Cortisol hormone Cortisol inhibits glucose uptake, stimulates protein degradation, promotes both lipolysis & gluconeogenesis Gluconeogenesis: conversion of amino acids into carbohydrates at liver

Control over cortisol ACTH from anterior pituitary stimulates cortisol secretion Negative feedback from cortisol inhibits hypothalamus and anterior pituitary

Cushing’s syndrome Excessive cortisol - often due to tumor at pituitary or adrenal gl. Excessive gluconeogenesis

Cortisone injections: Patients take cortisone (converts to cortisol) for anti-inflammatory effects (allergies, arthritis, trauma). Immune system is suppressed.

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)

Adrenal gland: sex hormones DHEA from adrenal cortex is a source of ‘opposite’ sex hormone in men and women ACTH controls adrenal androgen secretion DHEA testosterone in women

Adrenal medulla Functions 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.

Pancreas: endocrine hormones Alpha cells release glucagon Beta cells release insulin Islets of Langerhans

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.

Metabolism Anabolism – building large molecules from smaller ones, requiring energy Promoted by insulin, GH Catabolism – breaking down large molecules into smaller ones. Energy is released Promoted by glucogon, cortisol

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.

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 adipose Glycogen (pink) in liver cells

Blood glucose levels Glucose 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 glucose Insulin

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

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

Apple vs. Pear

Adipose and insulin resistance Diabetes, insulin resistance (IR) is associated with obesity, lack of exercise When storage at fat cells is exceeded, free fatty acids (FA) in blood increase

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.

“Indifferent” ducts of embryo Y chromosome present Y chromosome absent Male Female uterus ovary vagina penis testis

Determining gender Sex chromosomes determine gonadal sex (testis-determining factor) Phenotypic sex is depends on development of external genitalia

Differentiation of genitalia depends on whether testosterone is present At 7 weeks Undifferentiated genitalia

Intersex individuals experience opposite sex hormones during early development or are insensitive to normal hormones. Some examples: Androgen insensitivity Lack of enzyme for testosterone production Congenital adrenal hyperplasia (enzyme missing to produce cortisol, aldosterone. Steroids converted to androgens instead.)

Male reproductive anatomy

Descent of the testes During fetal development, testes move from abdomen into scrotum Inguinal area is a common spot for hernias (intestine pokes through abdominal wall) The scrotum provides a cool area optimal for spermatogenesis

Sperm production Epididymis The cells of Leydig in testes secrete testosterone (T) T secreted at puberty produces 2o sex characteristics, spermatogenesis, & maintain tracts Ductus deferens Seminiferous tubules

Sperm production Spermatogenesis: spermatogonia (2N) spermatozoa (N) Epididymis Spermatogenesis: spermatogonia (2N) spermatozoa (N) Ductus deferens Seminiferous tubules

Meiosis Mitosis Sertoli cell Sertoli cell Lumen of seminifeous tubule Spermatids Secondary spermatocyte Meiosis Sertoli cell Primary spermatocyte Sertoli cell Spermatogonium Mitosis

Controlling sperm production Unlike females, males produce sperm from puberty onward Spermatogenesis controlled by LH and FSH

LH & FSH in males LH acts on Leydig cells for T prod’n FSH acts on Sertoli cells for sperm prod’n (inhibin provides negative feedback)

Causes of infertility? Sperm production, viability influenced by: Smoking, marijuana use Alcohol abuse Anabolic steroids, overly intense exercise, stress Tight underwear, pants Environmental pollutants (pesticides, lead, paint, radiation, heavy metals)

Sperm storage Spermatids become motile and are stored in epididymis and ductus deferens

Making something to swim in Seminal vesicles supply fructose, prostaglandins for muscle contraction, & fibrinogen Prostate gland secretes alkaline fluid and clotting enzymes Bulbourethral glands add mucus for lubrication Urinary bladder Seminal vesicle Prostate gland Bulbourethral gland Ductus deferens Testis

Signals for erection and ejaculation Arousal Pudenal nerves carry signals from penis to lower spinal cord & brain Spinal reflex and brain send PNS signals to penile arterioles Arousal causes muscle contractions that incr. physical stimulation – positive feedback Ejaculation Dramatic shift to SNS – contractions move semen to urethra and out