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