Endocrine System Flashcards
(posterior part of thyroid)
Parathyroids
Production of ADH, oxytocin, and regulatory hormones
HYPOTHALAMUS
Anterior lobe:
ACTH, TSH, GH, PRL, FSH, LH, and MSH
Posterior lobe:
Release of oxytocin and ADH
PITUITARY GLAND
Thyroxine (T4)
Triiodothyronine (T3)
Calcitonin (CT)
THYROID GLAND
(Undergoes atrophy during adulthood)
Thymosins
(Chapter 22)
THYMUS
Each is subdivided into:
Adrenal medulla:
Epinephrine (E)
Norepinephrine (NE)
Adrenal cortex:
Cortisol, corticosterone. aldosterone, androgens
ADRENAL GLANDS
Epinephrine (E)
Norepinephrine (NE)
Adrenal medulla:
Cortisol, corticosterone. aldosterone, androgens
Adrenal cortex:
(on posterior surface of thyroid gland)
Parathyroid hormone (PTH)
PARATHYROID GLANDS
Renin Erythropoietin (EPO)
Calcitriol
(Chapters 19 and 27)
KIDNEY
Numerous hormones (detailed in Chapter 24)
DIGESTIVE TRACT
Testes (male):
Androgens (especially testosterone), inhibin
Ovaries (female):
Estrogens, progestins.
inhibin
GONADS
Insulin, glucagon
PANCREATIC ISLETS
Leptin
Resistin
ADIPOSE TISSUE
Natriuretic peptides:
ANP and BNP
(Chapter 21)
HEART
Melatonin
PINEAL GLAND
can be defined as the complicated network of nerves that carry messages or signals from and to the spinal cord and brain to other parts of the body.
NERVOUS
it is the collection of glands, which produces hormones that function in regulating the body’s growth and
development, metabolism, tissue function, reproduction, sleep, anger, emotions and other internal functions.
ENDOCRINE
creates the localized
response which is temporary and reversible
NERVOUS
the response is spread widely and is permanent.
• primarily work in sending signals to various parts of the body with the help of hormones and act as the chemical
messenger.
ENDOCRINE
the rate of response is fast and early to the stimuli by the action potentials and neurotransmitters
NERVOUS
it responds slowly by secreting hormones, travelling through the circulatory system to the target tissue
ENDOCRINE
the mode of transmission of the signal is through the neurotransmitters which along neurons transmit electrochemical signals
NERVOUS
the hormones provide the chemical signals and are used to transmit the signal to the target tissue located at any part of the body
ENDOCRINE
the mode of
transmission of the signal is through the neurotransmitters which along neurons transmit electrochemical signals
NERVOUS
the hormones provide the chemical signals and are used to transmit the signal to the target tissue located at any part of the body
ENDOCRINE
electrical
signals are sent by use of neurons
NERVOUS
the hormones are transferred
through the blood stream or other body fluid to send any messages or signals.
ENDOCRINE
Functions of Endocrine System
Controls homeostasis
2. Maintains water balance
3. Controls uterine contractions
4. Controls milk production
5. Regulates ions (calcium, sodium, potassium)
6. Regulates metabolism and growth
7. Regulates heart rate and blood pressure
8. Monitors blood glucose levels
9. Aids the immune system
10. Reproductive functions
Types of Chemical Signal
Intracellular:
Intercellular:
produce in one of part a cell and move to another part of same cell
Intracellular
released from one cell and bind to receptors on another cell
• Intercellular:
Types of Intercellular Signals
Autocrine:
Paracrine:
Neurotransmitter and neuromodulators
Pheromones:
Hormones and neurohormones:
:
- released by cells and a have local effect on same cell type
- Ex. Eicosanoids (released in response to
inflammation)
Autocrine
:
- released by cells that affect other cell types in close proximity
- Ex. Somatostatin (inhibits insulin secretion)
Paracrine
(inhibits insulin secretion)
Somatostatin
(released in response to inflammation)
Eicosanoids
- secreted by nerve cells
- Ex. Nervous system function
Neurotransmitter and neuromodulators
:
- secreted into env’t and modify behavior and physiology of other individual in same species
- Ex. Women and menstrual cycles
Pheromones
- secreted into blood and bind to receptor sites
- Ex. Epinephrine and insulin
Hormones and neurohormones:
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
Eicosanoids (prostaglandins, thromboxanes, prostacyclins, leukotrienes)
Autocrine
Somatostatin, histamine, eicosanoids
Paracrine
Acetylcholine, epinephrine
Neurotransmitter
Thyroid hormones, growth hormone, insulin, epinephrine, estrogen, progesterone, testosterone, prostaglandins
Endocrine
Components of Hormones
Receptor site:
Target tissues:
Specificity:
location on a cell where hormone binds (lock)
Receptor site:
group of cells that respond to specific hormones
• Target tissues:
specific hormones bind to specific receptor sites
• Specificity:
How does this work?
- Hormones are secreted by endocrine glands directly into bloodstream
- Hormones travel to all parts of body
- Hormones (key) bind to receptor site (lock) on target tissue
- Hormones are secreted by - directly into —
endocrine glands, bloodstream
- Hormones (key) bind to — on target tissue
receptor site (lock)
- Hormones travel to
all parts of body
How do hormones cause change?
• Alter cell activity of target tissues by increasing or decreasing cell’s normal processes
• Change permeability of cell membrane by opening or closing ion channels
Synthesis of proteins
Alter cell activity of target tissues by —
increasing or decreasing cell’s normal processes
• Change permeability of cell membrane by -
opening or closing ion channels
Types of Hormones
Water soluble:
Lipid hormones:
- includes proteins, peptides, amino acids
- most common
- Ex. Growth hormone, antidiuretic, prolactin, etc.
• Water soluble:
- includes steroids and eicosanoids
Ex. LH, FSH, androgens
• Lipid hormones:
(glucagon, prolactin)
Membrane-bound receptor
Water-soluble hormone
(thyroid or steroid)
Lipid-soluble hormone
The endocrine system produces two main types of hormones:
1.steroid hormones
2.nonsteroid hormones
, such as cortisol, are manufactured from cholesterol.
Steroid hormones
• Each type of steroid hormone is composed of a central structure of - carbon rings attached to distinctive side chains that determine the hormone’s specific and unique properties.
four
• Within the endocrine cells, steroid hormones are synthesized in the
smooth endoplasmic reticulum (ER).
Since steroid hormones are —, they combine with a protein carrier that transports them through the bloodstream.
hydrophobic
• can pass through the membrane of a target cell.
Fat-soluble steroid hormones
Once inside the target cell, steroid hormones attach to a —-in the cytoplasm.
• This hormone- receptor complex then enters the nucleus, where it binds with and activates a specific gene on the cell’s DNA molecule.
• The activated gene then produces an — that initiates the desired chemical reaction within the cell.
protein receptor molecule
enzyme
, such as adrenaline, are composed of either proteins, peptides, or amino acids.
Nonsteroid hormones
• These hormone molecules are not fat-soluble, so they usually do not enter cells to exert their effect. Instead, they bind to receptors on the —
• This combination substance then triggers a specific chain of chemical reactions with the cell.
surface of target cells.
Lipid-soluble hormones diffuse through the.
plasma membrane
bind to cytoplasmic receptors and travel to the nucleus or bind to nuclear receptors.
Some bind receptors in the cytoplasm and then move into the nucleus.
Lipid-soluble hormones
The hormone-receptor complex binds to a hormone response element on the
DNA, acting as
transcription factor.
The binding of the hormone-receptor complex to DNA stimulates the synthesis of —, which codes for specific proteins.
messenger RNA (mRNA)
The mRNA leaves the nucleus, passes into the cytoplasm of the cell, and binds to —, where it directs the synthesis of specific proteins.
ribosomes
The - produce the cell’s response to the lipid-soluble hormones-for example, the secretion of a new protein.
newly synthesized proteins
Ex. Blood glucose levels (insulin)
Blood levels of chemicals:
• Other hormones:
Ex. —- signals thyroid gland to release thyroid hormone
TSH
Nervous system:
Ex. — and fight or flight response
Epinephrine
tells body when homeostasis is reached
Negative Feedback:
The —- secretes a tropic hormone, which travels in the blood to the target endocrine cell.
