winter months, when the day length is short.
Seasonal affective disorder (SAD)
What is thought to be the cause of seasonal affective disorder?
overproduction of melatonin
What can be used to help relieve seasonal affective disorder?
exposure to sunlight or artificial light as bright as sunlight
This is located behind the sternum between the lungs.
Thymus
The thymus secretes several hormones involved in?
immunity
What is one of the causes of muscle atrophy that accompanies aging?
hGH production by the anterior pituitary gland decreases
As humans age, a decrease in metabolic rate, an increase in body fat. and hypothyroidism is cause by?
The decrease in the production of thyroid hormones
During aging of the human body, what can lead to a decrease in bone mass and possibly osteoporosis?
parathyroid hormone levels ride and calcitonin levels fall
What happens to the insulin production by the pancreas as we age?
It slows
As we age, what happens to the sensitivity of receptors to glucose?
they decline
In older people, what happens to blood glucose levels?
They increase faster and return to normal slower.
These hormones regulate the menstrual cycle, control development of feminine secondary sex characteristic, maintain pregnancy, and prepare the mammary glands for milk production and secretion.
Estrogen, progesterone, FSH, and LH
This is the main hormone produced and secreted by the testes.
testosteron
This hormone regulates the production of sperm and controls development of masculine secondary sex characteristic.
testosterone
This is a small endocrine gland attached to the roof of the third ventricle of the brain.
Pineal gland
The pineal gland secretes what hormone?
melatonin
Melatonin is derived from?
Serotonin
More melatonin is released when?
During sleep and in darkness
Melatonin is thought to contribute to?
setting the body’s biological clock.
This is a type of depression that affects some individuals during the winter months, when the day length is short.
Seasonal affective disorder (SAD)
What is thought to be the cause of seasonal affective disorder?
overproduction of melatonin
What can be used to help relieve seasonal affective disorder?
exposure to sunlight or artificial light as bright as sunlight
This is located behind the sternum between the lungs.
Thymus
The thymus secretes several hormones involved in?
immunity
What is one of the causes of muscle atrophy that accompanies aging?
hGH production by the anterior pituitary gland decreases
As humans age, a decrease in metabolic rate, an increase in body fat. and hypothyroidism is cause by?
The decrease in the production of thyroid hormones
During aging of the human body, what can lead to a decrease in bone mass and possibly osteoporosis?
parathyroid hormone levels ride and calcitonin levels fall
What happens to the insulin production by the pancreas as we age?
It slows
As we age, what happens to the sensitivity of receptors to glucose?
they decline
In older people, what happens to blood glucose levels?
They increase faster and return to normal slower.
