Answer:
Explanation:
1- closely packed osteons or haversian systems, used to provide strength and protection to bones.
2- Spongy bone consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavities that contain red bone marrow. provides balance to the dense and heavy compact bone by making bones lighter so that muscles can move them more easily.
Answer:
E) A pH less than 7
Explanation:
if a solution has a higher concentration of hydronium ions than pure water , it has a pH lower than 7
Answer:
Clubmosses
Explanation:
I don't really have an explanation
The correct order is:
- Action potential arrives at the axon terminal.
- Calcium ions enter the axon terminal.
- Synaptic vesicles fuse to membrane of axon terminal.
- Acetylcholine is released into the synaptic cleft.
- Acetylcholine binds to its receptors on the junctional folds.
- Junctional folds become depolarized.
- Action potential is initiated on the sarcolemma.
Action potential travels through the membrane of the presynaptic cell causing the channels permeable to calcium ions to open. Ca2+ flow through the presynaptic membrane and increase the Ca concentration in the cell which will activate proteins attached to vesicles that contain a neurotransmitter (e.g. acetylcholine). Vesicles fuse with the membrane of the presynaptic cell, thereby release their contents into the synaptic cleft-space between the membranes of the pre- and postsynaptic cells. Neurotransmitter binds to its receptors on the postsynaptic membrane and its binding causes depolarization of the target cell (muscle cell).