The hormone from the target endocrine cell travels to its target.
anterior pituitary gland
The hormone from the target endocrine cell also has a —- effect on the anterior pituitary and hypothalamus and decreases secretion of the tropic hormone.
negative-feedback
The anterior pituitary gland secretes a tropic hormone, which travels in the blood to the target endocrine cell.
The hormone from the target endocrine cell travels to its target.
The hormone from the target endocrine cell also has a negative-feedback effect on the anterior pituitary and hypothalamus and decreases secretion of the tropic hormone.
Negative feedback by hormones
The hormone from the target endocrine cell also has a — effect on the anterior pituitary and increases secretion of the tropic hormone.
positive-feedback
The anterior pituitary gland secretes a tropic hormone, which travels in the blood to the target endocrine cell.
The hormone from the target endocrine cell travels to its target.
The hormone from the target endocrine cell also has a positive-feedback effect on the anterior pituitary and increases secretion of the tropic hormone.
Positive feedback by hormones
Small gland in brain
• Controlled by hypothalamus
• Divided into 2 regions: anterior and posterior
• Secretes at least 6 hormones
Pituitary Gland
• Divided into 2 regions of pituitary gland:
anterior and posterior
Pituitary gland excretes at least — of hormones
Six
Anterior Pituitary Gland
- Target tissues: most
- Functions: stimulates growth of bones, muscles, and organs
Growth Hormone:
Abnormalities:
Too much GH causes -
Too little GH causes -
giantism
pituitary dwarfism
—- within the nervous system cause releasing and inhibiting hormones (blue circles) to be secreted from nerve cells of the hypothalamus.
Stimuli
secrete releasing and inhibiting hormones.
Hypothalamic nerve cells
— leave capillaries, bind to membrane-bound receptors, and influence the secretion of hormones from anterior pituitary cells.
pass through the hypothalamic-pituitary portal system to the anterior pituitary.
Releasing and inhibiting hormones
Target tissues: thyroid gland
- Functions: regulates thyroid gland secretions
- Abnormalities:
Too much TSH, thyroid gland enlarges
Thyroid-Stimulating Hormone (TSH):
Too much TSH -
thyroid gland enlarges
- Target tissue: ovaries
- Function: promotes ovulation and progesterone
• LH (Luteinizing) for females:
- Target tissue: follicles in ovaries
- Function: follicle maturation and estrogen
secretion
FSH (Follicle-Stimulating) for females:
GONADOTROPINS
FSH (Follicle-Stimulating) for females:
LH (Luteinizing) for females:
- Target tissues: kidneys
- Functions: conserve water
- Abnormalities:
Diabetes insipidus:
Antidiuretic Hormone (ADH):
- low ADH
- kidneys to produce large amounts of dilute (watery) urine
- can lead to dehydration and thirst
Diabetes insipidus:
- Target tissues: uterus
- Functions: increases uterine contractions during
labor
Oxytocin
In the posterior pituitary gland, - cause the release of hormones (red circles) from the axons into the circulatory system.
action potentials
Stimuli within the nervous system stimulate — nerve cells to produce action potentials.
hypothalamic
• One of largest glands
• Requires iodine to function
Thyroid hormones:
- Target tissues: most
Strerroid
- Functions: regulates metabolic rates and is
Thyroid Gland
— Decreased metabolism
- Weight gain, reduced appetite, fatigue
- Low temp. and pulse
- Dry, cold skin
- Myxedema in adults
- Cretinism in infants
Hypothyroidism
— Increased metabolism
- Weight loss, increased appetite, nervousness
- Higher temp. and pulse
- Warm, flushed skin
- Graves’ disease (leads to goiter)
Hyperthyroidism:
Abnormalities of Thyroid Gland
Hyperthyroidism:
Hypothyroidism
causes increased release of thyroid hormones (T3 and T4) into the general circulation.
TSH
also have an inhibitory effect on the secretion of TSH-releasing hormone from the hypothalamus and TSH from the anterior pituitary.
