VME 3001 Exam 3

1 in __ dogs have some form of heart disease by age ___

3; 10

cardiovascular disease usually has ________ symptoms prior to becoming severtr

few

The main function of the cardiovascular system

distribute blood throughout the body

blood from the __________ system is oxygenated

pulmonary

oxygenated blood is brought to vital organs via _________ circulation

systemic

One of the main problems with cardiovascular disease is that blood flow is no longer ________

unidirectional

4 functional components of each circulatory system division

-pump

-distribution system

-exchange region

-collection system

the heart is the _______ source of the cardiovascular system

energy

2 separate pumps in the heart

atrium and ventricles

the right side of the heart provides...

circulation into the pulmonary system

the left side of the heart provides...

blood flow into the systemic circulation

atria

upper side of each compartment

ventricle

receives blood from atria, projects it outward

heart is mechanically and electrically ___________

interdependent

pumping energy or "heart beats" are...

rhythmic contractions initiated by specialized myocardial cells

heart valves open and close based on __________________

pressure gradients

Diastole

ventricular relaxation

Aortic> ventricular pressure

-ventricular filling

-aortic valve closed, mitral valve open

Systole

ventricular activation

Aortic< ventricular pressure

-both valves closed, systolic contraction increases pressure, aortic valve opens

Mitral valve

-mitral valve opens in one direction

-valve between left atrium and left ventricle

Tricuspid Valve

valve between right atrium and ventricle

aortic valve

opens to aorta

What do heart valves maintain?

unidirectional flow

The blood is red in the diagrams because it is oxygenated, that is the...

pulmonary circulation, left side of heart

blood is blue in the diagrams because it has been ______________ and it is going to pass through the _______________. This is the ______ side of the heart

deoxygenated; pulmonary system; right

What occurs when flow through the heart valves is abnormal?

heart murmurs

Cardiac value =

stroke volume X heart rate

When pressure increases in the ventricle, there is a _____________ in volume

decrease

(before it leaves, known as end-diastolic volume, after it leaves, known as end-systolic volume)

arterial pressure

the blood volume from the heart is transferred into the arterial system

diastolic pressure

lowest value of arterial pressure

systolic pressure

highest value of arterial pressure

Arterial circulation

-pressure storage

-greatest resistance outflow

-pressure w/in arterial system is a function of volume in minus volume out at any moment

Basic features of the vascular system or distribution system

-blood transports metabolic substrates to tissues and metabolic waste products away from tissues

-arteries and arterioles regulate flow to select vascular beds

Mean Arterial Pressure

CO x TPR

(cardiac output X total peripheral resistance)

Arteries surrounded by thick layer of ________ muscle

smooth

Total peripheral resistance (TPR)

overall resistance of arterial vasculature to allow volume in to leave to next component of vascular system (capillaries)

Changes in resistance occur via mechanisms _________ or _________ to vascular smooth muscle

intrinsic or extrensic

MAP is __________ regulated

tightly

If CO or TPR decreases, MAP...

drops (vasodilation)

If MAP drops....

less driving force to maintain constant flow through peripheral vasculature

Want to maintain MAP around ___mmHg

100mmHg

What will modify CO/TPR to bring MAP back to setpoint?

rapid adjustments

exchange occurs at the level of the ____________

capillaries

How thick are capillary walls?

1 cell

things that drive transport

changes in pressure

what transport blood back to heart?

venules and veins

lymph system takes in extracellular ___________ to send it back to the circulatory system

blood

Collecting System- Venous Side

-thin walled, highly compliant, low pressure

-Volume storage available for quick recruitment

Lymph and venous vessels ________ and empty into right and left _______ veins

converge; subclavian

Blood Flow

the volume of blood that moves past a particular point in the cardiovascular system in a given time

typical flow through aorta of dog

2.5 L/min

(cardiac output)

Blood Pressure

the force that causes blood to flow

What is the relationship between flow and pressure?

flow is proportional to the pressure differences in btw 2 points

Blood pressure in ventricle

120mmHg

blood pressure in capillaries

35 mmHg

blood pressure in venules

very low

Balance of flow in a well functioning system

flow out of left = flow out of right

2 factors that determine flow

-pressure or energy pushing the liquid

-resistance in the system to flow

the greatest resistance to flow

vessel diameter

flow equation

F= (P1-P2)/R

Physiological changes that affect blood flow demands

-meal intact/ absorption

-exercise

-sleep

potential diseases with the circulatory system that cause changes in presure

-heart valve dysfunction

-changes in vascular smooth muscle constriction

-volume loss (dehydration/ hemorrhage)

Coordinated cardiovascular function is regulated by:

-Autonomic Nervous System

-Hormonal Regulation

RAAS

Vasopressin

Epinephrine

"Thermostat" for cardiovascular system

medulla

How is autonomic output integrated in the medulla?

