Answer:
4,3,1,5,2
4. Vesicles full of acetylcholine are stored at the axon terminal.
3. Action potential arrives at the neuromuscular junction.
1. Action potential is propagated in the sarcolemma.
5. Acetylcholine is released into the synaptic cleft.
2. Acetylcholine binds to ligand gated sodium channels.
Explanation:
Nerve impulse is generated from somatic motor neurons and reaches neuromuscular junction. The nerve impulse specifically reaches a region named 'synaptic end bulbs' at axon terminal. These synaptic end bulbs are in turn connected to the motor end plate region of a sarcolemma.
As soon as the nerve impulse reaches neuromuscular junction, it triggers the opening of voltage gated ion channels which in turn facilitate the influx of Ca²⁺ from the extracellular fluid to the inside of neuron where synaptic vesicles containing neurotransmitter acetylcholine are already stored.
The Ca²⁺ causes the exocytosis of synaptic vesicles which fuse with the plasma membrane of motor neuron as a result of which acetylcholine is released in the synaptic cleft.
The acetylcholine further binds with the acetylcholine receptor which is present at the motor end plate of a skeletal muscle fibre. These receptors are ligand gated ion channels.
Binding of acetylcholine with its receptor causes the ion channels to open and cations like Na⁺ enter the muscle fibre so as to make the electric potential inside the muscle positive.
Answer:
Typically in mammals, the gender of an organism is determined by the sex chromosomes. In the case of humans, this happens to be the X and the Y chromosomes. So as you may recall, if you are XX, you are female. If you are XY, you are male.
Answer:
Why do we need active transport?
Moving Against a Gradient
Small substances constantly pass through plasma membranes. Active transport maintains concentrations of ions and other substances that living cells require in the face of these passive movements. A cell may spend much of its metabolic energy supply maintaining these processes.
Explanation:
Hope That helped
Answer:
Center seeking is a force that makes a body follow a curved path
So the trpohic pyramid is basically the producers and secoundary abs primary consumers and all that but what comes first so the weakest animals that the animals eat above it
