Module 4 ANP

What do all cell membranes contain?

Proteins and carbohydrates.

Which membrane components are mostly the same between people?

Most membrane proteins and carbohydrates.

What are examples of membrane components shared between people?

Sodium-potassium pumps and sodium channels.

Antigens

Proteins or carbohydrates that are unique to an individual.

How are blood groups determined?

By the antigens present on a person's blood cells.

What are examples of ABO blood-cell antigens?

A, B, and O blood-group markers.

What happens if a person lacks a certain blood antigen?

They have an antibody against the missing antigen.

Rh factor

A protein found on the surface of red blood cells.

Rh-positive (Rh+)

Red blood cells have the Rh protein.

Rh-negative (Rh-)

Red blood cells do not have the Rh protein.

Where was the Rh factor first discovered?

In rhesus monkeys.

About what percentage of Americans are Rh-positive?

About 85%.

When does the Rh factor become important?

When blood types mix, such as during pregnancy or childbirth.

Does Rh status normally harm a person's health?

No; it matters mainly when incompatible blood mixes.

What Rh combination is shown in the pregnancy diagram?

An Rh-positive father and an Rh-negative mother.

What usually happens during the first Rh-positive pregnancy?

The first pregnancy is generally unaffected.

What can happen when maternal and fetal blood cross during delivery?

The mother becomes sensitized and forms anti-Rh antibodies.

What remains in the mother after Rh sensitization?

Anti-Rh antibodies.

What can residual anti-Rh antibodies do in a later Rh-positive pregnancy?

Attack Rh factors on the second fetus's red blood cells.

Are Rh antibodies formed spontaneously?

No.

How many Rh-incompatible infusions may be needed for a serious reaction?

Two infusions.

What happens when blood mixes during the first pregnancy or delivery?

The mother forms antibodies.

What can maternal antibodies do during a second Rh-positive pregnancy?

Destroy the baby's red blood cells.

Hemolytic disease of the newborn

Destruction of a newborn's red blood cells by maternal antibodies.

What is used to prevent Rh-related hemolytic disease before birth?

RhoGAM.

According to the slide, what does RhoGAM contain?

Antibodies against Rh antibodies.

When is RhoGAM given?

At 28 weeks and within 72 hours after delivery.

What does RhoGAM suppress according to the slide annotation?

The mother's immune system.

AB blood type

A and B antigens; no anti-A or anti-B antibodies; can receive A, B, AB, or O.

Why is type AB called the universal recipient?

It can receive A, B, AB, or O blood.

Type AB frequency by U.S. population group

White 4%; Black 4%; Asian 5%; Native American <1%.

B blood type

B antigen; anti-A antibodies; can receive B or O.

Type B frequency by U.S. population group

White 11%; Black 20%; Asian 27%; Native American 4%.

A blood type

A antigen; anti-B antibodies; can receive A or O.

Type A frequency by U.S. population group

White 40%; Black 27%; Asian 28%; Native American 16%.

O blood type

No A or B antigens; anti-A and anti-B antibodies; can receive only O.

Why is type O called the universal donor?

Its red blood cells have no A or B antigens.

Type O frequency by U.S. population group

White 45%; Black 49%; Asian 40%; Native American 79%.

Which ABO blood type is noted as most prevalent in the United States?

Type O.

What happens to incompatible blood cells during a transfusion reaction?

The recipient's immune system destroys them.

Agglutination

The initial clumping reaction in an incompatible transfusion.

What problem does agglutination cause?

Clogging of small blood vessels.

What happens to clumped red blood cells?

They rupture or are phagocytosed.

What is released when clumped red blood cells rupture?

Hemoglobin enters the bloodstream.

How does a transfusion reaction affect oxygen carrying capacity?

It decreases it.

How does a transfusion reaction affect blood flow?

It decreases blood flow.

What can hemoglobin in kidney tubules cause?

Acute renal failure.

Hemostasis

The process that stops bleeding from a blood vessel.

What mechanisms dominate during normal homeostasis?

Anti-hemostatic mechanisms.

