Endocrine system Flashcards
State five ways that the endocrine system maintains homeostasis?
Altering metabolism Regulating growth and development Regulating reproduction Regulate circadian rhythms Regulate activity of smooth muscles, cardiac muscle and glands.
Explain the difference in receptor location for both water soluble hormones and lipid soluble hormones?
- Water soluble hormones circulate freely in the blood
- Lipid-soluble hormones diffuse through the cell membrane and bind to receptors within target cell.
Explain why water-soluble hormones cannot be administered via the oral route?
Water-soluble hormones cannot be administered via the oral route as they are destroyed by digestion so they must be injective.
Describe the difference between endocrine & exocrine glands and give an example of each type of gland
- Endocrine glands release hormones into the interstitial fluid, then diffuse into the blood
- Exocrine glands release enzymes and secretions into ducts
Name the organ that has both endocrine & exocrine functions?
The pancreas is both an endocrine and exocrine organ
Explain how hormones are inactivated and excreted from the body?
Inactivated by the liver and excreted by the kidneys or faeces
Describe the three stimuli that trigger hormone secretion?
- Signals from the nervous system
- The level of a chemical in the blood
- Another hormone
Describe the structure and location of the pituitary gland
The pituitary gland is connected to the hypothalamus and infundibulum. It is called the master gland because it secretes hormones and most of these control other endocrine glands. It consists of a smaller posterior lobe and a larger anterior lobe
Name the two hormones released from the posterior pituitary
Two hormones released from the posterior pituitary gland are oxytocin and antidiuretic hormone (ADH).
Name the six hormones produced by the anterior pituitary
Growth hormone GH Thyroid stimulating hormone TSH Adrenocorticotropic hormone ACTH follicle-stimulating hormone FSH, luteinizing hormone LH, prolactin
State the stimulus for GH growth hormone?
A releasing hormone from the hypothalamus stimulates the anterior pituitary to release GH
State the stimulus for TSH (Thyroid-stimulating hormone)?
Decreased Metabolic rate and prolonged cold
State the stimulus for FSH?
GnRH stimulates the pituitary gland to produce follicle-stimulating hormone
State the stimulus for LH?
LH release is stimulated by gonadotropin-releasing hormone (GnRH)
State the stimulus for prolactin?
The end of pregnancy
State the stimulus for oxytocin?
oxytocin is stimulated by physical stimulation of the nipples
Describe three clinical situations that arise from alterations to secretion of Growth Hormone (GH)
- Hyposecretion during growing years results in dwarfism
- Hypersecretion in childhood results in giantism
- Hypersecretion in adulthood results in acromegaly
What are the two clinical conditions associated with alterations in the secretion of thyroxine.
Hypothyroidism
Hyperthyroidism
Describe Hyperthyroidism?
Over-activity of thyroid gland causes increased level of thyroxine and increased metabolic rate, rapid pulse, increased blood pressure, increased temperature, weight loss
Describe hypothyroidism?
Causes decreased level of thyroxine and slow heart rate, low body temperature, lethargy, weight gain ect
State the mineral needed by the body to produce thyroxine
Iodine
State the location of the adrenal glands?
The adrenal glands are located on top of the kidneys
What are the two areas in the adrenal glands?
The two areas within each gland is the adrenal cortex and adrenal medulla.
What does the adrenal cortex secrete?
The adrenal cortex secretes cortisol & aldosterone
What does the adrenal medulla secrete?
The adrenal medulla secretes adrenalin & noradrenalin.
State the stimulus for secretion of cortisol?
During stress higher levels of cortisol are produced
State the stimulus for secretion of adrenaline?
Stimulated by stressful situation and exercise, sympathetic stimulation – fight or flight
State the stimulus for secretion of noradrenalin?
Stress situations
Describe the three effects of cortisol?
- helps cope with stress
- depresses the immune response
- raises BGL and BP
State a clinical situation where glucocorticoids (cortisol) might be prescribed
To supress the inflammatory response in chronic conditions and are prescribed for organ transplant patients to avoid organ rejection
Name two situations that would cause the release of adrenaline
Strong emotions such as fear and angry
State six effects/actions of adrenaline
- Increases rate and force of heart contraction -Increases cardiac output
- Increases blood pressure
- Increases blood flow to the myocardium, liver, skeletal muscles
- Dilate airways
- Increase blood glucose levels
- Pupillary dilation
State six effects/actions of adrenaline
- Increases rate and force of heart contraction Increases cardiac output
- Increases blood pressure
- Increases blood flow to the myocardium, liver, skeletal muscles
- Dilate airways
- Increase blood glucose levels
- Pupillary dilation
State the main effect/action of noradrenaline
Noradrenaline works on alpha 1 receptors resulting in vasoconstriction to increase BP
Name the two hormones that control blood calcium levels
- Parathyroid hormone (PTH) – increases blood calcium levels
- Calcitonin – decreases blood calcium levels
State three uses for calcium in the body
- Building strong bones and teeth.
