Answer:
i) iv) ii) iii)
Explanation:
The excitable cell begins being in a resting state, with a negative charge, -70 mV. First (i) there is a stimulus of influx of sodio into the cell, if the stimulus is strong enough and exceeds -55 mV, the threshold potential, then an action potential will occur. (iv) A strong influx of sodium that deporalizes the cells causes a change to a positive charge in the cell. (ii) Then potassium efflux from the cell in large quantities, which repolarizes the cell. (iii) With a continuous efflux of potassium the cell can become more negative than the resting potential, this is called hyperpolarization.
Answer:
The capillary membranes that filter substances moving between the cerebral blood vessels and the brain are called the blood-brain barrier.
Explanation:
Capillaries are the smallest type of blood vessel in the body. Capillaries enable the exchange of substances between the blood and surrounding tissues. They are thinner than arteries and veins, because their walls are made up of only a single layer of endothelial cells, the flat cells that line all blood vessels. Capillaries function to deliver nutrients and oxygen to tissues and remove the byproducts of cellular reactions, such as water and carbon dioxide.
The Blood-brain barrier is an anatomic and biochemical barrier that protects the brain from potentially harmful substances. It is a highly selective membrane barrier at the brain microvessel level which aids transport between the systemic circulation and the central nervous system.
The Blood–brain barrier restricts the passage of pathogens, aids in ensuring solutes are diffused in the blood, and hydrophilic or large molecules into the cerebrospinal fluid, while allowing the diffusion of hydrophobic molecules (oxygen, carbondioxide, hormones) and small polar molecules.
All you need is :
one egg
vinegar
and a glass or bowl that is taller than the egg
tilt the glass when you put the egg in so it doesn't brake then pour vinegar in to cover the egg and watch as its shell disolves
Conduction, idk if this is what you’re looking for but i hope this helps
Answer:During inspiration, the posterior air sacs expand, pulling air into the primary bronchi, which terminate near the far end of the lungs. While some of the air is diverted through secondary bronchi near the back of the lungs and into parabronchi, most of it passes directly into the posterior group of air sacs.
Explanation: brainliest pls