Circulatory System Transport System

We have two Circulatory Systems1. Cardiovascular System 2. Lymphatic System

Thoracic Cavity

Heart

w/in

mediastinum

Bicuspid/mitral A/V valve

(2 flaps)

Tricuspid A/V valve

(3 flaps)

Chordae Tendinae

Aortic Semilunar

Lt ventricle AortaPulmonary Semilunar

Rt ventricle Pulmonary Artery

4 valves prevent backflow & blood moves in 1 direction

Right

DeO2

Left

O2

Our Heart is like 2 Hearts in One

The Right Heart

•Right Atrium

•Right Ventricle

•Receives DeO2

blood

from body

The Left Heart

•Left Atrium

•Left Ventricle

•Pumps O2 Blood

to Body

Right Left

start

start

Systemic Circulation

Movement of blood from Lt Ventricle

body

includes hepatic portal circulation of liver

& renal circulation of kidneys

Lt coronary artery

Lt coronary vein

Rt coronary artery

Rt coronary vein

Coronary Circulation

To myocardium

Angina Pectoris: Severe chest pain when myocardium deprived of adequate O2.

Coronary artery no longer supplies enough O2 to heart muscle.

Veins harvested for bypass (prevent graph vs host rejection).

Pg 259 fig 11-4

Heart Attack Myocardial Infarction

Flow to a section of heart muscle becomes blocked.

If not restored quickly, section of heart muscle damaged from lack of oxygen & begins to die.

Damaged heart muscle loses its ability to contract

Remaining heart muscle must compensate for weakened area.

Minimize damage to the heart muscle during a heart attack. This damage occurs when blood flow is totally cut off to an area of the heart. Stents: tiny mesh tube that is inserted in narrowed area to keep it open. Some coated with medication to help prevent the artery from closing again.

Deflated balloon catheter inserted into narrowed coronary artery. Balloon is inflated, compressing the plaque & restoring size of artery. Relieves chest pain caused by reduced blood flow to the heart.

AbioCor artificial heart

2 poundslife expectancy 30 days – 6months

Can extend life for those awaiting heart transplant donor

Heart Conduction

Heart contracts in absence in external stimuli

4 structures embedded in heart wall

generate & conduct electrical impulses through heart muscle

cause atria & then ventricles to contract

Sinoatrial Node (SA node) Pacemaker in Rt Atrium wall Impulse starts & spreads in all directions through both atria contraction

Impulse reachesAtrioventricular Node (AV node) between Rt atrium & Rt. ventricleRelayed to Bundle of His (AV bundle) Rt & Lt branches along septumandPurkinje fibers 0ff 2 AV bundles

To ventricles contraction

Disease can damage conduction system

Artificial Pacemaker

Electrical device causes heart contractions

maintains adequate blood flow2 components to pacemaker

*pulse generator, computer chip (brains) & battery

*wires (leads) carry electrical signals to & from heart. 

Pulse generator under skin sends electrical signal to heart.  2 leads inserted through an arm vein are attached to the heart's Rt atrium or Rt ventricle or both.

Electrocardiogram (ECG or EKG)

Heart conduction generates electrical currents picked up from body surface

Graphic record of heart’s electrical activity

3 waves: deflection represents electrical activity associated with contraction & relaxation of atria & ventricles

Damage to cardiac muscle affects conduction system distinct changes in ECG diagnosis & treatment

Depolarization: electrical activity w/ contraction of heart muscle

Repolarization: relaxation of heart muscle

P wave: atrial depolarization (contraction)

QRS complex: ventricular depolarization (contraction)

T wave: ventricular repolarization (relaxation)

*Atrial repolarization wave masked by QRS complex

Vessel Structure Arteries & Veins: 3 layers

Tunica Externa outermost

Tunica Media middle

Thicker in arteries vs veins maintain BP for blood

distribution to body

Smooth muscle: Autonomic NS control

Tunica Interna innermost (fibrous, endothelial tissue)

CNS (brain/spinal cord)

NS sensory

PNS somatic (skeletal muscle/effecters)

motor

autonomic (sm & cardiac muscle & glands/effecters)

↑sympathetic ↓parasympathetic

adrenaline ↑ SA node impulses acetylcholine ↓ SA Node impulses

veins

Arteries

•Carry blood Away from the Heart

•Are DEEP, near Bones for protection

Blood Vessels

Arteries: carry blood away from heart

Arterioles capillaries

O2 (except for pulmonary arteries)

•under pressure

•pre-capillary sphincters regulate blood

flow into capillaries (deeper than veins)

Blocked carotid artery stroke

Prevent with Endarterectomy

Arteries have a thick (Invol.) muscular wall

Blood is moving very fast, under high pressure

Smaller Arteries branch into smaller Arterioles

Many arterioles have sphincters

Veins: carry blood to heart are superficial

Capillaries venules veins

DeO2 (except for pulmonary veins)

