Session 1 - Homeostasis and Examining Cells Flashcards
What effect does Interleukin 6 (IL-6) have on body temperature? Why?
It increases the core body temperature set point in the hypothalamus. This initiates heat generation and raises the body temperature to a point where the immune system can work optimally
What is Pyrexia?
A fever (Core Body Temperature above 38.5’C)
What is the normal range of blood pH and why.
Normal - pH 7.4
Arteries - pH 7.45
Veins - pH 7.35
Variation due to CO2 concentration
What are the symptoms of Acidosis
Headaches, Confusion, Tiredness, Tremors, Coma
What are the 2 main causes of acidosis?
Metabolic Acidosis - increased lactic acid production or inability to excrete acid via kidneys
Respiratory Acidosis - increased CO2 conc. due to HypOventilation
What is the normal range of Core Body Temperature and why may this vary?
37’C +/- 0.5’C
Varies with circadian rhythm (lowers when sleeping), menstrual cycle can cause increased variation.
Give an example of a typical Antacid
Aluminium Hydroxide
What change in pH results in a positive double of the concentration of H+ ions
Negative 0.3 change in pH
1) What are the 2 main ways pH is regulated?
2) What are the 2 main buffer systems?
1) Lungs - Respiratory Balance and Kidneys - Metabolic Balance
2) Extracellular - Carbonic Acid/Bicarbonate Buffer
Intracellular - Sodium Phosphate Buffer
How is water distributed in the body?
Average Male (70kg)
TBW - 60% = 42L
ICF - 2/3 TBW (28L) : ECF - 1/3 TBW (14L)
Interstitial Fluid - 3/4 ECF (10.5L) : Plasma Volume - 1/4 ECF (3.5L)
What is the standard osmolality of body fluids and what are the main contributors to this?
≈ 280 mOsm/kg
Glucose 190 mOsm/kg Sodium Chloride (Na = 40 & Cl = 40)
What is more frequently used osmolarity or osmolality? What is the difference?
Osmolality is more frequently used now. It has units mOsm/KG where as osmolarity is mOsm/Litre
What are the 4 types of tissue?
1) Epithelial
2) Muscle
3) Nerve
4) Connective
Name the most common form of permanent fixation? What is this (conc.) and why? Name another form of fixation, non-permanent.
Fixative Formalin - 37% Formaldehyde, 0.9% Sodium Chloride (isotonic solution) to allow for better formaldehyde penetration.
Frozen Section
How does formaldehyde act as a fixative?
Reacts with amino groups on amino acids within proteins and forms a methylated bridge between protein chains.
What is the role of the Nucleolus?
Site of the Ribosomal RNA synthesis
What are cisternae?
Flattened sacs (associated with SER or Golgi apparatus)
Why do mitochondrial diseases follow a female lineage?
Inherit all your mitochondria from your mother
What is the role of peroxisomes?
Site of peroxide production. H2O2 is used to oxidise other substrates like phenols, formic acid, formaldehyde and alcohol.
What is the main role of intermediate filaments?
To hold a cell together and prevent lysis. This is done by forming a tough supporting mesh work within the cytoplasm which is anchored to desmosomes
What type of proteins are dynein and kinesis?
They are attachment proteins that are able to bind to organelles and move structures along microtubules.
What is the primary role of microtubules?
Provide a network of highways within the cell that allow for the move movement of molecules and organelles to distant parts of the cell.
What is the primary role of micro filaments?
They are dynamic and allow for a cell to contract and change shape. Eg. Cilia on microvilli to move and propel intestinal contents.
What are 5 stages in preparing a biopsy for H&E staining?
1) Fixation
2) Embedding
3) Clearing
4) Staining
5) Dehydration
