Answer:
A neuron has a cell body, an axon and dendrites. Apart from these structures, the white myelin sheath covers the axons. The gaps where myelin sheath is absent are called nodes of Ranvier. Axon terminals are the extreme ends of the axon from where nerve impulse is carried to the dendrites of the post synaptic neuron.
Explanation:
A neuron has a cell body, an axon, and dendrites.
Cell body: It is the metabolic center of the neuron and does not take part in the conduction of nerve impulse.
Axon and dendrites: These are the extensions arising from the cell body. Dendrites are smaller and more in number while axon is a single large extension.
The function of the axon is to carry the nerve impulse from the cell body to the axon terminals. Dendrites receive the nerve impulse from the axon terminal and pass it to the cell body. The ends of axons are called axon terminals. They synapse with dendrites of postsynaptic neurons.
The myelin sheath is the fatty layer present on long axons and serves to accelerate the rate of conduction of nerve impulse. The nodes of Ranvier are the gaps where the myelin sheath is not present.
Which of the meninges is a delicate connective tissue membrane that clings tightly to the brain like cellophane wrap following its every convolution?
Answer:
Pia mater
Explanation:
Three meninges cover the brain and spinal cord. Pia mater refers to the deepest meninx of the brain. It is a thin delicate layer of connective tissue. It is a transparent connective tissue layer like that of cellophane. Being a transparent and thin tissue layer, it looks like a cellophane wrap adhered to the surface of the brain.
The delicate connective tissue membrane that clings tightly to the brain and follows its convolutions is the pia mater, which is the innermost layer of the meninges.
The meninges are a series of protective membranes that cover the brain and spinal cord. Among the layers of the meninges, the innermost layer that clings tightly to the brain and follows its every convolution is called the pia mater.
This delicate connective tissue membrane is directly adjacent to the surface of the brain, fitting into the grooves and indentations of the cerebral cortex. The pia mater ensures that the brain's surface is well-protected, adapting to its intricate structures.
The other two layers of the meninges include the dura mater, which is the tough, fibrous, outermost layer, and the arachnoid mater, which is situated between the dura and pia mater and resembles a spider web.
Binding Ca2+ to the troponin complex causes ____________ to move
a. troponin
b. actin
c. the myosin binding site
d. tropomyosin
Answer:
Tropomyosin
Explanation:
The calcium binding to troponin and induces the muscle contraction. The active binding site gets exposed due to the calcium binding.
The calcium ions then attaches with troponin molecule. This changes the shape of troponin and removes the tropomyosin protein from the binding site. No ATP is available during this process.
Thus, the correct answer is option (d).
Answer:
d. tropomyosin
Explanation:
Binding Ca2+ to the troponin complex causes the tropomyosin to move.
Tropomyosin is a protein that helps muscle contraction.
Explain the significance of retinal changes in a patient with high blood pressure.
Answer:
Explanation:
The retina is layer of tissues that surrounds the surface of the back of the eyeball. It consists of several layers that consists of photoreceptors which detects the color and intensity of light. The retina is affected by the blood pressure levels.
When the blood pressure becomes high the retina blood vessel may become thick. This may cause the blood vessels to become narrow, this restricts the flow of blood reaching the retina.
The high blood pressure may cause damage to the retinal blood vessels, as it restricts the function of retina. The high blood pressure inside the optic nerve may cause the problem of vision. This situation is called as hypersentive retinopathy.
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?
A) gamma aminobutyric acid
B) acetylcholine
C) cholinesterase
D) norepinephrine
Answer:
B) acetylcholine
Explanation:
Acetylcholine is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle.
24. What is/are the major potential energy product(s) formed in the Krebs Cycle (not the same as end-products formed a the end of cellular respiration)?
a. NADH/FADH2
c. Carbon dioxide
b. Adenosine Tri-phosphate
d. Glucose
Answer: a. NADH/FADH2
Explanation:
Complete oxidative degradation of glucose can be compartmentalized into four main biochemical steps: glycolysis, the formation of acetyl-CoA, the Krebs (citric acid or tricarboxylic acid cycle) and the electron transport chain where oxidative phosphorylation is performed. During respiration, an organic compound (usually sugar) is completely oxidized to form CO2 and H20. The Krebs cycle is the set of reactions leading to complete oxidation of glucose. It occurs in the mitochondria of eukaryotes and the cytoplasm of prokaryotes. Per each degraded glucose molecule, resulting in the final of the Krebs cycle:
• 6 molecules of NADH.
• 2 molecules of FADH2
• 2 molecules of ATP
• 4 molecules of CO2
Which gives our answer What is/are the major potential energy product(s) formed in the Krebs Cycle? a. NADH/FADH2 because 8 molecules of them in total are made.