Search results for: 'long%20term%20control'

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By: Administrator, Views: 594

The humerus is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a rounded head, a narrow neck, and two short processes (tubercle...

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Bone Growth and Remodeling

By: HWC, Views: 6952

• After birth, bones grow in thickness and length. • Bones grow in diameter via appositional growth at the periosteum. • Epiphyseal plates enable lengthwise growth of long bones, such as the humerus, by interstitial growth. • Bone remodeling accommodates changing needs. • While th...

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Body plan of euglena Animation

By: HWC, Views: 982

Euglenoids are single-celled organisms that live in lakes and ponds. A contractile vacuole pumps out the water that diffuses into the cell from its hypotonic surroundings. The body is covered by a translucent pellicle composed of flexible strips of a protein-rich material. Light passe...

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Requirements for nervous signals

By: HWC, Views: 6621

• The function of neurons is to allow communication between cells, thereby maintaining homeostasis. • Electrical signals, called membrane potentials, travel along the membranes of the neurons. • Voltage variability and distance traveled determine the type of nervous signal. 1. Graded...

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Bone tissue types - compact and spongy

By: HWC, Views: 6748

Bone tissue types • There are two types of bone tissue: compact and spongy. • All the bones of the skeleton have both kinds of bone tissue. • Compact (dense) bone • Arranged in osteons (Haversian systems), units of lamellae laid down in adjoining series of concentric rings. • P...

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DNA Replication Factory and Protein

By: HWC, Views: 6138

DNA (deoxyribose nucleic acid) carries all the genetic information needed to re-create itself and to pass on the characteristics of the organism. The “factory” model of DNA replication hypothesizes a specific nuclear structure in which the molecular machinery for replication forks are brou...

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Hormonal regulation of blood pressure - RAA system

By: HWC, Views: 7104

■ Long-term regulation of MABP is under hormonal control. • Hormones that affect blood pressure and volume: the renin-angiotensin-aldosterone (RAA) system, antidiuretic hormone (ADM), and atrial natriuretic peptide (ANP). ■ Most important hormonal regulator of MABP. Activated by drop in...

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Green alga life cycle Animation

By: HWC, Views: 1245

Chlamydomonas zoospores are haploid flagellated cells. As long as conditions are favorable, these cells reproduce asexually. As many as sixteen cells may form by mitosis within a parent cell. Daughter cells escape when the cell wall ruptures. When conditions become less favorable, the...

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Rods and Cones Animation

By: Administrator, Views: 10062

A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes...

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