Respiratory system Flashcards

Question

Larynx is

Answer 1

Larynx is supported by the hyoid apparatus  Very delicate structure – need to be gentle when intubating and extubating animals  ** Cats are very prone to laryngospasm  The pattern and number of laryngeal cartilages varies among species

Answer 2

Epiglottis  Arytenoid cartilages (paired)  Thyroid cartilage (adam’s apple)  Cricoid cartilage

Answer 3

The epiglottis is leaf-shaped and is located rostrally  Projects forward from the ventral portion of the larynx  Tip is usually tucked up dorsal to the caudal rim of the soft palate while the animal is breathing

Answer 4

Epiglottis is pulled back to cover the opening of the larynx (the glottis),  Prevents the swallowed material from entering the larynx

Answer 5

The vocal folds

Answer 6

Articulates with the hyoid apparatus  Attaches muscles associated with swallowing and phonation

Answer 7

Connects the thyroid cartilage to the trachea  Maintains the shape of the larynx so air may pass through

Answer 8

The laryngeal cavity - contains the vocal folds which run from the arytenoid cartilages to the interior floor of the thyroid cartilage

Answer 9

Arytenoid cartilage and the vocal cords form the boundaries of the glottis (opening into the larynx)

Answer 10

Voice production Prevention of aspiration of foreign bodies Control of airflow to and from the lungs

Answer 11

Causes phonation by relaxing and tightening the vocal cords as air pass over them causing them to vibrate  The pitch can be changed from a low pitch (relaxed vocal cords – open glottis) to a high pitch (tightened vocal cords – closed glottis)

Answer 12

Mainly through the trapdoor effect of epiglottis and muscle contractions which pull entire larynx forward and fold the epiglottis back over its opening  Backed up by vocal folds  Can meet in the midline to close the glottis

Answer 13

By adjusting the size of the glottis with the vocal folds and by closing the glottis with the epiglottis

Answer 14

Tracheal Bifurcation or Carina  Occurs at about the level of the heart

Answer 15

Trachea is composed of C-shaped hyaline cartilage with the opening of the "C" dorsal  Prevents the trachea from collapsing on inspiration  Allows the trachea to change in size

Answer 16

Trachea is lined with pseudostratified ciliated mucosa, like the nasal passages  Works to trap foreign bodies  Trapped material is moved cranially towards the pharynx where it is swallowed

Answer 17

Mucous helps trap foreign bodies  If there is large amount of dust in the air then an increased amount of mucus is produced  Accumulates and irritates the lining of the trachea  Stimulates coughing which clears the passageway

Answer 18

Starts with the bronchi and ends with the alveoli  Includes all the air passages in between  All the structures of the lower portion of the respiratory tract are located in the lungs

Answer 19

Air passages from bronchi to alveoli are collectively called the bronchial tree because the divide into smaller and smaller branches, just like a tree

Answer 20

Bronchi divide into smaller bronchi until they are tiny bronchioles  These branch smaller. The smallest branches called alveolar ducts which terminate in alveolar sacs  Alveolar sacs look like a bunch of grapes

Answer 21

bronchodilation (with relaxation of the smooth muscle) during increased oxygen demand and bronchoconstriction during rest

Answer 22

Can also get bronchoconstriction with irritants in the lungs – can lead to breathing difficulty. Examples are:  Feline asthma (allergic bronchitis)  Horses get ‘heaves’, a chronic allergic condition, usually to dust and fungal spores in hay

Answer 23

Numerous alveoli make up each alveolar sac  Sites for gas exchange  Alveoli are tiny, thin walled sacs  Surrounded by a network of capillaries

Answer 24

surfactant that reduces the ‘stickiness’ (surface tension) of the alveolar walls: assists in expansion during breathing and helps prevent complete lung collapse  Very important with premature babies  Surfactant often not properly formed  Contributor to non-viability of premature animals

Answer 25

to exchange oxygen for carbon dioxide in the blood

Answer 26

 Each lung is a cone-shaped structure with its base at the diaphragm and apex close to the thoracic inlet  Lateral side of each lung is in contact with the thoracic wall  Except at the cardiac notch where it is in contact with the heart

Answer 27

Left cranial and caudal lobe  Left cranial lobe is partially subdivided and some call the caudal part the left middle lobe  Right cranial, middle and caudal lobe and an accessory lobe.  Horse: left and right lobes and an accessory lobe

Answer 28

Each lung has a small, well defined area on its medial side called the hilus where air, blood, lymph and nerves enter and leave the lung  The only area of the lung that is “fastened in place”

Answer 29

Cut a piece of lung and place it in some water:  If lung sinks - no air ever entered the lungs and the animal was born dead  If lung floats - air has entered the lungs so newborn was born alive

Answer 30

pulmonary circulation  The blood vessels get smaller and smaller as they branch their way down to the alveoli

