L3 Autonomic Nervous System

There are two main nervous systems, the [blank_start]central and the peripheral[blank_end]. The [blank_start]peripheral[blank_end] nervous system is further divided into the somatic, autonomic, and enteric systems. The ANS is divided into: 1. [blank_start]Sympathetic[blank_end] nervous system - mobilises the body’s nervous system fight-or-flight response; it is also constantly active at a basal level to maintain homeostasis. 2. [blank_start]Parasympathetic[blank_end] nervous system - regulates organ and gland functions during rest and is considered a slowly activated, dampening system(rest and digest, feed and breed).

The autonomic nervous system (ANS) is located in the hypothalamus, and the medulla oblongata acts to integrate autonomic function after receiving feedback.

Choose the two correct statements.

Everything done in the nervous system involves 3 fundamental steps: 1. A sensory function detects internal and external [blank_start]stimuli[blank_end] 2. An [blank_start]interpretation[blank_end] is made (analysis) 3. A [blank_start]motor response[blank_end] occurs (reaction) Three main types of neurons take part in this process: • [blank_start]Sensory[blank_end] neurons carry signals from the outer parts of your body (periphery) into the central nervous system. This makes them [blank_start]afferent[blank_end]. • Interneurons connect various neurons [blank_start]within[blank_end] the brain and spinal cord (entirely within the [blank_start]CNS[blank_end]). • [blank_start]Motor[blank_end] neurons carry signals from the central nervous system to the outer parts (muscles, skin, glands) of your body. This makes them [blank_start]efferent[blank_end].

An AP has two main phases, depolarizing and repolarizing. After depolarisation occurs above a [blank_start]threshold[blank_end] potential, an [blank_start]action[blank_end] potential occurs. There is then a [blank_start]refractory[blank_end] period, where the neuron cannot be [blank_start]re-stimulated[blank_end], followed by repolarisation to the [blank_start]resting membrane[blank_end] potential.

Signal transmission at the synapse is a one-way transfer from a presynaptic neuron to a postsynaptic neuron, which turns an electric signal into a chemical signal. Labelnof transmission across a synapse from 1 to 6. [blank_start]5[blank_end]. The neurotransmitter binds to ligand-gated receptors on the postsynaptic membrane. [blank_start]2[blank_end]. Voltage-gated Ca2+ channels open and Ca2+ flows inward to the presynaptic neuron. [blank_start]4[blank_end]. The neurotransmitter crosses the synaptic cleft. [blank_start]3[blank_end]. Ca2+ influx triggers release of the neurotransmitter. [blank_start]1[blank_end]. AP reaches the end bulb of axon terminals. [blank_start]6[blank_end]. The postsynaptic neuron receives the chemical signal and in turn generates an electrical signal (postsynaptic potential).

A neurotransmitter (chemical) can be excitatory, inhibitory, or both(in different locations).

Many neuronal cell bodies are called a [blank_start]ganglion[blank_end]. Many [blank_start]ganglia[blank_end] form a [blank_start]plexus[blank_end].

Choose the correct statements.

In the PNS, the neurotransmitter [blank_start]acetylcholine (ACh)[blank_end] is released at both synapses. In the SNS, [blank_start]ACh[blank_end] is released at the presynaptic neuron and [blank_start]norepinephrine/epinephrine[blank_end] is released at the postsynaptic neuron. ACh binds to [blank_start]muscarinic and nicotinic[blank_end] receptors. Norepinephrine/epinephrine binds to [blank_start]adrenergic alpha or beta[blank_end] receptors.

Chose the correct statement.