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Summary of female reproductive cycle days 1-28

By: HWC, Views: 8145

■ The first five days of the cycle include the menstrual phase. ■ Progesterone and estrogen levels are low. ■ Menses occurs. ■ GnRH pulses more frequently promoting FSH and LH levels to rise. ■ Primary follicles are stimulated to develop. ■ Days five through thirteen consist o...

Role of the respiratory system - effect of altered ventilation rates

By: HWC, Views: 7582

• Dissociation of the chemical substances in the body fluids can result in the production of free hydrogen ions. • The pH scale is used to measure the concentration of hydrogen ions in solution. • Normal blood pH values vary around 7.4. • When hydrogen ion concentration increases, t...

Biological organic compounds

By: HWC, Views: 7114

Biological organic compounds contain covalent bonds, mainly C-C and C-H bonds, but also both C and H bonded to such other atoms as O and N. Some of these covalent bonds are nonpolar. Others are polar, either because one atom in the group "hogs" electrons away from other atoms in the group, or...

How Hemoglobin Picks Up and Delivers Oxygen

By: HWC, Views: 7027

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...

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

By: HWC, Views: 7945

• 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. •...

How eudicots (true dicots) differ from monocots Animation

By: HWC, Views: 2551

Most flowering plants are either monocots or eudicots. They have the same tissues, but slightly different features. Monocot seeds have a single cotyledon, or seed leaf. Eudicot seeds have two cotyledons. Monocot flowers usually have petals and other floral parts in multiples of three. Flow...

Cortisol (protein catabolism, gluconeogenesis, vasoconstriction & anti-inflammation)

By: HWC, Views: 7301

• Stressors stimulate production of hypothalamic releasing hormones, corticotropin releasing hormone, hormone (CRH) and adrenocorticotropic hormone (ACTH) stimulate. • These hormones promote increased production of 1 cortisol from the zona fasciculata cells of the adrenal cortex. • Cort...

How does an animal choose what food to eat?

By: HWC, Views: 7182

One might assume that natural selection has influenced the foraging behaviors of animals, and that most animals forage efficiently, spending the least energy to gain the most nutrients. This is the underlying assumption of optimality modeling, a scientific approach to studying foraging behavior. ...

Cytotoxic T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 8030

• Most cells which have CD8 on their surface become cytotoxic T cells (Tc cells). • CD8 T cells recognize a foreign antigen when it is presented in conjunction with the protein, MHC-I. • Nearly all nucleated cells in the body express MHC-I molecules. • T cells that recognize self-pe...