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Optic Nerve and Optic Disk Animation (Part 1 of 2)

By: Administrator, Views: 10919

Inner Layer Blind spot: the absence of rods and cones in the area of the optic disk creates a blind spot on the retina's surface; the only part of the retina that is insensitive to light. Inner Layer The eye contains approximately 120 million rods that are sensitive to dim light. The rods ...

Stimulus (introduction)

By: HWC, Views: 7399

• Blood pressure determines the flow of blood to and from capillaries. • Low blood pressure results in reduced blood flow. • High blood pressure can cause blood vessels to break. In humans, sensitivity is due to portions of the nervous system called receptors. Receptors are typicall...

Factors that affect conduction rates (myelination, axon diameter & temperature)

By: HWC, Views: 7855

• Several factors determine the rate of conduction of action potentials: • Myelination • Axon diameter • Temperature • The step-by-step depolarization of an axon is called continuous conduction and occurs along unmyelinated axons. • Neurons in the PNS have many axons that ...

Calvin cycle (The light-independent reactions )

By: HWC, Views: 7479

The light-independent reactions of photosynthesis occur in the stroma of the chloroplast. Carbon dioxide enters the leaf through tiny pores or stomata and diffuses into the chloroplast. The first stage of the Calvin cycle is the attachment of a carbon dioxide molecule to a 5-carbon ribulose bi...

Chloroplast Structure & Light Dependent Reactions (Photosystem 1 and 2 Cyclic Electron Flow)

By: HWC, Views: 7299

The leaf is the principle photosynthetic organ of the plant. This is a cross section of a leaf. The rectangular-shaped cells are part of the photosynthetic tissue called the palisade mesophyll. Each photosynthetic cell can contain several hundred organelles known as chloroplasts. The chlorop...

Rods and Cones Animation

By: Administrator, Views: 11147

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...

Body plan of euglena Animation

By: HWC, Views: 2046

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...

Labor and Childbirth - The Three Stages of Labor: Dilation, Expulsion & Placental مراحل الولادة

By: HWC, Views: 8165

Regulation of labor and birth - effects of estrogen and oxytocin on onset of labor • Just prior to birth, high placental corticotropin-releasing hormone levels stimulate the production of more estrogen. • High estrogen levels overcome the inhibitory effects of progesterone on uterine sm...

What are the Parts of a Plant Cell?

By: HWC, Views: 6774

Every chloroplast in a plant cell is packed with stacks of flattened sacs called thylakoids. The thylakoid membranes contain chlorophyll, as well as most of the other components required for the light reactions of photosynthesis. The chlorophyll-containing structures within the membranes are c...