T3 and T4
- Target tissues: bones
- Functions: secreted when blood Ca?+ levels
Calcitonin:
- Target tissues: bones and kidneys
- Functions: regulates blood Ca?+ levels
(more than calcitonin)
Parathyroid hormone (PTH):
osteoclasts break down bone matrix and less Ca 2+ is lost in urine.
Ca 2+ is low
then osteoclasts don’t break down bone matrix and more Ca 2+ is lost in urine
If Ca2+ is high
• On kidneys
• 2 regions medulla and cortex
Adrenal Glands
Adrenal Medulla (inner portion):
- Target tissues: heart, blood vessels, liver, fat cells
• Epinephrine/Norepinephrine:
stimulated by
• Stress
• Physical activity
• Low blood glucose levels
Hypothalamus
Target tissue
• Increases release of glucose from the liver
• Increases release of fatty acids from fat stores
• Increases heart rate
• Decreases blood flow through blood vessels of internal organs and skin
• Increases blood flow to skeletal muscles and the heart
• Decreases function of visceral organs
• Increases blood pressure
• Increases metabolic rate in skeletal muscles
Adrenal gland
Adrenal Cortex (outer portion):
- Type of mineralocorticoids
- Target tissues: kidneys
- Functions: causes Nat and H2O to be retained and
K+ to be secreted, indirectly involved with blood pressure and blood volume
Aldosterone
Adrenal glands
(outer portion):
Adrenal Cortex
Adrenal gland
(inner portion):
Adrenal Medulla
causes increased secretion of aldosterone, which primarily affects the kidneys.
Angiotensin II
stimulation of the kidneys causes Na’ retention, K• excretion, and decreased water loss.
Aldosterone
Increased blood K• levels or decreased blood Na’ levels cause the adrenal cortex to — the secretion of aldosterone into the general circulation.
increase
- Type of glucocorticoids
- Target tissues: most
- Functions: increases breakdown of fat and protein for energy uses reduces inflammatory and immune responses
Cortisol:
acts on its target tissues to increase protein breakdown and blood glucose.
Cortisol
acts on the hypothalamus and anterior pituitary to decrease ACTH secretion.
Cortisol
Target tissue
• Increases fat and protein breakdown
• Increases blood glucose levels
• Has anti-inflammatory effects
ACTH-releasing hormone
- Target tissues: most
- Functions:
Males: secondary sexual characteristics
Females: sex drive
Androgens:
- Causes: too little insulin or faulty insulin receptors
- Symptoms: exaggerated appetite, excess urine, dehydration, thirst, fatigue
- Type I: insulin dependent (daily injections required)
- Type II: insulin independent, often found in obese people, can be treated often found in obese people, can be treated with a diet that can be turned into type 1
Diabetes mellitus:
- (daily injections required)
- often found in obese people, can be treated with a diet that can be turned into type 1
Type I: insulin dependent
Type II: insulin independent,
The three P’s of diabetes are
• These terms correspond to
- increases in thirst,
— urination, and
- appetite,
polydipsia, polyuria, and polyphagia.
increases in thirst,
polydipsia
Increase in urination,
polyuria
Increase in appetite,
polyphagia.
Pineal Body (Gland)
•:
Target tissues: hypothalamus
Functions: plays a role in onset of puberty and
controls circadian rhythms. Light
Melatonin
• A hormonal imbalance causes women to have irregular periods, abnormal hair growth, excess acne and weight gain.
• It can lead to diabetes, increased risk of metabolic syndrome and infertility.
Polycystic ovary syndrome (PCOS)
When a woman’s ovaries don’t produce enough estrogen, bones become brittle and weak.
• Although it is more common in women, men sometimes have it when testosterone levels get too low.
• People with an overactive parathyroid gland (hyperparathyroidism) may also have weak bones
Osteoporosis:
overactive parathyroid gland ()
hyperparathyroidism
Consists of the ductless glands.
• It coordinates with the nervous system.
• Involvement in the synthesis and secretion of hormones.
• Include energy production, utilization, and the control of the
composition of the extracellular water and electrolytes.
• Involve in maintaining normal growth and development.
ENDOCRINE SYSTEM
An organic substance that is needed by our body in enough
quantities to express a neurological response.
