Pulmonary%20Circulation-%20THIS%20IS%20A%20REVIEW!!!!

1
Pulmonary Circulation- THIS IS A REVIEW!!!!

• ______________ blood enters the lungs from ______
  ventricle of heart through the Pulmonary
  ________.
• Pulmonary trunk splits into left and right
  pulmonary arteries that enter the two lungs
• The vessels become arterioles, capillaries, and
  venules.
• Oxygenated blood returns to the left atrium in
  the Pulmonary _______.

2
Thoracic Cavity

• Bound by __________ vertebrae dorsally, ______
  _____________ muscles laterally, the __________
  ventrally, and the _____________caudally.
• Mediastinum area between lungs REVIEW!!!

3
Pleura- REVIEW!!!

• Serous membrane that lines thoracic cavity and
  covers the lungs.
• __________ layer covers the lungs
• __________ layer lines the cavity
• Space between the two pleural layers is filled
  with a small amount of pleural _________ to
  prevent friction. (same in abdomen, pericardium).
  Too much fluid is called an ______________.

4
Diaphragm

• Thin, dome-shaped sheet of skeletal muscle
• Forms caudal boundary of thorax
• Base of lungs lie directly on the cranial surface
  and the liver lies on the caudal surface
• Important respiratory muscle
• Dome-shaped when ___________
• Flattens when it __________
• Enlarges volume of thorax and aids inspiration

5
Process of Respiration

• Pressure within the thorax is ____________ with
  respect to atmospheric pressure.
• Pulls lungs tight against the thoracic wall
• Flexible nature of lungs allows them to conform
  with shape of the thoracic wall.
• Pleural fluid provides __________.
• Lungs follow movements of thoracic wall
• Negative intrathoracic pressure helps draw blood
  through ________ in the mediastinum and into
  atria

6
Pneumothorax

• Leakage of air into thorax ? Loss of negative
  pressure in lungs
• (causes collapsed lung)
• Causes
• Penetrating wound of chest
• Rupture of alveoli
• Rx
• Remedy cause
• Remove air from thorax
• Needle/syringe (aka ____________________)
• Chest tube

7

• Inspiration is the process of drawing air into
  lungs (inhalation)
• Results from increasing volume of thoracic cavity
  by inspiratory muscles
• Main inspiratory muscles ___________ and
  ____________ intercostal muscles
• Expiration is the process of pushing air out of
  lungs (exhalation)
• Results from decrease in size of thoracic cavity
• Main expiratory muscles ___________ intercostal
  muscles and ____________ muscles

8
Respiratory Volumes

• ___________ volume volume of air inspired and
  expired during one breath.
• Varies according to bodys needs.
• Smaller when animal is at rest and larger when
  excited and active.
• __________ volume volume of air inspired and
  expired during one minute.
• Calculated by multiplying the tidal volume by
  breaths per minute.
• __________ volume volume of air remaining in
  the lungs after maximum expiration.
• Residual volume always remains, lungs will never
  be completely emptied of air.

9
Alveolar Gas Exchange- REVIEW!!

• Simple _________ of gas molecules from areas of
  _____ concentration to areas of _____
  concentration.
• _____ diffuses from the alveolar air into the
  blood of the alveolar capillary
• _____diffuses from the blood into the alveolus

10
Respiratory Center

• Even though all of the inspiratory and expiratory
  muscles are skeletal muscles under voluntary
  control, breathing does not require a conscious
  effort.
• Breathing is controlled by an area in the
  _________ ___________ of the brain stem known as
  the Respiratory Center.
• Directs timing and strength of contraction
• Can be consciously controlled for brief periods.

11
Mechanical Control System

• __________ receptors in the lungs set limits on
  routine resting inspiration and expiration.
• Respiratory center sends out nerve impulses when
  lungs inflate to a certain point
• Stops muscle contractions that produce
  inspiration and starts contractions to produce
  expiration
• Another set of nerve impulses sent when lungs
  deflate sufficiently
• Stops expiration and starts the process of
  inspiration again

12
Chemical Control System

• Adjusts normal rhythmic breathing pattern
  produced by mechanical control system
• Chemical (peripheral) receptors in carotid artery
  and aorta monitor blood _____, ____, and ____.
• Central chemical receptors are located in the
  medulla oblongata.

13
Chemical Control System

• Blood level of CO2 and blood pH linked
• __CO2 in blood and __blood pH triggers
  respiratory center to increase rate and depth of
  respiration
• __CO2 in blood and __blood pH triggers
  respiratory center to decrease rate and depth of
  respiration

14
Chemical Control System

• _______ - decrease in blood O2 level
• Slight hypoxia triggers respiratory center to
  increase the rate and depth of breathing
• Severe hypoxia - neurons of the respiratory
  center can become so depressed that adequate
  nerve impulses cannot be sent to the respiratory
  muscles
• Can cause breathing to decrease or stop
  completely