A&PII FINAL EXAM

What is the second step in the mechanism of action of a lipid soluble hormone?

the complex can act on DNA, and cause protein production

What are the three functions of the blood?

Protection, transportation, and regulation

What 4 components does the blood transport?

nutrients, hormones, wastes, and gases (o2/co2)

What does protection include when concerning the blood?

The inclusion of WBC's and platelets

What three things does the blood regulate?

pH, osmolarity of tissues, temperature regulation

What are the two main components of blood?

plasma and formed elements

Plasma is the _____ part of blood

fluid

Plasma comprises what percent of blood volume?

55%

What important macromolecule is present in plasma?

Proteins

Albumin in the plasma contributes to what important characteristic of blood?

Blood's thickness

The formed elements are comprised of what?

cells suspended in plasma

Formed elements make up what % of blood volume?

45%

Where do all formed elements originate?

Red bone marrow

Which specific bones have red bone marrow?

the sternum, coxals, and ribs

RBC's have what specific shape?

biconcave disc

RBC's have such a short lifespan because:

they have no nucleus or organelles

The RBC's main purpose is to:

transport O2, CO2, and H+

WBC's main purpose is to:

defend the body against foreign agents and microorganisms

Platelets are comprised of:

small cell fragments

The platelet's main purpose is to:

form clots, in order to plug vessel walls to stop bleeding

RBC production is also known as what?

Erythropoiesis

Where does erythropoiesis occur?

red bone marrow

When is erythropoiesis stimulated?

-Decreased O2, detected by kidneys (hypoxia)

When the kidneys detect hypoxia, they increase the production of:

EPO

EPO targets ________ to ________

the red bone marrow, produce more RBC's to compensate

Erythropoiesis occurs in what kind of loop?

negative feedback loop

Pernicious anemia:

caused by low RBC ct due to lack of b12

Iron deficiency anemia:

lacl of iron in hemoglobin leads to low O2 transport to tissues. Low O2= Low ATP

Sickle cell anemia:

abnormal Hb due to incorrect amino acid sequence

what are some effects of sickle cell anemia?

clogged capillaries, hemolysis, anemia

define polycythemia

RBM overproduces RBC's

what are some effects of polycythemia?

Increased viscosity slows blood flow and ultimately decreases venous return

What demographic is polycythemia more common in?

men due to production of testosterone

Define leucopenia

abnormally low WBC count

What condition is leucopenia often seen in?

AIDS

Define leukocytosis

Abnormally high WBC count

When does leukocytosis normally occur?

During time of acute infection

Define leukemia

dramatic increase in WBC's

What is unique about the secondary cells produced in leukemia?

They are malignant (cancerous) cells, and do not function properly

What is the function of neutrophils/monocytes?

phagocytize microbes

What are the two functions of eosinophils?

phagocytize antigen-antibody complexes, and allergen response

What are the two functions of basophils?

Basophils are responsible for the symptoms during an allergic reaction (heparin and histamine secretion), and also serves as an anticoagulant

What is the main function of the B-lymphocyte?

produces antibodies that attach to antigens on foreign microbes

What are the two functions of T-lymphocytes?

directly attacks foreign microbes (killer t-cell), or can act as a B-lymphocyte

How is a B-lymphocyte activated?

When a foreign antigen binds to it's receptor

After the binding of the foreign antigen, what does the B-cell do?

produce plasma cells, which manufacture antibodies specific to the antigen

What is unique about the B-lymphocyte response?

Some B-lymphocytes will remain as memory cells, which can respond quickly in the event of an attack by the specific antigen.

What is the primary exposure in vaccination?

The first exposure to an antigen, which contain weakened/dead cell fragments.

Primary exposure triggers what in the B-lymphocytes?

the antigen-antibody response

What is the secondary exposure concerning vaccination?

Any exposure to the same antigen as in the vaccine will be fought off quicker than if no vaccination was administered.

What are the three steps in repairing a damaged blood vessel?

Vascular spasm, platelet plug formation, coagulation

What happens in the vascular spasm?

smooth muscle contracts, causing vasoconstriction, and platelets release factors to decrease blood loss.

How does the platelet plug form?

