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Bone cells and tissues - tissue composition and cells

By: HWC, Views: 10159

Bone tissue consists of bone cells secreting bone matrix. • The extracellular bone matrix is a connective tissue that is hard, yet flexible. • Collagen fibers provide flexibility. • Inorganic mineral salts (primarily calcium phosphate, or hydroxyapatite) provide hardness. • Togethe...

Isovolumetric VC, Ventricular ejection, Isovolumetric & Passive ventricular filling

By: HWC, Views: 9226

• Isovolumetric means that blood volume does not change. • Ventricular blood volume and cell length remain constant. • With valves closed and contraction continuing, ventricular pressure continues to rise. • Ventricular pressure rises above arterial pressure. • Increased ventr...

Bone elongation - processes at the epiphyseal plate

By: HWC, Views: 9521

• 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...

Nerve Impulse Transmission Animation

By: Administrator, Views: 12754

How nerves transmit impulses. Stimulation of a nerve occurs at a receptor. Sensory receptors Specialized to specific types of stimulation such as heat, cold, light, pressure, or pain. React by initiating a chemical change or impulse. All-or-none principle Means that no transmission occ...

Sister chromatids of a metaphase chromosome animation

By: HWC, Views: 7447

At metaphase, the chromosomes are duplicated and are at their most condensed. In each chromosome. two identical sister chromatids are held together at a constricted region called the centromere. When a chromosome is condensed, interactions among chromosomal proteins keep loops of DNA tightly ...

Transcription—A molecular view

By: HWC, Views: 5005

Transcription, as related to genomics, is the process of making an RNA copy of a gene's DNA sequence. This copy, called messenger RNA (mRNA), carries the gene's protein information encoded in DNA. During transcription, a DNA molecule is copied into RNA molecules that are then used to translate...

Calvin Cycle Explained!

By: HWC, Views: 9118

he light-independent reactions make sugars by way of a cyclic pathway called the Calvin cycle. The cycle begins when rubisco attaches a carbon from carbon dioxide to ribulose bisphosphate. The molecule that forms splits into two molecules of PGA. Each PGA gets a phosphate group from ATP a...

Fetal development - Weeks 9 to 38

By: HWC, Views: 9530

Weeks 9-12 • Fetal development during the third month includes: • A large head, about 1/2 the length of the fetus. • Visible eyes and ears. • A detectable heartbeat. • Kidneys that form urine. • Gender identification. • Weak, undetectable body movements. • By the e...

Genetic distance between human groups

By: HWC, Views: 6153

One proposed family tree for modern humans. This family tree is based on nucleic-add hybridization studies of many genes and immuno-logical comparisons. Branch points show presumed genetic divergences. This data indicates that the greatest genetic distance separates humans native to Afri...