Archive for category: Biology

The cardiovascular (CV) system consists of the heart, and blood vessels (arteries, capillaries and veins).

What are the functions of the CV system?  ___________________________________________________

The heart is a hollow, ___________-shaped, muscular pump within the _________; it rests on the _________.

The average adult heart is ___________ cm long and ___________ cm wide.

The heart lies posterior to the sternum; its apex extends to the _________ intercostal space.

The pericardium consists of two layers: the outer, tough connective tissue _________ pericardium, surrounding a more delicate double-layered sac that surrounds the heart.

The inner layer directly covers the heart and is called the _________ pericardium, or _________.

At the base of the heart, the inner layer folds back to become the __________ pericardium.

Between the visceral and parietal layers of the pericardium is a potential space called the _________ cavity; it is  filled with ________ fluid, which reduces friction.

The wall of the heart is composed of three distinct layers.  The outermost layer, the __________, is made up of

connective tissue and epithelium, and contains  blood and lymph capillaries along with __________ arteries that

provide blood to the heart.  It is the same as the _________ pericardium.

The middle layer, called __________, consists of cardiac muscle and is the thickest layer of the heart wall.

The inner __________ is smooth and is made up of connective tissue and epithelium, and is

continuous with the endothelium of major vessels joining the heart.

The heart has four internal chambers: two upper chambers and two lower chambers.  A __________ divides the

chambers on the left side from those on the right.

Upper chambers, ___________,  receive blood returning to the heart, and have thin walls and ear-like auricles

projecting from their exterior.

Below them, the thick-muscled ___________ pump blood to the body and lungs.

The right atrioventricular (AV) valve, called __________ valve, and left AV valve, called either ____________ or

the __________ valve, have cusps to which strings called ________ ________ attach.  These strings are, in turn,

attached to ___________ muscles in the inner heart wall, which contract during ventricular contraction to prevent

the backflow of blood through the AV valves.

Where are the semilunar valves found?  _________________________________________________________

What is their function?  ______________________________________________________________________

Rings of dense connective tissue surround the pulmonary trunk and aorta to provide attachments for the heart

___________ and _________ _fibers_.  These tough rings prevent dilating of tissue in this area.

Superior and inferior vena cava, __right atrium__, __tricuspid____, __right   ventricle_,

___pulmonary____, _pulmonary trunk, pulmonary arteries, pulmonary capillaries  of lungs, _

pulmonary veins_, _left atrium__, _bicuspid / mitral_ valve, _left    ventricle___, __aortic  valve, and through the

arteries to provide blood to the body cells.

Which part of the pathway is pulmonary?  _____________________________________________________

Which part of the pathway is systemic?  _______________________________________________________

________________________________________________________________________________________

What is the function of pulmonary circulation?  _________________________________________________

Of systemic circulation?  ___________________________________________________________________

The first branches off of the aorta, which carry oxygen-rich blood, are the right and left _________

arteries that feed the heart muscle itself.  Branches of these arteries feed many capillaries of the myocardium.

The heart muscle requires a continuous supply of oxygen-rich blood, so smaller branches of arteries often have

_________ as alternate pathways for blood, should one pathway become blocked.

___________ veins drain blood from the heart muscle, and carry it to the coronary   _________, which drains into the right atrium.

The cardiac cycle consists of the atria beating in unison, called atrial _________, while the ventricles rest, called

ventricular _________.  This is followed by the contraction of both ventricles, called ventricular _________, while

the atria relax, called atrial _________.  Then the entire heart relaxes for a brief moment.

During the cardiac cycle, pressure within the heart chambers rises and falls.  These pressure changes open and

close _________.

When the atria fill, pressure in the atria is ______________ than that of the ventricles, which forces the

_________ and _________ valves open.

Pressure inside atria rises further as they contract, forcing the remaining blood into the ventricles.

When the ventricles contract, pressure inside them ______________ sharply, causing the ___________ and

________ valves to close, and the ___________ and ___________ valves to open.

As the ventricles contract, __________ muscles contract, pulling on _________________ and preventing

the backflow of blood through the tricuspid and mitral valves.

