Endocrine System Final Hormones and Target cells and Actions
Hypothalamus: Neuroendocrine The hypothalamus links the nervous and endocrine systems by way of the pituitary gland. One function is to secrete releasing hormones and inhibiting hormones that stimulate or inhibit (like their names imply) production of hormones in the anterior pituitary. The other function sends hormones produced by nerves in hypothalamus through the pituitary stalk to the posterior lobe of the pituitary gland where these hormones are released directly into the bloodstream. These hormones are anti-diuretic hormone and oxytocin.
Hypothalamus and anterior pituitary
Hypothalamus and anterior pituitary
The Mother Gland
Growth Hormone Growth hormone (GH), also called somatotropin or human growth hormone, peptide hormone secreted by the anterior lobe of the pituitary gland. It stimulates the growth of essentially all tissues of the body, including bone. GH is synthesized and secreted by anterior pituitary cells called somatotrophs, which release between one and two milligrams of the hormone each day. GH is vital for normal physical growth in children; its levels rise progressively during childhood and peak during the growth spurt that occurs in puberty.
Thyroid hormones HPT Cascade Anterior pituitary and hypothalamus both sense concentration of T3/T4 and increase TRH and TSH if concentration is low, decreases TRH and TSH if concentration is high If iodine levels are insufficient Thyroid cant make T3/T4 HPT Cascade
Thyroid and Parathyroid blood Calcium levels Homeostasis competing negative feedback loops
Pancreas and Glucose Homeostasis Two competitive negative feedback loops Muscle cells and brain cells use tremendous amounts of glucose per day In a healthy person this is dynamic staying near the set point except after meals or after fasting
Regulation of blood glucose levels a story by the numbers 1. Your blood glucose levels are high due to an improper diet of candy bars and soda. This abnormal increase in glucose stimulates the beta cells of the pancreas gland to secrete insulin hormone. 2. This hormone travels to the liver and stimulates the synthesis of glycogen from glucose. 3. This hormone also causes the transport of glucose into the body cells. To be burned as fuel. 4. Soon your blood glucose levels decrease. 5. Unfortunately you are unable to eat another meal for several hours and your glucose levels decrease. 6. This condition stimulates the alpha cells of your pancreas gland to release glucagon hormone. 7. This hormone acts on the liver to breakdown glycogen into glucose. 8. Glucagon also acts on the adipose tissue to breakdown triglycerides. 9. Eventually, your glucose levels return to normal. 10. The regulation of sugar works by insulin inhibiting alpha cells and glucagon inhibiting beta cells.
Female Hormones HPO cascade
HPA Axis (cascade)
Increased water retention Calcitonin Blood calcium Thyroid Bone Hormone Regulated by: Released from: Target Physiological effect ADH Osmotic pressure Posterior pituitary Kidney Increased water retention Calcitonin Blood calcium Thyroid Bone Decrease blood calcium GH Blood Growth Hormone Anterior Pituitary Body cells Cell division and growth Glucagon Blood glucose Pancreas Liver Increased blood glucose Insulin Blood Glucose Decreased blood glucose Oxytocin Pregnancy Uterus Uterine contraction PTH Blood Calcium Parathyroid Increased blood calcium T3/T4 Cell metabolism Increased cell metabolism Prolactin Childbirth Anterior pituitary Mammary glands Breast milk ejection IGF Blood growth hormone
Cortisol and Oxidative Stress ACTH signals adrenal glands to release more cortisol Normal glucose provides energy for stress Cortisol: Pulls Glucose from glycogen in liver. Breaks down muscle and converts it to amino acids then to glucose. Lack of dopamine prevents ACTH inhibition Chronic/ persistent Inflammation from excess body fat Increased Body fat Elevated Blood glucose Damages dopamine releasing neurons of hypothalamus Increased insulin production Insulin resistance Oxidative stress
Stressors