GMS6530 FINAL EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
Diaphragm
Large, flat muscle at the bottom of the chest cavity that helps with breathing
-Contraction: Flattens diaphragm, enlarging thoracic cavity and pulling air in
-Relaxation: allows diaphragm to bulge upwards, compresses lungs, expells lungs.
Accounts 2/3 of airflow
Internal and external intercosta muscles
Synergists to diaphragm
-Located between ribs
-Add about 1/3 of air that ventilates the lungs
Normal Quiet expiration
As muscles relax, structures recoil to original shape and size of thoracic cavity
forced expiration muscles
Rectus abdominis, internal intercostals, and
other lumbar, abdominal, and pelvic muscles
Greatly increased abdominal pressure pushes
viscera up against diaphragm incr
neural control of breathing
, No autorhythmic pacemaker cells for respiration, as in
the heart
Exact mechanism for setting the rhythm of respiration
remains unknown
Breathing depends on repetitive stimulation of skeletal
muscles from brain
-stimulation of skeletal muscles causes brain to act
brain stem respiratory centers
Automatic, unconscious cycle of breathing is controlled by three pairs of
respiratory centers in the reticular formation of the medulla oblongata and the
pons
Respiratory nuclei in medulla
Ventral respiratory group (VRG)
Primary generator of the respiratory rhythm
Produces a respiratory rhythm of 12 breaths per minute
Dorsal respiratory group (DRG)
Modifies the rate and depth of breathing
Pons
Pontine respiratory group (PRG)
Adapts breathing to special circumstance
Respiratory nuclei medulla
COMPLETE SOLUTIONS VERIFIED
Diaphragm
Large, flat muscle at the bottom of the chest cavity that helps with breathing
-Contraction: Flattens diaphragm, enlarging thoracic cavity and pulling air in
-Relaxation: allows diaphragm to bulge upwards, compresses lungs, expells lungs.
Accounts 2/3 of airflow
Internal and external intercosta muscles
Synergists to diaphragm
-Located between ribs
-Add about 1/3 of air that ventilates the lungs
Normal Quiet expiration
As muscles relax, structures recoil to original shape and size of thoracic cavity
forced expiration muscles
Rectus abdominis, internal intercostals, and
other lumbar, abdominal, and pelvic muscles
Greatly increased abdominal pressure pushes
viscera up against diaphragm incr
neural control of breathing
, No autorhythmic pacemaker cells for respiration, as in
the heart
Exact mechanism for setting the rhythm of respiration
remains unknown
Breathing depends on repetitive stimulation of skeletal
muscles from brain
-stimulation of skeletal muscles causes brain to act
brain stem respiratory centers
Automatic, unconscious cycle of breathing is controlled by three pairs of
respiratory centers in the reticular formation of the medulla oblongata and the
pons
Respiratory nuclei in medulla
Ventral respiratory group (VRG)
Primary generator of the respiratory rhythm
Produces a respiratory rhythm of 12 breaths per minute
Dorsal respiratory group (DRG)
Modifies the rate and depth of breathing
Pons
Pontine respiratory group (PRG)
Adapts breathing to special circumstance
Respiratory nuclei medulla
