Midterm 2 Flashcards
(53 cards)
1
Q
3 components of the cardiovascular system
A
- heart
- blood vessels
- blood
2
Q
heart
A
-muscular pump that circulates a fluid medium (blood) through a closed system of conduits (blood vessels)
3
Q
blood vessels (arteries vs. veins)
A
- closed system of conduits/channels
- arteries conduct blood away from the heart
- veins conduct blood towards the heart
4
Q
blood
A
- the fluid medium that travels in the vasculature
- a moving connective tissue that contacts ever cell in the body
- transport medium for nutrients, cellular waste products, electrolytes, hormones, oxygen, cells
5
Q
layers of the heart muscle (ventricular wall)
A
- pericardium (outermost layer, sac around heart)
- myocardium (heart muscle)
- endocardium (inner lining)
6
Q
sections of the pericardium
A
- fibrous layer (outer)
- serous layer (inner; contains parietal and visceral/ epicardium layers)
7
Q
systole
A
- ventricular contraction
- made obvious when blood ejects through open aortic valve into the aorta
- closed AV valves
8
Q
cardiac muscle
A
-striated, branched, (thankfully) involuntary
9
Q
automaticity function (in myocytes/ cells in muscular tissue in the heart)
A
- beat without nerve input
- innate rhythmic beating
10
Q
internal conduction system of the heart (left to right)
A
- muscle cells in heart walks that send signals to heart muscle and tell it to contract
- SA node (pacemaker, bc cells fire faster here)
- AV node (conduction pauses to allow atria to contract before ventricles)
- bundle of His
- purkinje fibers
11
Q
unique anatomic features of cardiac myocytes
A
- branching (connects muscle fibers side-to-side)
- intercalated discs (connects fibers end-to-end)
12
Q
intercalated discs contain…
A
- gap junctions
- desmosomes
13
Q
interior anatomy of the heart
A
- right pulmonary artery
- superior vena cava (from head)
- right pulmonary vein
- right atrium
- right AV valve
- inferior vena cava (from body)
- right ventricle
- interventicular septum
- aorta
- left pulmonary artery
- left pulmonary vein
- left atrium
- left AV valve
- left ventricle
14
Q
vasculature scheme
A
- arteries
- arterioles
- capillaries
- venules
- veins
15
Q
arteries wall
A
- mostly smooth muscle layer
- holds shape with thick wall
16
Q
vein walls
A
- less smooth muscle
- more collapsable
- valves in the lumen keep blood flowing upward
- venous valves
17
Q
capillary walls
A
- formed of a single squamous cell: endothelial cell
- pores between cells for water and small molecules to pass through
18
Q
how action potential travels down specialized conduction system from specialized fibers through myocardium
A
- intercalated discs and their gap junctions
- myocradiac muscle is branched to facilitate rapid spread of depolarization
- electric current from SA nodal cells, to BOH and purkinje fibers and into the ventricle wall
19
Q
cardiac cycle
A
-each sequence of contraction (systole, closed AV valves) and relaxation (diastole, open AV vales)
20
Q
lub-dub
A
- heard upon auscultation (listening to the heart)
- lub: S1, closure of the 2 AV valves
- dub: S2, closure of the 2 seminar valves (pulm and aortic)
21
Q
cause of heart murmur
A
-valve is leaking
22
Q
2 modifications designed to allow blood to bypass lungs
A
- foramen ovale
- ductus arterioles
23
Q
foramen ovale
A
- flap between R and L atria
- enables blood to flow directly from RA to LA
- means blood bypasses lungs
24
Q
ductus arteriosus
A
- channel that connects pulmonary artery to aorta
- enables blood flow directly from PA to aorta
- allows blood to bypass lungs and directly into systemic side of circulation
25
cardiac output / CO
- volume of blood leaving the heart
- CO= stroke volume x heart rate (L or mL/min)
- stroke volume increases with force of contraction from positive inotropy
26
respiration
- the exchange of oxygen and CO
| - continuously ongoing at 2 levels in the body (internal and external)
27
internal respiration
- exchange of oxygen and CO gases between tissue cells and capillaries
- O2 goes into cell from capillary for CO2 use, then back out into the capillary
- takes place in the tissues
28
external respiration
- exchange of oxygen and CO gases between the bloodstream and inhaled air in the lungs
- O2 goes from the cell into the pulmonary capillary and CO2 goes from the capillary into the cell
