Cardiovascular System
Advanced Biology Spring 2013
Vocabulary Development
 Angio- vessel
 Phleb- vein
 Ather- porridge
 Scler- hard
 Brady- slow
 Syn- together
 Diastol- dilation
 Systol- contraction
 Edem- swelling
 Tachy- rapid
 Gram- something written
 Lun- moon
 Myo- muscle
 Papill- nipple
Introduction
 Cardiovascular system- all blood vessels, capillaries, veins,
arteries, & heart make up the cardiovascular system
 Blood vessels form 2 circuits:
 Pulmonary circuit- sends oxygen poor blood to the lungs to
pick up oxygen & unload carbon dioxide
 Systemic circuit- sends oxygen rich blood & nutrients to all
body cells & removes wastes
Structure of the Heart
 Size & Location of the Heart
 Size varies with body size (average adult: 14 cm long & 9 cm
wide)
 Inside the thorax
 Rests on the diaphragm
Structure of the Heart
 Coverings of the Heart
 Pericardium- encloses the heart & the proximal ends of the
large vessels that are attached to it
 Fibrous pericardium- outer fibrous layer that protects the double layered
serous membrane
 Parietal pericardium- inner lining of the fibrous pericardium
 Visceral pericardium- inner most layer of the double membrane &
directly covers the heart muscle
 Pericardial cavity- space between the parietal & visceral pericardia filled
with fluid
Structure of the Heart
 Wall of the Heart
 3 distinct layers:
 Epicardium- outer layer
 Protects the heart by reducing friction
 Serous membrane consists of connective tissue
 Includes capillaries & nerve fibers
 Myocardium- middle layer
 Thick & consists mostly of cardiac muscle tissue that pumps blood out of
the heart chambers
 Endocardium- inner layer
 Consists of epithelium & underlying tissue
 Contains blood vessels & specialized cardiac muscle fibers called Purkinje
fibers
 Lines all chambers of the heart & covers the structures that project into
them
Structure of the Heart
 Heart Chambers & Valves
 Divided into 4 hollow chambers; 2 left & 2 right
 Atria- upper chambers
 Thin walls
 Receive blood returning to the heart
 Auricles- small projections of the atria that increase atrial volume slightly
 Right & left atrias are separated by the interatrial septum
 Ventricles- lower chambers
 Force blood out of the heart into arteries
 Right & left ventricles are separated by the interventricular septum
 Ventricles & atria on each side of the heart are separated by atrioventricular
orifice which is guarded by an AV valve (atrioventricular valve)
Structure of the Heart
 Heart Chambers & Valves
 Right atrium
 Receives blood from 2 large veins: superior vena cava & inferior vena cava
 Both return blood low in oxygen from tissues
 Coronary sinus- drains blood into the right atrium from the myocardium
of the heart
 Right atrium is separated from the right ventricle by a tricuspid
valve (right atrioventricular valve)
 Allows blood to flow from the right atrium into the right ventricle but
not in the other direction
Structure of the Heart
 Heart Chambers & Valves
 Right Ventricle
 Thinner muscular wall than the left ventricle
 Pumps blood short distance through the pulmonary trunk which divides
into the left & right pulmonary arteries that lead to the lungs
 Pulmonary valve is at the base of the trunk (pulmonary semilunar
valve) & prevents blood from flowing back in the right ventricle from
the pulmonary trunk
Structure of the Heart
 Heart Chambers & Valves
 Left atrium
 Receives blood from 4 pulmonary veins (2 from each lung)
 Blood passes from the left atrium to the left ventricle through the
atrioventricular orifice through a mitral valve (bicuspid valve; left
atrioventricular valve)
o Prevents blood from flowing back into the left atrium from the left
ventricle
Structure of the Heart
 Heart Chambers & Valves
 Left Ventricle
 Contracts & sends blood through the aorta which branches out and sends
blood to all parts of the body
 Aortic valve (aortic semilunar valve; tricuspid)
o opens to allow blood to leave the left ventricle but not to go back
into the left ventricle
 Mitral & tricuspid valves are also called atrioventricular
valves because they are between the atria and ventricles
 Pulmonary & aortic valves are called semilunar valves
because of the half-moon shaped cusps
Path of Blood Through the Heart
 Blood from systemic circuits
 Venae cavae & coronary sinus
 Right atrium
 Through tricuspid valve
 Right ventricle
 Through pulmonary valve
 Pulmonary trunk
 Pulmonary arteries
 Alveolar capillaries (lungs)
 Pulmonary veins
 Left atrium
 Through mitral valve
 Left ventricle
 Aortic valve
 Blood to the systemic circuit
Blood Supply to the Heart
Aorta
Right coronary
artery
Left coronary artery
Posterior
interventricular
artery
Marginal artery
Circumflex artery
Anterior
interventricular
artery
Myocardial
capillaries in
ventricular walls
Myocardial
capillaries in walls of
right atrium & right
ventricle
Myocardial
capillaries in wall of
left atrium & left
ventricle
Myocardial
capillaries in
ventricular walls
Cardiac Veins
Coronary sinus
Right atrium
Heart Actions
 Actions are regulated so that…
 Atria contract, atrial systole, while the ventricles relax,
ventricular diastole
 Ventricles contract, ventricular systole, while the atria relax,
atrial diastole
 Both atria & ventricles relax for a brief moment
 These actions make up a complete heartbeat and is called the
cardiac cycle
Heart Actions
 Cardiac Cycle
 Changes in pressure in the heart chambers during a cardiac
cycle cause valves to open & close
 During ventricular diastole (atrial systole) the pressure difference
between atria & ventricles opens the AV valves allowing the ventricles to
fill
 During ventricular systole (atrial diastole) the AV valves are closed, atria
are relaxed and blood flows back into the atria as the ventricles contract
Blood Vessels
 Form a closed circuit of tubes that carries blood from the
heart to the body cells and back
 Includes:
 Arteries
 Arterioles
 Capillaries
 Venules
 Veins
Blood Vessels
 Arteries & arterioles conduct blood away from the ventricles
of the heart & lead to capillaries
 Arteries- carry blood at high pressure
 Arterioles- arteries sub divide into progressively thinner tubes
& give rise to arterioles
 Capillaries- smallest-diameter blood vessels, connect the
smallest arterioles & venules
 Venules & veins return blood from the capillaries to the atria
 Venules- microscopic vessels that come from capillaries and
merge to form veins
 Veins- carry blood back to the atria & follow pathways similar to
the arteries
Paths of Circulation
 Pulmonary circuit- consists of vessels that carry blood from
the heart to the lungs and back to the heart
 Systemic circuit- carries blood from the heart to all other
parts of the body and back again & include coronary
circulation
Paths of Circulation
 Pulmonary Circuit
 Pulmonary trunk of right ventricle
 Pulmonary trunk is divided into the left & right pulmonary
arteries, which enter the right & left lungs
 Lobar Branches
 3 in right
 2 in left
 Lobar branches divide into arterioles
 Arterioles divide into networks of capillaries
 Alveolar capillaries exchange gases between the blood & air
 Taking out carbon dioxide and putting in oxygen
Paths of Circulation
 Pulmonary Circuit cont…
 Pulmonary venules
 Alveolar capillaries send oxygen rich blood here
 Pulmonary venules join to form smalls veins
 Small veins join to form the 4 pulmonary veins return blood to
the left atrium
 2 from each lung
Paths of Circulation
 Systemic Circuit
 Freshly oxygenated blood moves from the left atrium to the left
ventricle
 Left ventricle contracts pushing blood into the aorta, which
branches out and sends oxygenated blood to all of the body
tissues
 Left ventricle contraction is also responsible for the force that returns
blood to the right atrium to start the pulmonary circuit
Arterial System
 Aorta
 Largest diameter artery in the body
 Extends upward from the left ventricle & arches over the heart
to the left & descends just in front of and to the left of the
vertebral column
 several branches
Arterial System
 Principal Branches of the Aorta
 Ascending aorta- part of the aorta that sends blood up; first part
of the aorta
 Aortic sinus- swelling in the aortic wall, behind each cusp of the aortic
valve
 Right & left coronary arteries begin here
 Includes the arch of the aorta
Arterial System
 Arch of the Aorta
 3 major branches of the ascending aorta
 Brachiocephalic- supplies blood to the tissues of the upper limb & head
o Divides into:
• Right common carotid artery- carries blood to the right side of the neck
and head
• Right subclavian artery- carries blood to the right arm


