CARDIOVASCULAR SYSTEM Flashcards
Location of the heart
between the two lungs, 2/3 to the left
Membrane that surrounds and protects the heart and holds it in place.
PERICARDIUM
tough, inelastic, dense irregular connective tissue layer. It prevents overstretching of the heart, provides protection, and anchors the heart in place.
Outer fibrous pericardium
a thinner, more delicate membrane that forms a double layer around the heart.
Inner serous pericardium
Two parts of the pericardium:
- Outer fibrous pericardium
2. Inner serous pericardium
Two parts of the inner serous pericardium:
a. Outer parietal layer
b. Inner Visceral Layer
Fused to outer fibrous pericardium
Outer Parietal Layer
Also known as epicardium. Adheres tightly to the surface of the heart
Inner Visceral Layer
thin film of fluid between the parietal and visceral layers. It reduces friction between the membranes as heart moves.
PERICARDIAL FLUID
space that contains the pericardial fluid.
PERICARDIAL CAVITY
inflammation of the pericardium.
PERICARDITIS
Chambers of the heart:
- Atria
2. Ventricles
two upper chambers
Atria
two lower chambers
Ventricles
partition between atria
◊ Contains fossa ovalis (remnant of foramen ovale)
INTERATRIAL SEPTUM
Deoxygenated blood pathway
- SVC, IVC, CS
- RA
- RV
- PT
- R&L PA
Oxygenated blood pathway
- Lungs
- PV
- LA
- LV
- AA
Prevents backflow of blood
VALVES OF THE HEART
Two types of valves
- Atrioventricular
2. Semilunar
2 types of atrioventricular valves
- Tricuspid valve
2. Bicuspid (Mitral) valve
2 types of semilunar valves
- Pulmonary valve
2. Aortic valve
lies between atrium and ventricle
ATRIOVENTRICULAR VALVES
prevent blood from flowing back into the heart
SEMILUNAR VALVES
valve from RA to RV
Tricuspid valve
valve from LA to LV
Bicuspid valve
valve from RV to PT
Pulmonary valve
valve from LV to Aorta
Aortic valve
TRUE OR FALSE
The blood flow of the heart comes from areas of LOW blood pressure to HIGH blood pressure
FALSE
The blood flow of the heart comes from areas of HIGH blood pressure to LOW blood pressure
Movement of blood controlled by
- contraction and relaxation of myocardium
2. opening and closing of valves
remnant of foramen ovale
fossa ovalis
separates the RV from LV.
INTERVENTRICULAR SEPTUM
wrinkled pouch-like structure at the anterior surface of each atrium. It increases the capacity of the atrium to hold greater volume of blood.
AURICLE
flow of blood through the numerous vessels in the myocardium.
CORONARY CIRCULATION
: Principal coronary arteries that originate as branches from the ascending aorta.
: Deliver oxygen and nutrients throughout the heart muscle.
Left and Right Coronary Arteries
: Large vein on the posterior surface of the heart.
: Collects deoxygenated blood with carbon dioxide waste.
: Empties into the RA.
Coronary Sinus
: Connections where 2 or more arteries supply the same region,
: Provide alternative routes for blood to reach a particular organ or tissue of the body.
: Provide detours for arterial blood if a main route becomes obstructed.
Anastomoses
% of the cardiac muscle fibers that are specialized – generate action potentials over and over and do so in a rhythmical pattern.
1%
maintains heart rhythm
Natural pacemaker
: set route of action potentials to ensure coordinated contraction of heart muscles
Conduction system
2 important functions of the conduction system of the heart:
- Natural pacemaker
2. Conduction system
5 components of the conduction system of the heart:
- Sinoatrial node (SA node)
- Atrioventricular node (AV node)
- Atrioventricular bundle / AV bundle / Bundle of HIS
- L&R Bundle Branches
- Purkinje Fibers
: Located at the right atrial wall, inferior to the opening of the SVC.
: Begins cardiac excitation; location where an action potential spontaneously arises.
: Natural pacemaker of the heart
: Action potentials about 100 times per minute
Sinoatrial node (SA node)
: Located in the interatrial septum, anterior to the opening of the coronary sinus.
: Action potential slows considerably, providing time for the atria to empty their blood into the ventricles.
