Book 2 Flashcards
(210 cards)
1
Q
What are the classifications of burn wounds?
A
1st degree: only epidermis
2nd degree: full thickness epidermal necrosis
3rd degree: full thickness through dermis
4th degree: involves muscle/fascia
5th degree: bone
2
Q
What are the 3 ways in which heat is transferred to the patient during burns?
A
Conduction = direct contact
Convection = hot air
Radiation = electromagnetic energy converted to heat
3
Q
What is the time/duration of a burn that results in:
Failure of the Na pump
Epidermal necrosis
Full thickness burn
A
Failure of the Na pump: 40-44 C
Epidermal necrosis: 60 C for 1 sec
Full thickness burn: >70 C for < 1 sec
4
Q
What are the zones of tissue in a burn?
A
- ZONE OF COAGULATION = zone of destruction, no viable tissues
- ZONE OF STASIS = ↓ in deformability of RBCs + ↓ vascular luminal diameter –> ↑ interstitial pressure + ↑ capillary permeability
- ZONE OF HYPEREMIA = primary zone of inflammatory response to burn (viable tissues). Local inflammation –> vasodilation + ↑ vascular permeability, edema, influx of inflammatory cells
5
Q
Why do burns heal slower than normal wounds?
A
<5% of FGF-2, fewer wound healing cytokines, and no capillary endothelial chemotactic/proliferative activity
6
Q
How does scald temperature impact the zone of stasis in burns?
A
Local lymph flow and protein content increase proportionately with scald temp
7
Q
Arterial supply and venous drainage of the spleen?
A
Arterial = Celiac A –> Splenic (+ L Gastric + Hepatic)
Venous = Splenic v –> Gastrosplenic v –> Portal v
8
Q
What is the difference between dog and cat spleens?
A
Dog = sinusoidal
Cat = nonsinusoidal (nodular hyperplasia is uncommon)
9
Q
How much of the body’s RBC mass does the spleen hold? Platelet mass?
A
RBC: 10-20%
Platelet: 30%
10
Q
What are the 3 pools of blood in the spleen?
A
Rapid: 90%, takes 30 sec to rejoin circulation
Intermediate: 9%, takes 8 min to rejoin
Slow: 1%
11
Q
What are the muscle origins of the external abdominal oblique, the internal abdominal oblique, and the transversus abdominus?
A
ext abd oblique: 4/5th thru 12th rib
int abd oblique: TL fascia caudal to last rib to tuber coxae
transversus abdominis: lumbar portion from transverse processes of lumbar vertebrae/TL fascia + costal portion from 12-13th ribs + 8-11 costal cartilages
12
Q
Which diaphragmatic crura is larger?
A
Right
13
Q
What are the 1 minor and 3 major openings in the diaphragm?
A
AORTIC HIATUS = most dorsal: aorta, azygous + hemiazygos v + lumbar cistern of TD
ESOPHAGEAL HIATUS = more dorsal: esophagus + blood supply + dorsal/ventral vagal trunks
CAVAL FORAMEN = dorsal portion of central tendon to R of midline: caudal vena cava (adventitia fuses with tendon)
Minor Foramina of Morgagni = sternocostal triangles: cranial epigastric a (termination of internal thoracic a)
14
Q
What is the innervation of the diaphragm?
A
Phrenic n - C5-7
(C5-C7 all dogs go to heaven)
15
Q
What runs through the inguinal canal? Through the vascular lacunae?
A
Inguinal Canal = vaginal process + spermatic cord [male]/round lig [female] + ext pudendal vessels + genital n
R/L Vascular Lacunae = femoral a/v + lymphatics + saphenous n
16
Q
What is the TP and cell count for the following types of fluid:
Normal peritoneal fluid
Transudate
Modified transudate
Exudate
A
Normal peritoneal fluid: <2 ; <300
Transudate: <2.5 ; <1500
Modified transudate: 2.5 - 5 (or 7.5) ; 1500 - 7000
Exudate: >3 ; >7000 (or >5000)
17
Q
How much fluid can the peritoneum absorb per hour?
A
3-8% body weight/hr
18
Q
What is the normal intraperitoneal pressure? What pressure is seen with acute abdominal compartment syndrome?
A
Normal 2-7.5 cmH2O
Comp Syndr: >20-25 cmH2O
19
Q
What organs are retroperitoneal?
A
Kidneys, ureters, adrenals, aorta, CVC, lumbar LN
20
Q
Splanchnic circulation receives what % of cardiac output and blood vol?
A
25% CO, 20% blood vol
21
Q
Innervation of the lips/cheeks?
Blood supply to upper lip? Lower lip?
A
Motor = CN 7, sensory = CN 5
Upper: infraorbital A
Lower: facial A
22
Q
What are the gustatory and non-gustatory taste buds?
A
Gustatory: Fungiform, vallate, and foliate
Non-Gustatory: Filiform, conical
[restaurants have fungi (mushrooms), foliage (lettuce), and valet parking; we don’t eat filamentous stuff (mold) or traffic cones]
23
Q
What is the innervation of the tongue?
A
Motor: CN 12
Sensory: CN 5, 7, 9
24
Q
What are the phases of swallowing?
