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Male Reproductive System - The gonadotropin releasing hormone

By: HWC, Views: 8481

• Hormonal mechanisms that influence male reproductive function involve endocrine tissues contained in the: • Hypothalamus of the brain. • Anterior pituitary. • Testes. • In the hypothalamus, certain neurosecretory cells secrete gonadotropin- releasing hormone (GnRH). • GnRH ...

Stroke volume - contractility definition

By: HWC, Views: 7346

Contractility is the forcefulness of contraction of cardiac muscle. • Inotropic agents are substances that increase or decrease contractility (and stroke volume). • Positive inotropic agents increase contractility and will increase stroke volume and cardiac output. • Negative inotropi...

Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 7861

• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...

Lactation and Breast Feeding

By: HWC, Views: 8550

Regulation of lactation - breast preparation • Pregnancy hormones trigger breast changes to prepare for feeding the new baby. • The amount of the hormone prolactin, essential to the initiation of lactation, increases steadily throughout pregnancy. • However, high levels of both estroge...

Fetal development - Weeks 9 to 38

By: HWC, Views: 7881

Weeks 9-12 • Fetal development during the third month includes: • A large head, about 1/2 the length of the fetus. • Visible eyes and ears. • A detectable heartbeat. • Kidneys that form urine. • Gender identification. • Weak, undetectable body movements. • By the e...

Endocytosis - pinocytosis, receptor mediated and Transcytosis

By: HWC, Views: 7626

Pinocytosis is the process in which a cell "drinks" a tiny droplet Of extracellular fluid, including its solutes. Pinocytosis (Cell Drinking) is the process by which the cell takes in fluids (as well as any small molecules dissolved in those fluids). • The plasma membrane folds inward to...

Sperm Formation Animation

By: Administrator, Views: 454

A man’s reproductive system is specifically designed to produce, store, and transport sperm. Unlike the female genitalia, the male reproductive organs are on both the interior and the exterior of the pelvic cavity. They include: the testes (testicles) the duct system: epididymis and vas def...

The primary factors that affect circulation - MABP, CO and SVR

By: HWC, Views: 8070

Introduction Blood flow is determined by the relative intensities of factors that drive and resist moving blood. • Cardiac output (CO) equals the mean arterial blood pressure (MABP, a driving force) divided by systemic vascular resistance (SVR, a resisting force). • Hormones and the cen...

Hemoglobin's affinity with oxygen - carbon dioxide, temperature and bisphosphoglycerate (BPG)

By: HWC, Views: 7833

• The carbon dioxide gas is temporarily converted to carbonic acid in red blood cells by the enzyme carbonic anhydrase, and then further converted to hydrogen and bicarbonate ions. • The result of increased carbon dioxide is decreased pH causing the Bohr effect. • Elevated carbon dioxid...