Search results for: 'Barr body'

Watch Later 2:19

By: HWC, Views: 8349

• 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 1:27

Hydrogen bonds - role in the body

By: HWC, Views: 8038

A hydrogen bond is the electromagnetic attraction between polar molecules in which hydrogen is bound to a larger atom, such as oxygen or nitrogen. This is not a sharing of electrons, as in a covalent bond. Instead, this is an attraction between the positive and negative poles of charged atoms. ...

Watch Later 2:37

Cellular Defects - Osteoblasts, Osteoclasts and Osteocytes

By: HWC, Views: 7344

■ Metabolically active bone-building cells that secrete astroid. ■ Cover surfaces of newly formed bone and respond to growth stimuli ■ Less responsive to growth factors as the body ages. ■ Contribute to hone loss once their reproductive and biosynthetic potential lessens....

Watch Later 1:22

How Hemoglobin Picks Up and Delivers Oxygen

By: HWC, Views: 7052

All of the cells in our bodies require oxygen (02) for survival and must release carbon dioxide (CO2) as a waste product. The respiratory and circulatory systems work together as delivery systems for these gases. The lungs exchange these gases between the environment and the bloodstream. The bloo...

Watch Later 2:24

Chemical Buffers - protein buffer, phosphate buffer system and bicarbonate buffer system

By: HWC, Views: 7976

• There are a variety of chemicals in body fluids that prevent the fluids from undergoing large changes in. • These chemicals buffer or regulate fluctuations in H+ concentration. • Chemical buffers: • Bind to H+ ions when there are too many in a solution so pH remains normal. •...

Watch Later 3:27

Embryonic development - week 1 and 2

By: HWC, Views: 7707

The first through eighth weeks after fertilization are called the embryonic. Week 1 • Within a day, the zygote begins mitotic cell division (cleavage) forming blastomeres. By the 4th day, the blastomeres have formed a solid ball called a morula. • The morula enters uterine cavity ar...

Watch Later 2:18

Introduction to Eating Disorders

By: Administrator, Views: 10631

An eating disorder is a mental disorder defined by abnormal eating habits that negatively affect a person's physical or mental health. They include binge eating disorder where people eat a large amount in a short period of time, anorexia nervosa where people eat very little and thus have a low bo...

Watch Later 3:45

Barriers - eye structures, digestive mucosa, respiratory mucosa & genitourinary mucosa

By: HWC, Views: 8048

• Eyebrows, eyelids, eyelashes and conjunctiva serve to trap microbes preventing their invasion. • Tearing (lacrimation) is a protective mechanism that washes away microbes that attempt to enter the eyes. • Salts, mucus, and lysozymes in tears neutralize substances and bacteria. �...

Watch Later 1:57

Major Elements in Biological Molecules: Proteins

By: HWC, Views: 7159

Proteins are chains of amino acids linked by peptide bonds. The 20 different amino acids used to make all proteins differ only in their side chains, and the properties of these side chains account for the great diversity of protein structure and function. Collagen is an example of how a prote...

Search Results