Left Common Carotid- carries blood to the left side of the neck
Left Subclavian Artery- carries blood to the left arm
Arterial System
 Descending Aorta
 Directly in front of the vertebral column
 Thoracic aorta- part of the descending aorta above the diaphragm
 Branches include:
o Bronchial artery- supplies blood to the bronchi
o Pericardial artery- supplies blood to the pericardium
o Esophogeal artery- supplies blood to the esophagus
o Mediastinal artery- supplies blood to the mediastinum (area above
the diaphragm surrounding the heart and lungs)
o Posterior intercostal artery- supplies blood to the thoracic wall
 Abdominal aorta- part of the descending aorta that is below the
diaphragm
 Divides into several different arteries
Arterial System
 Branches of the Abdominal Aorta










Celiac artery- supplies organs of the upper digestive tract
o Splits into gastric, splenic, and hepatic arteries
Phrenic artery- supplies the diaphragm
Superior mesenteric artery - supplies portions of the small & large
intestines
Suprarenal artery- supplies the adrenal glands
Renal artery- supplies the kidney
Gonadal artery- supplies the ovaries or testes
Inferior mesenteric artery- supplies the lower portion of the large
intestine
Lumbar arteries- supply the posterior abdominal wall
Middle sacral artery- supplies the sacrum & coccyx
Common iliac artery- supplies the lower abdominal wall, pelvic organs,
and lower limb
Arterial System
 Arteries to the Brain, Head, & Neck
 Branches of the subclavian & common carotid arteries supply
blood to the structures of the head, brain, and neck
 Vertebral arteries – come from the subclavian arteries
Basilar artery- runs along the ventral brainstem & branches out leading
to the pons, midbrain, & cerebellum
 Posterior cerebral arteries- supplies parts of the occipital & temporal
lobes of the cerebrum
 Thyrocervical arteries- branches and supplies blood to thyroid gland,
parathyroid glands, larynx, trachea, esophogus, & pharynx
 Costcocervical arteries- supply blood to muscles in the neck, back, &
thoracic wall

