Chapter 20, Endocrine system Flashcards
Endocrine glands
Secretes hormones, Ductless, has many blood vessels throughout.
How do endocrine and nervous systems communicate
Through signals throughout the body.
Hormones
can only affect target organs or cells( must have receptors for that organ).
Three chemical classes of hormone
Protein hormone(Chains of amino acids), a steroid hormone(Type of lipid-derived from cholesterol), biogenic amines( Small molecules made by altering the structure of amino acid).
Negative feedback
the stimulus starts the process and a hormone causes the process to slow down or turn off
Positive feedback
accelerates the original process, ensuring it
continues or speeding it up.
Hypothalamus
Is the master control center of the endocrine
system. Controls the secretion activities of the adrenal medulla. Produces oxytocin (OT) and antidiuretic hormone (ADH). Controls release of regulatory hormones from the anterior pituitary
gland
Pituitary Gland
Also called Hypophysis, located inferior to the hypothalamus
Anterior pituitary
Divided into three different areas: Pars distalis, Pars intermedia, Pars tuberalis
Anterior pituitary hormones
Thyroid-stimulating hormone, Adrenocorticotropin hormone, Growth hormone, Gonadotrophic cells, Prolactin, Melanocyte-stimulating hormone
Posterior pituitary
Two regions: pars nervosa and Infundibular stalk.
Posterior pituitary hormones
Oxytocin, Antidiuretic hormone
Thyroid gland
Largest gland devoted to endocrine activities. Butterfly shape.
Hyperthyroidism
When your thyroid produces too much TH
Hypothyroidism
When your thyroid produces too little TH
Hashimotos
the immune system attacks the thyroid, can cause hypothyroidism
Goiter
Caused by lack of iodine in the diet.
Parathyroid glands
Small glands located at the posterior surface of the thyroid gland. Secretes Parathyroid hormone and enables blood to clot.
Parathyroid cells
Chief cells and Oxyphil cells
Adrenal glands
Paired glands on the superior border of the kidneys
Adrenal cortex
Three layers: Zona Glomerulosa, Zona fasciculata, Zona reticularis.
Zona Glomerulosa
Produces mineralocorticoids such as aldosterone
Zona fasciculata
Produces glucocorticoids such as corticosterone
Zona reticularis
Produces gonadocorticoids
Corticosteroids
Steroid hormones produced by the adrenal cortex
Mineralcorticoid (Aldosterone)
Regulate electrolyte composition and concentration in body fluids
Glucocorticoids (corticosterone, cortisol)
Regulate blood glucose levels, stimulate lipid and protein metabolism
Gonadocorticoids
Sex organ cell growth/protein synthesis
Adrenal medulla
Forms the inner core of the adrenal gland. Secretes norepinephrine and epinephrine.
Fight or flight responses
Heart rate increases, Digestive rate decreases, pupils dilate, Bronchi of lungs dilate, piloerection(goosebumps), Blood vessels constrict, perspiration.
Pancreas
Has both exocrine and endocrine functions. 98-99% of pancreatic cells are pancreatic acini. 1-2% are pancreatic islets.
Pancreas hormones
Pancreatic islet cells secrete: Alpha cells, Beta cells, F cells, and Deta cells
pineal gland
Secretes melatonin, in the posterior region of the epithalamus
Thymus
Located just superior to the heart and just deep to the sternum
Kidney
Hormones help regulate electrolytes, erythrocyte production, blood volume, and blood pressure
Heart
Atrial cells secrete atrial natriuretic peptides, lower blood sugar
gonads
produce sex hormones
