Series of ductless glands that release chemical signals in the form of hormones into the bloodstream to stimulate another target tissue
Glands of the endocrine system
Hypothalamus
Pituitary gland (Master gland)
Thyroid glands
Adrenal glands
Testes
Ovaries
Mammary glands
Hormones
Chemical signals released into the bloodstream by ductless glands, based on molecular composition
Hypothalamus
Central operating unit that acts as the mediator between the endocrine system and nervous system
Directly commands the pituitary gland (master gland)
Detects abnormal hormone concentration and makes adjustments
Hypothalamus vs Pituitary gland (master gland)
Hypothalamus detects abnormality, produces hormone to tell pituitary gland what to produce, pituitary gland does not produce hormones randomly but under strictly controlled conditions
Hormones synthesized by the hypothalamus
TRH
CRH
ADH/AVP
Oxytocin
TRH
Directly targets the pituitary gland, synthesized by the hypothalamus if there is a decrease in T3 or T4 concentration
CRH
Directly targets the pituitary gland, produced in response to low blood sugar
ADH/AVP
Antidiuretic hormone that directly stimulates the kidney to prevent urination, synthesized by the hypothalamus
Oxytocin
Synthesized by the hypothalamus, does not directly stimulate the pituitary gland, stimulates lactation and uterine contraction
Nephron
Functional unit of the kidney with 5 different parts
Keyword: Hyperosmolarity
Causes of hyperosmolarity
Hormones of the anterior pituitary gland
Growth hormone (GH)
TSH
ACTH
FSH & LH
Prolactin
Growth hormone (GH)
Synthesized by the anterior pituitary gland, stimulates growth of various tissues, affected in dwarfism, gigantism, and acromegaly
TSH
Thyroid stimulating hormone that targets the thyroid gland to produce T3 and T4
CRH
Hormone that stimulates the pituitary gland to produce ACTH, targets the adrenal cortex to produce cortisol
FSH & LH
Stimulating hormones that target the testes and ovaries
Prolactin
Synthesized by the pituitary gland, stimulates the mammary gland to produce milk
Hormones of the posterior pituitary gland
ADH/AVP
Oxytocin
ADH/AVP
Antidiuretic hormone that regulates blood pressure, body temperature, and social behaviours in males
Oxytocin
Releases milk
Disorders of the posterior pituitary gland
Diabetes insipidus (low ADH/AVP)
SIADH (overproduction of ADH)
Diseases of the thyroid gland
Primary hypo/hyperthyroidism
Secondary hypo/hyperthyroidism
Primary hypo/hyperthyroidism
Problematic organ is the thyroid gland, affected by surgical removal, autoimmune disorders, etc.
Secondary hypo/hyperthyroidism
Normal thyroid gland, abnormal pituitary gland
Adrenal glands
Cortex
Medulla
Layers of the adrenal cortex
Zona glomerulosa (aldosterone)
Zona fasciculata (cortisol)
Zona reticularis (sex hormones)
Aldosterone
Hormone that retains sodium in the bloodstream and excretes potassium
Adrenal gland zones
ZG
ZR
ZS
Adrenal gland zones
ZG produces aldosterone
ZF produces cortisol
ZR produces sex hormones
Adrenal cortex
Outermost layer is ZG
Responsible for salt control
Concentration in patients with primary hyperthyroidism
TSH - decrease
T3 - increase
T4 - increase
Concentration in patients with secondary hypothyroidism