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How Hemoglobin Picks Up and Delivers Oxygen

By: HWC, Views: 5908

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...

Embryonic development - week 1 and 2

By: HWC, Views: 6672

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...

Hormonal feedback loop components & Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 6452

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 ...

Gastrulation: cross section of the frog

By: HWC, Views: 5715

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...

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

By: HWC, Views: 6538

• 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...

Amniocentesis and CVS Animation

By: HWC, Views: 3572

Amniocentesis and chorionic villus sampling (CVS) are prenatal diagnostic tools. In amniocentesis, which can be performed as early as 14 weeks into the gestation period. A syringe needle is inserted through the abdominal and uterine walls to withdraw some amniotic fluid. The fluid contains...

Spermatogenesis Animation

By: Administrator, Views: 9903

Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. T...

Atrial natriuretic peptide (vasodilation) & Aldosterone

By: HWC, Views: 6326

• Certain situations will cause the body's stress level to rise. • increased blood pressure will stretch the atria of the heart, stimulating the secretion of atria natriuretic peptide (MP). • ANP causes muscle cells in blood vessels to relax. • Blood pressure is lowered as a result ...

Stress and Immune System Animation

By: Administrator, Views: 9860

How stress and the immune system are linked. Immune response declines with age, limiting body's ability to identify and fight foreign substances. Loss of thymus cortex leads to reduced production of T lymphocytes, including T cells, NK cells, B lymphocytes. Frequency and severity of infectio...