The Heart and Blood Vessels

Chapters 22 + 23

What vessels take blood away from the heart and branch into smaller forms?

arteries

What vessels bring blood back to the heart and merge into larger forms?

veins

Through contractions of its chambers, where does the heart pump blood to in the body?

lungs and tissues of the body

What are the arteries and veins that enter and leave the heart?

great vessels

How does blood flow through the heart?

unidirectionally

What circulation pumps blood to the lungs and is on the right side?

pulmonary circulation

What circulation pumps blood to the tissues of the body and is on the left side?

systemic circulation

How is the pressure of the pulmonary circulation compared to the pressure of the systemic circulation?

low

What is the tough sac where the heart is enclosed in?

pericardium

What is the outer layer of the pericardium?

fibrous pericardium

What is the inner layer of the pericardium?

serous pericardium

What is the layer of serous pericardium right up under the fibrous pericardium?

parietal layer

What is the layer of serous pericardium that is tight onto the heart?

visceral layer

What is the pseudo-cavity where the percardium, with the heart enclosed, is located?

mediastinum

What space is between the two layers of the pericardium?

pericardial cavity

What is the pericardial cavity filled with, that reduces friction between the beating heart and other structures in the thoracic cavity?

serous fluid

What is the outer layer of the wall of the heart, formed from the visceral layer of the pericardium?

epicardium

What types of tissues does epicardium contain?

simple squamous epithelium, areolar connective tissue

What is the middle layer of the wall of the heart?

myocardium

What type of tissue does myocardium contain?

cardiac muscle tissue

What is the inner layer of the wall of the heart?

endocardium

What type of tissue does endocardium contain?

areolar connective tissue

What receives blood from the body and the lungs, respectively?

right and left atrium

What pumps blood to the lungs and the body, respectively?

right and left ventricles

What is the heart’s ability to generate its own electrical impulses, leading to contraction?

autorhythmicity

Where does the electrical impulses of autorhythmicity start in, located in the roof of the right atrium, near the entrance of the superior vena cava?

sinoatrial node

What do the electrical impulses of autorhythmicity innervate, causing them to contract simultaneously?

right and left atrium

What do the electrical impulses of autorhythmicity pass, located in the floor of the right atrium?

atrioventricular node

After the pause in the atrioventricular node, the impulse travels to where, extending into the interventricular system?

atrioventricular bundle

Once in the septum during autorhythmicity, what does the atriventricular bundle bifurcate into?

right and left bundles

What do the right and left bundles during autorhythmicity spread the impulse to, starting the myocardial fibers in the ventricles, contracting from the apex of the heart towards the atrium?

Purkinje fibers

What autonomic branch slows down the heartbeat?

parasympathetic branch

What autonomic branch speeds the heartbeat up?

sympathetic branch

What is the process of the time from the start of a single heartbeat to the start of the next heartbeat?

cardiac cycle

What is it when a chamber contracts during a cardiac cycle?

systole

What is it when a chamber relaxes during a cardiac cycle?

diastole

During both systole and diatole, for a short period of time, are all the valves of the heart open or closed at the same time?

closed

What joins arteries to veins?

capillaries

What is the most inner layer of the walls of arteries and veins?

tunica intima

What tissue types does the tunica intima contain?

simple squamous epithelium, areolar connective tissue

What is the middle layer of the walls of arteries and veins?

tunica media

What tissue type does the tunica media contain, and what does it cause?

smooth muscle tissue, can cause vasoconstriction or vasodilation

What is the outer layer of the walls of the arteries and veins?

tunica externa

What type of tissue does the tunica externa contain?

connective tissue

To accommodate a blood supply to large blood vessels, what small arteries are found in the tunica externa?

vaso vasorum

What is the largest type of arteries, and what do they branch into?

elastic, branch into muscular arteries

What are the medium-sized arteries?

muscular

What is the inner ring of a muscular artery, separating the tunica intima from the tunica media?

internal elastic lamina

What is the outer ring of a muscular artery, separating the tunica media from the tunica externa?

external elastic lamina

What are the smallest types of arteries?

arterioles

Where are arterioles found?

tunica media

When arterioles are contracted (sympathetic), how does the blood pressure change?

increase

When arterioles are relaxed (parasympathetic), how does the blood pressure change?

decrease

What are the smallest of the blood vessels?

capillaries

What layer of the walls of the vessels do capillaries consist of?

tunica intima

Capillaries are the only blood vessels where what can occur between blood and tissues?

metabolic exchange

What do capillaries form?

capillary beds

What is each capillary bed fed by, which supplies true capillaries?

metarteriole

What does the metarteriole become after the last true capillary branches off?

thoroughfare channel

What does the thoroughfare channel connect to, which becomes the venous system?

postcapillary venule

What is the most common, completely lined type of capillary?

continuous capillary

What capillary contains pores that allow for fluid exchange and is found in the kidneys?

fenestrated capillary

What capillary contains large gaps and an incomplete basement membrane and can transport large molecules and cells to/from the blood?

sinusoid

What drains capillaries and returns blood to the heart?

veins

Veins contains 60% of the blood volume at rest, which is known as the?

blood reservoir

What is the smallest type of veins?

venules

What is the smallest venule?

postcapillary venule

What occurs in the postcapillary venules?

diapedesis

Where do the small and medium veins travel to?

muscular arteries

Where do the large veins travel to?

elastic arteries

What pump squeezes veins when muscle contracts and forces the blood in the vein to travel toward the heart?

skeletal muscle pump

What pump functions in the abdominopelvic cavity?

respiratory pump

In the respiratory pump, what does the diaphragm do on inhalation?

contract

On inhalation in the respiratory pump, what happens to the volume, the pressure, and the veins?

decreasing the volume in the abdominal cavity, increasing the pressure, the veins are compressed

In the respiratory pump, what does the diaphragm do on exhalation?

relax

On exhalation in the respiratory pump, what happens to the volume, the pressure, and the veins?

decreasing the volume in the thoracic cavity, increasing the pressure, the veins are squeezing

What exists when the systolic and diastolic pressure are NOT equal?

pulse

Where is blood pressure the greatest?

aorta

How does blood pressure change in the superior and inferior vena cava when they empty into the right atrium?

decreases to almost zero

What type of circulation consists of blood vessels that extend to all body regions?

systemic circulation

What circulation is responsible for oxygenating blood?

pulmonary circulation

What separates the atria from the ventricles and is made up of dense regular connective tissue?

fibrous skeleton

What is at the superior end of the right ventricle, where it connects to the pulmonary semilunar valve and is a smooth area?

conus anteriosus

What forms 2/3 of the cerebral arterial circle?

right and left carotid arteries

What forms the remaining 1/3 of the cerebral arterial circle?

basilar artery

What three abdominal veins make up the hepatic portal system?

inferior mesenteric vein, superior mesenteric vein, splenic vein

What are the basilic and cephalic veins joined by?

median cubital vein

What is the order of veins that allows for blood return in the thoracic and abdominal walls?

hemiazygos vein, accessory hemiazygos vein, azygos vein, superior vena cava