Answer 31

Capillaries network around each alveolus of the alveolar sac  The capillaries are so small that only one blood cell can move through the vessel at a time  Ideal for CO2 to diffuse from the blood cell into the alveolus and O2 from the alveolus into the blood cell

Answer 32

Dorsally: the thoracic vertebrae  Laterally: the ribs  Ventrally: the sternum  Caudally: the diaphragm  Cranially: 1st pair of ribs, 1st thoracic vertebrae and cranial part of sternum (manubrium)- this area is known as the thoracic inlet

Answer 33

Main contents are the lungs, heart, large blood vessels, nerves, trachea, esophagus, lymphatic vessels and lymph nodes  Note: the diaphragm is a thin sheet of skeletal muscle and the primary muscle used in respiration

Answer 34

A thin membrane which covers the organs and structures in the thorax and lines the inside of the thoracic cavity.  Parietal pleura – lines the thoracic cavity  Visceral pleura – covers the thoracic organs

Answer 35

Between the two pleura is a space containing a small amount of lubricating fluid  Ensures that no friction occurs during movement (especially breathing)

Answer 36

Mediastinum – the junction of these 2 serosas near the thoracic midline  The portion of the thorax between the lungs that contains the heart and all the other thoracic structures  Except the lungs

Answer 37

Air is drawn into the lungs  Oxygen is transferred from the alveoli into the blood.  CO2 in the blood is moved into the lungs  The waste CO2 is expelled into the environment

Answer 38

Process of drawing air into the lungs – inhalation  Power is provided by the diaphragm and the external intercostal muscles  Diaphragm is normally dome-shaped – it contracts and flattens on inspiration  Normal resting (abdominal) respiration  External intercostals are found between the ribs  Pull the ribs up and forward to expand the thoracic cavity  May be assisted by the shoulder, neck, and chest muscles  Stretching limb forwards during running helps expand the chest, landing compresses the chest

Answer 39

Forced expiration is powered by the internal intercostal and abdominal muscles  Internal intercostals are found between the ribs deep to the externals  Pull caudally and rotate the ribs to decrease thoracic volume  Abdominal muscles contract and push abdominal organs against the diaphragm to restore the dome shape and decrease thoracic volume

Answer 40

Increased respiratory activity and effort- difficulty breathing

Answer 41

Absence or cessation of breathing

Answer 42

Increase in both rate or depth of breathing or both

Answer 43

Shallow rapid breath

Answer 44

8 to 16 brpm

Answer 45

volume of air exchanged during ONE BREATH  Varies depending on the needs of the animal – exercising vs rest

Answer 46

volume of air exchanged during ONE MINUTE of breathing  Equals the tidal volume X number of breaths per minute

Answer 47

volume of air remaining in the lungs after maximum expiration

Answer 48

maximum amount of air that can be expired after a maximal inspiration

Answer 49

Vital capacity + residual volume

Answer 50

Room Air contains about 20% oxygen and about 0.03% carbon dioxide  Blood entering lung capillaries has a much higher concentration of carbon dioxide and a lower concentration of oxygen  Oxygen and carbon dioxide diffuse through the capillary and alveolar walls down their concentration gradients  Results in a movement of carbon dioxide from the blood into the alveoli and oxygen from the air in the alveoli to the blood

Answer 51

Exchange rate is affected if the distance the gas must cover increases – e.g. interstitial fluid (edema) in the lung  Can severely impact the amount of O2 absorbed!

Answer 52

from inhalation of irritants, trauma from endotracheal intubation, or excessive panting in brachycephalic and obese dogs

Answer 53

If part of the lung collapses or has airway obstruction, oxygen levels in the alveoli decrease and the body responds with a local hypoxic vasoconstriction  This decreases the blood circulating through parts of the lung that aren’t allowing good gas exchange

Answer 54

such as high altitude, it creates overall vasoconstriction in the lungs  Leads to increase in vascular resistance  Results in pulmonary hypertension  Causes right heart to work harder to pump against the resistance  May lead to right heart failure and peripheral edema  High mountain disease in cattle

Answer 55

Total pressure of a mixture of gases is the sum of pressures of each individual gas  Therefore each individual gas has its own pressure that is part of the total atmospheric pressure – i.e. it has a partial pressure  Gases can also have a partial pressure dissolved in a solution

Answer 56

Muscles involved in breathing are under voluntary control  The process of breathing is normally under involuntary control

Answer 57

Has different control centers for inspiration, expiration, and breath holding  All are subconscious  Can be overridden by conscious control

Answer 58

responsible for setting the rate  Primarily works through the inspiratory area (expiration is the passive result of inspiratory effort ending)  Has an automatic rhythmic signal for inspiration

Answer 59

Signal travels down the phrenic nerve to the diaphragm and through the intercostals nerves to the external intercostals muscles  Expiratory area is usually only activated during forced expiration