Atrioventricular node (AV node)
: Located in the interventricular septum
: Only site where action potentials can conduct from the atria to the ventricles.
Atrioventricular bundle / AV bundle / Bundle of HIS
: Course through the interventricular septum toward the apex of the heart.
L&R Bundle Branches
: Has a large diameter
: Rapidly conduct action potential, first to the apex of the ventricles and then upward to the remainder of the ventricular myocardium.
Purkinje Fibers
action potential conduction are recorded by electrodes placed on the skin
Electrocardiogram/ ECG (or EKG)
3 components of the electrocardiogram:
- P wave
- QRS wave
- T wave
atrial depolarization (atrial contraction)
P wave
ventricular depolarization
QRS complex
ventricular repolarization (ventricular relaxation
T wave
downward deflection
Q
large upright triangular wave
R
downward wave
S
one cardiac cycle is equal to?
one heartbeat
TRUE OR FALSE
The two atria RELAX while the two ventricles CONTRACT
FALSE
The two atria CONTRACT while the two ventricles RELAX
phase of contraction
SYSTOLE
phase of relaxation
DIASTOLE
3 PHASES OF CARDIAC CYCLE:
- Relaxation period
- Atrial Systole
- Ventricular Systole
begins at the end of a cardiac cycle when the ventricles start to relax and all 4 chambers are in diastole.
Relaxation Period
contraction of atria
Atrial Systole
contraction of ventricles
Ventricular Systole
volume of blood ejected per minute
CARDIAC OUTPUT
The cardiac output is determined by the:
Stroke volume x heart rate
Average stroke volume of a resting adult
70 mL
Average heart rate of a resting adult
75 bpm
amount of blood ejected by the left ventricle during each contraction.
STROKE VOLUME
3 FACTORS THAT INCREASE SV AND HR:
- Degree of stretch
- Forcefulness of contraction
- Pressure required to eject blood
The nervous system regulation of the heart originates in the cardiovascular (CV) center in the medulla oblongata
AUTONOMIC REGULATION OF HEART RATE
4 Other regulators of heart rate:
Cardiac accelerator nerves
Vagus (X) nerves
Baroreceptors
Chemoreceptors
sympathetic neurons that reach the heart travel here. They innervate the conduction system, atria, and ventricles Releases norepinephrine that increases HR.
Cardiac accelerator nerves
parasympathetic neurons travel here. Extends to the conduction system and atria. Releases acetylcholine (ACh) that decreases HR.
Vagus (X) nerves
sensory receptor that provides output to the CVS. Sensitive to blood pressure changes. Located in the arch of the aorta and carotid arteries (arteries in the neck that supply blood to the brain).
Baroreceptors
neurons sensitive to chemical changes in the blood, detect changes in blood levels of chemicals such as O2, CO2, and H+.
Chemoreceptors
exercise must be at least ___ to elevate cardiac output and accelerate metabolic rate
20 minutes
exercise that works large body muscles
Aerobic exercise
recommended sessions per week to improve cardiovascular health
3-5 sessions a week
decrease in the diameter of the blood vessel lumen
VASOCONSTRICTION
increase in the diameter of the blood vessel lumen
VASODILATION
enumerate the 5 blood vessels
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
Carry blood away from the heart to body tissues.
Their walls consist of 3 layers: endothelium, smooth muscle, and an outer layer
ARTERIES
Regulate blood flow from arteries into capillaries.
ARTERIOLES
3 layers of the artery:
- endothelium
- smooth muscle
- outer layer
Connect arterioles to venules; exchange vessels.
CAPILLARIES
Similar in structure to arterioles; their walls are thinner near the capillary end and thicker as they progress toward the heart.
VENULES
Are structurally similar to arteries, but their middle and inner layers are thinner. The outer layer of veins is the thickest layer. The lumen of a vein is wider than an artery.
VEINS
TRUE OR FALSE
Blood flows from regions of HIGHER pressure to regions of LOWER pressure
TRUE
Blood flows from regions of HIGHER pressure to regions of LOWER pressure
TRUE OR FALSE
the GREATER the pressure difference, the GREATER the flow
TRUE
the GREATER the pressure difference, the GREATER the flow
: Generated by contraction of the ventricles
: The pressure exerted by blood on the walls of a blood vessel
: Depends in part on the total volume of blood in the cardiovascular system (about 5 liters).