Arterial System
 Arteries of the Head, Neck, & Brain cont…
 Common carotid arteries divide to form internal & external carotid
articles
 External Carotid Artery
 Upward on the side of the head & branches out to structures in the neck,
face, jaw, scalp, & base of the skull
 Main vessels of the external carotid artery
 Superior thyroid artery- hyoid bone, larynx, thyroid gland
 Lingual artery- tongue, muscles of the tongue, salivary glands beneath the
tongue
 Facial artery- pharynx, palate, chin, lips, nose
 Occipital artery- scalp on the back of the skull, the meninges, mastoid
process, muscles of the neck
 Posterior auricular artery- ear & scalp over the ear
 Terminates by dividing into maxillary & superficial temporal arteries
Arterial System
 Arteries of the Head, Neck, & Brain cont…
 Internal Carotid Artery
 Provides the major blood supply to the brain
 Major branches:
 Ophthalmic artery- supplies the eyeball & muscles & accessory organs
associated with the orbit
 Posterior communicating artery- forms part of the cerebral arterial
circle
 Anterior choroid artery- supplies the choroid plexus within the lateral
ventricle of the brain & to nerve structures of the brain
 Terminates by dividing into the anterior & middle cerebral arteries
Arterial System
 Arteries to the Shoulder & Upper Limb
 Subclavian artery passes through the first rib and clavicle and
turns into the axillary artery
 Axillary artery- supplies branches to structures in the axilla &
chest wall, part of the mammary gland, the upper end of the
humerus, the shoulder joint, muscles in the back, shoulder, &
chest
 Turns into the brachial artery when it leaves the axilla
 Brachial artery- along the humerus to the elbow; supplies the
triceps and other muscles in the upper arm
 Branches at the elbow into the radial & ulnar arteries
Arterial System
 Arteries of the Shoulder & Upper Limb cont…
 Ulnar artery- travels down the ulnar side of the forearm to the
wrist; supply blood to the flexor and extensor muscles in the
forearm
 Radial artery- continuation of the brachial artery, travels down
the radial side of the forearm to the wrist; supplies the lateral
muscles of the forearm
Arterial System
 Arteries of the Thoracic & Abdominal Walls
 Branches from the subclavian artery and the thoracic aorta feed
the thoracic & abdominal walls
 Internal thoracic artery- originates in the base of the neck and
passes downward behind the upper six ribs
 Branches in to 2 anterior costal arteries at each rib

Anterior costal arteries- supply the intercostal muscles
 Posterior intercostal arteries- branch from the thoracic aorta &
supply the intercostal muscles, the vertebrae, the spinal cord, &
deep muscles of the back
Arterial System
 Arteries of the Pelvis & Lower Limb
 Common iliac arteries- branch from the abdominal aorta at the pelvic
brim & supply blood to the pelvic organs, gluteal regions, & lower
limbs
 Descend & divide into internal & external branches
 Internal iliac artery branches include:
 Iliolumbar artery- supplies the ilium & muscles of the back
 Superior & inferior gluteal arteries- supplies the gluteal muscles, pelvic
muscles, & skin of the buttocks
 Internal pudendal artery- supplies the alimentary canal, the external
genitalia, & the hip joint
 Superior & inferior vesicular arteries- supplies the urinary bladder & in males
also the supply the seminal vesicles & prostate gland
 Middle rectal artery- supplies the rectum
 Uterine artery- supplies the uterus & vagina
Arterial System
 Arteries of the Pelvis & Lower Limb cont…
 External iliac artery- provides the main blood supply to the
lower limb
 2 large branches: inferior epigastric artery & deep circumflex iliac artery
Supply the muscles & skin in the lower abdominal wall
 Femoral artery- has many branches
 Superficial circumflex iliac artery- supplies lymph nodes & skin of the
groin
 Superficial epigastric artery- supplies the skin of the lower abdominal
wall
 Deep femoral artery- supplies the hip joint & muscles of the thigh;
largest branch of the femoral artery
 Deep genicular artery- supplies the distal ends of thigh muscles & the
anastomosis around the knee joint

Arterial System
 Arteries of the Pelvis & Lower Limb
 Popliteal artery- supply blood to the knee joint & to certain
muscles in the thigh & calf
 Femoral artery becomes the popliteal artery
 Anterior tibial artery- runs between the tibia & fibula &
supplies the skin & muscles in the anterior & lateral regions of
the leg
 Posterior tibial artery- beneath the calf muscle & supplies the
skin, muscles, & other tissues of the lower leg
 Medial & lateral plantar arteries-supply the instep, heel, & toes
 Fibular artery- extends downward along the fibula