-negative feedback

-setpoint regulation from HYPO

Intrinsic mechanisms regulate arterial pressure by altering _____________

vascular tone

extrinsic mechanisms regulate arterial pressure by altering...

vascular tone or modulating blood volume on arterial side

Baroreceptors

-short term regulator of blood pressure

-stretch receptors

-on aortic arch and bifurcation of carotid

-detect arterial pressure changes through changes in stretch on vessel walls

Degenerative Mitral Valve Insufficiency

-incomplete closure

-small breeds

-bidirectional flow

-murmur during systolic

-75-80% canine cardiac diseases

-cavelier king charles and dachshund

-often inherited

-may onset earlier in males

Cardiovascular changes associated with CHF

Trigger: decr CO, decr MAP

Compensation Baroreflex: incr HR, incr contractility, incr renin, incr vasopressin

--> incr sympathetic drive

--> incr Na+ & water retention, incr Na+ intake, incr blood vol, incr edema

Left Ventricular Failure Treatment

-inotropic drugs

-beta blockers

-diurectics

-angiotensin II blockers

--angiotensin II converting enzyme inhibitors

-aldosterone blockers-combined therapy

-vasodilators

Dr. Cassle's "BLUF" bottom line up front

-Dogs are indispensible working assets

-unique challenges and medical conditions

-human/animal bond

Working dogs in Egypt 7000BCE

-mummification and anubis

-humans and animals hunted together

-earliest breeds- Saluki

Mastiffs in Egypt and Europe

-Alexander the Great

-Britons/Caesar's invading armies

Napoleon working dogs

sentinels in alexandria

dalmations

-croatian province used them as sentinel dogs

-modern day intruder detection

First recorded use of dogs in the U.S. army

1835 the 2nd seminole war

-bloodhounds tracked down seminoles and runaway slaves

Working dogs in the civil war 1865

-sentry, messengers, mascots

the world's 1st military war dog training school

1884- Germany

Working dogs in WWI

-hitler made regular use of military dogs

-search and rescue ambulance dogs

-cigarette delivery

-red cross

WWII Dogs for defense

-1st time in U.S. military history that marked official recognition of working war dogs by armed forces

tactical dogs

used gas masks in WWII

messenger dogs

under 15 inches tall and under 15 pounds

-1 master in rear, 1 in front lines and dog traveled between the two

pack dogs

carried ammunition of 40 pounds to front lines

Korea

-german shepherd

-small arms fire training

Vietnam

-sentry dog proven

-heat casualties

-transition to patrol dog

Why use dogs as service animals?

-special senses

-loyalty and companionship

-trainability and versatility

-diversity

-deterrence

Specialized and Search Dogs

-search and rescue

-tracker dogs (bloodhound)

-brown tree snake dogs (jack russel)

-termite dogs

Assistance dogs

-guide dog (blind/visually impaired)

-hearing dog (deaf/hearing impaired)

-Service dog (other disability, i.e. seizure)

ADI working towards

Standardize working dogs

-laws

-training

-stay w/in 24 in of human, correctly respond 90% of time, inconspicuous

accessibility

-public domain

-appropriateness

behavior

-inconspicuous

-consistent

Categories of Military Working Dogs

-MWD: Patrol, PE, PD

-Mine detection

-specialized search dog

-combat tracker dogs

-contract K9s

Military working dog breeds

-german shepherd

-malinois/belgian shepherd

-labrador retrievers

-springer spaniels

-german shorthaire pointers

-smaller breeds (navy)

Traditional MWD

-law enforcement agencies (patrol, PE, PD)

-military police asset

-training at lackland AFB, TX

-Dod and DHS

Specialized Search Dogs

-camp pendleton (springer spaniel)

-emergent request

-infantry asset

-off-leash

-train LAFB, YPG

Combat Tracker Teams

-camp lejeune

-canine and human trackers with security

-navy seal team 6 (may 2011, aug 2011)

Robby's Law

nov 6, 2000

-facilitate adoption of MWD

-sec def may make available for adoption

-suitability for adoption

-authorized recipients

-w/o charge

-liability and expense released

-sec def annual report

MWD elemental medical challenges

-temp variation

-infectious diseases

MWD athletic medical challenges

-orthopedic injuries

-gastric-dilation volvulus

MWD War fighter medical challenges

-chemical/bio warfare

-trauma/PTSD

classifications of heat injury

-heat stress

-heat exhaustion

-heat stroke

clinical presentation of heat injury

-heavily panting

-body temp >106 deg

-bright red mucous membrane

-weak pulse

-come in stuporous or depressed