Cellular Physiology, Genetic & Integument System

Module 1-2

What is a state of homeostasis?

Everything is in equilibrium in the system within their norm. This allows the body to have its optimal function. Disease and injury are cases in which the homeostasis is disturbed.

Describe and give an example of this modes of chemical signaling : autocrine

The cell is secreting molecule to itself.

Ex. when you talk to yourself while studying

Describe and give an example of this modes of chemical signaling : Paracrine

The cell secrete molecule to a nearby cell

Ex. When you ask your mom that is in the next room where had she put AGAIN your favourite snack.

Describe and give an example of this modes of chemical signaling : Hormonal

The cell secretes molecules that goes in the blood stream to reach a distant cell.

Ex. When you WhatsApp you parent by obligation while you are travelling.

What is the different between passive transport and active transport.

In passive transport, it’s only base on the concentration gradient in and out of the cell. (ex. osmosis)

In active transport, it goes against his concentration gradient. The transportation will then need a lot of ENERGY (ATP) to counter it.

In older individuals, what body composition lowers and increases compared to adult.

INCREASE= body fat

LOWER = water body %

What are the 4 physiological causes of edema ?

1. An elevated hydrostatic pressure (ex. hypertension = more tension on capillary walls = water will be pushed out of the vessel

2. Increase in membrane permeability (ex. inflammation)

3. Low oncotic pressure (ex. malnutrition leading to less albumin in the blood which helps retaining water in the vessel)

4. Lymphatic obstruction (ex. lymphoma)

What does atrophy mean?

Cell decrease in size for energy to be redistributed toward a more optimal

Whats is hypertrophy?

Cell size getting bigger. Most of the time, it is the body trying to maintain homeostasis.

What is hyperplasia?

Increase in number of cell.

What is metaplasia?

Change in cell type from one normal form to another normal form known by the body.

What is dysplasia

Abnormal growth or development of cells, often leading to tissue architecture changes.

An injury causes cell to be unable to use oxygen, what compound will be secreted?

Free radial is a compound secreted in response to reduced oxygen availability. (Causing the lactate level in the blood to go up, that is why when the lactate level is high in one patient, it is an emergenc y since some cell in the body are undergoing anaerobic metabolism.)

Why can’t we reperfuse an organ that underwent ischemia rapidly?

Rapid reperfusion can lead to reperfusion injury. After not being able to provide for some time due to lack of nutrition, the cell of this organ will be kind of rusty leading them to create rusty molecules (ex. free radical) when reperfuse. When replenish too fast, it will lead this accumulation of rusty molecules in the body leading to oxidative stress that lead to multiple pathological effect (ex. mutation, cell membranes damage, etc.)

What are the 2 type of cell death?

Necrosis and apoptosis

What is the 3 main components we have to analyze when looking at our blood gaz?

pH

Bicarbonate

CO2

Recall the compensatory mechanisms for the different acid base disorder

1. Respiratory acidosis: the kidneys will react by retaining bicarbonate (basic)

2. Metabolic acidosis: the lungs will react by eliminating Co2 (acidic) through hyperventilation

3. Respiratory alkalosis: the kidneys will react by excreting bicarbonate and increasing hydrogen retention (acidic)

4. Metabolic alkalosis: the lungs will react by retaining CO2 through hypoventilation

What is Recessive Inheritance ?

An individual that is affected by a condition due to the fact that they have the 2 recessive alleles in their gene.

What happen if DNA Polimerase is mutate?

The role of the DNA polymerase is to read the strand and add the pair corresponding to their nucleotide. (A-T ; G-C.) If mutated, it won’t do his job efficiently and create a mutation of the gene leading to the production of improper protein.

How many pair of sex chromozone do we have?

1 pair : XX or XY

What is the diffenrence between Polyploidy and Aneuploidy?

Polyploidy is a chromosomal aberrance that is a multiple of 23. For example, cells could have 46 pairs of chromosomes in this case.

Aneuploidy is a chromosomal aberrance as well that is just one pair of chromosomes that is either missing or in excess.

Compare to all the other type of chromosome breakage, what make Reciprocal Translocation be different of the other?

Reciprocal translocation is a chromosomal rearrangement where segments from two different chromosomes are exchanged.

What is epigenetics?

It is a field of studt interested in the relationship between the genetic and the environment (think about the twin study 😉 )

What main role does the hypodermis have?

It forms a cousin and lubricant for the contact from the skin to the organ.

What causes wrinkle?

Genetic isn’t the main cause of wrinkle.

Indeed, it is the environment exposure that increases the risk of people to have wrinkle (ex. UV exposure, smoking, pollution, inflammation, etc.)

What are the risk factor of having Acne Vulgaris?

1. Hyperkeratinization ( accumulation of dead skin in the follicule leading to sebacious oil to not be drain efficiently)

2. Increase in sebum production

3. Increase in proliferation of P. Acne Bacteria

4. Ruptude of sebaceous folicule.

What population are more at risk of having Kaposi Sarcoma?

Immunocompromised

Explain why a frameshift mutation is the most severe kind of protein alteration

Because the insertion or deletion of a number of neucleotide that is not a multiple of 3 disturbs the reading of all of the following codons in the protein.

Explain why se(X)-linked inherited genes disproportionately affect males

This because males only have one X chromosome (unlike females who have 2), and any anomaly on that chromosome will be expressed in the phenotype as they lack a second X chromosome to mask it.

Following an intense burn, lack of pain from the area would suggest that the burn reached which layer of the skin?

It would indicate that the dermis was compromised since nerves are located in the dermis. Therefore, a loss of sensation would mean that the nerves were damaged.

Explain why patients with frostbite are at risk of reperfusion injury during the thawing process.

Frostbite causes the cells to be in a state of hypoxia because of a lack of blood flow. The thawing process, if done too quickly, can lead sudden restoration of blood flow, leading to an excess supply in O2, and reactive oxygen species (ROS) to be produced.

what is the main difference between isotonic, hypertonic and hypotonic fluids

isotonic: 0.9% saline soln for fluid resuscitation

hypertonic: salt water

hypotonic solutions: tap water with less solute

when would you prescribe isotonic fluid to a patient and why

when the patient is experiencing major hemorrhage, causing loss of blood and leading to hypovolemia. Isotonic bcuz ratio H20 : solute = ratio of healthy homeostasis state of body fluids

what can hypertonic solutions cause if given excessively and why

Hypernatremia bcuz intracellular fluid leave cells to travel extracellularly to balance the high sodium concentration, leading to shrivelled cells and dehydration

what can hypotonic solution cause if given excessively and why

swollen cells because extracellular fluid will travel into the cells to restore homeostasis and the sodium concentration, which can lead to water intoxication and hyponatremia