HORMONES
• A small gland located at the base of the brain.
• Intimately associated with the pituitary gland.
• Secretes hormones that travel by the fertile system and
stimulate the anterior pituitary glands.
• Production of ADH, oxytocin, and regulatory hormones.
Hypothalamus
A small gland located at the base of the brain, depression
of the skull.
• Connected to the brain with a short stalk called the
“infundibulum.”
Pituitary Gland
Divided into two: Pituitary Gland
- ACTH, TSH, GH, PPL, FSH, LH, and MSH
- Release of oxytocin and ADH
- Anterior Lobe (Adenohypophysis):
- Posterior Lobe (Neurohypophysis):
- responsible for growth and development
Thyroxine (T4)
(Undergoes atrophy during adulthood)
• Located between the upper part of the sternum and
pericardium
• Hormone: Thymosins - controls metabolic weight.
Involvement in the formation of WBC
Thymus
- controls metabolic weight. Involvement in the formation of WBC
Thymosins
(Small muscles located above the kidney)
Adrenal Glands
(Glucogenesis, sodium retention,
potassium excretion in the kidney)
Aldosterone
▪ The gland that promotes the “fight or flight”
reaction
Adrenal Medulla:
• Consists of both an exocrine (with ducts) and an endocrine
(ductless) gland.
(Endocrine part secrete the hormone insulin)
Pancreas/Pancreatic Islets
• - lowers the blood sugar. Inadequate secretion leads to diabetes.
Insulin
Located in the testes or ovary.
Gonads
COMPONENTS OF THE ENDOCRINE SYSTEM
• secrete their product directly into the bloodstream
• molecules that are released from one location, move to
another location and produce a response
Endocrine glands:
Chemical signal:
2 TYPES OF PROTEIN
Ex. Keratin in hair and skin
Ex. Enzymes (Catalysts) and hormones
- Structural Protein
- Regulatory Protein
HORMONE RECEPTORS AND MECHANISMS OF
ACTION
- Lipid Soluble Hormones bind to -
- Water Soluble Hormones bind to -
- Intracellular Receptor Hormones
Nuclear Receptors
Membrane-Bound Receptors
Target tissue: testes
Function: sperm production and testosterone
LH for males:
Target tissue: seminiferous tubules (testes
Function: sperm production
FSH for males:
Target tissues: most
Functions: regulates metabolic rates and is needed for growth
Thyroid hormones:
Organ in the abdomen
PANCREAS
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 the form of
glycogen
Insulin:
Target tissues: liver
Function:
▪ regulates blood glucose levels
▪ between meals glucose levels drop and
▪ glucagon is secreted
▪ glucagon allows glycogen to be broken into
glucose
Glucagon:
: TESTES
o Target tissues: most
o Functions: aids in sperm and reproductive organ
development and function
Testosterone
OVARIES
o Target tissues: most
o Functions: involved in uterine and mammary gland
development and menstrual cycle
• Estrogen/Progesterone:
THYMUS GLAND
•:
o Target tissues: immune system tissues
o Functions: promotes immune system
o Development and function
Thymosin
▪ A disorder that affects the way the body uses the
energy from the food we eat.
▪ It develops when the pancreas doesn’t make
enough of a hormone called insulin, or insulin
doesn’t work as it should.
Diabetes
happens when the thyroid doesn’t
produce enough hormones
▪ occurs when it creates too many
hormones
Hypothyroidism
Hyperthyroidism
▪ In men, can cause erectile
dysfunction.
▪ It can also cause memory and concentration
problems, changes in muscle strength, and low
sex drive.
▪ It happens when the testes do not produce enough
of the sex hormone, testosterone.
Hypogonadism (low testosterone)
Ductless -
Ducts -
endocrine
exocrine
. Excretes, responsible for Na and K secretion in kidney
Andrenal cortex
Atleast. Three hormones
Secretes 6 hormones
Posterior lobe.
Anterior lobe.
Located between the upper part of the sternum and
pericardium
Thymus
. Fight emergency reactioins
Adrenal medulla
- male pattern baldness, irreversible
Strerroid
Type of diabetes
- aging, starts at forty before
- Lifestyle
Type two diabetes