•little to no pressure•valves prevent backflow•muscle contractions keep blood moving in veins towards heart

(more superficial than arteries)

Varicose Veins

Faulty valves in the veins blood pools distends veins

Treatment

Sclerotherapy: Injection causes vein to seal shut scars fades

Laser surgery: Direct & Accurate Sends strong bursts of light onto vein fades

Surgical Ligation and Stripping: Veins tied & removed

Deeper veins take over circulation for treated veins

Comparison of Artery and Vein

Capillaries Connect Artery to Vein

arteriole venule

Capillary bed diffusion

gas/nutrient exchangeO2 DeO2

Where does Blood do All its Work?

WHY???

Walls of Arteries & Veins are too thick and Blood is moving much too fast to do its work!

Blood Pressure forces some of the Plasma minus large blood proteins to leak out of Capillary (Filtration) into the Tissues

Exchange of ALL Nutrients, Gases, & Wastes occurs here

Too much Tissue Fluid = Edema

Major Arteries & Veins

Major Arteries & Veins

Hepatic Portal Circulation

Blood flow through liver

Veins from (pg 268 fig 11-13 & overhead)

spleen, stomach, pancreas, gallbladder, intestines

Sent to liver via PORTAL VEIN

(lies between 2 capillary beds) for

glucose absorption glycogen

Detoxification

Blood leaves liver via HEPATIC VEIN

Inf. Vena Cava

Renal Circulation

Blood flow through kidneys (excretory system)

Dirty (O2) blood in through renal artery

Clean (DeO2) blood out through renal vein

Fetal Heart Structures (pg 270 fig 11-14)

Ductus Venosus: bypass immature liver Inf Vena Cava

To Bypass Non Functional LungsForamen Ovale: shunts blood from Rt to Lt Atrium

Ductus Arteriosis: connects Aorta & Pulmonary Artery (shunts blood in Rt. Ventricle to Pulmonary Artery Aorta amniocentiesis/FLM (fetal lung maturity)http://www.wellesley.edu/Biology/Courses/111/mammalian.html

Fetal Circulation

Nutrient-Waste exchange with mom via Placenta

3 umbilical vessels

2 sm umbilical arteries

1 lg umbilcal vein

Pulse: Artery expanding & recoiling

Radial

Temporal

Carotid

Brachial

*Dorsal Pedis (front surface of foot, below ankle bend)

Adult 70 beats/min

Child 100 beats/min (No steam, sauna)

Tachycardia ↑ heart beat

Bradycardia ↓ heart beat

Blood Pressure: pressure or push of blood

Measure of pressure on arterial walls in mm of Hg with sphygnomonometer & stethescope

Exists in all vessels

Highest in arteries (aorta) – Lowest in veins (vc)

Gradient keeps blood circulating

Force to keep blood moving

aorta arteries arterioles capillaries

CLOSED SYSTEM

High BP hypertensive

can rupture vessels stroke

Low BP hypotensive ↓circulation so ↓O2

hemorrhage leads to rapid ↓ in BP

BP result of volume in vessels

↑ blood volume in arteries = ↑ pressure on artery walls

↓ blood volume in arteries = ↓ pressure on artery walls

BP changes

↑ with exercise for ↑ O2 to muscles

↑ metabolism for ↑ energy

Normal BP 120 systolic (as ventricles contract)

80 diastolic (as ventricles relax)

Closed circuit

Volume of blood in arteries determined by

*amount of blood heart pumps into arteries

*how much arterioles drain out of them

Cardiac Output: vol of blood pumped into arteries

Diameter of arterioles determines how much blood drains into capillaries

Stronger heart beat ↑ BP

Weaker heart beat ↓ BP

If ↑ heartbeat

& vol out of Lt ventricle not ↓

leads to ↑ BP

If ↑ heartbeat

& vol out of Lt ventricle (cardiac output) ↓ b/c of

rapid pumping,

leads to ↓ BP

Blood Pressure & Viscocity

↓ viscocity = ↓ BP

Hemorrhage fluid from interstitial spaces moves into & dilutes blood

Transfuse plasma to ↓ viscocity

Lymphatic System

•Some Plasma (minus blood proteins filters (“leaks”) out of capillaries into Tissues

•Now called Tissue (Extra cellular) Fluid, much will drawn back into capillaries by Serum Albumin

•More Tissue Fluid will be drawn into Lymphatic vessels, now called Lymph

•Lymph will pass through Lymph Nodes where it will be purified by WBCs

•Lymph is emptied into Subclavian Veins where it is now part of the Plasma

Cellulites: Infection of deep subcutaneous layer