Lecture 1 Flashcards
Test 1
What is anatomy?
The study of the structures and parts in living organisms
What are the 2 types of anatomy?
Gross - Visible with the eye
Microscopic - Needing a microscope to see
What is physiology?
The study of physical and chemical factors that are responsible for the origin, development, and progression of life
What is homeostasis?
Healthy conditions in the body that are maintained at near constant conditions to keep cells in good working order by using sensors and control mechanisms.
How many cells are in the body?
About 35 trillion
How many RBC are in the body?
About 25 trillion
Who coined the phrase regarding homeostasis in 1929?
Walter Cannon
What is the internal environment?
Extracellular fluid
Everything under the skin
According to homeostasis, what will happen if your internal temperature drops?
Your body will sense this and begin to shiver to bring your body temperature back up.
What happens when you’re paralyzed and your body temperature drops?
Your body loses the ability to shiver therefore you lose the control mechanism put in place to keep your body warm. Hence why we use bair huggers in the OR.
What goes in must equal…
what comes out
What is input?
Nutrients (food)
What is Output?
Energy and waste by-products
What is output energy?
Work, heat, potential energy
What are waste by-products?
CO2, protons, H2O, urea, solid waste
Why are sensors important in homeostasis?
They help to adjust for changing conditions; cannot adjust properly without functional sensors.
How does anesthesia effect the body’s ability to maintain homeostasis?
Anesthesia alters system physiology and removes the body’s sensory effects of the nervous system; CRNA does the work of the nervous system (work that usually the negative feedback response would do)
What happens around the cell when the cell metabolism increases?
The composition of the fluid around the cell changes to allow for nutrients to flow into the cell to maintain homeostasis.
What helps removes byproducts in the cardiovascular system?
Veins
What are the energy compounds cells need?
O2, sugars, fats, chemicals
How do the kidneys assist in homeostasis?
Maintains BP
ECF buffering for pH and electrolytes
How does the GI system assist in homeostasis?
Replaces nutrients in the blood being used/consumed by cells
How do the lungs assist in homeostasis?
Regulates blood gases
How do peripheral vascular beds assist in homeostasis?
The consist of arterioles, capillaries, and venules; which regulates blood flow to peripheral tissues and organs (vasoconstriction/vasodilation); nutrients and gas exchange; temperature; fluid balance; and waste removal.
How does the heart assist in homeostasis?
The heart consists of 2 pumps that share the septum wall. These pumps assist in gas exchange going into the lungs.
How does the liver assist in homeostasis?
The liver changes the chemical compositions of some substances into more useable forms; It also detoxifies or removes ingested chemicals into the bile to be excreted via feces.
What is Negative Feedback and how does it work?
It is a major control system in the body; Almost all systems are managed by this; changes are sensed and the body reacts to counter the change.
In Negative Feedback, the change is always ____________ to the stimuli.
Negative
What is the Negative Feedback response for increased CO2?
Increased ventilation to decrease CO2. This change is NEGATIVE to the stimuli.
What is the relationship between the PNS and the SNS?
They have opposite effects on the same organs to help maintain homeostasis.
What is the Negative Feedback change for a decreased MAP with SNS and PNS?
The NEGATIVE change is there is an increase in the SNS outflow and a decrease in the PNS outflow.
What is the Negative Feedback change for a decreased MAP with AVP/ADH?
Arginine Vasopressin and Antidiuretic hormone increase
What is the Negative Feedback change for a decreased MAP with ANP?
Atrial natriuretic peptide decreases
What is positive feedback and how does it work?
Stimuli causes a change in the body, with positive feedback, that change is amplified.
What are checkpoints in Positive feedback?
They are safety valves, which is a point to where the amplified change stops
What happens if the Positive Feedback response doesn’t stop at the checkpoint?
This is called a vicious cycle; can result in severe organ failure and/or death.
What is a vicious cycle?
It is when in positive feedback response continues and does not stop at the checkpoint.
What is the positive feedback response during labor and birthing?
Oxytocin-induced uterine contractions which is amplified to stretch the cervix and to have stronger contractions
What is the checkpoint for laboring?
Birth
What is the positive feedback response during a cut blood vessel?
Damaged endothelial cells liberate clotting factors and promote platelet plug formation and coagulation. This is amplified as time goes by.
What is the checkpoint for an injured blood vessel?
Bleeding stops
Describe the pathology of Positive Feedback in Severe Hemorrhage.
The loss of blood causes causes an initial drop in MAP and decreased coronary blood flow; which cause a decrease in cardiac output; which further decreases MAP
Describe the pathology of Positive Feedback in Sepsis/Necrosis.
The systemic infection causes cellular death; upon cellular death, the cells release byproducts into the ECF in which affect neighboring cells
Describe the pathology of Positive Feedback in Severe Acidosis.
CNS is depressed which decreases respiratory drive; this worsens acidosis (pH decreases)
Describe the pathology of Positive Feedback in Diabetic Renal Inflammation/Hyperfiltration.
Decrease in nephron regeneration can lead to renal failure d/t increasing workload on remaining nephrons
Describe the pathology of Positive Feedback in Peripheral Acidotic conditions.
