Exam 3

Question 1

What is blood made of (in your answer include the fluid, major cell types, and molecules)

Answer 1

.42 Red Blood Cells
---Lymphocytes, monocytes/macrophages, neutrophilis, eosinophils, basophils, HEMOGLOBIN
.01 White Blood Cells
.58 Plasma Volume
---Water
---Ions
---Organic molecules (amino acids, proteins, glucose, lipids, Nitrogeneous waste)
---Trace element/vitamins
---Gases (CO2, O2)

Question 2

Describe the primary differences between blood, plasma and serum

Answer 2

Blood is composed of plasma and R/W Blood cells.

Serum is the liquid part of blood after coagulation–no clotting factors like fibrinogen

Plasma is the liquid, cell-free part of blood that has been treated with anti-coagulants.

Question 3

Describe how we prevent stored whole blood from clotting

Answer 3

Chelators like EDTA or Citrate (Ca2+) are used to prevent clotting in the blood when it’s stored. Ca2+ is required for several steps of the coagulation cascade, by removing Ca2+ from the blood, coagulation is ceased.

Question 4

Draw a diagram of the human heart and label its parts and major vessels

Answer 4

DIAGRAM

Vena Cava-rA-(tricuspid valve)-rV-(pulmonary valve)-Pulmonary Artery-lungs-Pulmonary Vein-lA-(mitral valve)-lV-(aortic valve)-Aorta

Question 5

Provide a diagram that shows how blood flows through the heart

Answer 5

DIAGRAM

Vena Cava-rA-(tricuspid valve)-rV-(pulmonary valve)-Pulmonary Artery-lungs-Pulmonary Vein-lA-(mitral valve)-lV-(aortic valve)-Aorta

Question 6

Provide a diagram showing the spread of electrical excitation in the human heart and the corresponding signal measured via an ECG

Answer 6

DIAGRAM

SA-Bachman’s bundle passes signal to left Atria, both r/l atrium contract together-

AV–signal received from SA node. slowly passes signal to ventricles. Signal passes down bundle of HIS and back up outer wall of both ventricles. V’s contract together from bottom up.

Question 7

Describe what a left ventricular assist device (LVAD) is and does

Answer 7

Bridge to transplant. The pump drains the left ventricle and pumps the blood into the aorta and out to the rest of the body. it aids by relieving the load and allowing the heart to heal.

Question 8

Provide a diagram that compares blood pressure the velocity of blood flow and total area of the large arteries, arerioles, capillaries, venules and veins

Answer 8

DIAGRAM

tricolored graph

Question 9

What are the three layers of tissue that make up a blood vessel and provide one characteristic that is different between an artery and a vein

Answer 9

1. Endothelium
2. Smooth Muscle
3. Fibrous connective tissue

veins have less smoothe muscle. Veins have a larger mean diameter and a smaller mean wall thickness.

Question 10

What is atherosclerosis? Describe on bioenineering approach for its treatment

Answer 10

Narrowing of an artery’s lumen as the result of material build up or wall thickening (stenosis) Angioplaty with drug eluting and bioresorbable stents. Stents are used to prevent restenosis

Question 11

EKG wave

Answer 11

P-atrial depolarization
(Q-
R
S)-Ventricular depolarization
T-ventricular repolarization
U

Question 12

Define Excretion

Answer 12

Process by which products of metabolism and other non-useful materials are eliminated from an organism.

CO2, H2O, undigested materials

Question 13

How does the major blood supply of the liver differ from that of the kidney?

Answer 13

The liver has 2 sources, Hepatic artery (oxygenated blood) and digestive tract( Hepatic Portal Vein deoxygenated but nutrient and enzyme rich).

Kidney has one source of blood.

Question 14

What is the structural unit of the liver?

Describe its design

Answer 14

Liver lobule=filter blood
Blood enters at each corner of the hexagon edge (triad)
Blood mixes in sinusoids (capillaries of lobule) (endothelial fenestrations/ no basal lamina)
Drains flow from edge triad to the central vein
Blood is filtered by Hepatocytes (liver cells) and Kupffer Cells (special macrophages of the liver)

Question 15

What is meant by the term biotransformation and how does it aid excretion of fat soluble compounds

Answer 15

Biotransformation is the chemical modifications made by an organism on a chemical compound (like nutrients, drugs, microbes, toxin.s)
Modifications are made to render molecules more safe or useable, or to facilitate removal/excretion

Question 16

What is a Kupffer cell? Where are they located? What role do they play in excretion?

