Autonomic Nervous System

19.The autonomic nervous system division of the PNS consists of nerves which control all of the involuntarymuscles, organs, glands, and sensory pathway nerves.

Just to make it even more complicated the PNS and the CNS also have systems of their own. Which are named the voluntary

The autonomic nervous system (ANS) is a branch of the central nervous system (CNS) that divides into two divisions. The sympathetic (SNS), fight or flight division, and the parasympathetic (PNS), rest and digest division both seek to regulate involuntary visceral motor control by transmitting their signals from the CNS to cardiac muscles, the heart and blood vessels; smooth muscles, the stomach and intestines; and glands, sweat and salivary. The SNS increases heart rate by transmitting its impulses onto short, myelinated preganglionic neurons that trigger the release of acetylcholine (ACh) onto nicotinic cholinergic receptors found on the postganglionic cell. The impulse then travels along long, unmyelinated adrenergic postganglionic neurons,

When a skeletal muscle fires it is caused by a signal in a motor neuron. Voltage gated sodium channels open up after a threshold stimulus of -55mV is reached. Next, Sodium ions move into the cell membrane, thus depolarizing the cell at +30mV, which is its action potential. Sodium channels close and Potassium channels open. Potassium moves out, which repolarizes the cell. Hyperpolarization

In general, the heart receives continuous input from the autonomic nervous system (ANS) and/or endocrine system, which release chemicals that alter both the rate and force of heart muscle contraction. The ANS is composed of two antagonistic divisions, called the sympathetic and parasympathetic nervous systems; the sympathetic division, often referred to as the “fight or flight” system, speeds up heart rate through Norepinephrine release onto beta-1 adrenergic receptors on the heart. The parasympathetic division, referred to as the “rest or digest” system, slows heart rate through Acetylcholine release onto muscarinic receptors on the heart.

The adrenal medulla is stimulated by the sympathetic nervous system to release norepinephrane and epinephrine in response to stress.

The components of the nervous system that are involved in physical sensation are Central Nervous system and Peripheral Nervous System. “The Central Nervous System’s role is to integrate, process, and coordinate sensory and motor commands” (Bartholomew). CNS controls only the spinal cord and the brain. The PNS controls the nervous system outside the spinal cord. The function of PNS is to send “sensory division to the central nervous system to be process” (Bartholomew).

Afferent neurons are responsible for sending sensory information from the body to the central nervous system, while interneurons communicate signals within one another within the central nervous system. Efferent neurons transfer signals from the central nervous system to effector organs, one of these including muscles. Integrating the three composes the peripheral nervous system.

The autonomic nervous system (ANS) is composed of two parts called the parasympathetic nervous system and the sympathetic nervous system. The parasympathetic nervous system (PNS) is involved with sleeping, digesting meals, and making new blood cells and antibodies. The sympathetic nervous system (SNS) is involved with the “fight or flight” response and is associated with stress.

Parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.(p.11 ) The parasympathetic system is the opposite of the sympathetic nervous system.

We have two systems within the Autonomic Nervous System. The sympathetic nervous system and the parasympathetic nervous system.

The other part is the central nervous system (CNS), which is made up of the brain and the spinal cord. The CNS acts as a control centre and sends the signals to the needed neurons. It then brings a response via glands and muscles which maintain homeostasis (Sherwood, 2016). The PNS divides into the two following systems; the autonomic and the somatic. This controls involuntary and voluntary movements of the body such as heart muscles or skeletal muscles (Sherwood, 2016). The autonomic nervous system is then divided into the sympathetic and the parasympathetic nervous systems (Sherwood, 2016). The sympathetic system controls responses in our body which is also known as the 'fight or flight' reaction. This reaction increases the heart rate and blood pressure within the body as well as the production of adrenaline (Colbert et al, 2012). The parasympathetic nervous system has the opposite effect of the reaction, and controls the resting and digestion systems in the body. This decreases the heart rate and blood pressure therefore it does not trigger of a production of adrenaline (Colbert et al, 2012). The nervous system transmits and communicates around the body via a network of neurons. These are stimulated to trigger an electric impulse (Cohen, 2014). The electric impulse begins at the dendrites and proceeds down the body of the neurone

According to UC Davis Health Sports Medicine,” Heart rate refers to the number of times the heart beats per minute, and is directly related to the workload being placed on the heart.” (UC Davis Health,2017) Heart rate can be managed by two different branches of the autonomic nervous system that supply nerve impulses to the heart. The sympathetic nervous system is the fight or flight mechanism and releases hormones like epinephrine and norepinephrine to increase heart rate. The parasympathetic nervous system is the rest and digest mechanism and releases achetylcholine, which is a hormone that will decrease the heart rate. The vagus nerve is part of the autonomic nervous system, specifically the parasympathetic system. The autonomic nervous system

The somatic nervous system consists of efferent nerves responsible for stimulating muscle contraction, including all the non-sensory neurons connected with skeletal muscles and skin. The somatic nervous system controls all voluntary muscular systems within the body, and also mediates involuntary reflex arcs. Somatic nervous system carry information to the somatic effectors, which are the skeletal muscles. These motor pathways make up the somatic motor division. The somatic nervous system also includes the integrating centers that receive the sensory information and generate the efferent response signal.1 The somatic nervous system consists of three parts as well as the ANS. Spinal nerves are peripheral nerves that carry sensory information into the spinal cord and motor commands. Cranial nerves are the nerve fibers which carry information into and out of the brain stem. Association nerves integrate sensory input and motor output, numbering in the thousands. These systems within the PNS work together with the CNS to regulate bodily function and provide reactions to external

Take notice of figure.1 in the illustrated diagram that the sympathetic nervous system originates in the spinal cord. Specifically, the cell bodies of the first neuron are located in the thoracic and lumbar spinal cord. Axons from these neurons project to a chain of ganglia located near the spinal cord. In most cases, this neuron makes a synapse with another postganglionic neuron in the ganglion. A few preganglionic neurons go to other ganglia outside of the sympathetic chain and synapse there. The postganglionic neuron then projects to the "target" - either a muscle or a gland.