Transcript Cardio-vascular system

CARDIO-VASCULAR SYSTEM
• Principles
• Structures
• Two circuits
– Pulmonary
– Systemic
• Fetal Circulation
• Heart Details
• Other details
Larry M. Frolich, Ph.D.,Human Anatomy
What Does C-V System do?
• Circulate blood throughout entire body
for
– Transport of oxygen to cells
– Transport of CO2 away from cells
– Transport of nutrients (glucose) to cells
– Movement of immune system components
(cells, antibodies)
– Transport of endocrine gland secretions
Larry M. Frolich, Ph.D.,Human Anatomy
How does it do it?
• Heart is pump
• Arteries and veins are main tubes (plumbing)
– Arteries Away from Heart
– Veins to Heart
• Diffusion happens in capillaries (oxygen,
CO2, glucose diffuse in or out of blood)
Larry M. Frolich, Ph.D.,Human Anatomy
Overall Organization of System
• Heart/Great Vessels-1 Route
• Smaller aa. vv.--many
routes (collateral
circulation)
• Capillaries—network
where diffusion
occurs
Larry M. Frolich, Ph.D.,Human Anatomy
Collateral Circulation
Larry M. Frolich, Ph.D.,Human Anatomy
Walls of Arteries and Veins
• Tunica externa
– Outermost layer
– CT w/elastin and collagen
– Strengthens, Anchors
• Tunica media
– Middle layer
– Circular Smooth Muscle
– Vaso-constriction/dilation
• Tunica intima
– Innermost layer
– Endothelium
– Minimize friction
• Lumen
Larry M. Frolich, Ph.D.,Human Anatomy
pg 546
Artery/Vein differences
Arteries (aa.)
Direction Blood Away from
of flow
Heart
Pressure Higher
Veins (vv.)
Blood to Heart
Walls
Lumen
THICKER: Tunica
media thicker than
tunica externa
Smaller
THINNER: Tunica
externa thicker
than tunica media
Larger
Valves
No valves
Valves (see next)
Larry M. Frolich, Ph.D.,Human Anatomy
Lower
Larry M. Frolich, Ph.D.,Human Anatomy
Capillaries
• Microscopic--one
cell layer thick
• Network
• Bathed in
extracellular matrix
of areolar tissue
• Entire goal of C-V
system is to get
blood into
capillaries where
diffusion takes
place
Larry M. Frolich, Ph.D.,Human Anatomy
Two circulatory paths
Systemic
Pulmonary
Larry M. Frolich, Ph.D.,Human Anatomy
GREAT VESSELS
•Aorta
•IVC, SVC
•Pulmonary Trunk
•Pulmonary Veins
Larry M. Frolich, Ph.D.,Human Anatomy
Heart Chambers and Valves
Larry M. Frolich, Ph.D.,Human Anatomy
Right Heart Chambers: Pulmonary Circuit
• Right Atrium (forms most of posterior of heart)
– Receives O2-poor blood from body via IVC, SVC, Coronary sinus
– Ventral wall = rough Pectinate muscle
– Fossa Ovalis- on interatrial septum, remnant of Foramen Ovale
• Right Ventricle
– Receives O2-poor blood from right atrium through tricuspid valve
– Pumps blood to lungs via Pulmonary Semilunar Valve in
pulmonary trunk
– Trabeculae Carnae along ventral surface
– Papillary Muscle-cone-shaped muscle to which chordae tendinae
are anchored
– Moderator Band-muscular band connecting anterior papillary
muscle to interventricular septum
Larry M. Frolich, Ph.D.,Human Anatomy
Left Heart Chambers: Systemic Circuit
• Left Atrium
– Receives O2-rich blood from 4 Pulmonary Veins
– Pectinate Muscles line only auricle
• Left Ventricle (forms apex of heart)
– Receives blood from Left Atrium via bicuspid valve
– Pumps blood into aorta via Aortic Semilunar Valve to body
– Same structures as Rt Ventricle: Trabeculae carnae,
Papillary muscles, Chordae tendinae
– No Moderator Band
Larry M. Frolich, Ph.D.,Human Anatomy
Heart Valves: Lub*-Dub**
• *Tricuspid Valve: Right AV valve
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–
–
–
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3 Cusps (flaps) made of endocardium and CT
Cusps anchored in Rt. Ventricle by Chordae Tendinae
Chordae Tendinae prevent inversion of cusps into atrium
Flow of blood pushes cusps open
When ventricle in diastole (relaxed), cusps hang limp in ventricle