Answer 16

Kupffer cells are macrophages found in the liver. They filter blood in the sinusoids (capillaries). Phagocytizes pathogens or damaged red blood cells and platelets.

Question 17

Describe the lymphatic system and its role in the body

Answer 17

Drainage system for allt organs/tissues
contains 3L lymph/ lymphocytes/waste products
Processed in Lymph nodes, GI tract, kidney and heart

Filtered blood is sent back to the GI tract via lymphatic vessels (bile ducts)

Question 18

What is meant by 1st pass metabolism? Why is it important to the fields of pharmacology and drug delivery?

Answer 18

1st pass metabolism refers to Metabolism in the liver of substances (particularly drugs) after they are absorbed via the gastrointestinal track. d

We have to calculate how much drug is needed at the active site, and put enough into the capsule that the amount reaches the target area. Or a different delivery must be used to bypass the GI tract.

Question 19

Describe 1 technique to engineer a replacement for a failed liver

Answer 19

Decellularizing the liver. Using weak soaps, salts and enzymes, all of the funcitonal parts of the liver are removed. The ECM is left. Blood is added to liver to use all of the formerly active and functioning ECM

Question 20

Roles of the Liver

Answer 20

Produces
-bile salts
-albumin
-antioxidants
-clotting factors
-complement factors
Process Nutrients
Biotransformation
Filter Blood

Question 21

What are the 4 functions of a kidney?

Answer 21

1. Removal of Water soluble waste products and excess water
   2 Removal of Urea
2. Respond to ADH and control amount of water in urine. Regulates the volume and composition of extracellular fluid, regulates blood pressure, regulates acid-base balance
3. Production of erythropoietin (blood cell formation) and enzymes

Question 22

Draw a diagram that shows how glomerular filter works. Label the principle pressures involved in the process

Answer 22

Diagram

Question 23

Draw a diagram of the nephron and show where and how reabsorption occurs

Answer 23

Diagram

Question 24

How are passive and active transport mechanisms used to reabsorb critical solutes back into the blood?

Answer 24

Passive reabsorption of water uses osmosis, and uses diffusion across concentration gradients

Active transport uses energy driven transport proteins.

Question 25

What is ADH? How does it help your body to regulate the volume and concentration of extracellular fluids?

Answer 25

ADH is a protein producd by the hypothalamus and is delivered to the kidney via the blood stream. When ADH is absent, lare volume of water in dilute urine When ADH is present, small volume of concentrated urine.

Question 26

How is kidney failure treated and describe one major limitation with this treatment

