Transcript Lesson 5. circulatory system - Blyth-Biology11

Chapter 12: Circulatory System
Primary Tissue Layers
• Endoderm
– innermost layer
– digestive and respiratory tracts and other organs
• Mesoderm
– middle layer
– muscle, connective tissues, blood vessels
• Ectoderm
– outer layer, develops to skin
Simpler Circulatory System
• Open System
– no closed vessels
– Interstitial fluid surround
cells
– sinus: body cavity
surrounding internal organs
Simpler Circulatory Systems
• Closed System
– true blood vessels
– pumping system
• Purpose
–
–
–
–
–
Bring O2 and Nutrient to cells
Take wastes away from cells
Chemical messages
Maintain balance
Transport immune cells
Blood Vessels and the Heart
Fig 12.2
p 480
Heart – Superior view
The Heart
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•
•
•
•
•
Right side = incoming blood
Left side = outgoing blood
Septum = separates these sides
Atria = holds blood
Ventricle = pumps blood
Semilunar valves = prevents backflow
Learning Check
• Pg 481, Q 1-6
Arteries
• carry blood away from heart
• usually O2 rich (Except for
__________)
• connective tissue and muscle
• walls elastic and thick
• precapillary sphincters control
blood flow
Artery Problems
• Aneurysm
– bulge in artery
• Arteriosclerosis
– build up of plaque in
artery
Veins and Capillaries
• Veins
– carry blood to the heart
– usually O2 poor (Except for __________)
– valves push blood towards heart
– smooth surface
• Capillaries
– smallest blood vessels for gas exchange
Blood flow in veins
• Valves prevent
backflow
• Less pressure than
arteries
• Skeletal muscles
contract and pump
blood back to the
heart
Arterioles and Venules
• Arteries to arterioles to capillaries
• Capillaries to venules to veins
Circulation Types
• Systemic Circulation
– oxygenated blood to tissue
and deoxygenated blood to
heart
• Pulmonary Circulation
– between lungs and heart
– deoxygenated blood goes to
lungs and oxygenated blood
goes to heart
Components of Blood
• 55% fluid = plasma
– electrolytes, protein for immunity
and clotting
• 45% Red Cells
– erythrocytes, leukocytes, platelets
– produced in bone marrow
• 1% White Blood Cells
– Functional immune system cells
Stem Cells Bone Marrow
Erythrocytes
• Red blood cells
• no nucleus and biconcave =
max oxygen
• hemoglobin and iron carry
oxygen
• White blood cells in spleen
remove old RBC’s –gives color
to feces (bilirubin)
• anemia = deficiency in
hemoglobin or RBC
Leukocytes
• White blood cells
• RBC outnumber WBC by 700:1
• immune system, phagocytosis
• concentrated in lymph nodes
• pus = dead WBC and microbe
Leukocytes
• Neutrophils
– Most abundant
• Eosinophils
– Found in mucus lining of digestive and respiratory system
• Basophils
– Aids immunity by attracting phagocytes
• Lymphocyte (B and T cells)
– Secrete proteins called antibodies and aid in immune memory
• Monocyte
– Become specialized phagocytes called macrophages that engulf
bacteria
Leukocytes
Antibodies and Antigen
Platelets
• Fragmented rbc
• initiate blood clotting
• no nucleus
• fragile – rupture over torn blood vessel
Blood Clotting
• Blood vessel breaks, releases
chemicals that attract platelets
• Platelet ruptures and release
chemicals to produce
thomboplastin
• When calcium present
thromboplastin reacts with
prothrombin to produce thrombin
• Thrombrin reacts with fibrinogen
to produce fibrin
Learning Check
• Pg 486, Q 7-12
Functions of Blood: Transport
• Transport nutrients from intestine
• Transport gasses
• Transports and removes waste
– minerals and cell waste to kidneys for excretion
– CO2 from cells to lungs for expiration
Functions of Blood: Temperature Regulation
• Balancing loss of heat from the body with the
production of metabolic processes
• Mammals control heat by changing the
volume of blood in the skin
• Voluntary of involuntary? Controlled by
autonomic branch of the nervous system
Autonomic Nervous System
• involuntary responses
• Vasoconstriction: narrowing blood vessels
• Vasodilation: widening blood vessels
Factors effecting constriction
• Blood pressure
– An increase in BP is offset by vasodilation. If BP is too low,
vasoconstriction will occur
• Metabolic activity
• Exercise
– Vasodilation
• Drugs
– Alcohol and nicotine result in vasodilation
Countercurrent Heat Exchange
The Heart’s Tempo
Setting the Heart’s Tempo
• myogenic muscle = not
attached to nerve.
• Sinoatrial (SA) node =
pacemaker
• Atriventricular (AV)
node = impulse passed
to ventricels
Conducting the Signal
• Purkinjie Fibers
– pass through the septum to carry
rythym
• Autonomic Nervous System
– involuntary responses
– Sympathetic = stress, increase heart
rate
– Parasympathetic = relaxation,
decrease rate
Electrocardiograph
• P wave = atrial contractions
• QRS wave = ventricular contractions
• T wave = ventricle recovers
Electrocardiograph
“lub”
“dub”
Heart Sounds
Heart Sounds
• Diastole
– relation of heart
– atria fill with blood
• Systole
– contraction of ventricles
– blood going out of heart
• Systolic/Diastolic Pressure
– pressure in arteries during these events
Blood Pressure
• Stated as Systolic pressure over Diastolic
Pressure
• Need stethoscope and a sphygmomanometer
How to Check Pressure
• Inflate the bladder to close off flow to brachial artery
• Listening to pulse, slowly release air until pulse is
heard and read the pressure – Systolic
• Slowly release air until no pulse is heard and then
read the pressure – Diastolic
• Healthy = 120/80 (units = mmHg)
Regulating Heart Rate
• Sympathetic
– release epinephrine
– increase cardiac output
– constrict arteries
• Parasympathetic
– opposite
Cardiac output and stroke volume
• Cardiac output is amount of blood pumped out by
the heart in mL/min. Cardiac output = heart rate x
stroke volume
• Stroke volume is the volume of blood pumped out of
the heart with each heartbeat
• If the average person has a stroke volume of 70 mL
and a resting heart rate of 70 beats per minute, what
is the cardiac output?
Cardiovascular Fitness
• Capacity of the heart, lungs and blood vessels
to deliver oxygen to working muscles
• Look up table 12.3 on pg 492
• What do you notice?
• Rank the fitness of the three individuals
Cardiovascular Fitness
• Cardiovascular fitness
– Enlarges ventricles
– Increses elasticity
– Strengthening the ventricle walls
• Cardiovascular changes increase the stroke volume
• Good indication of fitness is how long it takes the
heart to return to resting HR after strenuous exercise
Learning Check
• Pg 491, Q 13-18