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Structures of the Eye Animation

By: Administrator, Views: 2092

Orbit A cone-shaped cavity in the front of the skull that contains the eyeball. Formed by the combination of several bones and is lined with fatty tissue that cushions the eyeball. This cavity has several foramina (openings) through which blood vessels and nerves pass. Largest opening is the ...

Embryonic development - Week 3

By: HWC, Views: 7775

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...

Metabolic Rate, Heat and Thermoregulation - response to heat and cold stresses

By: HWC, Views: 7967

• A neuron group in the anterior portion of the hypothalamus controls heat balance. • Neurons in the preoptic region of the hypothalamus integrate signals that come from thermoreceptors. • The temperature control center in the preoptic region propagates control signals to two other part...

A Human Karyotype Preparation Animation

By: HWC, Views: 4905

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...

HIV Infection: Viral life cycle

By: HWC, Views: 7094

The series of steps that HIV follows to multiply in the body. The process begins when HIV encounters a CD4 cell. The seven steps in the HIV life cycle are: 1) binding; 2) fusion; 3) reverse transcription; 4) integration; 5) replication; 6) assembly; and 7) budding. Many viruses f...

Coaductile pathway, Timing of contraction signal & Conduction system and ECG

By: HWC, Views: 7941

• When the system is healthy, the signal to contract the entire conduction system originates in the SA node - known as the heart's pacemaker. • The SA node triggers contraction because it depolarizes at a faster rate than other parts of the conduction system. • The wave of excitation fr...

Lipid absorption - end products & transport mechanism

By: HWC, Views: 7274

• The end products, fatty acids and monoglycerides, depend on bile salts for absorption. • Bile salts form micelles (tiny spheres), which ferry fatty acids and monoglycerides to epithelial cells. • Free fatty acids, monoglycerides, and some phospholipids and cholesterol molecules, dif...

Causes of Angina

By: Administrator, Views: 11160

Angina is a type of chest pain caused by reduced blood flow to the heart. Angina (an-JIE-nuh or AN-juh-nuh) is a symptom of coronary artery disease. Angina, which may also be called angina pectoris, is often described as squeezing, pressure, heaviness, tightness or pain in your chest.

Nucleic acid digestion - brush border enzymes, end products & transport mechanism

By: HWC, Views: 7532

• Further digestion occurs at the microvilli (brush border) of the epithelial cells of the villi in the small intestine. • Two brush border enzymes complete nucleic acid digestion: • Phosphatases, which catalyze the cleavage of a phosphate to form a nucleoside (nitrogenous base and pent...