BLOOD PRESSURE
opposition to blood flow
VASCULAR RESISTANCE
3 FACTORS OF VASCULAR RESISTANCE
- Size of the blood vessel lumen
- Blood viscosity
- Total blood vessel length
NEGATIVE FEEDBACK SYSTEMS control blood pressure and blood flow through:
Heart rate
Stroke volume
Vascular resistance
Blood volume
: Regulate heart rate and stroke volume
: Neural and hormonal negative feedback systems
: Receives input from proprioceptors, baroreceptors, and chemoreceptors
The CARDIOVASCULAR (CV) CENTER in the medulla oblongata
4 HORMONES THAT HELP REGULATE BLOOD PRESSURE
- Renin-angiotensin-aldosterone (RAA) system
- Epinephrine & norepinephrine
- Antidiuretic hormone (ADH)
- Atrial natriuretic peptide (ANP)
Kidney secrete the this enzyme to increase B.P.
Renin-angiotensin-aldosterone (RAA) system
Sympathetic stimulation makes adrenal medulla release this to increase cardiac output.
Epinephrine & norepinephrine
Produced by Hypothalamus and released by posterior pituitary. Causes vasoconstriction and increased B.P.
Antidiuretic hormone (ADH)
Released by the cells in the atria of heart. Causes vasodilation and lowers B.P.
Atrial natriuretic peptide (ANP)
Blood vessels are organized into ____ that carry blood throughout the body.
CIRCULATORY ROUTES
2 MAJOR CIRCULATORY ROUTES:
- SYSTEMIC CIRCULATION
2. PULMONARY CIRCULATION
Includes the arteries and arterioles that carry blood containing O2 and nutrient from the left ventricle to systemic capillaries throughout the body, plus the veins and venules that return blood containing CO2 and wastes to the right atrium.
SYSTEMIC CIRCULATION
4 Parts of the aorta:
- Ascending aorta
- Arch of aorta
- Thoracic aorta
- Abdominal aorta
Takes deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood from the lungs to the left atrium.
PULMONARY CIRCULATION
Collects deoxygenated blood from the veins of the gastrointestinal tract and spleen and directs it into the hepatic portal vein of the liver. This routing allows the liver to extract and modify nutrients and detoxify harmful substances in the blood.
HEPATIC PORTAL CIRCULATION
: Exists only in the fetus. It involves the exchange of materials between fetus and mother via the placenta. The fetus derives O2 and nutrients from and eliminates CO2 and wastes into maternal blood.
FETAL CIRCULATION
the alternate expansion and elastic recoil of an artery with each heartbeat. It may be felt in any artery that lies near the surface or over a hard tissue.
PULSE
is the pressure exerted by the blood on the wall of an artery when the left ventricle undergoes systole and then diastole. It is measured by a sphygmomanometer.
BLOOD PRESSURE
the force of blood recorded during ventricular contraction.
SYSTOLIC BLOOD PRESURE (SBP)
the force of blood recorded during ventricular relaxation.
DIASTOLIC BLOOD PRESSURE (DBP)
normal blood pressure of a young adult male
< 120/80
GENERAL CHANGES IN THE CVS AS YOU AGE:
- Stiffness of the aorta
- Reduction in cardiac muscle fiber size
- Progressive loss of cardiac muscular strength
- Reduced cardiac output
- Decline in maximum heart rate
- Increase in systolic blood pressure
the major cause of heart disease and death in older Americans.
CORONARY ARTERY DISEASE (CAD)
increases with age.
CONGESTIVE HEART FAILURE (CHF) & ATHEROSCELOSIS
most common disorder affecting the heart and blood vessels and is the major cause of heart failure, kidney disease, and stroke. About 50 million Americans have this.
HYPERTENSION / PERSISTENTLY HIGH BLOOD PRESSURE
a failure of the CVS to deliver enough O2 and nutrients to meet metabolic needs.
SHOCK
a thin, weakened section of the wall of an artery or a vein that bulges outward, forming a balloon-like sac. If untreated, it enlarges and the blood vessel wall becomes so thin that it bursts.
ANEURYSM
4 Common causes of aneurysm:
- Atherosclerosis
- Syphilis
- Congenital blood vessel defects
- Trauma
4 Results of aneurysm:
- Massive hemorrhage
- Severe pain
- Stroke
- Death
Branch of the ascending aorta that supplies the heart.
