1. Once the action potential reaches the axon terminus, the information needed to be sent through the synapse to the muscle fibe
r. How is this signal sent. 2. Explain the process of contraction of the sarcomere addressing what signals the muscle to contract, how the signal is transmitted into the fiber, and the role of calcium, and ultimately how the contraction occurs
Synapses are junctions at axon terminals where they connect to dendrites of other neurons at these junctions chemical reactions occur in order to facilitate the passage of information as chemical signals. There are several neuron types which include sensory motor and into neurons which bridge the two.
1. At neuromuscular junctions, electrical signals are transmitted:
The action potential travels along the membrane until the synapse where it’s electrical depolarization leads to the opening of channels allowing only sodium ions to enter
these flow through a presynaptic membrane until the concentration is built up, activating ion sensitive proteins attached to vesicles containing neurotransmitters like acetylcholine
this leads to changes in the proteins leading to the fusion with the membrane of the presynaptic cell, so vesicles are open and neurotransmitter is released. The neurotransmitter diffuses across to chemical receptors on the presynaptic cell where they bind temporarily. This increases the permeability of the sarcolema to Na+;a new action potential is generated
2. Contraction of the sarcomere occurs via several steps.
This action potential in the muscle, travels along T-tubules, and Ca+ ions are released by the sarcoplasmic reticulum into the sarcoplasm
Ca and troponin combine, pulling myosin filaments, exposing the actin filament's myosin binding sites
cross-bridge formation occurs, leading to the sliding of filaments.
ATP drives cross-bridge cycling while mysosin pulls on actin strands
muscle fibers shorten and contract
later ACH is degraded in the synapse. Na ions are not released, and the action potential is not transmitted.
the Ca channels on the SR close, while Ca is reabsorbed stopping Ca-troponin binding, closing myosin binding sites on actin and leading to cross bridge separation. The muscle fiber relaxes in their resting states.
Answer: it’s a made up of molecules called nucleotides. Each nucleotides contain a phosphate group, a sugar group and nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G), and cytosine (C)
The organ is the LUNGS. The lungs excrete carbon dioxide and water vapour through metabolism. The lungs are used for breathing in humans, through the lungs we take in oxygen which is carried by the blood to all the part of the body and we exhale carbon dioxide which is a waste product generated as a result of the reactions that occur in the body.
produce a layer of enzyme laden mucus that captures dirt and destroys inhaled bacteria
<h3><u>Explanation;</u></h3>
Secretions from the highlighted glands <em><u>produce a layer of enzyme laden mucus that captures dirt and destroys inhaled bacteria </u></em>
<em><u>During inhalation airt that contains dust particles or bacteria or other microorganisms may enter the air ways. </u></em>
<em><u>The layer of the airway covering the airways, is rich in antimicrobial compounds and mucins that are responsible for removal bacteria and other microorganisms from the airway .</u></em>
<em><u>This layer consist of mucus that traps, kills, and also inactivates the bacteria. </u></em><em><u>It also contains periciliary fluid which keeps mucus at optimum distance from the underlying epithelia, to enhance bacteria clearance and the motility of cilia.</u></em>
