Respiratory system Flashcards

1
Q

Function of the respiratory system

A

Major function - supply oxygen to body and remove CO2
 Phonation (voice production)
 Assist with body temperature control
 Regulation of acid-base balance
 Sense of smell (olfactory sense)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Respiration occurs on three levels in the body

A

External
Internal
Cellular respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

External respiration

A

The physical act of getting oxygen in and carbon dioxide out of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Internal respiration

A

The exchange of oxygen and carbon dioxide between the blood and the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cellular respiration

A

Which involves the production of ATP by the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Upper respiratory tract contains

A

Nose, nasal cavity, nasal sinuses, pharynx, larynx and trachea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The external structure of the nose contain

A

 External Nares or Nostrils.
 Supported by nasal cartilages
 Opened by muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Dilated nostrils are a sign of

A

are a sign that the animal is having trouble getting enough oxygen for its metabolic needs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The nose is lined with

A

hair to filter larger air-borne particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The skin surrounding the nostril

A

is continuous with, and forms part of, the muzzle
 Covered with hair and contains sebaceous and sweat glands.
 More rigid in rooting animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Function of the nose

A

Functions to warm, humidify, and filter air before it reaches the lungs
 Highly vascular, so any trauma causes significant hemorrhage
 Sneezing and coughing results when inflammation and debris irritate the sensitive mucosa
 Expels harmful substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Nasal cavity is

A

Separated from the mouth by the hard and soft palates
 Nasal Conchae or Turbinates - bony scrolls lined with mucous membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Nasal conchae or Turbinates

A

Protect against noxious gasses and trap particles.
 Numerous blood vessels below mucous membrane help warm the inspired air.
 Layer of mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Naso lacrimal ductus

A

Drain excess tears from the eyes into the nasal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Median Nasal Septum

A

Separates the nasal cavity into right and left halves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Nasal meatus

A

pathways between the conchae or turbinates
 Ventral Nasal Meatus runs just dorsal to the hard palate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Route for passing a stomach tube

A

Route for passing a stomach tube
 Tube is directed medially
and ventrally through the ventral nasal meatus to the nasopharynx
 Very vascular area: if the
tube is not manipulated gently, bleeding will occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

paranasal Sinuses

A

All domestic species have maxillary, frontal, sphenoid, and palatine sinuses
 Sinuses are bilaterally symmetrical, mucous membrane lined and air-filled
 Reduce weight of skull
 Clinically, they are infection prone
 Important in dentistry of the horse, dog and cat and in dehorning in cattle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Pharynx

A

The common passageway that connects the:
 Oral cavity with the esophagus =
OROPHARYNX
 Nasal cavity with the larynx = NASOPHARYNX
 A common passageway for both food and air
 Openings into the pharynx are - the mouth, 2 caudal nares, 2 eustachian (auditory) tubes, esophagus, and larynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Nasopharynx

A

Floor is formed by the soft palate
 Openings of auditory tubes:
 Connect middle ear to nasopharynx
 Equalize pressure on both sides of ear drum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Laryngopharynx

A

Common to both digestive and respiratory passages
Inspired air passes through the nasal cavity and enters the caudal nares
 Passes through the pharynx to enter the larynx (voice box)
 Food enters from the mouth, passes through the pharynx, and is forced into the esophagus by contractions of the pharyngeal muscles
 Larynx is closed by the epiglottis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Swallowing involves a complex series of actions

A

Stopping breathing
 Covering the opening into the larynx (the glottis)
 Moving the material to the rear of the pharynx
 Opening the esophagus
 Moving the material DORSALLY into the esophagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Larynx are joined to the pharynx by

A

The voice box
 Mucosa-lined, cartilaginous tube
joining the pharynx to the trachea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Larynx functions

A

Directs air to the trachea
 Prevents the aspiration of ingesta
 Houses the vocal organs
 Made of segments of cartilage connected to each other and surrounded by muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Larynx is

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Major cartilages of the larynx

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The epiglottis

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the function of the larynx while swallowing

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Arytenoid cartilages attach

A

The vocal folds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The thyroid cartilage in the larynx

