PBS Semester 1 Study Guide

define biomedical sciences

Application of principles of natural science to clinical medicine

what are the 3 parts of the hair shaft?

medulla (intermost)

cortex (middle

cuticle (outermost)

what are the 4 objective lenses of a microscope?

scanning: 40

low: 100

high: 400

oil: 1000

How to focus a microscope?

1. start w/ the lowest power

2. use the coarse adjustment knob

3. use the fine focus nob

1. loop

2. tented arch

3. whorl

4. arch

What is fingerprint minutiae?

Tiny characteristics within the fingerprint

How would you read a polygraph test?

Look at the graph for changes compared to the subject’s baseline control data

Define independent variable

variable that is changed or manipulated

Define dependent variable

Outcome, measurable effect

Define control variable

variables that remain constant

Define control group

A group in an experiment where the IV is not applied, serves as a standard for comparison

Difference between accuracy and precision

accuracy: how close a measurement is to it's true value

precision: the ability to reproduce the measurement

What are red blood cells?

(erythrocytes): transports oxygen from the lungs to the body tissues, and carry carbon dioxide back to the lungs

What are white blood cells?

(leukocytes): destroy bacteria and foreign invaders; fight disease

How does the angle affect the blood stain pattern in blood spatter?

• the longer the blood droplet, the smaller the angle

• bigger the angle the more elongated

• a 90 degree straight above angle the circular

• remember blood agglutinates with what type of blood it is

What is the universal donor and universal recipient?

universal donor: O

universal recipient: AB

What is DNA?

A molecule that carries genetic info and found in the cells of all living things

Define antigen and antibody

antigen: proteins found on the surface of the cell membrane (RBCs)

antibody:opposite of antigens (found in the plasma)

What are the DNA instructions for?

Instructions to build proteins

What are the building blocks of DNA?

Nucleotides (phosphate, sugar, nitrogenous bases)

What are the 3 parts of a nucleotide?

nitrogenous bases: adenine and thymine, guanine and cytosine

What is the backbone of DNA?

Phosphates and sugarsW

What type of bond holds the 2 DNA strands together

Nitrogenous bases, hydrogen bond

Chargaff’s Rule gives us the base pairing rules. What are they?

• adenine = thymine

• guanine = cytosine

Difference between a purine and pyrimidine?

• purines: double ring structure (A + G)

  • Pure As Gold

• pyrimidines: single ring structure (T and C)

  • Cut The Pie

Define genes and chromosomes

• gene: segments of DNA that provide the instructions for a specific protein

• chromosomes: tightly coiled packages of DNA - the nucleus

What makes DNA different from each other?

Different sequences of the bases

What are the 3 steps to perform DNA fingerprinting and analysis?

1. Break open the cell and the nucleus

2. Purify the DNA

3. Precipitate the DNA

4. Clean the DNA

What kind of charge does DNA have? Which direction will DNA travel through a gel?

• Negative

• Negative to the positive end

How many mL are in a uL? How many uL are in a mL?

• mL to uL

  • mL x 1000 = uL

• uL to mL

  • uL / 1000 = mL

What are the general steps to an autopsy?

1. external examination

2. internal examination

3. examination of organs

Who can perform an autopsy?

Medical examiner and coroner

Define manner, mechanism, and cause of death

manner: the circumstances that resulted in death (natural, unnatural, homicide, suicide, accident or unknown)

mechanism: what happens physiologically to result in death aka how the body reacts (cardiac arrest)

cause: what directly caused the victim’s death (gunshot)

What is rigor mortis, algor mortis and livor mortis (lividity)?

rigor mortis: after the body stops function, muscles contract and stiffen

algor mortis: after death, the body begins cooling or heating to match the temperature of the body’s surroundings (postmortem change in body temperature)

livor mortis: blood at the mercy of gravity, blood settles and collects on the body facing the ground. bluish color seen on skin where blood pools

Equation to convert equation between Celsius to Fahrenheit

F = (C x 1.8) +32

Equation to convert between Fahrenheit to Celsius

C = (F-32) / 1.8

Define ambient temperature

The temperature of the surroundings

(has to between 68-73)

Glaister equastion

98.4-rectal temperature / 1.5 = apx hours since death

difference between physiological, estimated and legal time of death

physiological: the time when the decedent’s vital functions actually ceased

estimated: the time the medical examiner estimates the death occurred

legal: time of death recorded on the death certificate when the body was found

What does a toxicologist do?

analyzes these sample for the presence of any substances that may have contributed to the decedent’s death

What are the 5 main components of the digestive system and what do they do?

1. oral cavity: food enters

2. esophagus: transports food from mouth to stomach

3. stomach: breaks down food

4. small intestine: continues to break down food and absorbs nutrients

5. large intestine: reabsorbs water and forms waste

What are confirmatory test?

Specific tests that can determine the exact identity and composition

What are platelets?

(thrombocytes): small cell fragments involved in blood clotting

What is plasma?

plasma: liquid that holds all cell fragments (antibodies found here)