Heart sounds can be described as a “lubb-dupp” sound.  The first sound (lubb) occurs as the ___________

contract and the ___________ and _________valves are closing.  The second sound (dupp) occurs as

__________ relax and aortic and __________ valves are closing.

A mass of merging fibers that act as a unit is called a functional __________; one exists in the atria

and one in the ventricles.

Specialized cardiac muscle tissue conducts impulses throughout the myocardium and comprises the cardiac

conduction system.  A self-exciting mass of specialized cardiac muscle called the _________ node (_________ node),

located in the posterior right atrium, generates the impulses for heartbeats.  Therefore, it is also called the

_________ of the heart.

Impulses spread next to the atrial ______________; it contracts, and impulses travel to the junctional fibers

leading to the __________ node (_________ node) located in the septum.

Junctional fibers are small, allowing the atria to contract before the impulse spreads rapidly over the ventricles.

The impulse proceeds to the next conduction structure, the ___________ bundle (Bundle of _His_),  which splits into

the left and right _________ _________.  These branches give rise to __________ fibers, which lead into the

ventricular myocardium and the papillary muscles.

The first wave, the _________ wave, corresponds to the __________ of the atria.

The __________ complex corresponds to the ___________ of the ventricles and hides the ___________

of the atria.

The ___________ wave ends the ECG pattern and corresponds to ventricular ___________.

In each case, depolarization leads to contraction of the chamber, and repolarization leads to relaxation.

The amount of blood pumped at any time must adjust to the current needs of the body (more is needed during

strenuous exercise).  The SA node is innervated by branches of the _____________ and ___________

divisions of the nervous system, so the CNS helps to control heart rate. Impulses from the former speed up and

impulses from the latter  slow down heart rate.

The ___________ control center of the __________   ___________ maintains a balance between the

two autonomic divisions of the nervous system in response to messages from ____________, which detect

changes in blood pressure.

Impulses from the _________ or _________ may also influence the cardiac control center.  Body

temperature and the concentrations of certain ___________ also influence heart rate.

The blood vessels (arteries, arterioles, capillaries, venules, and veins) form a closed tubular system that carries

blood away from the heart, to the cells, and back again.

Arteries are strong, elastic vessels adapted for carrying high-pressure blood away from the heart.

Arteries become smaller as they divide and become ___________.

The wall of an artery consists of an inner endothelial layer, called the tunica _______.  The middle layer, called the

tunica ___________  is made up of smooth muscle and elastic connective tissue.  The tunica __________ is the

outermost layer of connective tissue.

Arteries are capable of ___________ as directed by sympathetic impulses; when impulses are

inhibited, the diameter of the vessel increases, which is called _________.

Capillaries are the smallest vessels, consisting only of a layer of _________, through which substances

are exchanged with tissue cells.

Areas with a great deal of metabolic activity (leg muscles, for example) have higher densities of capillaries.

__________ sphincters can regulate the amount of blood entering a capillary bed, and are controlled

by the ___________ concentration in the area.  If blood is needed elsewhere in the body, the capillary beds in

less important areas are shut down.

Blood entering capillaries contains high concentrations of __________ and _________ that diffuse out of the

capillary wall and into the _________ ___________.

Why do plasma proteins remain in the blood?  ___________________________________________

____________ pressure drives the passage of fluids and small molecules out of the capillary at this point.

At the venular end of the capillary, ___________ pressure , due to the proteins in the blood, causes much of the

tissue fluid to return to the bloodstream.  ____________ capillaries collect excess tissue fluid and return it to the

circulation.

Small vessels called ___________ lead from capillaries, and merge to form larger ___________ that

return blood to the heart.

Veins have the same three layers as arteries, and have flap-like __________ inside to prevent backflow of

blood.

How do veins differ from arteries?  _____________________________________________________

Blood pressure is the force of blood against the inner walls of blood vessels anywhere in the cardiovascular

system, although the term “blood pressure” usually refers to ___________ pressure.

Arterial blood pressure rises and falls, following a pattern established by the cardiac cycle.  During ventricular

contraction, arterial pressure is at its __________ or _________ pressure.  When the ventricles are relaxing,

arterial pressure is at its ___________  or ___________ pressure.

The surge of blood that occurs with ventricular contraction can be felt at certain points in the body as a

__________.

What are the four factors that affect blood pressure?  _____________________________________________ ______________________________________________________________________________________________

Blood pressure  is partially determined by ____________ output and ___________resistance.

