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A pseudounipolar neuron has one axon that projects from the cell body for relatively a very short distance, before splitting into two branches. Pseudounipolar neurons are sensory neurons that have no dendrites, the branched axon serving both functions. [2] The peripheral branch extends from the cell body to organs in the periphery including ...
The action potential passes along the cell membrane causing the cell to contract, therefore the activity of the sinoatrial node results in a resting heart rate of roughly 60–100 beats per minute. All cardiac muscle cells are electrically linked to one another, by intercalated discs which allow the action potential to pass from one cell to the ...
Afferent neurons are pseudounipolar neurons that have a single process leaving the cell body dividing into two branches: the long one towards the sensory organ, and the short one toward the central nervous system (e.g. spinal cord). These cells do have sensory afferent dendrites, similar to those typically inherent in neurons. [1]
As an action potential (nerve impulse) travels down an axon there is a change in electric polarity across the membrane of the axon. In response to a signal from another neuron, sodium- (Na +) and potassium- (K +)–gated ion channels open and close as the membrane reaches its threshold potential. Na + channels open at the beginning of the ...
This schematic illustrates the four different types of glial cells, all of which possess cellular processes: ependymal cells (light pink), astrocytes (green), microglia (red), and oligodendrocytes (light blue). Cell bodies of neurons are in yellow (Their axons are surrounded by myelin, produced by oligodendrocytes).
Pseudounipolar neurons initially develop as bipolar cells, but at some point the two processes that extend from the cell body fuse to form a single neurite. [4] The pseudounipolar neuron's axon then splits into two branches. Sensory neurons with cell bodies in the dorsal root ganglia of the vertebrate spinal cord are pseudo-unipolar: one branch ...
These cells produce an electrical impulse known as a cardiac action potential that travels through the electrical conduction system of the heart, causing it to contract. In a healthy heart, the SA node continuously produces action potentials, setting the rhythm of the heart (sinus rhythm), and so is known as the heart's natural pacemaker.
There are currently four types of adenosine receptors found in the heart. [19] After binding onto a specific purinergic receptor, adenosine causes a negative chronotropic effect due to its influence on cardiac pacemakers. It also causes a negative dromotropic effect through the inhibition of AV-nodal conduction. [20]