- Clotting blood
- Sending and receiving nerve signals.
Describe three actions of PTH
- Stimulates osteoclast to reabsorb bone & raise blood calcium
- Enhance reabsorption of calcium by the kidneys
- Activates vitamin D to become calcitriol which is needed to absorb calcium from food
Describe an actions of calcitonin
Lowers blood calcium levels
What is calcitriol also known as?
Active vitamin D
State two effects of calcitriol
- Increasing absorption of calcium and phosphate from the intestine
- Enhances the action of parathyroid hormone which resorbs bone
State two effects of calcitriol
- Increasing absorption of calcium and phosphate from the intestine
- Enhances the action of parathyroid hormone which resorbs bone
Name the two hormones that specifically regulate BGL’s
- Insulin
- Glucagon
Name the specific cells that secrete these two hormones insulin and glucagon?
Pancreas
Describe the actions of insulin and glucagon?
- Insulin, the dominant hormone after eating, lowers blood glucose levels. It’s production is increased when blood glucose level are high
- Glucagon, the dominant hormone of the fasting state, raises blood glucose levels. It’s production increased when blood glucose levels are low
Name three other hormones that raise BGL’S
- growth hormone
- adrenalin
- glucagon
- cortisol
Name the hormone that is produced from the pineal gland and its locations?
Melatonin. in the brain
State the main function of this melatonin?
Melatonin contributes to the natural body clock
Name the three stages of the stress response
- Stage one: fight-or-flight response
- Stage 2: A slower resistance reaction
- Stage 3: Exhaustion
Name the hormone for stage 1 of the stress response?
- Adrenalin
Name the hormones for stage 2 of the stress response?
- cortisol
- growth hormone
- thyroxine
Describe the long term effects of prolonged cortisol
Wasting of muscle, suppression of the immune system, ulceration of the gastrointestinal tract, failure of the pancreatic beta cells which produce insulin
Name two health implications of stress
- Developing chronic disease
- dying prematurely
Describe four age related changes to the endocrine system
- Growth hormone decreases allowing muscle atrophy
- Adrenal cortex produces less aldosterone and cortisol
- Adrenal medulla continues to produce normal level of adrenaline
- Osteoporosis & fractures may result
Name the cells in the pancreas that produce insulin and the cells that produce glucagon?
Insulin is produced by beta cells
Glucagon is produced by alpha cells
If the insulin is not having the desired effect describe what will happen to blood glucose levels (what is the desired effect of insulin)?
• BGL will rise as there is an increase in the amount of glucose circulating in the blood.
Explain the effect of insulin on the body? (how does insulin work).
- accelerates facilitated diffusion of glucose into the cells (insulin is the key that unlocks the cell and allows the glucose to enter)
- increases the rate of conversion of glucose into glycogen (glycogenesis)
- increases uptake of amino acids and increases protein synthesis
- increases the rate of synthesis of fatty acids (lipogenesis)
- slows the breakdown of glycogen to form glucose (glycogenolysis)
- Slows the creation of glucose from lipids & amino acids (gluconeogenesis)
Name three (3) hormones that increase blood glucose levels?
Glycogen
Adrenaline
Cortisol
- An injection of insulin would do what?
C. Increase the conversion of glucose into glycogen
- An injection of insulin would do what?
Increase the conversion of glucose into glycogen
A hormone released by the kidneys that stimulates the absorption of calcium ions from the digestive tract is?
Calcitriol
Either a deficiency of insulin production by the pancreas, or defects in insulin receptors on target cells, result in the disease?
Diabetes mellitus
The concentration of calcium ions and phosphates in the blood is regulated by?
Parathyroid hormone
The posterior pituitary gland stores and secretes?
oxytocin and antidiuretic hormone
The release of cortisol is stimulated by?
ACTH
What stimulates the release of PTH from the parathyroid gland?
low levels of calcium ion in the blood
What hormones requires a releasing hormone from the hypothalamus for its secretion?
prolactin
What does the Adrenocorticotropic hormone stimulate?
stimulates the adrenal cortex to secrete glucocorticoids
What does the Adrenocorticotropic hormone stimulate?
stimulates the adrenal cortex to secrete glucocorticoids
The cell bodies of the axons of the posterior pituitary gland are actually located in the?
hypothalamus of the brain
