BI 256 Unit 5

The right and left coronary arteries arise from the descending aorta.

'False'.

Contraction of the ventricles begins at the apex and proceeds superiorly.

'True'.

The electrical event that begins each heartbeat occurs at the sinoatrial (SA) node.

'True'.

Together, leukocytes and platelets constitute roughly which percentage of whole blood volume?

1%

The percentage of erythrocytes in a normal volume of blood is about

45%.

Identify the letter indicating where lymph collected from the right arm enters the bloodstream.

A

Identify the letter that indicates the common iliac artery.

A

Identify the letter that indicates the left atrioventricular valve.

A

Identify the letter that indicates the left common carotid artery.

A

Identify the letter that indicates a papillary muscle, which acts as abd anchor point for chordae tendineae, and is composed of cells from the myocardium

B

Identify the letter that indicates the common carotid arteries.

C

Identify the letter indicating inguinal lymph nodes that filter lymph from the lower limbs.

E

The unusual shape of the erythrocyte is important because

It increases surface area for respiratory exchange across the plasma membrane.

Which of the following is false concerning the cardiac skeleton?

It is made of flaps of endocardium.

One location where lymphoid tissue is found is "in the frequently infected mucous membranes of the digestive, respiratory, urinary, and reproductive tracts." This description refers specifically to

MALT (Mucosa Associated Lymphoid Tissue)

The ____________ valve prevents backflow of blood from the left ventricle to the left atrium.

Mitral

The right atrium receives oxygen poor blood from the ______________ , ______________, and coronary sinuses.

The correct answer is: superior vena cava and inferior vena cava

The hepatic portal system has two distinct capillary beds separated by a portal vein. What are the functions of these two capillary beds?

The first picks up digested nutrients, and the second delivers these nutrients to liver cells.

Which of these statements regarding lymph capillaries is false?

They have precapillary sphincters that regulate drainage of lymph from tissues.

Which of the following is correct about the heart's blood supply?

Two coronary arteries originating from the aorta supply the myocardium.

A blood vessel that ranges from 0.3 mm to about 1 cm in diameter (medium sized)and has a large tunica media relative to the size of the lumen is

a muscular artery.

The blood protein that contributes osmotic pressure, keeping water from leaking out of the vessels, is called the

albumin.

The blood's globulins include

antibodies

Erythrocytes

are over 97% hemoglobin.

Hemopoiesis is

blood cell production.

The correct proximal to distal sequence of the three vessels branching from the aortic arch is

brachiocephalic, left common carotid, left subclavian.

Lymphatic vessels perform all of the following functions except

carrying blood

Which branch (or branches) of the abdominal aorta supplies the stomach?

celiac trunk

The atrioventricular valves cannot be inverted because of the attachment of ____________

chordae tendineae

Which of the following groups of cells are most structurally related?

eosinophils, basophils, and neutrophils

Hematocrit measures the percentage of blood volume that consists of

erythrocytes

The absence of a nucleus, mitochondria, and ribosomes is a telltale characteristic of __________

erythrocytes

Vessels of the small intestines, renal glomerulus, and synovial membranes that allow passage of fluid and solutes through "windows" or "pores"in the endothelium.

fenestrated capillaries

Intercalated discs contain __________ which allow ions (electrical signals) to pass between cells, allowing the direct transmission of impulses.

gap junctions

Megakaryocytes

give rise to platelets.

In a histological cross section through an artery, a vein, and a lymphatic vessel, one can recognize the lymphatic vessel because it

has the thinnest walls.

Clusters of lymph nodes occur in all of the following sites except

in bones and bone marrow.

Which artery arises from the inferior part of the abdominal aorta and supplies the distal half of the large intestine?

inferior mesenteric artery

The atrioventricular node is located in the

inferior part of the interatrial septum.

Adjacent cardiac muscle cells are joined by

intercalated discs

Present in most capillaries, these structures are absent in those of the blood-brain barrier.

intercellular clefts

Blood plasma

is approximately 90% water.

Set of lymphatic capillaries that collect fat-laden fluids from the intestinal tract.

lacteals

The ________ receives oxygenated blood from the pulmonary veins.

left atrium

The heart chamber that pumps oxygenated blood to the systemic circuit is the

left ventricle.

Lymph vessels drain lymph from all the lymphoid organs, as they do from almost all organs of the body. However, afferent lymph vessels enter (empty into) only one type of lymphoid organ, the

lymph node.

Small, bean-shaped organs abundant in the cervical, axillary, and inguinal regions.

lymph nodes

Of the three layers of the heart wall, the layer that contains cardiac muscle is the

myocardium

The most abundant white blood cell type is the

neutrophil

Structure that regulates blood flow into true capillaries.

precapillary sphincter

Valve responsible for preventing backflow of blood from the lungs into the heart.

pulmonary semilunar

The right ventricle pumps blood into the

pulmonary trunk (pulmonary artery)

The left ventricular wall of the heart is thicker than the right ventricular wall, so it can

pump blood with greater pressure.

Which of the following is not a normal component of lymph?

red blood cells

Lymphoid tissue is basically ________ connective tissue.

reticular

Newly developed blood cells enter the circulatory system by blood ___________, or wide capillaries, within the marrow.

sinusoids

Wide leaky capillaries found in bone marrow and spleen

sinusoids

The parasympathetic fibers of the vagus nerve

slow the heartbeat.

Macrophages that destroy aged and defective blood cells are present in the ________

spleen

The pulmonary circuit

supplies deoxygenated blood to the lungs so it can become oxygenated.

Functionally, there are no valves in arteries (as opposed to in veins) because

the blood pressure in arteries is high enough that there is no backflow of blood.

In humans, B lymphocytes originate ("are born") in

the bone marrow.

The pericardial cavity lies between

the parietal pericardium and the visceral pericardium.

A drop of blood returning to the heart from the head region would enter the heart through which vessel?

the superior vena cava

Lymph capillaries differ from blood capillaries in all of the following ways except that

their walls consist of endothelial cells

Which one of the following is NOT a way in which substances are exchanged across the capillary wall?

through tight junctions

Platelets function ______

to plug small tears in the walls of blood vessels and help to initiate clotting

Lymphoid organs located in the mucosal lining of the pharynx.

tonsils

Capillaries consist of only this layer.

tunica intima

The muscular ________of the lymphatic vessels contract(s) to help propel the lymph

tunica media

By definition, veins are

vessels that carry blood toward the heart