R&L Coronary Arteries
Branch of the brachiocephalic trunk that supplies the right side of the head and neck.
Right common carotid artery
Branch of the brachiocephalic trunk that supplies the right upper limb.
Right subclavian artery
Branch of the brachiocephalic trunk that supplies the left side of the head and neck.
Left common carotid artery
Branch of the brachiocephalic trunk that supplies the left upper limb.
Left subclavian artery
Branch of the thoracic aorta that supplies the bronchi of the lungs.
Bronchial arteries
Branch of the thoracic aorta that supplies the esophagus.
Esophageal arteries
Branch of the thoracic aorta that supplies the intercostal and chest muscles.
Posterior intercostal arteries
Branch of the thoracic aorta that supplies the superior and posterior surfaces of diaphragm.
Superior phrenic arteries
Branch of the abdominal aorta that supplies the inferior surface of diaphragm.
Inferior phrenic arteries
Branch of the celiac trunk that supplies the liver, stomach, duodenum, & pancreas.
Common hepatic artery
Branch of the celiac trunk that supplies the stomach and esophagus.
Left gastric artery
Branch of the celiac trunk that supplies the Spleen, pancreas, stomach.
Splenic artery
Branch of the abdominal aorta that supplies the small intestine, cecum, ascending & transverse colons, & pancreas.
Superior mesenteric artery
Branch of the abdominal aorta that supplies the Adrenal (suprarenal) glands.
Suprarenal arteries
Branch of the gonadal arteries that supplies the Ovaries (female).
Ovarian arteries
Branch of the gonadal arteries that supplies the Testes (male).
Testicular arteries
Branch of the abdominal aorta that supplies the Kidneys.
Renal arteries
Branch of the abdominal aorta that supplies the Transverse, descending, & sigmoid colons; rectum.
Inferior mesenteric artery
Branch of the common iliac arteries that supplies the Lower limbs.
External iliac arteries
Branch of the common iliac arteries that supplies the Uterus (female), prostate male). Muscles of buttocks, & urinary bladder.
Internal iliac arteries
Divides to form the right subclavian artery and right common carotid artery.
Brachiocephalic Trunk
Extends from the brachiocephalic trunk then into the axilla. Distributes to the brain and spinal cord, neck, shoulder, ad chest.
Right Subclavian Artery
Continuation of the RSA. Distributes to the shoulder.
Axillary Artery
Provides main blood supply to the arm. Commonly used to measure blood pressure
Brachial Artery
Passes along the lateral aspect of the forearm and through the wrist and hand. Common site for measuring radial pulse.
Radial Artery
Passes along the medial (ulnar) aspect of the forearm then into the wrist and hand.
Ulnar Artery
Formed by the ulnar artery. The arch extends across the palm and gives rise to blood vessels that supply the palm and fingers.
Superficial Palmar Arch
Formed by the radial artery. The arch extends across the palm and gives rise to blood vessels that supply the palm.
Deep Palmar arch
The right vertebral artery passes through the foramina of the transverse process of the cervical vertebrae and enters the skull through the foramen magnum to reach the inferior surface of the brain. Unites with the left vertebral artery to form basilar artery.
The vertebral artery supplies the posterior portion of the brain with blood. The basilar artery supplies the cerebellum, pons, and internal ear.
Vertebral Artery
Begins at the branching of the brachiocephalic trunk and supplies structures in the head. Near the larynx, it divides into the right external and internal carotid arteries.
Right Common Carotid Artery
Supplies structures external to the skull.
External Carotid Artery
Supplies structures internal to the skull.
Internal Carotid Artery
Divides into the same branches with the same names as the RCCA.
Left Common Carotid Artery
Divides into the same branches with the same names as the RSA.
Left Subclavian Artery
Enumerate the 10 arteries of the pelvis and lower limbs
- Common iliac artery
- Internal iliac arteries
- External iliac arteries
- Femoral Arteries
- Popliteal Arteries
- Anterior Tibial Arteries
- Posterior Tibial Arteries
- = Fibular Arteries
- = Medial Plantar Arteries
- = Lateral Plantar Arteries
Enumerate the 3 veins of the systemic circulation:
- Coronary Sinus
- SVC
- IVC
Main vein of the heart. It receives almost all venous blood from the myocardium. It opens into the RA between the opening of the IVC and tricuspid valve.
