Post on 30-Dec-2015
description
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