Cellular dysfunction, impaired blood flow, and reliance on anaerobic metabolism worsens acidosis.
Describe the pathology of Positive Feedback in Atherosclerotic Plaque Clotting.
Overactive clotting cascade causes clot formation inside the surface of an atherosclerotic plaque in the coronary artery which causes MI.
How many liters of blood is in the human body?
5 Liters
What happens if you lose 1L of blood?
1L is 20% of your blood. Your body will go into compensated shock which will trigger a Negative Feedback response and you will recover.
What happens if you lose 2L of blood?
2L id 40% of your blood. Your body will go into decompensated shock. Negative feedback is insufficient for this type of blood lose and positive feedback response. This vicious cycle will lead to death. Your body cannot recover from this without immediate interventions.
What effects anesthesia response?
Physiological changes and/or comorbidities
What is the smallest living unit?
A cell
What is a cell?
The most basic functional unit; Specialize in specific tasks; Are able to create their own ATP via enzymatic machinery; Usually able to replicate
What cells have difficulty replicating?
Neurons and heart cells; they replicate very slowly
How do cells create ATP?
Enzymatic machinery
What characteristic do lung cells have?
They are thin and narrow for gas exchange
What do skin cells do?
Sheild from environmental factors
What is Tissue comprised of?
Collection of cells
What are organs comprised of?
Collection of tissues
What is the body comprised of?
Collection of organs
What is responsible for the maintenance of the entire body?
Organs
Can RBC replicate?
No. RBC are produced by bone marrow progenitor stem cells
What happens when a cell can’t self-replicate?
There’s a progenitor cell nearby to assist in replication
What causes a cell to be unable to replicate?
Lack of nucleus; lack of DNA
What allows cells to produce, divide, and replicate?
DNA (genetic makeup)
How long to RBC live?
90 - 120 days
What dictates the function of the cell?
DNA
How much of a cell is water?
70-85%
With the exception of adipose cells
What is the cytoplasm?
Everything inside the cell wall excluding the nucleus
What is the cell membrane and what does it do?
“Cell wall” is a phospholipid bilayer that “keeps inside stuff in and outside stuff out”.
Where do chemical reactions take place?
Cytoplasm
What is the difference between ICF and the cytoplasm?
ICF is ONLY the fluid; the cytoplasm is everything inside the cell wall but not the nucleus. The cytoplasm includes ICF but they are not interchangable terms
What is the function of a nucleus?
To pack and secure DNA from viruses and bacteria.
Describe the nuclear membrane.
“Nucleus wall” is a double phospholipid bilayer. It is a very selective barrier.
Why is the nuclear wall selective?
When other things get through such as viruses and bacteria; gene manipulation can happen and cause things such as cancer, HIV, etc
What is the purpose of pores in the nuclear wall?
Pores allow transport from cytoplasm to inside nucleus.
How do steroids work?
They go into the nucleus via pores and change gene transcription to turn on stress response proteins
What is the endoplasmic reticulum?
“ER” It is an extension of the nuclear wall; produces fats and proteins; stores calcium in ER in muscles.
Where is the endoplasmic reticulum?
It is an extension to the nuclear wall
What are the different types of endoplasmic reticulum?
Granular (Rough) ER
Smooth ER
What happens in the rough ER?
Ribosomes produce proteins from amino acids then are sent in transport vesicles to the Golgi apparatus
What happens in the smooth endoplasmic reticulum?
fats/lipids are produced
___% of ribosomes and protein translation are in the rough ER
95%
___% of ribosomes and proteins are made in the cytosol
5%
What does DNA do?
DNA genes encodes for protein and lipid synthesis in the rough and smooth ER
What does the Golgi apparatus do?
It receives transport vesicles with proteins directly from the rough ER for post translational processing/modifications
What does secretory vesicles do?
contains modified proteins from the Golgi apparatus that move towards and fuses to the the cell wall to be secreted outside the cell
What does DNA mean?
Deoxyribonucleic acid
What does RNA mean?
Ribonucleic acid
What structure is a DNA?
Its a 3D structure that’s folded
Can RNA pass through nuclear wall?
Yes
-ase
enzyme proteins
What is an enzyme?
A protein that catalyzes chemical reactions
What is an organelle?
Internal specialized structure including lysosome, transport vesicles, mitochondria, and peroxisome
What does peroxisomes do?
Use oxidative reactions to degrade toxins in the liver
What does mitochondria assist in?
ATP production
What do lysosomes do?
They use acidic conditions to degrade proteins, lipids, nucleic acids, and carbohydrates
Glyco-
Sugar
Carboxy-
Carb
What produces ID tags?
Sugars and bacteria
What is a special property of sugar?
Sugar is sticky and is stuck to a protein. Sugar groups can stick to each other and hold cells together.
Why is the cytoplasm so important?
The chemical reactions that take place in the cytoplasm regulates acid/base balance and electrolytes
Where are the sensors for feedback located?
In the periphery
How many nephrons are in each kidney?
1 million
Do nephrons regenerate?
No
