The nervous system is a network of nerves and cells that carry messages to various parts of the body. The nervous system consists of the central nervous system and peripheral nervous system (Peate & Nair, 2016). The central nervous system is subdivided into the brain and spinal cord where it regulates and interacts with several body functions, whiles the peripheral nervous system sends sensory messages in and out of the central nervous system. The peripheral nervous system which is subdivided into the somatic nervous system controls the voluntary movement of the muscles and the autonomic nervous system controls involuntary movement. The nervous system collaborates with the endocrine system to maintain homeostasis (Marieb & Hoehn, 2016). The nervous system achieves homeostasis by reacting to receptors which sends nerve impulses to the brain as a regulating center (Peate & Nair, 2016).
The nervous system controls the skeletal muscle movement stimulated by an electrical signal channeled through by the motor neuron. This motor neuron is located in the middle of the muscle cell.
Botulism is a disease condition that prevents the muscle from releasing acetylcholine from the end of the nerves in muscles (Lawrence, Barous, Pravikoff, & Guide, 2017). Because of this, the blockage destroys the site where the acetylcholine will bind. Acetylcholine is a neurotransmitter released by neurons that stimulates skeletal muscle controlled by the central nervous system which is responsible for communication between muscle cell and motor neurons. Clostridium botulinum causes descending paralysis when acetylcholine release in the cell is disrupted. When there is disruption of exocytosis or neurotransmitters signal transmission of a nerve impulse to a muscle to contract is compromised (Lawrence, Barous, Pravikoff, & Guide, 2017).
The transmission of a nerve impulse results from electrical changes across from one end a membrane of a neuron to another. Polarization is established when there is a difference in electrical charge between the outside and inside of a membrane. To maintain polarization, an excess of sodium ion (Na+) on the outside and excess of potassium ions (K+) on the inside is maintained (Peate & Nair, Fundamentals of Anatomy and Physiology : For Nursing and Healthcare Students, 2016). Through a chain of chemical events of transmission, the dendrites which are part of the neuron picks up impulse through the axon to the next neuron. Depolarization occurs when sodium ions enter the neuron and the neuron becomes more positive because sodium has a positive charge. The opening of channels that allow positive ion flow into the cell causing depolarization (Peate & Nair, Fundamentals of Anatomy and Physiology, 2016).
The nervous system maintains homeostasis by communication between the central nervous system and the peripheral nervous system (Marieb & Hoehn, 2016). The central nervous system sends out impulses to the afferent muscles through the somatic nervous system to mediate voluntary movement, whiles the autonomic nervous system send impulse to efferent muscles to the brain (Marieb & Hoehn, 2016). The autonomic nervous system, a subdivision of the peripheral nervous system is further subdivided to the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is serves as a reservoir to mobilize energy while the parasympathetic nervous system serves as used when muscle cell is in a relaxed state. The nervous system consists of nerves connected to neurons that send signals through neurotransmitters to interpret messages to maintain homeostasis. The neurotransmitters stimulate other cells around the neurons which acts as chemical transport (Marieb & Hoehn, 2016) .
Botulism toxin inhibits the flow of acetylcholine at the neuromuscular junction (Lawrence, Barous, Pravikoff, & Guide, 2017). The disruption of the neuromuscular junction where nerve fiber is unable to transmit a signal to the muscle fiber causes homeostatic mechanism. Neurotransmitters vesicles is unable to fuse with presynaptic membrane through exocytosis to release acetylcholine because the axon has contact with the action potential (nerve impulse) (Lawrence, Barous, Pravikoff, & Guide, 2017). Binding of receptors on the sarcolemma is inhibited which blocks flow of calcium ion across the membrane and potassium ions out of the muscle cell (Peate & Nair, Fundamentals of Anatomy and Physiology, 2016). Nerve impulse inhibit the generation of muscle cell to travel to the myofibril to control muscle contraction (Peate & Nair, Fundamentals of Anatomy and Physiology, 2016).
A concept map is provided below to show the nervous system maintain homeostasis and the abnormal effect of clostridium botulinum effect in regulation of homeostatic balance.
Copyright 2019 - Education WordPress Theme.