University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

83

Pages:

2
Author:

Mariam A. A.

Dehydration Prolonged sun exposure & dehydration: Thermoreceptors Hypothalamus Sympathetic cholinergic nerves Sweat glands ↑ Sweat loss Fluid loss: Osmosis Aquaporins ↓ Urination ↓ Blood Volume (BV) ↑ Osmolarity Kidneys: JGA (Juxtaglomerular Apparatus) Renin release Aldosterone ↑ Na+ reabsorption ↑ H₂O retention Cellular changes: Cell shrinkage ↓ Membrane depolarization Mechanoreceptors ↓ Intracellular Ca2+ ↑ Ca2+ channels Other effects: Muscle weakness Fatigue Dizziness Confusion ↓ Blood flow ↑ Heart rate ↑ Respiratory rate Vasodilation Dehydration and Fluid Balance Liver → Angiotensinogen: Cleavage Angiotensin I Flow in blood Pulmonary artery Pulmonary vein ACE (Angiotensin-Converting Enzyme) Angiotensin II Angiotensin II: Vasoconstriction ↑ Blood pressure (BP) ↑ Heart rate (HR) ↑ Stroke volume (SV) ↑ Cardiac output (CO) Aldosterone release from adrenal gland Thirst stimulation ADH (Antidiuretic Hormone) release from posterior pituitary ADH → Collecting ducts: ↑ H₂O reabsorption ↓ Urination ↓ Fluid loss Cellular changes: Cell shrinkage ↓ Membrane depolarization Mechanoreceptors ↑ Intracellular Ca2+ ↑ Ca2+ channels Other effects: ↑ Osmolarity ↓ Blood volume (BV) ↓ Blood flow