Cardiac output is the product of ____________ volume and _______ rate, and a number of factors can affect these

variables.  Describe the factors that affect these variables:  ___________________________________ __ ___________________________________________________________________

The __________center of the __________ _________ in the brain stem can adjust sympathetic

impulses to ___________ in arteriole walls, adjusting blood pressure.

Blood pressure at the venular end of a capillary is almost 0.  So other factors help return the blood to the heart.

Contractions of ___________ muscles squeeze blood back up veins one valve at a time.

Differences in ___________ and ___________ pressures, derived from the breathing process, draw blood back

up the veins.

Blood vessels can be divided into 2 major pathways, the _________ circuit, which goes from

the heart to the lungs and back, and the _________ circuit, which goes from the heart to the body cells and back.

The ____________ is the body’s largest artery.  Be able to recognize and locate the following arteries:

·     Principal branches of the aorta

·     The branches of the ascending aorta are the right and left _________ arteries that lead to heart muscle.

·     Principal branches of the aortic arch include the _________, left common carotid, and left _________ arteries.

·     The descending (thoracic) aorta gives rise to many small arteries to the thoracic wall and thoracic viscera.

·     The abdominal aorta gives off the following branches: celiac, superior mesenteric, suprarenal, renal, gonadal, inferior mesenteric, and common iliac arteries.

·     Arteries to the head, neck, and brain include branches of the subclavian and common _________ arteries.

·     The _________ arteries supply the vertebrae and their associated ligaments and muscles.

·     In the cranial cavity, the vertebral arteries unite to form a _________ artery that ends as two posterior cerebral arteries.

·     The posterior cerebral arteries help form the circle of _________ that provides alternate pathways through which blood can reach the brain.

·     The right and left common carotid arteries diverge into the external carotid and internal carotid arteries.

·     Near the base of the internal carotid arteries are the carotid _________, which contain baroreceptors to monitor blood pressure.

·     The subclavian artery continues into the armpit area, where it becomes the _________ artery.

·     In the shoulder region, the axillary artery becomes the _________ artery that, in turn, gives rise to the ulnar and radial arteries.

·     Branches of the thoracic aorta and subclavian artery supply the thoracic wall with blood.

·     Branches of the abdominal aorta, as well as other arteries, supply the abdominal wall with blood.

·     At the pelvic brim, the abdominal aorta divides to form the _________ _________ arteries that supply the pelvic organs, gluteal area, and lower limbs.

·     The common iliac arteries divide into _________ and _________ iliac arteries.

·     Internal iliac arteries supply blood to pelvic muscles and visceral structures.

·     External iliac arteries lead into the legs, where they become the _________, popliteal, anterior tibial and posterior tibial arteries.

Veins return blood to the heart after the exchange of substances has occurred in the tissues.     Larger

veins parallel the courses of arteries and are named accordingly; smaller veins take irregular pathways and are

unnamed.

Veins from the head and upper torso drain into the ________ _______ ________.

Veins from the legs and lower trunk drain into the _________ _______ _________.  Both drain into the _________ atrium.

Be able to recognize and locate these veins:

·     The _________ veins drain the head and unite with the subclavian veins to form the brachiocephalic veins.

·     The upper limb is drained by superficial and deep veins.

·     The basilic and cephalic veins are major superficial veins.

·     The major deep veins include the radial, ulnar, brachial, and axillary veins.

·     Tributaries of the brachiocephalic and azygos veins drain the abdominal and thoracic walls.

    Veins from the Abdominal Viscera:

·     Blood draining from the intestines enters the _________ _________ system and flows to the liver first rather than into the general circulation.

·     Hepatic veins drain the liver, gastric veins drain the stomach, superior mesenteric veins lead from the small intestine and colon, the splenic vein leaves the spleen and _________, and the inferior _________ vein carries blood from the lower intestinal area.

·     Deep and superficial veins drain the leg and pelvis.

·     The deep veins include the anterior and posterior tibial veins, which unite into the _________ vein and then the femoral vein; superficial veins include the small and great _________ veins.

·     These veins all merge to empty into the common iliac veins, which then merge to form the _________ _________ _________.