A
- Oropharyngeal
1a. Oral (only voluntary), CN 5, 7, 12
1b. Pharyngeal, CN 9, 10
1c. Pharyngoesophageal, CN 9, 10 - Esophageal
- Gastroesophageal
25
Where do the following salivary gland ducts drain to:
Parotid
Zygomatic
Mandibular
Sublingual
Parotid = at level of upper PM4
Zygomatic = caudolateral to last molar
Mandibular = sublingual caruncle near frenulum
Sublingual = combined with mandibular and polystomatic directly into oral cavity
26
What organ is within the veil portion of the greater omentum?
Left limb of pancreas
27
What is the flow of saliva?
Acinus produces saliva --> intercalated ducts --> intralobular ducts --> interlobular ducts --> lobular ducts --> lobar ducts --> major excretory ducts
28
What are the layers of the esophagus? What is different between cats and dogs?
Adventitia (NO serosa!)
Muscularis - skeletal (caudal 1/3 is smooth in CATS)
Submucosa
Mucosa
29
What muscles make up the upper and lower esophageal sphincters?
UES: No thickening pr true sphincter, made of thyropharyngeus and cricopharyngeus
LES: Thickening of circumferential striated muscle (dogs) + diaphragmatic crural muscles + angle at which esophagus and stomach meet + folds of gastroesophageal mucosa
30
What is the segmental blood supply to the esophagus?
Proximal 1/3 = cranial and caudal thyroid arteries
Thoracic cranial 2/3 = bronchoesophageal
Thoracic caudal 1/3 = esophageal branches of aorta/intercostals
Termination: L gastric A
31
Segmental venous drainage of the esophagus?
Cervical: External jugular
Thoracic/caudal 1/3: Azygous v
Termination: portal system
32
What factors (4) contribute to a higher complication rate with esophageal surgery compared to other GI surgery?
- No serosa
- No omentum
- Constant motion/tension from swallowing: use feeding tube for 24 hrs to 7 d
- Segmental blood supply
33
What are the 3 categories of swallowing disorders?
Mechanical/anatomic
Functional/neuromuscular
Inflammatory/esophagitis
34
What is the blood supply to the stomach?
Celiac A
1. Splenic A --> L gastroepiploic A
2. Hepatic A --> R gastric + gastroduodenal --> cranial pancreaticoduodenal + R gastroepiploic
3. L gastric
35
What are the glands of the stomach? Where are they located and what do they secrete?
Parietal cells: body; intrinsic factor + acid
Chief cells: body; pepsinogen
Endocrine cells: body; serotonin + gastrin + histamine
Epithelial cells: Everywhere; bicarb + mucus
Mucous neck cells: body/antrum; mucus
36
Short gastric arteries supply the fundus of the stomach. Where do they originate from?
Originate from splenic branches of splenic A, anastomose with L gastric A
37
How do superficial gastric erosions heal? How about injuries extending into the submucosa?
Superficial heal rapidly by epithelial migration without proliferation
Deep heal with fibrotic repair and scar formation
38
What is special about collagen production in the GIT?
It is produced by both fibroblasts and smooth muscle cells
39
What is the functional unit of digestion/absorption? Where does secretion happen vs absorption?
Villi + crypt
Secretion in crypts, absorption in villi
40
What are the primary sources of intrinsic factor? Where is vit B12 (cobalamin) absorbed?
Pancreas (dogs and cats) and stomach (dogs only) produce IF
B12 abs in ileum
41
What are the two primary types of intestinal motility? What occurs when each type is impaired?
Segmental contractions for mixing and absorption, if impaired --> diarrhea
Peristaltic contractions for moving food aborad, if impaired --> ileus
42
What is the blood supply to each portion of the colon?
Cr mes --> common colic -->
Ascending colon: ileocolic A prox and R colic dist
Transverse colon: R colic prox and middle colic dist
Descending colon: middle colic prox and L colic (from cd mesenteric A) distal
Terminal colon: cranial rectal A (from cd mesenteric)
43
What prostaglandin is most important for maintaining gastric mucosa?
PGE2
44
What factors negatively affect healing in the colon? (Local and systemic)
Local: hypoperfusion, poor apposition, tension, infection, distal obstruction
Systemic: hypovolemia, transfusions, icterus, chemo, diabetes, zinc/iron deficiency
45
T/F: Anemia does NOT affect colonic healing until HCT is <15%
TRUE
46
T/F: Hypothyroidism and Cushing's disease have NOT been demonstrated to negatively affect colonic healing
TRUE
47
What is colonic wound strength at 48 hrs and 4 mos after injury?
48 hrs: 30% of normal
4 mos: 75% of normal (slower than small intestine)
48
What blood vessel marks the colorectal junction? What blood vessel is the primary blood supply to the rectum?
The cranial rectal A
49
What makes up the pelvic diaphragm? What is the primary blood supply?
Pelvic fascia + coccygeus m + levator ani m
Internal pudendal A and caudal gluteal A
50
What amount of bacteria is found in feces? What percent of that is anaerobes?
10^9 bacteria/g
90% anaerobes
51
What provides voluntary motor to the external anal sphincter? Sensory?
Motor = caudal rectal branch of pudendal n
Sensory = perineal branch of pudendal n
52
What are the different glands of the anus and perineum?
Circumanal glands - in SQ up to 4 cm out from anus, regress in females
Anal glands - tubuloalveolar glands, produce fatty secretions
Paranal sinus glands - in wall of anal sac and duct, produce smelly liquid
53
What is the innervation of the internal anal sphincter?
Pelvic plexus:
Parasympathetic fibers from S1-3 --> contract rectum and relax internal anal sphincter
Sympathetic fibers from hypogastric n --> relax rectum, contract internal anal sphincter
54
What % of hepatic blood flow and O2 supply comes from the hepatic A? What are its branches/what do they supply?
20% of blood flow, 50% of O2 supply
R lateral branch --> R lat and caudate lobes
R middle branch --> R med lobe
L branch --> L lat, L med, quadrate lobes
Cystic A branches from L branch --> GB
55
What % of hepatic blood flow and O2 supply come from the portal v? What are the branches of the portal v and what do they supply?
80% blood flow, 50% O2 supply
R branch --> R lat, caudate process
L branch --> L lat, L med, quadrate lobes
Central branch from L branch --> R med, papillary process
56
How many branches of the CVC drain the liver?
6-8 branches
57
What is the flow of bile from the liver to the duodenum?
Canaliculi --> interlobar ducts --> lobar ducts --> hepatic ducts --> CBD --> duodenum at major duodenal papilla
58
What % of functional liver mass must be lost to see hypoalbuminemia and hypoglycemia? How much must be lost to see hepatic encaphalopathy?
70-80%
70%
59
What are the differences between cats and dogs in terms of the CBD and pancreatic ducts?
DOGS = CBD enters duodenum at major duodenal papilla adjacent to pancreatic duct (Sphincter of Oddi). The majority of canine pancreatic secretions are through the accessory pancreatic duct which enters at the minor duodenal papilla
CATS = CBD + pancreatic duct join + enter at major duodenal papilla --> concurrent hepatic/pancreatic dz (only 20% cats have accessory pancreatic duct + minor papilla)
60
How much of the liver can be acutely removed? What leads to morbidity if more is removed?
70%
portal hypertension is the cause of morbidity
61
What % of total liver volume is made up by the:
L Lat + L Med lobes
R Med + Quad lobes
R Lat + Caud lobes
L Lat + L Med lobes: 44%
R Med + Quad lobes: 28%
R Lat + Caud lobes: 28%
62
Which coag factors are NOT synthesized in the liver? What must coag factors be depleted to in order to see a clinical coagulopathy?
Factor 8 and vWF
<15%
63
When does functional closure of the ductus venosus occur? Structural closure? What 2 factors stimulate closure? What does patency typically result in?
2-6 days after birth for functional closure
3 weeks after birth for structural closure
Cytochrome p450 and TXA2 stimulate closure
Patency leads to L sided intrahepatic shunt
64
What is the prevalence of congenital PSS in dogs? What percent of PSS are extrahepatic?
0.18%
65-75% EHPSS
65
How does ammonia cause signs of hepatic encephalopathy?
Ammonia prod by GI flora --> urea/glutamate via urea cycle
Glutamate is excitotoxic --> overactivation of NMDA R --> seizures
66
What percent of the pancreas has endocrine function? What are the 4 primary cells of the endocrine pancreas and what do they secrete?
2% endocrine, 98% exocrine
Alpha - glucagon, increase BG
Beta - insulin, decrease BG
Delta - somatostatin
F/PP - pancreatic polypeptide
67
What percent of dogs have a single duct from each limb of the pancreas that form a Y? What percent of cats LACK an accessory pancreatic duct?
68% of dogs have single duct from each limb that form a Y with the tail being the larger ACCESSORY pancreatic duct
80% of cats lack an accessory pancreatic duct
68
What are the exocrine secretions of the pancreas?
Inorganic components = bicarbonate, water, K, Na, Cl
Intrinsic factor
Zymogens (activated by enterokinase from duodenum which activates trypsin) = trypsinogen, chymotrypsinogen, proelastases, procarboxypeptidase, amylases, lipase, prophospholipase A2, carboxylesterase
69
How are pancreatic exocrine secretions regulated?
Duodenum secretes secretin and cholecystokinin and enterokinase
Cholecystokinin --> stimulates release of digestive enzymes
Secretin --> stimulates pancreas to release bicarb to neutralize gastric HCl
Enterokinase --> cleaves trypsinogen to trypsin which activates other zymogens
70
What are gastrinomas?
Pancreatic islet cell tumors where somatostatin secreting delta cells undergo malignant transformation to cells that excrete excessive gastrin
Results in gastric acid hypersecretion --> GI ulcers and erosions
Enzymatic maldigestion d/t loss of alkaline environment in proximal duodenum
Delayed gastric emptying (antral hypertrophy)
71
What is the maximum gastric capacity?
22-30 mL/kg
72
When using a feeding tube, how much fluid is required for hydration?
50-100 mL/kg/day, more if sick
73
What is refeeding syndrome?
IC cations depleted, plasma levels can still appear normal
With feeding, cations rush into cells --> low K/Phos/Mg --> fluid retention, ECG changes, dyspnea, V/D, ileus, renal dysfunction, tetany
74
Where does the nasal alar fold extend from?
extension of the ventral nasal conchae, fuses with the wing of the nostril
75
What are the 4 paired processes of the arytenoid cartilages? What type of joints are the articulations?
Cuneiform, corniculate, vocal, muscular
Articulations are synovial joints
76
What are the extrinsic muscles of the larynx and their innervation?
Thyropharyngeus m and cricopharyngeus m
CN 9 and 10
77
What are the intrinsic muscles of the larynx and their innervation?
Cricoarytenoideus dorsalis, cricoarytenoideus lateralis, thyroarytenoideus, arytenoideus transversus, hyoepiglotticus --> recurrent laryngeal n from CAUDAL laryngeal n (from CN X)
Cricothyroideus --> external branch of CRANIAL laryngeal n (from CN X)
Internal branch of cranial laryngeal n = sensory
78
What is the vascular supply of the larynx?
Cranial and caudal thyroid arteries
79
What is unique about the arytenoid cartilage in cats?
It lacks cuneiform and corniculate processes, has no aryepiglottic folds, and no ventricles/saccules
80
What are the functions of the cricoarytenoid dorsalis and lateralis?
Dorsalis - abducts arytenoid cartilages to open rima glotis
Lateralis - closes rima glottidis
81
What is the main innervation to the trachealis muscle and tracheal mucosa?
RIGHT vagus n and recurrent laryngeal n
82
The pulmonary arteries travel along what surface of each bronchus?
Craniodorsal aspect
83
What are elastance and compliance in the lungs?
Elastance = degree of recoil after inspiration, = change in P / change in V
Compliance = measure of lung distensibility, = change in V / change in P
84
What is surfactant produced by and how does it affect compliance?
Alveolar type II cells
surfactant --> decrease surface tension --> increase compliance (easier to inflate lungs)
85
What amount of airway resistance is attributed each to nares, larynx, and small airways during inspiration? Expiration?
Nares: 79% insp / 74% exp
Larynx: 6% insp / 3% exp
Small airways: 15% insp / 23% exp
Basically 80/5/15 insp and 75/5/25 exp
86
What is the primary controller of alveolar ventilation? When is hypoxic ventilation drive initiated?
PaCO2 is the major controller of ventilation
Hypoxic ventilation is stimulated when PaO2 < 60 mmHg
87
What is Fick's law?
rate of gas transfer through tissue is proportional to surface area for diffusion, diffusion coefficient of gas, and difference in gas partial pressure between 2 sides; inversely proportional to tissue thickness
88
What does a right shift in the O2/Hb dissociation curve indicate? What causes this?
Right shift = reduced Hb affinity for O2 and increased unloading of O2 into tissues
Caused by hypercapnia, hyperthermia, acidosis, and increased 2,3-DPG
89
Which of the following causes of hypoxemia are O2-responsive?
Hypoventilation
Low FiO2
Diffusion impairment
V/Q mismatch
R to L shunting
Hypoventilation, low FiO2, and Diffusion impairment --> good response to O2
V/Q mismatch --> good response to O2 if increased V/Q (PTE), poor response if decreased V/G (atelectasis, pneumonia)
R to L shunting --> no response to O2
90
Hypoxemia corresponds to an SaO2 of ____
SaO2 < 90%
91
Degree of V/Q mismatch is calculated by what equation? What is normal?
A-a gradient: 150 - 1.1(PaCO2) - PaO2
A-a < 10 is normal
A-a > 30 indicates severe gas exchange impairment
92
How many ribs can be safely removed?
Up to 6 ribs
93
What muscle contains the internal thoracic A?
Transversus thoracis m
94
The scalenus m has a musculotendinous division at which rib?
5th rib
95
What is the difference in anatomy of the thoracic duct between dogs and cats?
Travels dorsolateral to the aorta on the RIGHT in dogs and crosses to the left at the level of T5-6
Travels on the LEFT in cats
96
Pleural fluid enters through which pleura and is absorbed through which pleura?
Enters through parietal pleura
Absorbed through visceral pleura
97
How does a pneumothorax affect V/Q?
Decreases V/Q
98
How is chylous effusion confirmed?
TG higher than plasma and cholesterol lower than plasma
modified transudate
99
What is normal PIP in an anesthetized and awake dog? Mean end expiratory pressure?
PIP: -9.34 cmH2O in anesth dog, -28.8 cmH2O in awake
MEEP: -5.12 cmH2O in anesth dog, 15 cmH2O in awake
100
What 4 factors can lead to the development of pleural effusion?
Increased systemic hydrostatic P
Decreased systemic osmotic P
Increased vascular permeability
Lymphatic obstruction or decreased flow
101
What thoracic structures are best approached via a right versus left thoracotomy?
Left thoracotomy: left side of heart, right ventricular outflow tract/pulmonary artery, esophagus/ligamentum arteriosum for PRAA, PDA
Right thoracotomy: right atrium, vena cava, azygos vein, trachea, esophagus
102
What are the first 2 branches of the aorta?
1. Brachiocephalic trunk
3. L subclavian A
103
What 2 types of work are accomplished by the heart during the cardiac cycle?
Generates P (potential E)
Ejects volume (kinetic E)
104
What does the area inside the P-V loop of the cardiac cycle represent?
Total work done by the heart in 1 cardiac cycle
105
What are the 3 major determinants of SV and how do changes in each affect the SV?
Preload: ↑= ↑ SV
Afterload: ↑= ↓ SV
Contractility: ↑= ↑ SV
106
What is the primary arterial supply to the heart in dogs? In cats?
Dogs: L coronary A
Cats: R coronary A
107
What is the LaPlace relationship for systolic wall stress?
SWS = SAP x (ventric radius / ventric wall thickness)
108
What are the degrees of AV block?
1st degree: R far from P
2nd degree: Longer, longer, longer, drop - that means you've got Wenkebach; if some Ps don't go through, that is Mobitz II
3rd degree: Ps and Qs don't agree
109
How does pericardial effusion affect cardiac function?
↑ pericardial P --> ↑ diastolic P --> ↓ SV from diastolic dysfunction/↓ preload --> ↓ CO --> ↑ SVP --> + RAAS --> ↑ Na + H2O --> ↑ vascular volume
ANP cannot (-) RAAS --> ↑ venous & portal pressure --> jugular v distention, liver congestion, ascites, edema
+(S) --> catecholamine release --> positive inotropic/chronotropic effects & vasoconstriction
Compression of coronary arteries --> poor myocardial perfusion
110
How does pulsus paradoxus occur?
Inspiration --> pericardial + RV pressure ↓ --> facilitate return to RA + RV + pulmonary flow --> shifts intraventricular septum to L --> ↓ LV EDV + L heart output --> ↓ systolic pressure
Can result in variation of systolic arterial pressures by >10 mmHg during respiration
111
What are the layers of the arteries? What is different about the layers of the veins?
TUNICA EXTERNA/ADVENTITIA [connective tissue + fibroblasts + collagen]
TUNICA MEDIA [elastic tissue + smooth mm]
TUNICA INTIMA [endothelial cells, fragile, damage = coagulation cascade]
Veins: muscle doesn't contract, intima has infoldings that act as one-way valves
112
What is a characteristic of branching vessels in terms of global surface area of the parent vessel vs. branches?
The branch of an artery is smaller in diameter than the parent artery
If one artery bifurcates, the combined diameters of the branching vessels are greater than the parent vessel
113
Which veins carry oxygenated blood?
Pulmonary and umbilical v
114
What suture sizes are recommended for which vessel sizes in vascular surgery?
< 2 mm = 7-0, 8-0
2-3 mm = 6-0
4-6 mm = 4-0, 5-0
115
What is the name for the pattern of perfusing vessels on the adventitial surface of a blood vessel?
Vaso vasorum
116
When should an arteriotomy/venotomy be positioned transversely? What is the limit of the incision length?
For vessels <4 mm diameter, don't exceed 180 deg of circumference
117
What is different between the left and right venous return from the ovaries?
R ovarian v --> CVC
L ovarian v --> L renal v --> CVC
(Same for testicular v)
118
What are the layers of the uterus? What is the most common uterine tumor?
Serosa, muscularis/myometrium, endometrium (thickest)
Leiomyoma (90%)
119
Gestation length in dogs and cats?
Dogs = 64 d
Cats = 66 d
120
At what points can parts of fetal skeletons be seen on radiographs in dogs and cats?
Dogs: fetal skeletons visible at 42 d, pelvis visible at 57 d
Cats: fetal skeleton visible by 37 d
121
What are the stages of parturition in dogs?
Stage 1: restless, V/D, nesting behavior, anxiety
Stage 2: expulsion of fetus, alternates w/ Stage 3: expulsion of placenta
Stages 2/3 can last up to 36 hrs and there can be up to 4 hrs in between puppies
Straining for 1 puppy should not last more than 30 min
122
What is progesterone at the surge before ovulation? What does it drop to about 18-30 hrs before birth?
Surge at ovulation: 1.5
Drop before birth: <2-3
123
What is the risk of pyometra in intact dogs and cats?
Dogs 25%
Cats 2%
124
What is the embryologic origin of the vagina?
cranial vagina is formed by fusion of the paired paramesonephric (Mullerian) ducts --> single tube that unites with the caudal urogenital sinus to produce the vestibulovaginal junction or cingulum
125
What size Fr, gauge, inch, and K wires are closest to 1 mm?
3 Fr = 1 mm
19 gauge = 1 mm
0.038 guide wire closest to 1 mm
0.035/0.045 K wires on either side of 1 mm
126
What are the 3 primary cells of the testes and what is their purpose?
Spermatogenic cells --> make spermatids
Sertoli/sustentacular cells --> form blood-testes barrier, (+) by FSH, (-) by inhibin
Leydig/interstitial cells --> produce testosterone, (-) by LH
127
What are the layers of the scrotum?
Skin
Tunica dartos (smooth m and collagenous elastic fibers)
Scrotal fascia
Tunica albuginea (testicular capsule)
128
What % of volume is within the left and right lungs?
Left 42%
Right 58%
129
Reasons the left side of the body is sinister
L ovarian/testicular/adrenal v all drain to L renal v before CVC
L ovary is bigger
L diaphragm crus is smaller
L testis/adrenal/thyroid/kidney are more caudal
L side more common for cleft lips
Thoracic duct is on the left in cats
L lung and liver have less volume
More likely to have multiple L renal As
130
Extrinsic muscles of the penis
Retractor penis
ischiocavernosus
bulbospongiosus
ischiourethralis
131
The prostate has full cellular content by what age? What are the two types of prostatic hyperplasia?
Full cellular content by 2 yo
Glandular hyperplasia in dogs <4-5yo, symmetric enlargement of secretory cells
Complex hyperplasia in dogs >5yo, more receptors and more responsive to androgens, stomal elements with asymmetric enlargement
132
What % of Beagles have BPH at 2 yo? 5 yo? 8-9 yo?
2 yrs = 16%
5 yrs = 50%
8-9 yrs = 70%
133
What percent of dogs and cats have multiple renal arteries from 1 kidney? Which side is more commonly affected?
13% dogs, 10% cats
L side more likely (sinister)
134
What is the flow of blood into and through the kidneys?
Renal A --> interlobar a --> arcuate a (c/m junction) --> interlobular a --> afferent glomerular arterioles --> glomeruli --> efferent glomerular arterioles --> vasa recta --> interlobular v--> arcuate v --> interlobar v --> renal v
135
What allows the kidneys to still receive arterial blood flow when the renal A is obstructed?
Capsular A from the phrenicoabdominal and adrenal A
136
What structure maintains hypertonicity of the glomerulus?
Vasa recta --> long capillaries that extend alongside nephrons from cortex to medulla
137
What maintains autoregulation of renal blood flow?
macula densa
138
How much urine is produced per day?
20-45 mL/kg/day or 1-2 mL/kg/hr
139
What percent of CO is renal blood flow?
25% (4 mL/min/g renal tissue in the cortex)
140
GFR = __% of renal plasma flow. GFR ___ with vasoconstriction of afferent arterioles.
20%
↓ with ↑ constriction of afferent arterioles
141
What accounts for 40-50% of renal medullary osmolarity? Active transport of Na/K/Cl occurs in which portion of the proximal loop of Henle?
UREA
Thick portion
142
What 3 things can decrease the kidney's concentrating ability
↑ blood flow from vasodilation
↑ arterial pressure
↑ blood vol (medullary washout)
143
Describe the RAAS system
Kidney JGA senses low ECF vol --> suspects ↓ renal perfusion --> releases renin --> converts angiotensinogen to angiotensin I ---> converted by ACE in lung to AT II --> causes vasoconstriction, Na/H2O retention in kidney, and aldosterone release --> (++) Na retention
144
Diameter of the feline ureter? What size ureteral stents are typically used?
0.4 mm; can place 0.8 mm / 2.5 Fr stents
145
Average size of the canine ureter? Average diameter in dogs 21-30 kg?
0.07 x length of L2
2-2.5 mm avg diameter
146
What percent of cats have a R circumcaval ureter? Left? Bilateral?
What percent with circumcaval ureter also have a duplicate CVC?
30% right, 1.6% left, 3.3% bilateral
7% also have double CVC
147
What are the layers of the ureter? How much of the thickness do they account for?
Adventitia
Central/muscular = 50% wall thickness
Inner mucosal = lamina propria 30%, transitional epithelium 15%
148
What 3 nerves innervate the bladder and what is the purpose of each?
Hypogastric n (S) L1-3 --> (+) B receptors in detrusor to relax it, (+) A receptors in internal urethral sphincter to contract it
Pelvic n (P) S1-3 --> (-) (S) innervation --> contract detrusor + relax internal urethral sphincter
Pudendal n (somatic, S1-3) --> voluntary motor to relax external urethral sphincter. Nicotinic cholinergic receptors. (Normally held in state of contraction)
149
How long does it take the bladder mucosa to heal? How long does it take full-thickness defects to reach 100% strength?
5 days for mucosa to heal
21 days for 100% strength
150
How quickly does the urethra heal if a strip of mucosa remains intact and urine is diverted?
7 days
151
The male feline preprostatic URETHRA is ___ mm in diameter while the penile urethra is ___ mm in diameter.
Pre-prostatic 2 mm diam
Penile 0.7 mm diam
152
What are factors that contribute to USMI?
Urethral tone/length
bladder neck position (pelvic bladder has more pressure on it and less on urethra so more likely to leak)
body size/breed
gonadectomy
hormones
153
Large and giant breed dogs are __x more likely to develop USMI
Spayed females are __x more likely
Large breed 7x more likely
Spayed females 8x more likely
154
What histologic changes are seen in the urethra after spaying female dogs?
Decreased smooth muscle content and increased collagen
155
How does a deficiency in estrogen likely lead to USMI?
reduced smooth muscle tone in urethra and reduced type I and II muscle fibers of striated urethralis muscle
156
What are the 3 most common drugs for treatment of USMI? What % of dogs are cured with single therapy treatment?
Estrogens (estriol) --> may increase smooth musc contractility and sensitivity to alpha adrenergics
Phenylpropanolamine/Proin (alpha agonist) --> acts on internal urethral sphincter
GnRH analogs --> decrease pituitary release of LH and FSH
50% are cured with single therapy treatment
157
What is the difference between Prazosin and Proin/phenylpropanolamine?
Prazosin = alpha-1 antagonist
Proin = alpha agonist
(Proin if you're goin', prazosin for sphincter antagonism)
158
What are steroids made from?
Cholesterol --> pregnenolone
159
What are the zones of the adrenal cortex?
Zona glomerulosa = mineralocorticoids AKA aldosterone, manages electrolyte balance and BP homeostasis
Zona fasciculata = glucocorticoids AKA cortisol, inhibits glucose uptake/metab, protein synth, vasopressin, and inflam. Stimulates lipolysis, protein catabolism, ↑ GFR/gastric acid secretion
Zona reticularis = sex steroids
160
What is going on in the adrenal medulla?
Synthesizes catecholamines (norepi and epi)
161
What cells are responsible for producing norepi/epi and what is the process of synthesis?
Tyrosin and phenylalanine from chromaffin cells --> dopa --> dopamine --> norepi --> epi
Tyrosine hydroxylase is the rate-limiting step
162
What is the ratio of epi/norepi in dogs and cats?
Cats: 70/30, Dogs: 60/40
163
What are the 4 adrenergic receptors and what are they responsible for?
alpha1 - vasoconstriction
alpha2 - sedation
beta1 - increase HR and contractility
beta2 - vasodilation
164
What is the maximum length of an adrenal gland on AUS? What is the size cutoff for suspected malignancy?
>1.5 cm is abnormal
>2 cm (20 mm) is concerning for malignancy
165
What is the main difference between aldosterone and cortisol?
Aldosterone lacks a hydroxyl group on C-17
Zona glomerulosa lacks 17-alpha-hydroxylase and therefore produces aldosterone
166
How are the majorities of cortisol and aldosterone transported in the blood?
Cortisol - 75% bound to transcortin
Aldosterone - 50% bound to albumin
167
Which catecholamine is more important in controlling metabolism? Why? What are its effects?
Epinephrine! 10x more potent at beta receptors
increases BG and (+) hepatic and skeletal m gluconeogenesis and glycogenolysis
causes vasodilation in skeletal muscle arterioles, coronary arteries, and veins
(Minimal change in BP due to concurrent increase in CO from incr HR/contractility via Beta 1 receptors)
168
What is the accuracy, PPV, and NPV of contrast CT in predicting vascular invasion of adrenal masses
Accuracy 95%
PPV 100%
NPV 90%
169
What is the blood supply to the thyroid glands?
Cranial and caudal thyroid arteries
170
What % of cats have functional accessory parathyroid tissue? What % of dogs? Where is it commonly found?
35-50% of cats
3-6% of dogs
Typically associated with the thymus
171
What hormones are produced by the thyroid gland and how?
Thyroglobulin stored in follicles with iodine --> thyroxine (T4) --> triiodothyronine (T3)
Majority of hormone secreted is T4, but T3 is the major active form
172
What percent of T3/T4 in the blood are free/active?
<1%
173
What is the feedback loop for thyroid hormone production?
TRH from hypothal --> TSH from pituitary --> negative feedback from T3/T4
174
Where are the internal and external parathyroid glands located?
External is craniodorsal
Internal is within parenchyma of caudal thyroid gland
External is extroverted - out front, sometimes not even in the thyroid gland, lord knows what he's doing
Internal is introverted - hiding inside the back of the thyroid
175
What is the blood supply to the parathyroid glands?
external = cranial thyroid artery
internal = branches from thyroid parenchyma
176
PTH is synthesized, stored, and secreted by which cells?
Chief cells of the parathyroid gland
177
What are the effects of PTH?
↑ iCa = ↓ PTH; ↓ iCa = ↑ PTH
PTH: ↑ Ca + ↓ phos in blood via:
1. bone [Ca + phos resorption]
2. kidney [↓ Ca + ↑ phos excretion]
3. intestinal (indirect) [↑ calcitriol formation from Vit D --> ↑ Ca + phos absorption in GIT]
178
What cells produce calcitonin?
Parafollicular cells AKA C-cells of the THYROID gland
179
What are the effects of calcitonin?
↓ bone resorption of calcium to prevent postprandial ↑ iCa
(calcitonin has NO effect on kidney or GIT)
180
Ectopic thyroid tissue is common. Where is it typically found?
Along the trachea, at the thoracic inlet, within the mediastinum, and along the thoracic portion of the descending aorta
181
What major vessels are found in the region of the ear canal and bulla?
1. Great auricular artery - branch of external carotid. Medial to dorsal apex of parotid salivary gland
2. External carotid A and Maxillary v - ventral to bulla
3. Internal carotid A - medial to bulla
4. Retroglenoid v - rostral to the osseous ear canal, can cause severe hemorrhage during TECA-BO
182
What is the primary innervation to the external ear canal and pinna and what path does the motor innervation follow?
