Answer:
The options are not given but they are gotten from another websites.
A. Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells.
B. Capillaries surrounding the brain have pores and are surrounded by membranes of astrocyte cells.
C. Capillaries surrounding the brain have no pores and are not surrounded by membranes of astrocyte cells.
D. Capillaries surrounding the brain have pores and are not surrounded by membranes of astrocyte cells.
The correct answer is option A.
Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells.
Explanation:
Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells because
Capillaries are tiny blood vessels in the circulatory system that connect aterioles to venules. They are the most abundant or they are much blood vessels. They can penetrate the tissues of the body which allow passage of food nutrients, oxygen in the body thereby allowing exchange of nutrients and oxygen between the body tissues and the blood.
Capillaries surrounding the brain have no pores and are surrounded by membranes of astrocyte cells while capillaries in the periphery Capillaries surrounding the brain have pores and are not surrounded by membranes of astrocyte cells.
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Answer:
The correct option is b. cones.
Explanation:
Cones and rods are specialized cells, called photoreceptor cells, that are found in the retina and are responsible for our vision.
Cones, allow to the human eye to have a visual acuity (ability of the eye to resolve, transmit sharp images and perceive small details in an object) and provide sensitivity to the color, are more concentrated in the central yellow spot known as the macula.
There are three different types of cones in color reception: "L cones" (sensitive to long wavelength, which is red), "M cones" (sensitive to medium wavelength, which is green) and "S cones" (sensitive to short wavelength, which is blue). Since color perception depends on the activation of these three types of nerve cells, it follows that the visible color can be determined based on three numbers called triestimulus values.
The rods are necessary for the perception of light and darkness and to adapt to night vision, because they are very sensitive to low intensity light. On the contrary, they become completely blind to bright light and, therefore, lack importance with regard to daytime vision or visual acuity.