In the central nervous system, the blood–brain barrier protects the neurons from many blood-borne substances by sealing the spaces among endothelial cells lining the internal surface of blood vessels. The structures that seal the intercellular spaces are In the central nervous system, the blood–brain barrier protects the neurons from many blood-borne substances by sealing the spaces among endothelial cells lining the internal surface of blood vessels. The structures that seal the intercellular spaces are

Tight junctions
Gap junctions
Communicating junctions
Desmosomes

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg