The human immunodeficiency virus (HIV) that causes the disease known as aids selectively infects helper T cells (CD4+).
This retrovirus also infects macrophages and dendritic cells. When CD4+ T cell numbers decrease below a critical level (due to the killing of this cells with different mechanisms), cell-mediated immunity is lost. As a result, the body becomes progressively more susceptible to infections, leading to the development of AIDS.
<span> HIV can be transmitted only via body fluids like blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk, which means that people usually get or transmit HIV through sexual behaviours and use of the needle. For HIV infection, these fluids must come in direct contact with a mucous membrane or damaged tissue. Another way is to be directly injected into the bloodstream (from a needle for example).</span>
Answer:
Surface area
Explanation:
The surface area to the volume ratio gets larger as the cell gets smaller and vice versa.
Krill should be ur answer hope this helps! have a nice day
A person who has cerebrospinal fluid draining from the ear probably has a fracture of the temporal bone.
<h3>What is Cerebrospinal Fluid?</h3>
All animals have cerebrospinal fluid (CSF), a transparent, colorless bodily fluid that is present in the tissue that covers their brains and spinal cords.
Specialized ependymal cells in the choroid plexus of the brain's ventricles create CSF, which is then absorbed in arachnoid granulations. About 125 mL of CSF are present at any given moment, and 500 mL are produced daily. The CSF protects the brain inside the skull mechanically and immunologically by acting as a shock absorber, cushion, or buffer. The cerebral autoregulation of cerebral blood flow is another essential role played by CSF.
The ventricular system and subarachnoid space, which are located surrounding and inside the brain and spinal cord, respectively, are occupied by CSF.
Learn more about CSF with the help of the given link:
brainly.com/question/7142724
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