Ventricular contraction increases pressure and forces cusps closed
• *Bicuspid (Mitral) Valve: Left AV valve
– 2 cusps anchored in Lft. Ventricle by chordae tendinae
– Functions same as Rt. AV valve
• **Semilunar valves: prevents backflow in large arteries
– Pulmonary Semilunar Valve: Rt Ventricle and Pulmonary Trunk
– Aortic Semilunar Valve: Left Ventricle and Aorta
– 3 cusps: blood rushes past they’re flattened, as it settles they’re pushed
down (valve closed)
Larry M. Frolich, Ph.D.,Human Anatomy
Another View
Larry M. Frolich, Ph.D.,Human Anatomy
Location of Heart in Thorax
pg 523
Larry M. Frolich, Ph.D.,Human Anatomy
Location of Heart in Chest
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Oblique Position
Apex = Left of Midline (5th ICS), Anterior to rest of heart
Base (posterior surface) sits on vertebral column
Superior Right = 3rd Costal Cartilage, 1” right midsternum
Superior Left = 2nd Costal Cartilage, 1” left midsternum
Inferior Right = 6th Costal Cartilage, 1” right midsternum
Inferior Left = 5th Intercostal Space at Midclavicular line
Larry M. Frolich, Ph.D.,Human Anatomy
• Epicardium (most
superficial)
– Visceral pleura
Heart
• Myocardium (middle layer)
– Cardiac muscle
– Contracts
• Endocardium (inner)
– Endothelium on CT
– Lines the heart
– Creates the valves
Wall
How does heart
muscle get blood
supply?
pg 524
Larry M. Frolich, Ph.D.,Human Anatomy
Blood supply to heart wall
• Rt and Lft Coronary Arteries
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–
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Branch from Ascending Aorta
Have multiple branches along heart
Sit in Coronary Sulcus
Coronary Heart Disease
• Cardiac Veins
– Coronary Sinus (largest)
– Many branches feed into sinus
– Sit in Coronary Sulcus
Larry M. Frolich, Ph.D.,Human Anatomy
Heart Innervation
• Heart receives visceral
motor innervation
– Sympathetic (speeds up)
– Parasympathetic (slows
down)
p. 534
Larry M. Frolich, Ph.D.,Human Anatomy
Fetal Circulation
•No circulation to lungs
•Foramen ovale
•Ductus arteriosum
•Circulation must go to placenta
•Umbilical aa., vv.
Larry M. Frolich, Ph.D.,Human Anatomy
Adult remnants of fetal circulation
Adult
Fetus
Fossa ovale
Foramen ovale
Ligamentum arteriosum
Ductus arteriosus
Medial umbilical ligaments
Umbilical aa.(within fetus)
Round ligament
(ligamentum teres) of liver
Ligamentum venosum
Umbilical v.(within fetus)
Medial umbilical ligament
Umbilical cord (leaving fetus)
Larry M. Frolich, Ph.D.,Human Anatomy
Ductus venosus
Hepatic Portal System
Larry M. Frolich, Ph.D.,Human Anatomy
Lymphatic System…The Players:
• Lymph- clear fluid from loose areolar CT around
capillaries
• Lymphatic capillaries (near blood capillaries) 
• Lymph collecting vessels (small, 3 tunicas, valves)
• Lymph nodes (sit along collecting vessels)-clean
lymph of pathogens, they are NOT glands
• Lymphatic trunks (convergence large collecting
vessels)
– Lumbar, intestinal, bronchomediastinal, subclavian, jugular
• Lymphatic ducts  empty into veins of neck
Larry M. Frolich, Ph.D.,Human Anatomy
Lymphatic System--Function
• Function: to collect excess tissue fluid collecting at
arteriole end and return leaked blood proteins to
blood (maintain osmotic pressure needed to take
up water into bloodstream)
• Lymph moved through vessels
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Pulse of nearby arteries
Contraction of surrounding skeletal muscle
Regular movement of body (wiggling legs)
Muscle in Tunica Media
• Lacteals-lymphatic capillaries w/unique function
– In mucosa of small intestine, receive digested fat from
intestine
– Fatty lymph becomes milky = Chyle
– Chyle goes to bloodstream
Larry M. Frolich, Ph.D.,Human Anatomy