A&P2 Lecture 6 Endocrine system

winniesmith1's version from 2017-05-19 13:49

Section 1

Question Answer
What does the endocrine system regulateGrowth.Development. Reproduction
What does the endocrine system consist ofHormones chemical messengers to relay information and instructions between cells. -Glands
What does the hypothalamus produceProduction of ADH, oxytocin, and regulatory hormones
What does the pineal gland producemelatonin
What does the anterior pituitary gland produce ACTH, TSH, GH, PRL, FSH, LH, and MSH.
What does the parathyroid glands produceParathyroid hormone (PTH)
What does the thyroid gland produceThyroxine (T4) Triiodothyronine (T3) Calcitonin (CT)
What do the adrenal glands produceAdrenal medulla: Epinephrine (E) and Norepinephrine (NE). Adrenal cortex: Cortisol, corticosterone, aldosterone, androgens.
What do the pancreatic islets produceInsulin and Glucagon.
What does the posterior lobe of the pituitary gland produceADH and oxytocin.

Section 2

Question Answer
What does the hypothalamus provideInterface between nervous and endocrine systems. Regulatory hormones affect pituitary function.
What does the pituitary gland controlAnterior pituitary: Hormones that control other endocrine organs. Posterior pituitary: Oxytocin and ADH release.
Method one of hypothalamus controlling other endocrine glandsProduction of ADH and oxytocin. Hypothalalmus stimulates posterior lobe of pituitary gland to release ADH/oxytocin.
Method two of hypothalamus controlling other endocrine glandsSecretion of regulatory hormones to control Activity of the anterior lobe of the pituitary gland
Method three of hypothalamus controlling other endocrine glandsNeural. Control of sympathetic output to adrenal medullae. Stimulated to secrete catecholamines.
Describe the hypophyseal portal systemNeurosecretory neurons at median eminence secrete regulatory factors --> Enter fenestrated capillaries in capillary bed in hypothalamus --> Portal veins --> Capillary bed in anterior pituitary

Section 3

Question Answer
Describe the feedback control of endocrine secretionHypothalalmus releases hormone (RH). Anterior lobe of pituitary then secretes hormone 1. This binds to target organ, which then secretes hormone two. Negative feedback system prevents levels increasing too high (from anterior lobe and hormone 2). Hormone 2 inhibits RH.
What is prolactin (PRL) regulationHypothalamus produces releasing factor (PRF) and inhibiting hormone (PIH). Stimulates mammary glands
What is growth hormone (GH) regulationHypothalamus produces releasing hormone (GH-RH) and inhibiting hormone (GH-IH)
What is the effect of growth hormoneActs on liver to promote release of somatomedins, e.g. Insulin like Growth Factors (IGFs) which: Stimulate tissue growth (particularly skeletal muscle and cartilage). Increase amino acid uptake/protein synthesis .
Growth hormone acts directly on tissue to do whatStimulate cell division in epithelial and connective tissue. Stimulate triglyceride breakdown in adipocytes. Stimulates liver glycogen breakdown.

Section 4

Question Answer
Where is the thyroid gland/structureanterior to thyroid cartilage of larynx. Two lobes connected by narrow isthmus.
What does the thyroid gland doStores and secretes thyroid hormones thyroxine (T4) and triiodothyronine (T3). Thyroid hormones increase sodium potassium ATPase production.
Describe thyroid folliclesHollow spheres lined by cuboidal epithelium, surrounded by capillaries. Contain colloid (protein rich fluid filling follicle). Follicle cells synthesise tyrosine rich thyroglobulin. Iodine incorporated to form thyroxine (T4) and triiodothyronine (T3).
Describe C cells Produce calcitonin. Important in calcium homeostasis. Reduces serum calcium: Deposition in bone. Increased excretion by kidney
Effects of thyroid hormonesIncrease oxygen and energy consumption. Increase heart rate. Increase sensitivity to sympathetic stimulation. Stimulates red blood cell formation. Affects activity of other endocrine tissues. Increases bone turnover.
What does the thyroid gland and iodine deficiency cause(low t4, high TRH) Derbyshire Neck/Goitre. a swelling of the thyroid gland and is now known to be caused by lack of iodine. It is almost unknown today because iodine is added to drinking water [and salt].
Describe the parathyroid glandsSmall glands (1.6g) on posterior of thyroid. Parathyroid (chief) cells produce parathyroid hormone (PTH). PTH is released to increase serum calcium when levels decline.

Section 5

Question Answer
Structure of adrenal glandcortex on outside and medulla on inside with cortex inbetween.
What does the cortex produceSteroid hormones (glucocorticoids)
What does the medulla producecatecholamines.
What is the adrenal gland made up of (layers)Adrenal medulla. then Adrenal cortex made up of: Zona reticularis, zona fasciculata, zona glomerulosa. Then the capsule.
What do catecholamines dofight or flight response: increased blood glucose and heart rate
What does the zona reticularis produceAndrogens (sex steroids)
What does the zona fasciculata produceglucorticoids e.g. cortisol; promote glucose synthesis, fat and protein catabolism; anti-inflammatory effects
What does the zona glomerulosa producemineralocorticoids e.g. aldosterone; affect electrolyte composition

Section 6

Question Answer
What does the pineal gland includeNeurons: colleterals from visual pathways. Pinealocytes
What do pinealocytes secretemelatonin: Lowest production during daylight.
What is the function of melatoninInfluences circadian rhythms. Antioxidant
The pancreatic islets include what two cells and what do they produce(islet of Langerhans) Alpha cells: produce glucagon, (increases blood glucose). Beta cells: produce insulin, (lowers blood glucos
What is diabetes mellitus and what could it result in (if untreated)Abnormally high blood glucose (hyperglycaemia). If untreated could result in Kidney damage, Retinal damage, Peripheral nerve damage, Increased cardiovascular disease risk
What is type 1 diabetes 1 insulin dependant diabetes mellitus: 5-10% of cases; often diagnosed in childhood, Pancreatic insulin production inadequate, Insulin injection required.
What is type 2 diabetesMost common; most often diagnosed in middle/older age, Reduced tissue response to insulin, Often managed with diet and exercise.

Section 7

Question Answer
Organs with secondary endocrine functions: Heart Secretes natriuretic peptides. Reduce blood pressure & volume
Thymus(Undergoes atrophy during adulthood) Secretes thymosins: promote lymphocyte development
Adipose TissueSecretes leptin: suppresses appetite
Digestive tractHormones involved in the coordination of system functions, glucose metabolism, and appetite
KineysSecrete: • Erythropoietin (EPO): red blood cell production • Calcitriol: promotes calcium absorption • Renin: involved in control of blood pressure & volume
Gonadstestes: Androgens (especially testosterone), inhibin. Ovaries: Estrogens, progestins, inhibin