ENDOCRINE SYSTEM Flashcards
- Controls homeostasis
- Maintains water balance
- Controls uterine contractions
- Controls milk production
- Regulates ions (calcium, sodium, potassium)
- Regulates metabolism and growth
- Regulates heart rate and blood pressure
- Monitors blood glucose levels
- Aids the immune system
- Reproductive functions
Function of Endocrine System
secrete their product directly into blood stream
Endocrine glands
molecules that are released from one location, move to another location, and produce a response
Chemical signal
2 components of the endocrine system
Endocrine glands
Chemical signal
produce in one of part a cell and move to another part of same cell
Intracellular (chemical signals)
released from one cell and bind to receptors on another cell
Intercellular (chemical signals)
2 types of chemical signals
Intracellular
Intercellular
- released by cells and a have local effect on same cell type
- Ex. Eicosanoids (released in response to inflammation)
Autocrine (Intercellular Signal)
- released by cells that affect other cell types in close proximity
- Ex. Somatostatin (inhibits insulin secretion)
Paracrine (Intercellular signals)
- secreted by nerve cells
- Ex. Nervous system function
Neurotransmitter and neuromodulators (intercellular signals)
- secreted into environment and modify behavior and physiology of other individual in same species
- Ex. Women and menstrual cycles
Pheromones (intercellular signals)
- secreted into blood and bind to receptor sites
- Ex. Epinephrine and insulin
Hormones and neurohormones (intercellular signals)
Secreted by cells in a local area; influences the activity of the same cell from which it was secreted
Autocrine
Produced by a wide variety of tissues and secreted into extracellular fluid; has a localized effect on other tissues
Paracrine
Produced by neurons; secreted into a synaptic cleft by presynaptic nerve terminals; travels short distances; influences postsynaptic cells
Neurotransmitter
Secreted into the blood by specialized cells; travels some distance to target tissues; results in coordinated regulation of cell function
Endocrine
5 types of intercellular signals
- autocrine
- paracrine
- neurotransmitter and neuromodulators
- pheromones
- hormones and neurohormones
location on a cell where hormone binds (lock)
receptor sites
group of cells that respond to specific hormones
target tissues
specific hormones bind to specific receptor sites
specificity
3 components of hormones
- receptor site
- target tissues
- specificity
How does response occur:
1. Hormones are secreted by endocrine glands directly into ____________.
2. __________ travel to all parts of body
3. Hormones (key) bind to ______ (lock) on ______ tissue
4. _________ occurs
- bloodstream
- Hormones
- receptor site, target
- Response
How does hormones cause change?
* Alter cell activity of ________ by increasing or decreasing cell’s
normal processes
* Change ___________ of cell membrane by opening or closing ion channels
* Synthesis of __________
- target tissues
- permeability
- proteins
Type of hormone:
- includes proteins, peptides, amino acids
- most common
- Ex. Growth hormone, antidiuretic, prolactin
Water soluble hormones
Type of hormone:
- includes steroids and eicosanoids
- Ex. LH, FSH, androgens
Lipid hormones
2 type of hormones
- water soluble hormones
- lipid hormones
5 ways of regulation of hormones
- Blood levels of chemicals:
Ex. Blood glucose levels (insulin) - Other hormones:
Ex. TSH signals thyroid gland to release thyroid hormone - Nervous system:
Ex. Epinephrine and fight or flight response - Negative Feedback:
tells body when homeostasis is reached - Positive Feedback
Hormone receptors and mechanisms of action:
1. Lipid Soluble Hormones bind to _________
2. Water Soluble Hormones bind to ____________
3. ____________ Receptor Hormones
- Nuclear Receptors
- Membrane-Bound Receptors
- Intracellular
9 endocrine organs?
- pituitary gland
- pineal gland
- thyroid
- thymus
- adrenals
- ovaries
- testes
- parathyroid
- pancreas
- THE MASTER GLAND
- Small gland in brain
- Controlled by hypothalamus
- Divided into 2 regions: anterior and posterior
- Secretes at least 6 hormones
Pituitary gland
What hormone is this and which produces it?
- Target tissues: most
- Functions: stimulates growth of bones, muscles, and organs
- Abnormalities:
Too much GH causes giantism
Too little GH causes pituitary dwarfism
Growth hormone (Anterior Pituitary Gland)
What hormone is this and where is is produced?
- Target tissues: Thyroid gland
- Functions: regulates thyroid gland secretions
- Abnormalities:
Too much TSH, thyroid gland enlarges
Too little TSH, thyroid gland shrinks
Thyroid stimulating Hormone (TSH), Anterior pituitary gland
What hormone is this and where is it produced?
- Target tissue: ovaries
- Function: promotes ovulation and progesterone production
LH (Luteinizing) for females, Anterior pituitary gland
What hormone is this and where is it produced?
