Presentation on theme: "Cortisol hormone Cortisol inhibits glucose uptake, stimulates protein degradation, promotes both lipolysis & gluconeogenesis Gluconeogenesis: conversion."— Presentation transcript:
1 Cortisol hormoneCortisol inhibits glucose uptake, stimulates protein degradation, promotes both lipolysis & gluconeogenesis Gluconeogenesis: conversion of amino acids into carbohydrates at liver
2 Control over cortisolACTH from anterior pituitary stimulates cortisol secretionNegative feedback from cortisol inhibits hypothalamus and anterior pituitary
3 Cushing’s syndromeExcessive cortisol - often due to tumor at pituitary or adrenal gl. Excessive gluconeogenesis
4 Cortisone injections: Patients take cortisone (converts to cortisol) for anti-inflammatory effects (allergies, arthritis, trauma). Immune system is suppressed.
5 What are stress effects? How can health be impacted? Stress responses:SNS effects (vasoconstriction, anxiety)Fat, sugar blood levels (diabetes, arterios)Fluid retained, BP (hyperten, heart disease)Immune system, sexual function, digestion all decrease (infertility, irritable bowel, ulcers, vomiting)
7 Adrenal gland: sex hormones DHEA from adrenal cortex is a source of ‘opposite’ sex hormone in men and women ACTH controls adrenal androgen secretionDHEA testosteronein women
8 Adrenal medullaFunctions as a modified postganglionic neuron of the sympathetic NS. It stores and secretes epinephrine and norepinephrine In addition to FOF responses, stimulates glucagon secretion and inhibits insulin secretion.
10 Insulin:storage and anabolism Insulin signals to fat and other tissues to take up glucose (GLUTs). Prevents the mobilization of fat. Liver takes up fatty acids, makes glycogen GH, cortisol, epinephrine, and glucagon inhibit insulin.
11 MetabolismAnabolism – building large molecules from smaller ones, requiring energyPromoted by insulin, GHCatabolism – breaking down large molecules into smaller ones. Energy is releasedPromoted by glucogon, cortisol
12 How the body controls metabolism Nutrients must be stored then released between meals. The brain needs a constant supply of glucose Most conversion of molecules occurs in the liver. Nutrients that cannot be formed this way are “essential” nutrients and must come from diet.
14 Storing energy in the body Excess glucose glycogen in liver and muscles (or adipose when there is much glycogen) Excess fatty acids triglycerides, in adipose Excess amino acids triglycerides, in adiposeGlycogen (pink) in liver cells
15 Blood glucose levelsGlucose levels are consistent over the day, range about 10-15%, through action of insulin and glucagon Between meals, body cells can burn fatty acids to spare glucose for the brain.Blood glucoseInsulin
16 Blood glucose levels and glycemic index With simple carbs (high glycemic index) glucose absorbed to blood rapidly - insulin spike that follows is large. Glucose reduced in blood With lower glucose levels, may crave food again
18 What is diabetes?Inadequate insulin action = diabetes mellitus (hyperglycemia) Type I “juvenile diabetes” - body cannot produce insulin – autoimmune disease Type II “adult diabetes” too little insulin made, or target cells are insulin resistant
20 Adipose and insulin resistance Diabetes, insulin resistance (IR) is associated with obesity, lack of exerciseWhen storage at fat cells is exceeded, free fatty acids (FA) in blood increase
21 Adipose and insulin resistance High FA may cause muscle and adipose to diminish their response to insulin (IR)Insulin less able to clear glucose from blood, still helps store fat.
22 “Indifferent” ducts of embryo Y chromosomepresentY chromosomeabsentMaleFemaleuterusovaryvaginapenistestis
23 Determining genderSex chromosomes determine gonadal sex (testis-determining factor)Phenotypic sex is depends on development of external genitalia
24 Differentiation of genitalia depends on whether testosterone is present At 7 weeksUndifferentiatedgenitalia
25 Intersex individuals experience opposite sex hormones during early development or are insensitive to normal hormones.Some examples:Androgen insensitivityLack of enzyme for testosterone productionCongenital adrenal hyperplasia (enzyme missing to produce cortisol, aldosterone. Steroids converted to androgens instead.)
27 Descent of the testesDuring fetal development, testes move from abdomen into scrotumInguinal area is a common spot for hernias (intestine pokes through abdominal wall)The scrotum provides a cool area optimal for spermatogenesis
28 Sperm productionEpididymisThe cells of Leydig in testes secrete testosterone (T)T secreted at puberty produces 2o sex characteristics, spermatogenesis, & maintain tractsDuctusdeferensSeminiferoustubules
35 Sperm storageSpermatids become motile and are stored in epididymis and ductus deferens
36 Making something to swim in Seminal vesicles supply fructose, prostaglandins for muscle contraction, & fibrinogenProstate gland secretes alkaline fluid and clotting enzymesBulbourethral glands add mucus for lubricationUrinary bladderSeminal vesicleProstate glandBulbourethralglandDuctus deferensTestis
37 Signals for erection and ejaculation ArousalPudenal nerves carry signals from penis to lower spinal cord & brainSpinal reflex and brain send PNS signals to penile arteriolesArousal causes muscle contractions that incr. physical stimulation – positive feedbackEjaculationDramatic shift to SNS – contractions move semen to urethra and out