13.0 Circulatory System

What is the layer that surrounds the heart

Pericardium (double layered sac)

Outerlayer = fibrous pericardium

Inner layer = serous pericardium

What is the prupose of the pericardium

Hold heart in place

Lubricate it

Protetion

How many chambers does the heart have and what separates them

Upper and lower chambers are separated by valves

Right and left side of the heart are separated by a septum

What are the upper (1,3) and lower (2,4) chambers of the heart claled

Upper = atria

Lower = ventricles

What is the right side of the heart and what does it carry?

Right atrium + ventricle = carries deoxygenated blood

What is the left side of the heart and what does it carry?

Left atrium + ventricle = carries oxygenated blood

Compare and contrast the pressures of ventricles and atria of the heart

Atria = Low pressure, sends blood to ventricles (not far)

Ventricles = high pressure, sends blood to lungs or systemic (far)

Valves of heart function

Prevent backflow of blood

Name all the valves in the heart that prevent backflow

Pulmonary valve

Tricuspid valve

Aortic Valve

Mitral Vavle

Where is the tricuspid valve located

Between right atrium and ventricle

Where is the pulmonary valve located

Right ventricle and pulmonary arteries

Where is the mitral valve located

Between left atrium and left ventricle

Where is the aortic valve located

Left ventricle and aorta

What distributes blood directly from the heart to the arteries of the body

Aorta

How many chambers in the following, fishes, amphibians, reptiles, birds and mammals

Fishes = 2 (A + V)

Amphibians + Reptiles = 3 (2A + V)

Birds and mammals = 4 (2A + 2V)

What is the sequence of valves does blood flow as it flows through the heart

Tricuspid → pulmonary → mitral → Aortic

TPMA

Compare and contrast arteries and veins

Veins = carry. blood back to the heart (deoxygenated)

Arteries = carry blood away from the heart (oxygenated)

What is the goal of the pulmonary circulation

Goal is to get deoxygenated blood to the lungs then bring that freshly oxygenated blood back to the heart

Pulmonary circulation

Blood is pumped from the right ventricle to pulmonary arteries

Blood gets reoxygenated at the capillaries of the lungs

Blood travels back to the heart via pulmonay veins to the left atrium

Blood in the _____ has the lowest concentration of oxygen in the entire body

Pulmonary artery

Blood in the ____ has the highest concentration of oxygen in the entire body

Pulmonary veins

Why is the pulmonary circulation an exception to arteries and veins carrying certain types of blood

Normally, veins carry deoxygenated blood and arteries carry oxygenated

But its opposite for the pulmonary arteries (carry deoxygenated), and pulmonary vein (carry oxygenated)

Systemic circuit

Freshly oxygenated blood goes to left atria → left centricle → aorta → entire body → blood reaches capillaries dropping off O2 → veins carry blood back to superior and inferior vena cava → right atrium → right ventricle

What happens ot oxygen at the capillaries at the body’s tissues?

Oxygen is delivered from red blood cells to tissues, and blood becomes deoxygenated

In capillaries, What are delivered and transported back i

Nutrients + O2 are delivered

CO2 and waste are transported back

What are the phases of the cardiac cycle

Systole - heart contracts

Diastole - heart relaxes

What are the pacemaker cells of the heart

SA node in the right atrium - generates electricity to keep the heart beating

How are the cardiac muscles separated and what do they contain

Separated by intercalated dscs

Contain gap juncitons

Conduction pathway of the heart

SA node

AV node - WHERE delay occurs

Bundle of His - located between both lower ventricles

Purkinje fibers - Causes Both ventricles to contract together

Phases of cardiac cycle

P wave = atria contraction

QRS complex = ventricles contraction/depolarization

T wave = ventricles repolarizing to prepare for another contraction `

In the cardiac cycle graph, why dont we see a bump when the atria repolarizes

Because that process is taken place at the same time when the ventricles are depolarizing

Cardiac output equation

CO = Stroke Volume x Heart Rate

CO - volume of blood moved by both ventricles each minute

SV - blood discharged from ventricles each contraction

HR - number of contractions per minute

Stroke volume formula

SV = End distolic volume (EDV) - End Sytolic Volume (ESV)

EDV = how much blood in the ventricles just before contraction

ESV = how much blood in the ventricles at the end of the contraction

Blood pressure formula

BP = Cardiac Output x Systemic vascular resistance

BP = pressure of circulating blood against the walls of vessels

SVR = resistance to the flow of blood (diameter, blood viscosity)

What are the four layers of arteries

Connective

Thick muscle layer

Elastic layer

Endothelium layer

Whay allows arterioles to regulate their diamter

Smooth muscle layer

What type of vessel is the smallest but has the greatest total surface area and cross sectional area

Capillaries

Name and compare the two pressures in vessels for capillary exchange

Hydrostatic pressure = pushing towards vessel walls. In capillaries causes fluid to flow out of vessel

Oncotic pressure = pressure of pushing inwards the vessels

What occurs at the arteriole end of the capillary?

Net filtration

Hydrostatic pressure high / Oncotoic pressure lower

What happens at the venous end of the capillary

Net reabsorption occurs

Hydrostatic pressure low / Oncoitic pressure stays the same

Precapillary sphincter

Rings of muscle that control blood flow (by contracting and relaxing)

Constrict = less nutrients and oxygen to tissues

Relax = more nutrients and oxygen to tissues

What is the smallest vein component

Venules

Veins layers

Connective tissue

Muscle (thin)

Elastic layer

Endothelium

Where does a fetus get its oxygen from

placenta

Ductus venosus; what is it, what it connects, what is its function

In fetuses, and connects the umbilical vein to the inferior vena cava

A shunt that bypasses the liver in the fetus to deliver oxygenated blood

Foramen Ovale; what is it, what is its purpose; what does it bypass

A hole in the septum between the two atria that allows blood to flow form the right to left atrium

• Bypasses the lungs and right ventricle so it can go to the body’s tissues faster since lungs arent functional yet

Ductus Arteriosus; what does it connect

Connects the pulmonary artery to the aorta

Similar to the foramen ovale

How are blood types catergorized

Your blood type is determined by the type of antigen you have

A antigen = blood type A

B antigen = blood type B

A + B antigen = blood type AB

O blood = Niether a and b antigen

Compare what would happen if we gave Type AB blood to someone who has Type O blood and vise versa

Donating typa AB to a Type O = immune response

Donating Type O to a Type AB = no immune response

What are the antibodies (not antigens) of each blood type

A = anti-B

B = anti-A

AB = none

O = anti-A and Anti-B

Rhesus Factor

Rh factor is another antigen on rbc

If present = + type

Lack = - type

Whats the TRUE universal blood type donor and recipient

O-

AB+ (have every type of antigen present in the RBC surface)

Which type of blood can only recieve blood from donors that share the same type

Type O blood

A father has blood type A and his father has type O blood, if the mother has blood type AB, what are the chances their child will have type B blood

set up punnet square

25%

Vasconstriction vs VASODILATION

VC = blood vessels constrict and increase pressure

VD = Widening of blood vessels and decreases pressure

Ways of controlling blood pressure

• Direclty by changing the cardiac output and regulating hormones

• Altering volume of blood in body (kidneys). More urine coming out = less blood volume. More urine held in = more blood volume

Order the blood pressure in our circulatory system

Arteries

Arterioles

Capillaries

Venules

Veins

Component of blood

55% liquid = called plasma

45% cellular componeents = red and white blood cells

Our blood is 55% plasma, what is the component of plasma

Aqueous mixture of;

Nutrients

Salts

Gases

Wastes

Hormones

Protines

Erythrocytes, leukocytes, thrombocytes

Erythrocytes = cells that carry oxygen and CO

Leukocytes (WBC) = iimmune cells that protect against pathogens

Thrombocytes = platelets

What is the most abundant cell type in blood

Erythrocytes

What molecules can bind to hemoglobin that we talked about

Oxygen

Carbo Dioxide

Carbon monoxide

What is a critical function of the bicarbonate buffering system

Keeps body to specific pH range

What happens when theres too much acid in the vlood

Bicarbonate buffering system combines acid with bicarbonate to from carbonic acid

What happens when theres too much base in the blood

Carbonic acid dissociates to neutralize it and forms bicarbonate

What is the major buffering system of the blood and where is it located in blood

Bicarbonate

Located in plasma = outside of the cells

What is the major buffering system INSIDE of the cells

Phosphate

Tight junctions act as the first barrier to prevent substance form crossing out of the blood to the ECS, what surrounds it

Astrocytes

When the platelets trigger the clotting cascade, what does this trigger

Triggers prothrombin (a zymogen) to be converted in its active form Thrombin

When thrombin is activated during a clotting cascade, what are its functions

Make more prothombin to make more thrombin

Convert fibrinogin to fibrin

What is the crucial last component of the clotting cascade

Fibrin = mesh of sticky protein strands that rap blood cells and platelets together to form a clot