Answer 26

``` Hemodialysis concerns: Interaction of blood with contacting surfaces Hemolysis of RBC Clotting Activation of complement pathways adhesion and activation of white blood cells and platelets increased cancer rates ```

Question 27

in the context of this course, what is meant by Mechanics? | Describe four subfields of the study of mechanics (2 from classical, 2 from continuum Mechanics)

Answer 27

Study of the behavior of physical boides when subjected to forces or displacements and the subsequent effect of those bodies on their environement 2 Classical: Statics, Dynamics 2 Continuum: Solid(solid tseformable), Fluid (fluids and solid deformable objects in fluids) Biomechanics is the study of the structure and function of biological systems by means of the methods of mechanics

Question 28

Define the term deformation | Describe how plastic deformation is different that elastic deformation

Answer 28

Deformation is the change in shape or size of an object, including fractures. Plastic- material deforms and remains in the deformed shape even after fore is removed, underlying molecular structure has been changed Elastic- Material deforms but can still go back to original shape because relative molecular structure is unchanged.

Question 29

Provide a diagram that shows a typical stress strain curve, label its axis, describe 5 properties that be determined from the curve

Answer 29

Diagram X-axis:Strain- dL/L0 Percentage Y-axis: Stress- pressure induced by a given strain MPa. - Young's modulus=slope of elastic elongation (stiffness) MPa. - Yield Strength=elastic/plastic- stress needed to cause plastic deformation - Ultimate Tensile Strength= max stress on plot MPa - Total Strain=max strain also called elongation at failure % - Toughness Area under the curve MPa.

Question 30

What is the finite element method? | How is it useful to the fields of bioengineering and medicine?

Answer 30

Divides complex differential equations into many simpler relationships/interactions Total set of relationships/interactions is called a mesh Each element in the mesh describes the relationship between 2 points or nodes Many computational software packages are available. Help provide accurate models. allows better understanding of physiology. Support previously untestable theories. Can be adapted to understand how different diseases and conditions will impact function. Accelerates creation of the innovation of new and improved treatments.

Question 31

Define what is meant by the term bioisntrumentation

Answer 31

Bioinstrumentation focuses on the development of devices for the study, diagnosis and treatment of disease. Uses knowledge from chem, materials science, optics, acoustics, electronics, measurement principles, mechanics, computation methods

Question 32

Provide a classification system for the different types of Bioinstrumentation and provide an example of each

Answer 32

1. Bioelectric - EKG (electro Cardio Gram) 2. Biophysical - Sphygmomanometer(BP), Ultrasound 3. Biochemical - Glucometer (diabetes), pregnancy test 4. Biomagnetic - MRI, MagStim, OctoBot

Question 33

Describe one instrument that we covered in class

Answer 33

MRI Measures realignments of protons in a magnetic field after exposure to an rf field. H2O protons are primarily measured. Can visualize distinct organs and even fine tissue structures due to differences in proton density, temp and chemical state. Can also use Hemoglobulin as a measurement fMRI or real time MRI

Question 34

X-ray imaging creates a negative image, explain

Answer 34

Black parts of the x-ray film are totally exposed to the X-rays. The white parts is film not fully exposed to x rays due to dense material preventing the x ray from reaching and exposing the film. Therefore, the image is created by preventing the x-ray to expose the film, thus creating a negative image.

Question 35

what is the contrast mechanism of x-ray imaging

Answer 35

The amount of x-ray that exposes the film. Created by the density and thickness of material the x-rays are passing through.

Question 36

how is CT imaging different from traditional Xray? | Describe how the CT imaging system works to create an image

Answer 36

(computer tomography) Created by rotating xray camera, taking many images. Images are stitched together using a computer. Results in 3-D image, with higher resolution

Question 37

How is ultrasound image generated? what is primary contrast mechanism?

Answer 37

Ultrasound images are generated by oscillationg pressure waves above the limit of human hearing. A crystal turns an electric current into sound waves, the waves are reflected, and the crystals turn the sound waves back into an electric current which produces an image. Contrast is generated by acoustic impedance.

Question 38

Describe how ultrasound is being used beyond imaging?

Answer 38

Therapeutic ultrasound is being used for several things. Localized drug delivery. Designing capsules that burst when hit with a certain frequency of sound wave allow the capsules to pass through the rest of the body, and then to be hit by that frequency at a certain point allowing localized drug delivery. Localized tumor ablation-cauterization Activate silicon nanoparticles to fight acne, massage underlying muslce tissue

Question 39

How does PET imaging work? describe how gamma rays are generated and detected

Answer 39

Positron Emission Topography A radio active contrast agent is used. The agent emits positrons. When positrons and electrons interact the annihilate one another and emit gamma rays. The patient is surrounded by gamma ray detectors that solve the physics problem of where the gamma rays originated. This is especially used in cancer imaging. The contrast agent is radioactive glucose. Cancer cells take an more of the glucose than other parts of the body, the PET scan reveals a higher concentration of the glucose in certain areas, leading to a cancer diagnosis.

Question 40

What is a contrast agent? Why are they used? What concerns exist about them?

Answer 40

Contrast agents are used to enhance the visibility of internal structures. Operate by increasing the contrast causing property of a tissue in a given imaging form. i.e. radio opacity, nuclear relaxation time, sound diffraction etc. some may be radioactive. almost all remain in the body for longer than it takes to get a successful image.

Question 41

Proximal Tube

Answer 41

``` In cortex Passively reabsorb H20 Passively reabsorb HCO3 Passively Reabsorb K Actively Reabsorb NaCl Actively Secrete H+ ```

Question 42

Descending Loop of Henle

Answer 42

Passively removes H20 | Creates concentration Gradient to a passively reabsorb NaCl

Question 43

Ascending Loop of Henle

Answer 43

Passively removes NaCl in lower part Actively removes NaCl No H2O reabsorption

Question 44

Distal Tube

Answer 44

Passively reasorbs H20 Actively reabsorbs HCO3 Actively Excteres K Actively excretes H

Question 45

Collecting Duct

Answer 45

Actively Reabsorb NaCl Passively reabsorb needed urea Passively reabsorb H20 if ADH is present

Question 46

Pressures in Glomerular Filtration

Answer 46

Glomerular hydrostatic pressure (55 mmHG) Blood colloid osmotic Pressure (-30 mmHG) Capsular hydrostatic pressure (-15 mm Hg)