Answer 60

Mechanical control and Chemical control

Answer 61

Sets limits on normal inspiration and expiration  Works through stretch receptor in the lung  Receptors feed back to the respiratory center, which signals the muscles of inspiration and expiration

Answer 62

Chemoreceptors monitor CO2, pH, and O2 contents in the blood  Located in the brain, carotid artery and aorta.  Signals the respiratory center if any of these are out of balance

Answer 63

Rising concentration of CO2 is more important than decreasing concentration of O2 in terms of stimulating breathing  CO2 and pH are linked  if CO2 is high, this drives pH down and blood becomes acidic  By increasing respiratory rate, the body can ‘blow off’ the excess CO2 and bring the pH back to normal

Answer 64

May blow off too much CO2  Animal may compensate by a period of breath-holding (apnea) until the CO2 levels rise enough to stimulate breathing again

Answer 65

Signal to increase rate with mild hypoxia  With severe hypoxia the neurons may become too depressed to signal  may lead to respiratory failure

Answer 66

protective reflex stimulated by irritation in the trachea or bronchi  Requires pressure against a closed glottis, then sudden release  Can be productive or non-productive – treated very differently

Answer 67

protective reflex stimulated by irritation in the nasal passages

Answer 68

slow deep breath stimulated by decrease in O2 levels in blood, by boredom, drowsiness, fatigue, or anxiety

Answer 69

deeper than normal breath that may be stimulated by decrease in O2 levels in the blood  Can be beneficial to give an occasional ‘sigh’ breath to anesthetized animals

Answer 70

spasmodic contraction of the diaphragm with a sudden closure of the glottis – usually temporary and harmless

Answer 71

mechanism to dissipate heat –increased respiratory rate with decreased tidal volume  Primarily moves air through the upper airways to exchange heat

Answer 72

The part of the respiratory system where there is no gas exchange.  Important during anesthesia. If a long endotracheal tube is placed with a long piece protruding, physiological dead space increases and reduces gas exchange.

Answer 73

destruction of alveolar membranes leads to larger lung chambers and decreased surface area available for gas exchange

Answer 74

is collapse of the alveoli – often results from airway obstruction or lack of surfactan

Answer 75

High pitched, upper resp problem

Answer 76

Low pitch, flaccid tissue vibrating in the airway

Answer 77

Inflammation and congestion of the paranasal sinuses  Can become so severe it obstructs drainage – very painful  May require surgical intervention – trephinate to drain

Answer 78

with vigorous exercise the soft palate rises and the epiglottis falls below it, reducing the diameter of the nasopharynx

Answer 79

Afflicted horses are known as "Roarers". Paralysis of the recurrent laryngeal nerve (usually the left) May be due to injury or genetics The vocal cords hang slack in the tracheal lumen and cause "roaring" sound when expired air passes over them during exercise, hence the name Obstructs air flow Can be surgically fixed – laryngeal tie-back or laryngeal ventriculectomy (removal of the ventricle on the affected side so the scar tissue holds the vocal fold out of the way of the air flow)

Answer 80

Like laryngeal hemiplegia but in dogs Older dogs with noisy respiration

Answer 81

(RAO – Recurrent Airway Obstruction) similar to chronic obstructive pulmonary disease – COPD in humans Chronic allergic disease of the horse characterized by constricted airways, laboured respiration, chronic cough, and lack of stamina. The horse is alert and does not have a fever. The disease is most common in stabled horses Average age of onset is 9-12 years Course of disease is progressive

Answer 82

Free air in the chest Can result from a hole in the chest wall and/or from a punctured lung The problem may be self-limiting and the air absorbed If large volumes of air enter the pleural cavity, the lung will collapse

Answer 83

An abnormal accumulation of fluid in the pleural space. Reduce ability of the lung to inflate. Lung lobes “float” in pleural fluid. Several causes: fluid can accumulate from heart failure, hemorrhage, lymph vessel leakage, pus, cancer

Answer 84

An abnormal accumulation of fluid in the airways and alveoli. Associated with circulatory disorders such as left ventricular failure, anaphylactic shock or severe allergies Auscultation of the chest may reveal fluid sounds

Answer 85

Inflammation of the lung. Usually reserved for infectious causes Pneumonitis for non infectious More serious and potentially life-threatening than bronchitis Mucus and fluids can accumulate and plug sections of the lungs, decreasing body’s ability to exchange gasses Note: aspiration pneumonia can occur if an anesthetized animal is not intubated or is extubated too early. Also with administration of mineral oil, etc.

Answer 86

is usually the result of trauma (H.B.C.'s in particular) but can also be congenital Depending on the size of the opening and whether abdominal contents have entered the chest, the animal may or may not show symptoms Can be life-threatening, particularly if the abdomen is opened and the hernia has not been diagnosed A considerable volume of abdominal viscera may gradually pass through a relatively small tear because of the negative pressure in the thorax.

Respiratory system Flashcards

(111 cards)