respiratory control centers

Examples of respiratory control centers in the following topics:

• Neural Mechanisms (Respiratory Center)

  • Involuntary respiration is controlled by the respiratory centers of the upper brainstem (sometimes termed the lower brain, along with the cerebellum).
  • The medulla oblongata is the primary respiratory control center.
  • The pnuemotaxic center sends signals to inhibit inspiration that allows it to finely control the respiratory rate.
  • The apneustic and pnuemotaxic centers work against each other together to control the respiratory rate.
  • Describe the neural mechanism of the respiratory center in respiration control

• Breathing Patterns

  • The respiratory rate is frequency of breaths over time.
  • The respiratory rate is controlled by involuntary processes of the autonomic nervous system.
  • In particular, the respiratory centers of the medulla and the pons control the overall  respiratory rate based on a variety of chemical stimuli from within the body.
  • Tachypnea: describes increased respiratory rate.
  • Bradypnea: describes decreased respiratory rate.

• Control of Autonomic Nervous System Function

  • The medulla oblongata, in the lower half of the brainstem, is the control center of the autonomic nervous system.
  • The autonomic nervous system (ANS) is the part of the peripheral nervous system which acts to control involuntary functions which are critical for survival.
  • The ANS participates in the regulation of heart rate, digestion, respiratory rate, pupil dilation and sexual arousal among other bodily processes.
  • The medulla's main functions are to control the cardiac, respiratory and vasomotor centers, to mediate autonomic, involuntary functions, such as breathing, heart rate and blood pressure, and to regulate reflex actions such as coughing, sneezing, vomiting and swallowing.
  • The medulla is a subregion of the brainstem and is a major control center for the autonomic nervous system.

• Neural Mechanisms (Cortex)

  • The primary motor cortex is the neural center for voluntary respiratory control.
  • This neural pathway is called the ascending respiratory pathway.
  • The center for diaphragm control is posterior to the location of thoracic control (within the superior portion of the primary motor cortex).
  • Additionally, other structures may override voluntary respiratory signals, such as the activity of limbic center structures like the hypothalamus.
  • There are three types of important respiratory nerves:

• Functions of the Brain Stem

  • The brainstem regulates vital body functions such as cardiac and respiratory functions and acts as a vehicle for sensory information.
  • The brain stem also plays an important role in the regulation of cardiac and respiratory function.
  • The medulla contains the cardiac, respiratory, vomiting, and vasomotor centers regulating heart rate, breathing and blood pressure.
  • The midbrain (mesencephalon) is associated with vision, hearing, motor control, sleep/wake, alertness, and temperature regulation.
  • The brainstem also has integrative functions, including cardiovascular system control , respiratory control, pain sensitivity control, alertness, awareness, and consciousness.

• Functional Anatomy of the Respiratory System

  • The respiratory system include lungs, airways and respiratory muscles.
  • If proper ventilation is not maintained, two opposing conditions could occur: respiratory acidosis (a life threatening condition) and respiratory alkalosis.
  • It is defined as volume of dead space times the respiratory rate.
  • The ventilation rate is controlled by several centers of the autonomic nervous system in the brain, primarily the medulla and the pons.
  • A normal human respiratory rate is 10 to 18 breaths per minute.

• Expiration

  • Exhalation (or expiration) is the flow of the respiratory current out of the organism.
  • These two types of expiration are controlled by different centers within the body.
  • The nervous system component that controls voluntary expiration is the motor cortex (the ascending respiratory pathway), because it controls muscle movements, but this pathway isn't fully understood, and there are many other possible sites in the brain that may also be involved.
  • The principle neural control center for involuntary expiration consists of the medulla oblongata and the pons, which are located in the brainstem directly beneath the brain.
  • While these two structures are involved in neural respiratory control, they also have other metabolic regulatory functions for other body systems, such as the cardiovascular system.

• The Respiratory System and Direct Diffusion

  • Respiratory processes that help organisms exchange O2 and CO2 range from simple direct diffusion to complex respiratory systems.
  • How often a breath is taken and how much air is inhaled or exhaled are tightly regulated by the respiratory center in the brain.
  • The complexity of the respiratory system correlates with the size of the organism.
  • Larger organisms have had to evolve specialized respiratory tissues, such as gills, lungs, and respiratory passages, accompanied by a complex circulatory system to transport oxygen throughout their entire body.
  • If the flatworm had a cylindrical body, then the cells in the center would not be able to get oxygen.

• Disorders of Acid-Base Balance

  • This failure in ventilation may be caused by depression of the central respiratory center by cerebral disease or drugs, inability to ventilate adequately due to neuromuscular disease (e.g., myasthenia gravis, amyotrophic lateral sclerosis, Guillain-Barré syndrome, muscular dystrophy), or airway obstruction related to asthma or chronic obstructive pulmonary disease (COPD) exacerbation.
  • There are two types of respiratory alkalosis: chronic and acute.
  • Acute respiratory alkalosis occurs rapidly.
  • Chronic respiratory alkalosis is a more long-standing condition.
  • A Davenport diagram illustrating the transition from respiratory acidosis to respiratory alkalosis.

• Chemical Composition of Bone

  • This failure in ventilation may be caused by depression of the central respiratory center by cerebral disease or drugs, inability to ventilate adequately due to neuromuscular disease (e.g., myasthenia gravis, amyotrophic lateral sclerosis, Guillain-Barré syndrome, muscular dystrophy), or airway obstruction related to asthma or chronic obstructive pulmonary disease (COPD) exacerbation.
  • There are two types of respiratory alkalosis: chronic and acute.
  • Acute respiratory alkalosis occurs rapidly.
  • Chronic respiratory alkalosis is a more long-standing condition.
  • Differentiate among the acid-base disorders: metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis