Transcript Chpt 8 Lecture - kilic

Heart and Blood Vessels
Major Arteries and Veins
Jugular vein
Carotid artery
Superior
vena cava
Inferior
vena cava
Renal vein
Common
iliac vein
Common
iliac artery
Subclavian vein
Subclavian artery
Aorta
Renal artery
Femoral vein
Femoral artery
Great saphenous vein
Blood Vessels—Arterial System
 Structure: endothelium, middle, outer layers
 Functions
 Arteries carry blood away from heart
 Arterioles and precapillary sphincters control pressure
 Capillaries exchange nutrients, waste, and defensive
cells between vessel and tissue
Arterioles and Capillaries
Capillary Structure
Blood Vessels—Venous System
 Structure: three layers, thin-walled
 Functions: carry blood toward the heart
 Mechanisms in blood return
 Contraction of skeletal muscles
 One-way valves
 Pressure changes associated with breathing
Blood Vessels—Venous System
Blood Vessels—Summary
Direction of
blood flow
Vein
Outer layer:
Connective
tissue
Middle layer:
Smooth muscle
with elastic
fibers
Inner layer:
Endothelium
Artery
Connective tissue
Smooth muscle
Endothelium
Venule
Arteriole
Capillary
Tissue
cells
Epithelial cells of
capillary endothelium
Lymphatic System
 Function
 Maintains blood volume
 Also functions in immune system
 Structure
 Blind-ended capillaries
 Lymphatic vessels
 Lymph is the circulating fluid
The Heart
Aorta
Superior vena cava
Left pulmonary artery
Right pulmonary artery
Pulmonary trunk
Left pulmonary veins
Pulmonary
semilunar valve
Right atrium
Right AV valve
Right ventricle
Left atrium
Aortic semilunar valve
Left AV valve
Left ventricle
Chordae tendineae
Papillary muscles
Septum
Inferior vena cava
Figure 8.7
The Heart
 Structure
 Layers: epicardium, myocardium, and endocardium
 Chambers: two atrias, two ventricles
 Valves
 Two atrioventricular valves: tricuspid and bicuspid
(mitral)
 Two semilunar valves: pulmonary and aortic
Pulmonary Circuit—
Oxygenation of Blood

Pathway

Deoxygenated blood from the body into heart
1.
2.
3.
Through the vena cava to the right atrium
Through the right atrioventricular valve to the right
ventricle
Through the pulmonary semilunar valve to the
pulmonary trunk and the lungs
Pulmonary Circuit—
Oxygenation of Blood

Pathway

Oxygenated blood from lungs to heart
1.
2.
Through the pulmonary veins to the left atrium
Through the left atrioventricular valve to the left ventricle
Systemic Circuit—Delivery of
Oxygenated Blood to Tissues

Pathway

Oxygenated blood from the heart to tissues
1.
2.
3.
Through the aortic semilunar valve to the aorta
Through branching arteries and arterioles to tissues
Through the arterioles to capillaries
Systemic Circuit: Return of Blood to
the Heart

Pathway

Deoxygenated blood returns to heart
1.
2.
From capillaries into venules and veins
To the vena cava and into the right atrium
Pulmonary and Systemic Circuits
Jugular vein
Carotid artery
Superior
vena cava
Inferior
vena cava
Renal vein
Common
iliac vein
Common
iliac artery
Subclavian vein
Subclavian artery
Aorta
Renal artery
Femoral vein
Femoral artery
Great saphenous vein
Cardiac Cycle
Heart Sounds and Heart Valves
 Lub-dub (typical heart beat)
 Sounds are valves closing
 Heart murmurs
Cardiac Conduction System
Coordinates Contraction
 SA node: cardiac
pacemaker
 AV node: relays
impulse
 AV bundle and
Purkinje fibers:
carry impulse to
ventricles
Electrocardiograms (EKG/ECG)
 Measure the electrical impulses of the heart
 Three formations
 P wave: impulse across atria
 QRS complex: spread of impulse down septum, around
ventricles in Purkinje fibers
 T wave: end of electrical activity in ventricles
 Arrythmias, ventricular fibrillation can be detected
Electrocardiograms (EKG/ECG) (cont.)
Blood Pressure
 Definitions
 Systolic pressure
 Diastolic pressure
 Measurement
 Sphygmomanometer
 What’s a “normal” reading?
 What would be considered “high” or “low” blood
pressure?
How Blood Pressure is Measured
Figure 8.16
Blood Pressure (cont.)
 Hypertension: high blood pressure
 The silent killer
 Hypotension: blood pressure too low
 Clinical signs: dizziness, fainting
 Causes: orthostatic, severe burns, blood loss
Regulation of the Cardiovascular System:
Baroreceptors

Baroreceptors: pressure receptors in aorta and
carotid arteries
 Steps in mechanism
1.
2.
3.
4.
5.
Blood pressure rises, vessels stretched
Signals sent to brain in the cardiovascular center
Heart signaled to lower heart rate and force of
contraction
Arterioles vasodilate, increasing blood flow to tissues
Combined effect lowers blood pressure
Regulation: Nervous and
Endocrine Factors
 Central Nervous System signals
 Sympathetic nerves: constrict blood vessels, raising
blood pressure
 Parasympathetic nerves: dilate blood vessels, lowering
blood pressure
 Hormones: epinephrine (adrenaline)
 Local requirements dictate local blood flow
 Exercise: increased blood flow and cardiac output
Cardiovascular Disorders
 Angina pectoris: a warning, chest pain
 Myocardial infarction/heart attack: permanent cardiac
damage
 Congestive heart failure: decrease in pumping
efficiency
 Embolism: blockage of blood vessels
 Stroke: impaired blood flow to the brain
Reducing the Risk of
Cardiovascular Disease
 Smoking: don’t
 Blood lipids: monitor cholesterol levels
 Exercise: regular and moderate
 Blood pressure: treat hypertension
Reducing the Risk of Cardiovascular
Disease (cont.)
 Weight: being overweight increases risk of heart attack
and stroke
 Control of diabetes mellitus: early diagnosis and
treatment delays onset of related problems
 Stress: avoid chronic stress
Cardiac Anatomy Practice