Hormones and Sex (Chapter 8)

Steroid

________ hormones- come from cholesterol, all have the same chemical backbone, all highly fat soluble and travel across tissue easily; androgens cluster- male, estrogens cluster- female o Testosterone (TEST) o Estradiol (EST) o Progesterone (PROG) o Cortisol- primary stress hormone, released from the adrenal glands Slide 4: Hormones as Ninjas Hormones act like NTs and bind at receptors that are on the actual cell surface They are small and fat- soluble, they can enter the cell and activate proteins in the cytoplasm They can also bind to the DNA machinery, in the nucleus of a cell, to influence gene expression.

reproductive organs

Slide 3: Puberty Prior to puberty, sex hormones are low, ________ are immature, and males and females differ little in appearance Puberty brings on the secondary sex characteristics Growth hormone- increase bone and muscle growth Adrenocorticotropic hormone- causes the gonads and adrenal cortex to release gonad and adrenal hormones which mature the genitals and secondary sex characteristics; adrenal cortex releases testosterone for males and females.

Cycle Masters

Slide 11: Sexual Response ________ and Johnson (1960s) Excitement Phase o When people contemplate sexual activity o Blood flows to genital, erection of the penis, female clitoris becomes swollen, nipples enlarge Plateau Phase o Pulse rate, breathing, and BP increase o Inhibition lifted and passions take control Orgasm Phase o Involuntary muscle contractions throughout the body o Further increases in breathing and heart rate o Vaginal contractions and male ejaculation Resolution Phase o Males enter a temporary refractory period o Sexual tension releases and a slow return to a normal state of arousal.

Testosterone

________ is higher than estrogens Hairline recession begins Facial and body hair Larynx enlarges Musculature develops Reproductive organs grow.

Neuroendocrine Cells

Slide 6: ________ A neuron that releases hormones into local or systemic circulation.

Slide 6

Neuroendocrine Cells A neuron that releases hormones into local or systemic circulation

Slide 9

Brain Differences Between the Sexes Males have a larger brain (11%) but also a larger body Prenatal hormone exposure

Slide 11

Sexual Response Cycle Masters and Johnson (1960s) Excitement Phase o When people contemplate sexual activity o Blood flows to genital, erection of the penis, female clitoris becomes swollen, nipples enlarge Plateau Phase o Pulse rate, breathing, and BP increase o Inhibition lifted and passions take control Orgasm Phase o Involuntary muscle contractions throughout the body o Further increases in breathing and heart rate o Vaginal contractions and male ejaculation Resolution Phase o Males enter a temporary refractory period o Sexual tension releases and a slow return to a normal state of arousal

hormones

chemicals secreted by an endocrine gland that are conveyed by the bloodstream and regulate target organs or tissues (act somewhat like NTs)

endocrine glands

secrete products to act on distant targets

endocrine communication

via bloodstream (hormones can travel long distances)

synaptic communication

diffusion across synapse

pheromone communication

outside the body, same species

neuroendocrine cells

neuron releases hormones into local or systemic circulation

protein hormones

peptide hormones; string of amino acids; large molecule, largest of the hormones

amine hormones

composed of a single amino acid that has been modified into a related molecule

steroid hormones

come from cholesterol, all have the same chem backbone, all highly fat soluble and travel across tissue easily; androgens cluster - male, estrogens cluster - female

posterior pituitary gland

rear of the gland, sits outside the BBB

supraoptic nucleus and paraventricular nucleus

densely packed with neuroendocrine cells, exit through the pituitary stalk and release hormone directly into gland

oxytocin

uterus contractions during childbirth, milk letdown reflex, orgasm, female pair-bonding, social affiliation

vasopressin

thirst/water regulation, male pair-bonding, social monogamy

anterior pituitary gland

releasing hormones produced by hypothalamus to control tropic hormone production

tropic hormones

anterior pituitary hormones that affect the secretion of hormones by other endocrine glands