Term
| What are the peripheral chemoreceptors? |
|
Definition
| Carotid Body, Aortic Body |
|
|
Term
| What are the central chemoreceptors? |
|
Definition
Receptors that are separated from the blood by the blood-brain barrier that are responsive to PCO2
. |
|
|
Term
| Which Respiratory Group is involved with inspiration? |
|
Definition
| Medually Dorsal Respiratory Group (DRG) |
|
|
Term
| Which Respiratory Group is involved with expiration? |
|
Definition
| Medullary Ventral Respiratory Group (VRG) |
|
|
Term
| Where does the automatic rhytmicity of normal respiration result from? |
|
Definition
| Results from activities of the neurons in the medulla. |
|
|
Term
| What is the Central Inspiratory Activity Generator? |
|
Definition
| Postulated group of cells located within the medullary reticular formation that collects a background amount of pro inspiratory information. |
|
|
Term
| Direct input to the DRG come from peripheral chemorecptors and apneustic centers via which nerves? |
|
Definition
| Via the vagus and glossopharyngeal nerves |
|
|
Term
| T/F: The VRG is more complex than the DRG. |
|
Definition
| True. It is composed of three groups 2 of which are associated with expiration, while the intermediate is involved with inspiration. |
|
|
Term
| When does the activity of the VRG come into play during respiration? |
|
Definition
| Usually the VRG is minimally active, but with forced expiration, it becomes very active. |
|
|
Term
| What is the Inspiratory Cutoff Switch? |
|
Definition
| A group of neurons within the medulla which acts on the DRG in a negative fashion. |
|
|
Term
What is the Apneustic Center?
What is apenustic breathing? |
|
Definition
Neurons from this group impinge upon the DRG and stimulate inspiration.
Series of prolonged inspiratory gasps that is ended by a brief and rapid expiratory effort. |
|
|
Term
| What is the Pneumotaxic Center? |
|
Definition
| This is group of neurons that can inhibit inspiration when stimulated. It is thought to be a fine tuning mechanism for breathing. |
|
|
Term
| What effect does the cortex have on breathing? |
|
Definition
| The cortex allows voluntary control of breathing. |
|
|
Term
| What is the role of chemoreceptors? |
|
Definition
| Chemoreceptors measure the content of oxygen, carbon dioxide, and hydrogen ion in various compartments. |
|
|
Term
| What is the major variable that is measured in chemoreceptors in regard to maintaining the rate and depth of inspiration? |
|
Definition
| PCO2 of arterial blood. The systems operates to maintain a value of 40 mmHg. |
|
|
Term
| Which chemoreceptor is more important in controlling respiration? Aortic or Carotid? |
|
Definition
|
|
Term
| T/F: The influence of oxygen on the carotid and aortic bodies is largest at higher oxygen partial pressures. |
|
Definition
| False. PaO2 under 50 mmHg will cause aortic and carotid receptors have to have a larger effect. |
|
|
Term
| What are the two types of cells that are in the carotid body? |
|
Definition
Type I Glomus Cells - these act as the real chemoreceptors
Type II Glial Cells - used to form a supportive framework for the environment of glomus cells |
|
|
Term
| In terms of percentage, how much influence do the peripheral chemoreceptors have on the entire control system? |
|
Definition
|
|
Term
| During normal conditions, which chemoreceptors have the primary influence on respiration? |
|
Definition
| Central. They originate over 75% of the afferent signaling that reaches the medullary centers. |
|
|
Term
| How does the blood brain barrier's permeability to CO2 play into respiration control? |
|
Definition
| CO2 diffuses into the CSF through the blood brain barrier to for carbonic acid which dissociates into H+ and HCO3-. The H+ diffuses into the chemoreceptor cell to stimulate it. |
|
|
Term
| What effect does [H+] have on respiration? |
|
Definition
| Higher [H+] leads to an increased respiratory rate. |
|
|
Term
| What are slowly adapting stretch receptors? |
|
Definition
| Receptors that are present in the walls of the tracheobronchial tree that respond to stretch of the airway muscles. |
|
|
Term
| What is the Hering-Breuer reflex? |
|
Definition
| This reflex is activated when lung volumes are larger to result in smaller tidal volumes and a decrease in frequency of breathing. This is used to protect the lungs from over-inflation. |
|
|
Term
| What are Rapidly Apdapting "Irritant Receptors"? |
|
Definition
| These are receptors that fire a rapid burst of neuronal activity when stimulated but then accommodate to the stimulus and decrease their firing rate. They are used to monitor airways for irritants and chemicals. |
|
|
Term
| What are Juxtacapillary or "J" receptors? |
|
Definition
| Act much like "Irritant Receptors" in sensing stimuli to result in rapid, shallow breathing, bronchoconstriction, and production of mucous. Result in foreign materials from being cleared from the alveolar area. |
|
|
Term
| Where are Proprioreceptors located, and what is their function? |
|
Definition
| Located in the joints, tendons, and muscles. These receptors monitor the position of muscles of respiration in order to control the level of contraction. |
|
|
Term
| What is the response of respiration to pain stimuli? |
|
Definition
| Initial apnea followed by rapid hyperventilation. |
|
|
Term
| What happens to breathing during sleep? |
|
Definition
| Decreased irregular rate during REM sleep. The basal metabolic activity takes over with little stimuli from external receptors. |
|
|
Term
| What happens to the lungs in the eldery? |
|
Definition
| Lung elasticity decreases, lung compliance increases and the functional residual capacity increases. |
|
|
