Lecture 14

Question 1

Active hyperemia

Answer 1

inc blood volume due to arteriolar dilation and expansion of the perfused capillary bed

Question 2

Passive congestion

Answer 2

a passive process in which inc blood volume within the vasculature of a tissue is due to impairment of venous outflow

Question 3

In what circumstances does active hyperemia develop?(2)

Answer 3

inc blood flow to GIT after eating

inc blood flow to skeletal muscle during exercise

Question 4

Why is active hyperemia a localized phenomenon

Answer 4

insufficient blood volume to permit generalized active hyperemia while maintaining adequate systemic blood pressure

Question 5

In what circumstances does localized passive congestion develop(2)

Answer 5

luminal obstruction of a vein or external compression of a vein
intestinal strangulation due to torsion or volvulus->compression of mesenteric arteries

Question 6

in what circumstances does generalized passive congestion develop?

Answer 6

Almost always congestive heart failure (left or right)
left-lungs
right-cranial and caudal vena cava

Question 7

How to grossly distinguish between active/passive hyperemia in a live animal?

Answer 7

active- appear red, swollen, warm, turgid, bright red O2 blood
Passive/congestion- red-purple to blue-black, poorly O2 blood

Question 8

Potential consequences of passive congestion of tissues(2)

Answer 8

venous hypertension (inc hydrostatic pressure within engorged veins)-> edema
if it develops slowly->acquired PSS

Question 9

Gross lesions during necropsy of animal that died of left sided congestive heart failure (2)

Answer 9

lungs are heavy, wet, rubbery. do not fully collapse

edema fluid pours from cut surface of lungs-stable foam

Question 10

Gross lesions during necropsy of animal that died of right sided congestive heart failure and why (2)

Answer 10

liver is swollen, dark red purple, venous blood oozes from cut surfaces
Blood from right side heart backs up into liver

Question 11

Edema

Answer 11

accumulation of excess body fluid

Question 12

Ascites

Answer 12

non inflammatory edema fluid within the peritoneal cavity

Question 13

hydothorax

Answer 13

non inflammatory edema fluid within the pleural cavity

Question 14

Hydropericardium

Answer 14

non inflammatory edema fluid iwthin the pericardial sac

Question 15

hydorcoele

Answer 15

non inflammatory edema fluid within cavity of tunica vaginalis of scrotum

Question 16

anasarca

Answer 16

severe generalized edema

Question 17

5 mechanisms that can lead to edema development

Answer 17

inc plasma hydrostatic pressure
dec plasma colloid osmotic pressure
lymphatic obstruction
inc vascular permeability
Na retention

Question 18

What circumstances lead to inc plasma hydrostatic pressure in capillary bed?(2)

Answer 18

impaired venous return to heart-> activation of RAAS

local obstruction of venous outflow

Question 19

Why is extracellular edema NOT expected with systemic hypertension

Answer 19

inc arterial BP causes reflex vasoconstriction of the pre capillary arteriole sphincter in order to protect the delicate capillary bed

Question 20

2 assays to initially categorize the edema fluid samples

Answer 20

protein [ ]

total nucleated cell count

Question 21

Transudate

Answer 21

cell poor, protein poor

Question 22

modified transudate

Answer 22

cell poor, but addition of protein

Question 23

exudate

Answer 23

cell rich and protein rich

Question 24

Gross features of edematous tissue

Answer 24

excess watery, colorless pale yellow clear non viscous fluid within interstitial tissues and or body cavities

Question 25

Potential consequences of edema(2)

Answer 25

impaired would healing

susceptible to secondary bacterial infection

Question 26

Severe edema can prove fatal, why? (2)

Answer 26

cerebral- inc intracranial pressure, stretching, compression of cerebral blood vessels
pulmonary- prevents ventilation and gas exchange

Question 27

Forces promoting fluid movement from plasma -> interstitum(2)

Answer 27

plasma hydrostatic pressure (inc)

interstitial colloid osmotic pressure

Question 28

Forces promoting fluid movement from interstitum -> plasma(2)

Answer 28

plasma colloid osmotic pressure (inc)

interstitial hydrostatic pressure

Question 29

Arteriole end has net

Answer 29

filtration pressure

Question 30

venular end has net

Answer 30

absorptive pressure