Sensory = CN 10
Motor = CN 7: exits through internal acoustic meatus with vestibular/cochlear n --> runs thru facial canal of temporal bone/middle ear --> exits **STYLOMASTOID FORAMEN** caudodorsal to osseous ear canal [crosses ventral to horizontal canal]
183
What are the chambers of the tympanic cavity?
Dorsal [epitympanum = smallest; incus + malleus]
Middle [mesotympanum = true tympanic chamber; cuboidal-columnar epithelium];
Ventral [hypotympanum = largest, inside bulla]
184
What is the physiology of sound conduction?
Auditory function stimulated by movement of endolymph in the cochlea
Sound waves --> nerve impulses via hair cells in ORGAN OF CORTI (on floor of cochlea) --> cochlear n --> brain
185
Vestibular function is stimulated by fluid movement in what structures?
Utricle, Saccule, and Semicircular Canals
186
What are the most common organisms in septic otitis media in the dog? What is the most common route of infection for dogs and cats?
Dogs - bacteria from external auditory meatus enter middle ear via tympanic membrane
- Staph pseud
- Pseudomonas
- Malassezia yeast
Cats - bacteria from nasopharynx enter auditory tube, associated with middle ear polyps, rarely infected
187
Eyelid muscles are innervated by the facial nerve EXCEPT which two?
Levator palpebrae superioris - trigeminal n
Muller's - sympathetic
188
What are the types of conjunctiva?
Palpebral
Fornix
Palpebral nictitans
bulbar nictitans
bulbar
189
What is Tenon's capsule?
Substantia propria, adjacent to epithelium (lymphoid follicles)
In between conjunctiva and sclera
190
What is the most important biomechanical quality of the conjunctiva?
Sectility - ability to be cut with a knife
- high in less mobile areas
191
What is the normal thickness of the cornea?
0.5 mm
192
What are the layers of the cornea?
OUTER [simple nonkeratinized stratified squamous, 6 cells thick; hemidesmosomes]
MIDDLE [stroma, aligned collagen/keratinocytes/fibrocytes/ground substance; majority of thickness]
INNER [single layer of endothelium with basement/Descemet’s membrane]
193
What is the innervation of the cornea?
Long ciliary nerve from trigeminal n
194
What are the cranial nerves? Where does each arise from?
I - Olfactory - olfactory bulb
II - Optic - diencephalon
III - Oculomotor - midbrain
IV - Trochlear - midbrain
V - Trigeminal - pons
VI - Abducens - medulla oblongata
VII - Facial - medulla oblongata
VIII - Vestibublocochlear - medulla oblongata
IX - Glossopharyngeal - medulla oblongata
X - Vagus - medulla oblongata
XI - Accessory - medulla oblongata
XII - Hypoglossal - medulla oblongata
On Old Olympus' Tiny Top A Friendly Viking Grows Vines and Hops
195
What are the external rotators of the hip? What are the primary hip stabilizers?
External rotators: piriformis, internal/external obturators, gemelli, quadratus femoris
Stabilizers: ligament of the head of the femur, joint capsule, dorsal acetabular rim
196
What is the blood supply to the tarsus? What is the venous drainage?
Cranial tibial artery (becomes dorsal pedal artery) and plantar branch of the saphenous artery
Venous drainage: medial and lateral saphenous veins
197
The tibial and peroneal/fibular nerves are branches of what nerve?
Sciatic n (L6-S1)
198
Cutaneous zones of the hindlimb?
Fibular (branch of sciatic L7-S1) - Dorsal paw/cranial crus
Tibial (branch of sciatic L7-S1) - plantar paw/caudal crus
Saphenous (branch of femoral L4-6): medial limb
199
Where does the majority of motion occur in the tarsus?
90% of motion occurs at the tarsocrural joint
200
What is the largest bone in the tarsus
Calcaneus
201
What is the MOA of sulfonamides and trimethoprim? What makes them bacteriostatic vs bactericidal?
Inhibit folic acid synthesis
Separately are bacteriostatic, together (TMS) = bactericidal
202
What is thought to be the cause of widespread resistance of MRSP/MRSA?
Overuse of cephalosporins
203
Which abx concentrate in WBCs?
Clindamycin, rifampin, erythromycin, fluoroquinolones
204
What is the most important method of bacterial resistance against aminoglycosides?
Destruction by microbial enzymes inside the cell
205
Which antibiotics are inactivated by an acidic pH?
Erythromycin ineffective when pH <7
Beta-lactams (penicillins, cephalosporins, carbapenems) and clindamycin ineffective when pH 6 or lower
206
Which abx cannot enter the CSF?
1st/2nd gen cephalosporins, aminoglycosides, clindamycin, vancomycin
207
What is the difference between hyperesthesia, hyperalgesia, and allodynia?
hyperesthesia - excessive response to a stimulus that is not worthy of a response
hyperalgesia - excessive response to a stimulus that is painful
allodynia - a pain response to a normally non-painful stimulus
208
What nerves are blocked in a brachial plexus block?
C6 = subscapular nerve
C7 = musculocutaneous and subscapular nerves
C8 = radial and axillary nerves
T1 = median and ulnar nerves
209
Why does epinephrine prolong the activity of local anesthetic agents?
Allows for decreased local perfusion and delayed rate of vascular absorption
210
Great job this is the last card!