What do intact endothelial cells release to oppose clotting?

Nitric oxide and prostacyclin.

What anticoagulant is released by basophils and mast cells?

Heparin.

Which fibrinolytic factors dominate during homeostasis?

Tissue plasminogen activator (tPA) and plasmin.

Fibrinolysis

The process of breaking down clots.

What response follows vascular injury?

Hemostasis.

What are the first three steps of hemostasis?

Vascular spasm, platelet plug formation, and coagulation.

What five stages are shown from vessel injury to clot removal?

Vascular spasm, platelet plug formation, coagulation, clot retraction, and thrombolysis.

What is the primary goal of vascular spasm?

Decrease blood flow and minimize blood loss.

What can directly trigger vascular spasm in smooth muscle?

Direct injury to the smooth muscle.

How do disrupted endothelial cells promote vascular spasm?

They release chemicals.

How do local pain receptors affect vascular spasm?

Their stimulation helps trigger the spasm.

How is tissue damage related to vascular spasm?

More damage causes more spasm; they are directly proportional.

What is the function of vascular spasm?

Slow blood flow so a platelet plug has time to form.

Which common vasospasm locations are shown?

Heart, brain, fingers, and toes.

What activates platelets at a damaged vessel?

Contact with exposed collagen.

How do platelets change after activation?

They swell and become sticky.

What does ADP do during platelet plug formation?

Acts as a potent aggregating agent.

What do serotonin and thromboxane A2 cause?

More vascular spasm and platelet aggregation.

Do platelets attach to non-exposed collagen?

No.

What prevents platelet adhesion in an intact vessel?

Prostacyclin and nitric oxide released by intact endothelium.

Where is collagen located before vessel injury?

In the subendothelial layer beneath the endothelium.

Coagulation

The process by which blood changes from a liquid to a gel.

How does coagulation strengthen a platelet plug?

It adds fibrin 'glue' and converts the plug into a blood clot.

Clotting factors

Plasma proteins, mostly made in the liver.

Which clotting factors require vitamin K for synthesis?

Factors II, VII, IX, and X.

What does each phase of the coagulation cascade have?

A specific end goal.

How is a clotting factor activated in the cascade?

Another factor clips part of the protein off, turning it into an enzyme.

What pathways make up Phase I of coagulation?

The intrinsic and extrinsic pathways.

What is the shared end goal of the intrinsic and extrinsic pathways?

Activation or formation of factor X.

What does factor X combine with other factors to form?

Prothrombin activator, also called prothrombinase.

What is Phase II of coagulation called?

The common pathway.

What conversion occurs in Phase II?

Prothrombin is converted into thrombin.

What conversion occurs in Phase III?

Thrombin converts soluble fibrinogen into insoluble fibrin.

What triggers both intrinsic and extrinsic pathways?

The same tissue damage.

Intrinsic pathway

Triggered by vessel-wall damage and uses factors within the blood.

Is the intrinsic pathway faster or slower?

Slower; it has more steps and a longer cascade.

Which factor starts the intrinsic pathway?

Factor XII.

Which factors are listed in the intrinsic pathway?

Factors XII, XI, IX, and VIII.

Extrinsic pathway

Triggered by tissue damage outside the vessel wall and uses factors outside the blood.

Is the extrinsic pathway faster or slower?

Faster; it has fewer steps and a shorter cascade.

Which factor starts the extrinsic pathway?

Factor VII.

Which factors are listed in the extrinsic pathway?

Tissue factor (III) and factor VII.

How does the amount of damage affect clotting speed?

More damage causes faster clotting.

What does X becoming Xa mean?

Factor X has become activated factor 10.

What does factor Xa help form?

Prothrombinase or prothrombin activator.

What activates prothrombin (factor II)?

Prothrombinase.

What does prothrombin (II) become when activated?

Thrombin (IIa).

What role does thrombin play in Phase III?

It acts as a catalyst.

Fibrinogen

A soluble protein converted into fibrin.

Fibrin

An insoluble protein that forms the clot framework.

What does fibrin form after it is produced?

Long, hair-like bands.