Butcher Quiz 6

What are the functions of the cardiovascular system?

-substrate delivery

-waste removal

-gas exchange

-endocrine signaling

-immune response

-thermoregulation

What is the golden window?

cessation of heart beat gives ~4 minutes before irreversible damage occurs

True or false? Impaired heart function causes damage to other organs?

true

How is cardiovascular function assessed?

-heart assessments

-circulatory assessments

-blood tests

-advanced imaging

Examples of heart assessments

-heart rate, rhythm, sounds, and murmurs

-blood pressure

-radiography, echocardiography, electrocardiography

Examples of circulatory assessments

-respiratory rate/effort

-capillary refill time

-mucous membrane color

-presence of edema

-exercise intolerance

Examples of blood tests

-troponin 1

-brain natriuretuc peptide (BNP)

-NT-proBNP

-pH

Examples of advanced imaging

CT and MRI

What is primary cardiovascular pathology?

direct problem with the cardiovascular system

Examples of primary cardiovascular pathology

-hemorrhage

-myocarditis

-congential malformations

-parasitic infection of heart and vessels

-Chagas disease

-hypertrophic cardiomyopathy

-heart failure and arrhythmias

What is secondary cardiovascular pathology?

problem with another organ that impacts the cardiovascular system

Examples of secondary cardiovascular pathology

-liver disease

-renal disease

-vomiting

-diarrhea

What is a key portion of homeostasis in the mammalian body?

maintainance of constant fluid volume

What aspects of fluid balance are important to regulate?

-total concentration of all solutes

-concentration of individual solutes

-total fluid volume

What solutes are found in body fluid?

-salts

-nutrients like glucose, proteins, and other organic molecules

-ions (calcium, hydrogen, etc.)

Where are changes to fluid balance monitored and corrected?

extracellular fluid (ECF)

What are the major components of ECF?

plasma and interstital fluid

What is plasma?

fluid in vasculature

What is interstitial fluid?

fluid outside the vasculature that is bathing the cells

What are the minor components of ECF?

transcellular fluid and lymph

What is the 60-40-20 rule?

total body fluid is 60% of body weight (BW), ICF is 40% of BW, and ECF is 20% of BW

What factors can impact the amount of total body fluid?

age, sex, and obesity

What body fluid change is associated with aging?

decrease in total body fluid (associated with an increase in % of body fat)

What is the percentage of BW of fluid in newborns?

70-75%

Do females have a higher or lower total fluid body weight than males?

lower- females total fluid BW is about 50%

As % body fat increases, what happens to % body water?

it decreases

What ions make up ~80% of total osmolarity in the ECF?

sodium and chloride

What ion makes up ~50% of total osmolarity in the ICF?

potassium

True or false? The pressure on both sides of a semi-permeable membrane must be equal.

false

How is osmotic pressure measured?

number of molecules striking a membrane per second

What is the most abundant substance that diffuses through the cell membrane?

water

Concentrations of what molecules are higher in the ICF?

-potassium

-phosphates

-magnesium

-organic acid ions

-proteins

Concentrations of what molecules are higher in the ECF?

-sodium

-chlorine

-calcium

-bicarbonate

True or false? Proteins can move between plasma and interstitial fluid.

false

Where is protein concentration higher, plasma or interstitial fluid?

plasma

True or false? The composition of plasma and interstital fluid is almost identical, except for proteins, because fluid is exchanged continuously through pores between capillary membranes.

true

What organ is in charge of regulating ECF composition?

kidneys

What does hematocrit look at?

fraction of blood composed of RBC's

What is the normal hematocrit value?

0.37-0.55

What does fractionation look at?

plasma vs serum

True or false? Blood contains both RCF and ICF.

true

What is the average blood volume?

5-8% of BW

What is the breakdown of plasma and RBC's in blood?

60% of blood volume is plasma, 40% is RBC's

REVIEW: What are the 3 primary body fluid compartments?

-ICF

-plasma (ECF)

-interstitial fluid (ECF)

REVIEW: What is the 60-40-20 rule?

60% BW, 40% ICF, 20% ECF

REVIEW: True or false? Blood has a higher % of water.

true

REVIEW: What are the cations and anions prevalent in the ICF?

K, Mg, phosphates, and proteins

REVIEW: What is not able to move between ECF compartments?

proteins

REVIEW: What is hematocrit?

packed red blood cell volume

What are muscles composed of?

myofilaments

What is the function of muscles?

movement and maintainance of position

What are the 3 type of muscle?

-cardiac

-skeletal

-smooth

How is muscle subdivided?

individual myofibers -> fascicles (group of myofibers) -> muscle

Characteristics of cardiac muscle

-braching cylindrical cells with one or two centrally located nuclei

-striated and has myofibrils and sarcomeres

-intercalated disks and purkinje fibers present

What is the inherent conduction mechanism of cardiac muscle?

slow leak of Ca2+ from sarcoplasmic reticulum -> automatic contractions (strong and forceful)

What are the functions of intercalated disks?

mechanically attach cells together and allow electrical conduction between cells

What are the 3 general types of vessels?

