autonomic nervous system

Examples of autonomic nervous system in the following topics:

• Autonomic Nervous System

  • The autonomic nervous system, the relay between the CNS and internal organs, is divided into the sympathetic and parasympathetic systems.
  • The autonomic nervous system (ANS) serves as the relay between the central nervous system (CNS) and the internal organs.
  • There are two divisions of the autonomic nervous system that often have opposing effects: the sympathetic nervous system and the parasympathetic nervous system .
  • Autonomic responses are mediated by the sympathetic and the parasympathetic systems, which are antagonistic to one another.
  • In the autonomic nervous system, a preganglionic neuron of the CNS synapses with a postganglionic neuron of the parasympathetic nervous system.

• The Nervous System

  • The nervous system is composed of the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves).
  • A classification of the nervous system can be performed under different aspects.
  • Two major divisions of the nervous system are the central nervous system (CNS) and the peripheral nervous system (PNS).
  • The autonomic nervous system, also part of the peripheral nervous system, controls internal body functions that are not under conscious control.
  • For example, when a prey animal is chased by a predator, the autonomic nervous system automatically increases the rate of breathing and the heartbeat.

• Sensory-Somatic Nervous System

  • The sensory-somatic nervous system transmits sensory information from the body to the brain and motor movements from the brain to the body.
  • The sensory-somatic nervous system is composed of cranial and spinal nerves and contains both sensory and motor neurons.
  • Sensory neurons transmit sensory information from the skin, skeletal muscle, and sensory organs to the central nervous system (CNS).
  • Unlike the autonomic nervous system, which has two synapses between the CNS and the target organ, sensory and motor neurons have only one synapse: one ending of the neuron is at the organ and the other directly contacts a CNS neuron.
  • Explain the role of the cranial and spinal nerves in the sensory-somatic nervous system

• Neurons and Glial Cells

  • In most types of vertebrate animals, it consists of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).
  • The PNS includes motor neurons (mediating voluntary movement), the autonomic nervous system (comprising the sympathetic nervous system and the parasympathetic nervous system, which regulate involuntary functions), and the enteric nervous system (a semi-independent part of the nervous system whose function is to control the gastrointestinal system).
  • The nervous system performs several functions simultaneously.
  • Some organisms, such as sea sponges, lack a true nervous system.
  • Octopi may have the most complicated of invertebrate nervous systems.

• Muscle Tissues and Nervous Tissues

  • Constriction of smooth muscle occurs under involuntary, autonomic nervous control in response to local conditions in the tissues.
  • The walls of blood vessels, the tubes of the digestive system, and the tubes of the reproductive systems are composed primarily of smooth muscle.
  • Skeletal muscle is under voluntary, somatic nervous system control and is found in the muscles that move bones.
  • Cardiac muscle is not under voluntary control, but is influenced by the autonomic nervous system to speed up or slow down the heart beat.
  • The main cell of the nervous system is the neuron.

• Hormonal Regulation of Stress

  • The sympathetic nervous system regulates the stress response via the hypothalamus.
  • The sympathetic division of the vertebrate autonomic nervous system has evolved the fight-or-flight response to counter stress-induced disruptions of homeostasis.
  • In the initial alarm phase, the sympathetic nervous system stimulates an increase in energy levels through increased blood glucose levels.
  • If glycogen reserves were the only energy source available, neural functioning could not be maintained once the reserves became depleted due to the nervous system's high requirement for glucose.
  • Glucocorticoids also have anti-inflammatory properties through inhibition of the immune system.

• The Vestibular System

  • Gravity, acceleration, and deceleration are detected by evaluating the inertia on receptive cells in the vestibular system.
  • The vestibular system has some similarities with the auditory system.
  • It utilizes hair cells just like the auditory system, but it excites them in different ways.
  • There are also projections to the temporal cortex, which account for feelings of dizziness; projections to autonomic nervous system areas in the brainstem, which account for motion sickness; and projections to the primary somatosensory cortex, which monitors subjective measurements of the external world and self-movement.
  • Identify the structures of the vestibular system that respond to gravity

• Adrenal Glands

  • These cells are innervated by pre-ganglionic autonomic nerve fibers from the central nervous system.
  • The release of epinephrine and norepinephrine is stimulated by neural impulses from the sympathetic nervous system.

• Hypothalamic-Pituitary Axis

  • The endocrine system uses chemical signals to communicate and regulate the body's physiology.
  • The collection of these glands makes up the endocrine system.
  • The hypothalamus in vertebrates integrates the endocrine and nervous systems.
  • In addition, it contains autonomic centers that control endocrine cells in the adrenal medulla via neuronal control.
  • A portal system carries blood from one capillary network to another; therefore, the hypophyseal portal system allows hormones produced by the hypothalamus to be carried directly to the anterior pituitary without first entering the circulatory system.

• Glia

  • While glia (or glial cells) are often thought of as the supporting cast of the nervous system, the number of glial cells in the brain actually outnumbers the number of neurons by a factor of ten.
  • Glial cells of the (a) central nervous system include oligodendrocytes, astrocytes, ependymal cells, and microglial cells.
  • Glial cells of the (b) peripheral nervous system include Schwann cells, which form the myelin sheath, and satellite cells, which provide nutrients and structural support to neurons.
  • (a) Astrocytes and (b) oligodendrocytes are glial cells of the central nervous system.
  • Describe the specific roles that the seven types of glia play in the nervous systems