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