-arteries

-veins

-lymphatics

What are the 3 layers of a vessel from inside to outside?

tunica intima, tunica media, tunica adventitia

What are the 3 forms of arteries?

-elastic arteries

-muscular arteries

-arterioles

Characteristics of elastic arteries

-conducting arteries (close to the heart)

-large diameter

-many elastic laminae in tunica media to maintain diastolic pressure

Characteristics of muscular arteries

-distributing artery

-most active in constriction and dialation to control blood pressure

-tunica media is mostly smooth muscle

-internal elastic lamina is commonly visable

-unmyelinated nerves access smooth muscle via tunica adventitia

What is the function of unmyelinated nerves in muscular arteries?

important control of vascular tone

Characteristics of arterioles

-tunica media is only 1-2 layers of smooth muscle

-internal elastic lamina in very small arterioles may be absent

-function is to regulate blood flow to capillary beds

Characteristics of capillaries

-small lumen

-flow is reduced but surface area is increased due to large number of capillaries

-one endothelial cell covers the lumen and are arranged longitudinally

What are the 3 types of capillaries?

-continuous

-fenestrated

-discontinuous

Characteristics of common capillaries

-continuous endothelium with junctional complexes

-allows gas exchanges, ions, fluid, glucose, leukocytes

-microvesicles act through endocytosis or exocytosis

What is the most common type of capillary?

continuous capillaries

What moves through fenestrated capillaries?

small molecules and proteins

Characteristics of discontinuous capillaries

-large gaps (30-40 um)

-free transfer of proteins, RBC's, WBC's, water

-facilitated by discontinuous basement membrane

Characteristics of venules

-low pressure

-most common site for exiting WBC's during inflammation

What order does the blood flow in after reaching capillaries?

capillaries -> post-capillary venules -> muscular venules -> veins

Characteristics of post-capillary venules

-large diameter

-wall is essentially endothelial cell and little connective tissue

-no tunica media

What are venous valves?

folds of tunica intima that prevent backflow of blood

Characteristics of endothelium

-lines the entire vascular system

-selectively permeable

-non-thrombogenic barrier

-modulate blood flow and vascular resistance

Characteristics of lymphatics

-important in lipid absorption from small intestine

-numerous in epidermis and mucous membranes

-used to transport WBC's to lymph nodes

-one-way system due to valves

-large luminal diameter

-very thin wall and irregular shape

REVIEW: How is increased thickness of the tunica media associated with blood pressure?

high vascular pressure

REVIEW: What part of the vasculature would most likely be affected by the sympathetic nervous system?

muscular arteries

REVIEW: Which layer of the blood vessel wall is primarily responsible for regulating vessel diameter and blood pressure?

tunica media

REVIEW: Which of the following blood vessels primarily functions as the site of nutrient and gas exchange?

capillary

REVIEW: Which type of muscle tissue is primarily responsible for the involuntary movements of internal organs?

smooth muscle

What are the components of the vascular tree?

aorta, arteries, arterioles, capillaries, venules, veins, vena cava

What is the composition of tunica adventitia?

collagen and connective fibers

What is the composition of tunica media?

smooth muscle and elastic fibers

What is the composition of tunica intima?

single-cell endothelial layer of simple squamous epithelium

Where do you want to measure blood pressure?

in a large artery as close to the aorta as possible

Characteristics of arteries

-high-pressure system

-thicker, more muscular walls, with thinner lumen

-thickest tunica media

-less distensible and less compliant

-more circular

-transport high-pressure blood from the heart

-hold less volume

Characteristics of veins

-low-pressure system

-thinner walls with larger lumen

-thinner tunica media

-vasa vasorum present

-more distensible and more compliant

-less circular shape (appears flattened)

-return low-pressure blood to the heart; act as a blood reservoir

-can hold large blood volume

What vessels act as elastic reservoirs?

large arteries (aorta)

Which vessels act as resistance vessels?

arterioles

What is the Windkessel effect?

the elastic effect of an arterial vessel upon distention

What happens when radius of a vessel decreases?

resistance increases

What vessels act as single cell layer exchange vessels?

capillaries

Characteristics of vena cava

-highly distensible

-sensitive to small pressure changes

-delayed compliance of vessels

-valves for one way flow

Why are valves needed in veins?

gravity and blood pooling

REVIEW: Which structure in blood vessels is typically composed of smooth muscle cells?

tunica media

REVIEW: Where is the highest pressure system located in the vascular tree?

arteries

REVIEW: True or false? All capillaries are perfused at all times?

false- controlled by precapillary sphincters

REVIEW: Based on Poiseuille's Equation, what do arterioles control change resistance?

radius

REVIEW: What terms describe characteristics of veins?

-low-pressure

-larger lumen

-thinner tunica media

-more distensible

-blood reservoir

Characteristics of right side of the heart

-pumps blood to the lungs via the pulmonary artery

-right atria fills from two venae cavae

-low-pressure, short distance circuit