Search results for: 'Human Thermostat'

Watch Later 1:51

By: HWC, Views: 7503

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...

Watch Later 2:19

Male Reproductive System - Testosterone

By: HWC, Views: 7257

• Under the influence of FSH and testosterone, Sertoli cells produce androgen-binding protein (ABP) that binds to testosterone and maintains high levels of the hormone near spermatogenic cells. • Testosterone stimulates the final stages of spermatogenesis. • In addition, testosterone is...

Watch Later 2:11

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

By: HWC, Views: 6801

• 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...

Watch Later 2:23

Hierarchical Sequencing Method - Sequence Tagged Sites

By: HWC, Views: 5880

In the hierarchical sequencing method, researchers begin by collecting cells. In humans, each cell contains 23 pairs of chromo-somes. Here we specifically track the DNA from just one of the 23 pairs. Chromosomes have a series of unique DNA sequences, called sequence-tagged sites (STSs), that a...

Watch Later 2:32

Phases of the ovarian cycle

By: HWC, Views: 7039

• The ovarian cycle is a monthly sequence of events, consisting of three phases: • Preovulatory • Ovulatory • Post ovulatory Preovulatory phase • prior to ovulation: Primary follicles develop into secondary follicles. • Follicular cells surrounding the primary oocyte In...

Watch Later 2:54

Mycobacterium tuberculosis: Drug Resistance and Natural Selection

By: HWC, Views: 5451

The evolution of drug resistance in microorganisms, such as M. tuberculosis, that cause human diseases is of particular concern to biologists. When Mycobacterium tuberculosis infects the lungs of humans, it causes the disease tuberculosis, also called TB. Once infected, the lungs act as a new...

Watch Later 3:41

Embryonic development - Week 3

By: HWC, Views: 6712

Week 3 (gastrulation) • Three primary germ layers are formed which provide cells for organ formation in the following months. • These germ cell layers are formed by a process known as gastrulation, which involves rearranging epiblast cells. • As cells from the epiblast migrate, a fain...

Watch Later 3:46

B cells and antibodies

By: HWC, Views: 7482

What Are Antibodies? Antibodies, also known as immunoglobulins, are Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body. When an intruder enters the body, the immune system springs into action. These invaders, which are called antigens, can be vi...

Watch Later 0:22

Labor and Delivery - Placenta Cord

By: Administrator, Views: 302

Soon after a baby is conceived, a support system, comprised of the placenta and umbilical cord, begins to develop. These two structures are essential for sustaining a healthy pregnancy, explains Donald Davis, an obstetrician in Medicine Hat, Alta., and past president of the Society of Obstetricia...

Search Results