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Conduction of action potentials

By: HWC, Views: 7141

• Action potentials must be rapidly conducted over long distances in order for the nervous system to communicate with other cells. • Propagation of an action potential uses processes similar to those that generate the potential at the trigger zone. • a When a graded potential reaches ...

Hyperglycemia Animation

By: Administrator, Views: 11510

Hyperglycemia means high (hyper) glucose (gly) in the blood (emia). Your body needs glucose to properly function. Your cells rely on glucose for energy. Hyperglycemia is a defining characteristic of diabetes—when the blood glucose level is too high because the body isn't properly using or doesn...

Types of antimicrobial substances (interferons & complement protein)

By: HWC, Views: 7035

• Found in blood and interstitial fluids. • Discourage microbial growth. • Include interferon and complement proteins. • Produced and released by virus-infected lymphocytes. • Enter new cells and inhibit viral replication. • Act against a large variety of viruses (non-speci...

Hormonal regulation of pregnancy - weeks 17 through 38

By: HWC, Views: 7233

• Estrogens increase uterine blood flow, maintaining the endometrium during pregnancy. • High levels of estrogen and progesterone inhibit the synthesis of milk. Progesterone inhibits myometrial contractions of the uterus to prevent premature birth. • Relaxin inhibits myometrial contract...

Factors that influence muscle tension - Sarcomere length and force, understretched and overstretched

By: HWC, Views: 7008

• Muscle tension generated through the contraction of muscle cells provides the force necessary for the muscular system to function. • The amount of tension produced depends on several factors: • Sarcomere length Frequency of stimulation • Motor unit size • Recruitment of moto...

Mitosis step-by-step

By: HWC, Views: 4947

During interphase, the chromosomes will be duplicated in preparation for mitosis, which divides the chromosomes, and cytokinesis, which divides the cell's cytoplasm. In early prophase, the duplicated chromosomes begin to condense. Each chromosome consists of two sister chromatids joined at the...

Second Messengers in the Inositol-lipid Signaling Pathway

By: HWC, Views: 6229

Extracellular signals produce specific responses in target cells through the action of intracellular second messengers. Here, we focus on three second messengers, IP3, DAG, and Ca2+, all involved in the inositol-lipid signaling pathway. A hormone-receptor signal on the cell surface leads to the a...

Bone elongation - processes at the epiphyseal plate

By: HWC, Views: 7199

• Interstitial lengthening occurs in only certain bones, primarily those of the appendages. • Such lengthening takes place at the epiphyseal plate, a layer of hyaline cartilage in the metaphysis of a growing bone. 1. Zone of resting cartilage. • Consisting of a hyaline cartilage pa...

Fermentation - When Oxygen Is Absent, Pyruvate to Lactate & Pyruvate to Ethanol

By: HWC, Views: 6507

Pyruvate is the end product of glycolysis. If oxygen is present, pyruvate enters the mitochondrion where further energy yielding reactions of the Krebs cycle will take place. However, if oxygen is not present, pyruvate will enter a pathway called fermentation. This pathway regenerates NAD+ fro...