- takes place in the lungs, at the capillary-alveolus interface
29
functions of the respiratory tract (other than respiration)
- phonation or vocalization
- body temperature regulation (long nasal passages warm air before lungs in cold and panting cools in heat)
- acid-base balance
- olfaction (smelling, CN 1)
30
upper respiratory tract
- nostrils (nares)
- nasal passages
- paranasal sinuses
- pharynx and larynx
- trachea
31
lower respiratory tract
- bronchi
- bronchioles
- alveolar ducts
- alveoli (areolar sacs)
32
nasal passages
- L and R separated by nasal septum
- hard and soft palate separate nasal passages form oral cavity
- scrolls create 3 passage ways: dorsal meatus, middle meatus, ventral meatus
- scrolls covered in respiratory epithelium (pseudostrat ciliated columnar)
33
nasal turbinates
- increase surface area to condition incoming air (humidity, warm, filter)
- highly vascular so bleed profusely
34
obstruction of nasal passages
- tracheostomy procedure places hole in trachea to allow airflow
- common in equids bc nostrils are flexible and distend to maximize airflow (worse if obstructed bc horses can't mouth breathe like dogs)
35
pharynx
- throat
| - where oral and nasal cavities converge into single pathway
36
larynx
- phonation/ voice results from exhaled air passing and vibrating vocal folds
- vocal cords are fibrous tissue bands connected to arytenoid cartilages (above) and epiglottis (under)
- abducted to breathe
- adducted to speak
37
laryngeal hemiplegia
- leads to condition called roaring
| - arytenoid falls and decreases airflow to 1/16th capacity
38
trachea
- fibrous tube from larynx down to bronchi (where it divides into 2 at Carina)
- C shaped cartilage rings
39
carina
-site of tracheal bifurcation (splits into 2) right and left main bronchi
40
collapsing trachea
- frequent in small dog breeds
- happens when dog is excited and breathes heavily
- tracheal C-shaped rings are flattened
- solution: place stent to hold open trachea
- non SX solution: anti-inflammatories, avoid excitement
41
alveoli
- tiny, thin-walled sacs
- one epithelial cell thick
- site of external respiration
42
alveolus
- lined by thin layer of moisture:
- water + other substances
- surfactant (liquid substance that decreases surface tension by attracting water molecules)
- surfactant keeps alveoli from collapsing (prob for premature babies)
43
overall mechanics of breathing
- air enters lungs because..
- when chest wall expands and diaphragm contracts
- negative pressure (vacuum) is created and air flows down pressure gradient
44
what muscles are used during inspiration
- diaphragm
- muscles expand dimensions of thorax
- lungs stick to inner surface of chest wall by thin liquid layer to expand with chest
- external intercostals
45
what muscles are used during expiration
- gravity
- elastic recoil of chest wall
- lungs
- internal intercostals
- abdominal muscles
46
pneumothorax
- leaking air into pleural cavity from negative vacuum pressure (where fluid attaches lungs to inner chest wall)
- lungs collapse or are re-expanded by chest tube
47
partial pressure
- pressure generated by oxygen, nitrogen and CO2
| - calculate each pressure individually based on % O2, N2, CO2 multiplied by overall pressure of that gas
48
partial pressure in alveolar lumen
P O2 = 100 mm Hg
| P CO2 = 40 mm Hg
49
partial pressure in alveolar capillaries
P O2 = 40 mm Hg
| P CO2 = 45 mm Hg
50
mechanical control of breathing
- stretch receptors in lung that fire when lung is close to max inspiration
- respiratory centers in medulla oblongata send impulses down motor neurons to cease contraction in muscles
- lung then enters expiratory cycle
51
chemical control
- if pH is low or CO2 is high chemoreceptors fire impulses from respiratory centers down motor neurons to respiratory muscles to breathe at a faster rate w/more volume
- peripheral chemoreceptors in aorta, carotid artery, and brainstem sense changes in blood or tissue pH, O2, CO2
52
tidal volume
-number of cc's of air breathed in during a single breath (mechanical controls breath depth)
53
pulmonary capillaries vs. systemic capillaries
- pulmonary: circulation of blood between heart and lungs (to originate blood)
- systemic: circulation of blood between heart and rest of body