Platelets are activated when they adhere to the damaged blood vessel. They release chemicals, like thromboxane A2, which aggregates other platelets to form a "plug".

How does coagulation work?

Coagulation is the formation of a "fibrin mesh" that holds the platelet plug in place.

The platelet plug activates which chemical?

Prothrombinase

Prothrombin + ________________ creates thrombin.

prothrombinase , Ca2+

Fibrinogen is converted to fibrin with the help of what chemical?

thrombin

What dissolves the clot when the damage has been repaired?

Plasmin

How does EDTA work?

binds to Ca2+, inhibiting proper clotting

How does heparin work?

Prevents thrombin formation, which in turn doesn't form fibrin

How does coumadin work?

Blocks activity of vitamin K, which is needed to synthesize clotting factors

How does aspirin work?

Prevents initial platelet aggregation

What is a thrombus?

A clot that stays in one location (thrombosis)

What is an embolus?

A clot that breaks off and travels through circulation (embolism)

Rh- types can receive/donate to what types?

give: -/+

receive: -

Rh+ types can receive/donate to what types?

give: +

receive: -/+

How can HDN be prevented?

administration of RhoGAM

Define ischemia:

A condition where there is reduced blood flow (reduced O2) to a specific part of the body

What is a myocardial infarction?

Where the presence of dead cardiac muscle tissue leads to heart attack

What is angina pectoris?

chest pain, often associated with reduced blood flow to heart (MI)

What is atherosclerosis?

a buildup of fats/cholesterol on artery walls

What is a stent?

an expandable mesh inserted into a blocked blood vessel to keep it open and regain blood flow

What does the conduction system of the heart allow?

For the heart to beat on it's own, in a coordinated, rhythmic matter

What is the purpose of intercalated discs?

They join cardiac muscles of the heart together, which allow conduction to be spread throughout the heart

What is the SA node known as?

The "pacemaker" of the heart

When the SA node fires, what impact does it have on the atria?

It causes the atria to contract

The SA node establishes what?

The baseline of heart rate (60-100bpm)

The SA node has what impact on Na+?

Spontaneously depolarizes Na+ (starts heartbeat)

Where is the AV node located?

In the interatrial septum

The AV node does what to the propagation of the electrical current?

Delays the current briefly

The AV node delay allows for what?

Allows for the atria to finish systole (contraction)

The AV bundle (Bundle of His) is located where?

In the interventricular septum

The AV bundle acts as a pathway for the electrical impulse to travel from ____________________________.

the atria to the ventricles

The AV bundle divides into branches. Why is this significant?

It allows the electrical impulse to be carried to the left/right side of the heart, to the respective ventricles

the Purkinje fibers are located where?

They're spread throughout the walls of the ventricles

The Purkinje fibers deliver impulse to the _______.

Cardiac cells

The Purkinje fibers delivering impulses to cardiac cells causes what to happen?

Ventricular systole (contraction)

Name the pathway of the heart's electrical current start to finish.

SA node --> AV node --> AV bundle --> Purkinje fibers ---> cardiac cells

What is the first phase of cardiac muscle tissue contraction?

Depolarization

Depolarization of cardiac membrane potential causes what electrical shift?

Cardiac cells inside the MP become more positive compared to cells outside the MP

What is the RMP of cardiac muscle fibers?

~-90mV

How is the RMP of cardiac muscle fibers brought to threshold?

By neighboring cells (due to intercalated discs)

What is the second phase of cardiac muscle tissue contraction?

the plateau phase

The plateau phase includes what being maintained?

depolarization

Why is the plateau phase significant?

it ensures contraction finishes before relaxation happens (no tetany!)

Explain the chemistry behind the plateau phase.

VG Ca++ channels slowly open to prolong depolarization, and some K+ channels now open

What is the third phase in cardiac muscle tissue contraction?

Repolarization

What is the charge of the cardiac cell MP, comparatively?

It's when the cardiac cell MP goes negatively compared to the MP outside of the cell.

The repolarization phase is characterized by what chemical change?

The opening of VG K+ channels, allowing K+ to exit the cell. Ca++ channels also close.

The P wave in an ECG defines ___________.

Atrial depolarization/contraction