- Target tissue: testes
- Function: sperm production and testosterone
LH (Luteinizing) for males, Anterior pituitary gland
What hormone is this and where is it produced?
* LH (Luteinizing) for females
* LH (Luteinizing) for males
Gonadotropins, Anterior pituitary gland
What hormone is this and where is it produced?
- Target tissue: follicles in ovaries
- Function: follicle maturation and estrogen secretion
FSH (Follicle-Stimulating) for females, Anterior pituitary gland
What hormone is this and where is it produced?
- Target tissue: seminiferous tubules (testes)
- Function: sperm production
FSH (Follicle-Stimulating) for males, Anterior pituitary gland
What hormone is this and where is it produced?
- Target tissues: mammary glands and ovaries
- Functions: milk production
Prolactin, Anterior pituitary gland
What hormone is this and where is it produced?
- Target tissues: kidneys
- Functions: conserve water
Antidiuretic Hormone (ADH), Posterior Pituitary Gland
What hormone is this and where is it produced?
- Target tissues: uterus
- Functions: increases uterine contractions during labor
oxytocin, posterior pituitary gland
What hormone is this and where is it produced?
- low ADH
- kidneys to produce large amounts of dilute (watery) urine
- can lead to dehydration and thirst
Diabetes insipidus, posterior pituitary gland
- One of largest glands
- Requires iodine to function
- Thyroid hormones:
- Target tissues: most
- Functions: regulates metabolic rates and is needed for growth
Thyroid gland
Abnormalities of thyroid gland:
– Decreased metabolism
– Weight gain, reduced appetite, fatigue
– Low temp. and pulse
– Dry, cold skin
– Myxedema in adults
– Cretinism in infants
Hypothyroidism
Abnormalities of thyroid gland
– Increased metabolism
– Weight loss, increased appetite, nervousness
– Higher temp. and pulse
– Warm, flushed skin
– Graves’ disease (leads to goiter)
Hyperthyroidism
decreases calcium
- Target tissues: bones
- Functions: secreted when blood Ca2+ levels are high or elevated
calcitonin
- Target tissues: bones and kidneys
- Functions: regulates blood Ca2+ levels (more than calcitonin)
Parathyroid hormone (PTH)
If Ca 2+ is _____then osteoclasts break down bone matrix and less Ca 2+ is lost in urine.
low
If Ca 2+ is _____ then osteoclasts don’t break down bone matrix and more Ca 2+ is lost in urine.
high
- Located on top of the kidneys
- Aka Suprarenal gland
- 2 regions - medulla and cortex
Adrenal gland
- Target tissues: heart, blood vessels, liver, fat cells
- Functions: released as part of fight or flight response
Epinephrine/Norepinephrine (Adrenal Medulla (inner portion))
- Type of mineralocorticoids
- Target tissues: kidneys
- Functions:
- causes Na+ and H2O to be retained and K+ to be secreted, indirectly involved with blood pressure and blood volume
Aldosterone (Adrenal Cortex [outer portion])
- Type of glucocorticoids
- Target tissues: most
- Functions:
1. increases breakdown of fat and protein for energy uses
2. reduces inflammatory and immune responses
cortisol
- Target tissues: most
- Functions:
Males: secondary sexual characteristics
Females: sex drive
Androgens
Insulin or glucagon?
- secreted by the beta cells of the Islets of Langerhans
- lowers blood glucose levels
- Target tissues: liver, skeletal muscle, adipose tissue
- Functions:
- regulates blood glucose levels
- after a meal glucose levels are high and insulin is secreted
- extra glucose is stored in form of glycogen
insulin
Abnormalities of pancreas:
Causes: too little insulin or faulty insulin receptors
Symptoms: exaggerated appetite, excess urine, dehydration, thirst, fatigue
Diabetes mellitus
Type of diabetes mellitus:
Insulin dependent daily injections required
Type I
Type of diabetes mellitus:
Insulin independent, often found in obese people can be treated with diet and treated with hypoglycemic agents
Type II
- secreted by the alpha cells of the Islets of Langerhans
- increases glucose
- Target tissues: liver
- Function:
- regulates blood glucose levels
- between meals glucose levels drop and glucagon is secreted
- glucagon allows glycogen to be broken down into glucose (glycogenolysis)
glucagon
- Target tissues: most
- Functions: aids in sperm and reproductive organ development and function
Testosterone
What produces testosterone?
Testes
- Target tissues: most
- Functions: involved in uterine and mammary gland development and menstrual cycle
Estrogen/progesterone
What produces estrogen/progesterone?
Ovaries
- Target tissues: immune system tissues
- Functions: promotes immune system development and function
Thymosin
What produces thymosin?
thymus gland
- Target tissues: hypothalamus
- “sleep-wake cycle”
- Functions: plays a role in onset of puberty controls circadian rhythms light affects its function
Melatonin (pineal gland)
What produces melatonin?
pineal gland
