Tri B - Endocrine System Flashcards
Describe Exocrine glands
Secrete into ducts
e.g. sweat glands, gastric glands
Describe Endocrine glands
No Ducts, secrete hormones into bloodstream
Acts at a distance
Describe some endocrine functions
Reproduction,
Metabolic rate
Immune response
Blood pressure
Digestive processes
Stress response
Compare Nervous and endocrine systems
NS releases neurotransmitters
ES releases hormones
NS is fast responding
ES is slower
NS is short acting
ES is longer lasting
Describe mechanisms of hormone action
Hormones bind to specific receptors on target cells
Number of receptors can increase or decrease (up or down regulation)
Describe the chemistry of hormones
2 groups
1. Water soluble - mostly proteins
2. Lipid soluble - steroids
Describe pituitary function and structure
Produces hormones that control other glands
Posterior - nervous tissue
2 hormones; oxytocin and ADH
Anterior - glandular tissue
6 main hormones
Describe hypothalamus function
Controls pituitary
Describe the posterior pituitary
Stores and releases oxytocin and ADH
Describe Anti-diuretic hormone (ADH)
Stimulated by dehydration
Increased water reabsorption by kidneys
Constricts arterioles if severe blood loss
Alcohol inhibits ADH
Describe the anterior pituitary
6 major hormones
Carried from hypothalamus via blood vessels to target cells
Under hormonal control by hypothalamus
Describe regulation of hormone secretion
- Signals from nervous system
- Chemical changes in blood
- Other hormones
Describe the control of blood glucose
Controlled by opposing actions of insulin and glucagon
Increases insulin decrease blood glucose
Increase glucagon increase blood glucose
Describe the adrenal glands
2 glands
Outer cortex - mineralocorticoids, glucocorticoids
Inner medulla - adrenaline and noradrenaline
Describe the different endocrine disorders
Too much hormone
Too little hormone
Reduced sensitivity of target cells
Describe thyroid disorders
Hypothyroidism - decreased BMR
- weight gain, cold/tired, slow HR
Hyperthyroidism - Increased BMR
- weight loss, feel warm, fast HR
Describe congenital hypothyroidism
Caused by lack of thyroid gland development
Results in physical and developmental delay if untreated
Treated with thyroxine
Describe Iodine deficiency disorders (IDD)
Thyroid hormone production needs iodine
Lack of iodine –> hypothyroidism
Effects child cognitive development
Endemic IDD - foetus depends on mothers thyroid hormones - effects baby’s development
Describe the causes and symptoms of hyperthyroidism
Graves’ disease - auto-immune
Exophthalmos - bulging eyes
Antibodies bind to TSH receptor sites on thyroid cells and mimic TSH
Describe some growth hormone disorders
Pituitary Dwarfism - Under secretion of GH
Giantism - Over secretion of GH
Acromegaly - Over secretion of GH in adults
Describe Acromegaly
Cant grow taller - epiphyseal plates sealed
Bone of hands, feet, cheeks and jaws thicken
May result from anterior pituitary tumor
