Phiso exam 4, Ch 17, 18,19

Hematocrit

The percentage of red blood cells in your total blood volume. Normal values are Women 37 to 47 and Men 42 to 50.

Components of Whole Blood

Red blood cells , white blood cells, platelets

Albumin

A plasma protein produced in the liver that maintains osmotic pressure.

Immunoglobins

Plasma proteins produced by plasma cells that are involved in the immune response.

Haptoglobin

A plasma protein produced in the liver that prevents damage of hemoglobin.

Erythropoiesis

The process where stem cells differentiate into erythroblasts which synthesize hemoglobin, expelling reticulocytes that mature into erythrocytes.

Reticulocyte

Immature red blood cells that are slightly larger, contain ribosomes, and aren't fully concave.

Characteristics of Erythrocytes

Erythrocytes are biconcave and lack many organelles.

Oxygen Transport by Hemoglobin

Each hemoglobin molecule can carry 4 oxygen molecules that attach to the heme groups.

EPO

A hormone produced by the kidneys that stimulates bone marrow to produce red blood cells.

Neutrophil Count in Bacterial Meningitis

An elevated neutrophil count is expected because neutrophils fight off infections.

Megakaryocyte

A large polyploid cell with a big nucleus.

Hemostasis Step 1

Vasoconstriction to make the hole smaller ( vascular spasm)

Hemostasis Step 2

Platelet plug to seal the hole (in a small vesel, this could be enough)

Hemostasis Step 3

Blood clotting for a more durable seal

Forms a fibrin mesh that covers the wound

Prothrombin to Thrombin

Prothrominase catalyzes the conversion, with prothrombin being inactive and thrombin being active.

Fibrinogen to Fibrin

Thrombin catalyzes the conversion, with fibrinogen being inactive and fibrin being active.

Thrombocytopenia

A bleeding disorder that results from not having enough platelets.

Hemophilia

A bleeding disorder resulting from the absence of clotting factor VIII.

What are the components of the intrinsic conduction system of the heart in order?

SA node, AV node, AV bundle

What is the depolarization rate of the SA node?

70-80 beats per minute

What is the depolarization rate of the AV node?

40-60 beats per minute

What is the depolarization rate of the AV bundle?

30 beats per minute

Which component of the intrinsic conduction system sets the pace under normal conditions?

The SA node

How does cardiac muscle action potential differ from skeletal muscle action potential?

Cardiac muscle has a plateau phase and does not hyperpolarize like skeletal muscle.

What does an ECG measure?

The electrical activity of the heart.

What does an EEG measure?

The electrical activity of the brain.

Why can't cardiac muscle go into tetany?

Due to long refractory and action potential duration.

Why is direct innervation of every cardiac myocyte unnecessary?

The intrinsic conduction system allows signals to travel through junctions between myocytes.

Which part of the intrinsic conduction system directly excites ventricular myocardial cells?

The Purkinje fibers.

In which direction does the depolarization wave travel across the ventricles?

From bottom to top.

cardiac cycle 1

Atrial systole, ventricular diastole

cardiac cycle 2

Atrial diastole, ventricular systole;

cardiac cycle 3

Ventricular systole

cardiac cycle 4

Atrial diastole, ventricular diastole

What is the second heart sound associated with?

The closing of the semilunar valves.

What causes increased heart rate after exercise?

A lack of parasympathetic stimulation.

What happens to cardiac output during tachycardia?

There may not be enough blood in the heart for effective pumping. Fast Irregular HR

How does the Frank-Starling law relate to stroke volume?

Increased venous return leads to greater ventricular filling and higher stroke volume.

Where should you position your stethoscope to auscultate the aortic valve?

Right sternal 2nd intercostal space during ventricular diastole.

What are arterioles known as and why?

Resistance vessels due to their ability to adjust resistance and regulate blood flow.

What impact does vasoconstriction have on blood flow?

It increases resistance and decreases blood flow to capillaries.

What are pericytes and their function?

Cells that wrap around capillaries to regulate blood flow and stabilize vessel walls.