Coronary Sinus
Drains blood into the superior part of the RA. It begins by the union of the right and left brachiocephalic veins and enters the RA. It drains the head, neck, chest, & upper limbs.
Superior Vena Cava (SVC)
The largest vein in the body. It begins by the union of the common iliac veins, passes through the diaphragm, and enters the inferior part of the RA. It drains the abdomen, pelvis, and lower limbs. It is commonly compressed during the later stages of pregnancy by the enlarging uterus, producing edema of the ankles and feet and temporary varicose veins.
Inferior Vena Cava (IVC)
Enumerate the 3 veins of the head and neck:
- Internal Jugular Veins
- External Jugular Veins
- Vertebral Veins
The dural venous sinuses drain blood from the cranial bones, meninges, and brain. The R&L internal jugular veins pass inferiorly on either side of the neck lateral to the internal carotid and common carotid arteries. They then unite with the subclavian veins to form the R&L brachiocephalic veins. From here, blood flows into the SVC.
General structures drained:
Brain (through the dural venous sinuses)
Face & neck
Internal Jugular Veins
The R&L EJV empty into the subclavian veins.
General structures drained are external to the cranium:
Scalp
Superficial and deep regions of the face
External Jugular Veins
The R&L vertebral veins empty into the brachiocephalic veins in theneck. They drain deep structures in the neck: Cervical vertebrae Cervical spinal cord Some neck mucles
Vertebral Veins
Enumerate the 3 superficial veins of the upper limbs
- Cephalic veins
- Basilic veins
- Medial Antebrachial veins
Enumerate the 5 deep veins of the upper limbs
- Radial veins
- Ulnar veins
- Brachial veins
- Axillary veins
- Subclavian veins
The pair begin at the deep palmar venous arches. Drain the palms.
Radial veins
The pair begin at the superficial palmar venous arches. Drain the medial aspect of the forearms, pass alongside each ulnar artery.
Ulnar veins
The pair accompany the brachial arteries that drain the forearms, elbow joints, and arms
Brachial veins
Ascend to become the subclavian veins that drain the arms, axilla, and upper part of the chest wall.
Axillary veins
Continuations of the axilla veins that unites with the internal jugular veins to form the brachiocephalic veins. They drain the arms, neck, and thoracic wall
Subclavian veins
Begin on the lateral aspect of the dorsal venous networks of the hands, networks of veins on the dorsum of the hands that drains the fingers. The drain blood from the lateral aspect of the upper limbs
Cephalic veins
Begin on the medial aspect of the dorsal venous networks of the hands and drain blood from the medial aspects of the upper limbs.
Basilic veins
Begin in the palmar venous plexuses, networks of veins on the palms. They drain the palms and forearms.
Medial Antebrachial veins
Enumerate the 2 superficial veins of the lower limbs
- Great Saphenous veins
2. Small Saphenous veins
The longest veins in the body begin at the medial side of the dorsal venous arches of the foot, networks of veins on the top of the foot that collect blood from the toes. The empty into the femoral veins and drain the leg and thigh, the groin, external genitals, and abdominal wall.
Great Saphenous veins
Begin at the lateral side of the dorsal venous arches of foot. They empty into the popliteal veins behind the knee and drain blood from the foot and leg. They have 9-12 valves.
Small Saphenous veins
Enumerate the 4 deep veins of the lower limbs
- Posterior tibial veins
- Anterior tibial veins
- Popliteal veins
- Femoral veins
They accompany the posterior tibial artery through the leg and drain the foot and posterior leg muscles. They drain blood from the fibular veins about two-thirds of the leg which serve the lateral and posterior leg muscles.
Posterior tibial veins
The pair arise in the dorsal venous arch and accompany each anterior tibial artery. They unite with the posterior tibial veins to form the popliteal vein. They drain the ankle joint, knee joint, tibiofibular joint, and anterior portion of the leg.
Anterior tibial veins
Formed by the union of the anterior and posterior tibial veins. They drain the skin, muscles, and bones of the knee joint.
Popliteal veins
Accompany each femoral artery and are continuations of the popliteal veins. They drain the muscles of the thigh, femur, external genitals, and superficial lymph nodes.
Femoral veins