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Cricoid Cartilage in the larynx

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Vocal folds

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What forms the glottis

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The three main functions of the larynx

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Voice production of the larynx

A

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)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Prevention if aspiration of foreign bodies larynx

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Control of airflow to and from the lungs larynx

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Trachea divides into two main bronchi at the

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Trachea is composed of

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Trachea is lined with

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Trachea and mucous

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Lower resp tract

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Bronchial tree

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Bronchioles

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Smooth muscles in the bronchial tree allows for

A

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

46
Q

Bronchoconstriction

A

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

47
Q

Alveoli

A

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

48
Q

Alveoli contain

A

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

49
Q

Function of the lung

A

to exchange oxygen for carbon dioxide in the blood

50
Q

Shape of lung

A

 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

51
Q

Structure of the lung animal specific

A

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

52
Q

Hilus

A

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”

53
Q

Standard necropsy test on lungs to see if animal was born dead or alive

A

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

54
Q

Blood supply to and from the lungs is

A

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

55
Q

Capillaries are and functions as

A

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

55
Q

Boundaries of the thoracic cavity

A

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

56
Q

Thoracic cavity

A

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

56
Q

Pleura

A

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

57
Q

Between the pleura

A

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

58
Q

Mediastinum

A

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

59
Q

Respiration

A

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

60
Q

Inspiration

A

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

61
Q

Forced expiration

A

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

62
Q

Dyspnea

A

Increased respiratory activity and effort- difficulty breathing

63
Q

Apnea

A

Absence or cessation of breathing

64
Q

Hypernea/hyperventilation

A

Increase in both rate or depth of breathing or both

65
Q

Tachypnea/polypnea

A

Shallow rapid breath

66
Q

Normal resp rate of bovine

A

18-20brpm

67
Q

Normal resp rat of porcine and equine

A

8 to 16 brpm

68
Q

Tidal volume

A

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

69
Q

Minute volume

A

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

70
Q

Residual volume

A

volume of air remaining
in the lungs after maximum expiration

71
Q

Vital capacity

A

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

72
Q

Total lung capacity

A

Vital capacity + residual volume

73
Q

Exchange of gases in alveoli

A

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

74
Q

Exchange rate is affected by what in alveoli

A

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!

75
Q

Laryngeal edema

A

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

76
Q

If part of the lung collapses

A

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

77
Q

Problem in generalized hypoxia

A

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

78
Q

Partial pressure of gasses

A

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

79
Q

Control of breathing

A

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

80
Q

Control of breathing By the respiratory center in the brainstem

A

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

81
Q

Medullary rhythmicity area

A

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

82
Q

Control of breathing is signaled by

A

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

83
Q

two main systems to control breathing

A

Mechanical control
and Chemical control

84
Q

Mechanical control of breathing

A

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

85
Q

Chemical control of breathing

A

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

86
Q

Concentration of O2 and CO2 effect breathing

A

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

87
Q

If artificial ventilation is provided at too high of a rate during surgery

A

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

88
Q

Oxygen sensors

A

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

89
Q

Cough

A

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

90
Q

Sneeze

A

protective reflex stimulated by irritation in the
nasal passages

91
Q

Yawn

A

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

92
Q

Sigh

A

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

93
Q

Hiccups

A

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

94
Q

Panting

A

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

95
Q

Physiological dead space

A

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.

96
Q

Emphysema

A

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

97
Q

Atelectasis

A

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

98
Q

Stridor

A

High pitched, upper resp problem

99
Q

Stertor

A

Low pitch, flaccid tissue vibrating in the airway

100
Q

Sinusitis

A

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

101
Q

Dorsal displacement if the soft palate

A

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

102
Q

Laryngeal hemiplegia

A

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)

103
Q

Laryngeal paralysis

A

Like laryngeal hemiplegia but in dogs
Older dogs with noisy respiration

104
Q

Heaves

A

(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

105
Q

Pneumothorax

A

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

106
Q

Pleural effusion

A

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

107
Q

Pulmonary edema

A

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

108
Q

Pneumonia

A

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.

109
Q

Diaphragmatic hernia

A

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.