Why are veins referred to as capacitance vessels?

They can store large amounts of blood due to their thin walls and wide lumens.

What is the reference point for measuring blood pressure?

The brachial artery.

What are the normal blood pressure values for a healthy adult?

120/80 mmHg.

What factors determine resistance in a vessel?

Vessel diameter, vessel length, and blood viscosity; diameter is the most important.

How does fluid intake affect blood viscosity?

It can decrease blood viscosity, making it thinner.

What happens to blood flow if a vessel's diameter is reduced to one-third its size?

The flow will slow down significantly.

Explain the relationship represented by the formula F = ΔP/TPR.

Flow (F) is equal to the pressure difference (ΔP) and is inversely proportional to total peripheral resistance (TPR).

What does a blood pressure reading of 120/70 indicate?

120 is the systolic pressure, and 70 is the diastolic pressure.

What role does the medulla oblongata play in blood pressure regulation?

It controls heart rate and has sensors for blood pressure.

What happens to baroreceptor reflex when standing up from lying down?

Baroreceptors sense pressure changes and activate the sympathetic nervous system while inhibiting the parasympathetic nervous system.

How do the kidneys influence mean arterial pressure (MAP)?

They regulate blood pressure through sodium and water retention.

What is the significance of a low blood pressure and rapid heart rate in an allergic reaction?

Weak heart contractions lead to low circulation and low blood pressure.

How do diuretics decrease blood pressure?

By lowering the amount of water and sodium retained in the body.

What effect do beta-blockers have on blood pressure?

They inhibit sympathetic responses, reducing heart rate.

How do calcium channel blockers affect blood pressure?

They block calcium from entering the heart and blood vessels, reducing contraction strength.

What happens to arterioles supplying leg muscles during exercise?

They vasodilate due to autoregulation.

What prevents mean arterial pressure from decreasing during exercise?

An increased heart rate compensates for the dilation of arterioles.

How are nutrients and gases transported between blood and tissues?

Through gas exchange in the lungs and filtration in the kidneys.

Function of blood

Transport, regulation, protection

How much plasma is in the compostion of blood

55%

How much buffy coat is in the compostion of blood

<1%

What makes up the buffy coat

leukocytes and platelets

How much of RBC make up blood composition

45%

What is the composition of plasma

water, electrolytes, plasma protein, nutrients, resp. gases, hormones

Erythropoiesis occurs in 

red bone marrow

erythropoiesis step 1

hematopoietic stem cell

erythropoiesis step 2

committed cell- proerythroblast

erythropoiesis step 3 phase 1

ribosome synthesis

erythropoiesis step 3 phase 2

hemoglobin accumulation

erythropoiesis step 3 phase 3

ejection of the nucleus

life span of RBC

120 days

how much albumin is in plasm

60%

how much globulis are in plasma

36%

How much Firbiogen is in plasma

4%

WBC percent of neutrophils

50-70%

WBC percent of eosinophils

2-4%

WBC percent of basophils

0.5-1%

WBC percent of lymphocytes

25%

WBC percent of monocytes

3-8%

Neutrophil function

Phagocyte with respiratory burst

Eosinophil function

amplified immune response

Basophil function

Contains histamine (attracts WBC)

Blood vessels get leaky and vasodilate

Lymphocyte function

targets specific pathogyens

T-Cells

B-Cells

T- cell function

Cellular immunity

attack specific cells

B-Cell function

humoral immunity

antibodies into the blood

Monocyte function

activates lymphocytes

Platelets come from

megakaryocytes

platelets contain granuloes that

clot blood

myeloid stem cells make everything except

lymphocytes

Too few RBC =

tissue hypoxia

Too many RBC=

high viscocity and risk of thrombosis

Low O2 triggers kidneys to release

Erytropoieten

Erytropoieten triggeres the production of

RB

What happens to the heme group during RBC breakdown

Its iron gets stored in the liver

Retraction (vascular spasm process)

platelets contract, causing dehydration

draws the edges together

stimulates tissue repair

Fibrinolysis

plasminogin turns to plasmin (breaks apart fiber)