Search results for: 'neurosecretory cells'

Watch Later 0:19

By: Administrator, Views: 432

At conception, the gender and other biologic traits of the new individual are determined. The zygote is genetically complete and immediately begins to divide, forming a solid mass of cells called a morula. When the developing embryo (stage of development between weeks 2 and 8) reaches the ute...

Watch Later 1:13

A Human Karyotype Preparation Animation

By: HWC, Views: 5046

Blood is collected from the person being analyzed. The blood is added to a growth medium that also contains a chemical that stimulates mitosis. The cells are allowed to grow in this medium for two or three days at body temperature. Colchicine is added to arrest cell division at metaphase. T...

Watch Later 3:41

Embryonic development - Week 3

By: HWC, Views: 7921

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 1:22

How Hemoglobin Picks Up and Delivers Oxygen

By: HWC, Views: 7192

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 3:27

Embryonic development - week 1 and 2

By: HWC, Views: 7853

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 2:38

Hormonal feedback loop components & Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 7692

The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: • Stimulus - a change in a body condition. • Production cell - an endocrine cell that produces a hormone after ...

Watch Later 2:01

Gastrulation: cross section of the frog

By: HWC, Views: 6949

Gastrulation Most animals enter a phase early in development called gastrulation. In this phase, a tiny ball or disc of cells rearranges to form three embryonic layers of tissue, called germ layers. The germ layers of the embryo—now called a gastrula—are called the endoderm, mesoderm, and eco...

Watch Later 2:14

Four Giant Convection Cells oF Earth

By: HWC, Views: 7212

Earth Has Four Giant Convection Cells Earth's climates range from dry and cold at the poles to wet and warm at the equator. These climates are dictated largely by the amount of solar radiation that a region receives. Solar radiation warms the Earth and the surrounding air, setting up convection c...

Watch Later 1:56

Renin/Angiotensin (water gain from urine & Na ion and water reabsorption)

By: HWC, Views: 7797

• Sensing declining blood pressure or blood volume, juxtaglomerular cells of the nephron release renin, an enzyme that promotes the formation of angiotensin II. • Angiotensin II targets smooth muscle cells in blood vessels that provide blood to the nephron. • Angiotensin II causes thes...

Search Results