The Night Before Exams Flashcards
What is the function of the Cerebellum?
Coordination of movement and balance.
What connects the two hemispheres of the Cerebellum?
Vermis
What tracts transmit through the superior peduncle of the cerebellum?
Ventral Spino cerebellar
What tracts transmit through the middle cerebellar peduncle?
Corticopontocerebellar
What tracts transmit through the inferior peduncle of the cerebellum?
Vestibulocerebellar, Dorsal spinocerebellar
What demarcates the upper and lower thirds of the abdomen?
Transpyloric and Transtubercular planes respectively.
What is the Transpyloric plane?
Also known as Addison’s plane, it is the line at the midpoint between the jugular notch and the superior border of the pubic symphysis.
What is the transtubercular plane?
The line between the iliac tubercles
What is the Rectus sheath?
An enclosure of the rectus abdominis muscle, is formed by the aponeuroses of the external and internal oblique muscles.
What forms the anterior wall of the rectus sheath?
External oblique aponeurosis and 1/2 of internal oblique aponeurosis.
What forms the posterior wall of the rectus sheath?
1/2 of internal oblique aponeurosis and the transversus abdominis aponeurosis. This ends at the arcuate line.
What is omentum?
Omentum is many sheets of visceral peritoneum
What is the greater omentum?
Omentum which connects the greater curvature of the stomach to the transverse colon and contains immune cells.
What is the lesser omentum?
Lesser curvature of the stomach to the liver it contains the flat Hepatogastric ligament and the Hepatoduodenal ligament which contains the portal triad at is free edge.
What are the four parts of the duodenum?
Superior, descending, inferior and ascending
Which salivary glands are dark staining?
Serous glands, such as the parotid and the submandibular.
What is the transport system for saliva?
Acini- Intercalated ducts - Striated ducts.
What is absorbed from and secreted into saliva?
Na+, Cl- is absorbed
HCO3- and K+ are secreted.
What is Vitamin C essential for?
Collagen synthesis.
What factors are essential so a compound can be pharmacologically active?
Lipophilic so it can cross the cell membrane
Non-ionised at pH 7.4
Able to bind to plasma proteins.
What are Phase I and Phase II reactions?
Phase I- biotransformation to make a molecule more soluble.
Phase II- glucuronidation - conjugation reactions using the enzyme Glucoronosyltransferase.
What are Cp450
Cytochrome P450 enzymes- they are microsomal and break down compounds using the Fe2+ ion.
Which clotting factors does the liver not produce?
IV- Ca2+, VIII- von Willebrand Factor
What are the two mechanisms for amino acid degradation?
Oxidative Deamination- occurs to glutamate and results in the formation of Ammonia and an Alpha Keto acid.
Transamination- aminotransferase enzymes transfer alpha-amino groups to keto acids.
What is the glucose alanine cycle?
A cycle transports nitrogen and carbon skeletons from the muscles to the liver. This increases the rate of glycolysis in the muscles and sends gluconeogenic and protein precursors to the liver. Transport occurs as alanine in the blood.
What is consumed and produced in one turn of the urea cycle?
3ATP and 4 High energy Nucleotides are consumed.
One mol of Urea is produced
Why is Ammonia neurotoxic?
Ammonia can cross the blood-brain barrier and is converted to glutamate in reverse oxidative deamination which leads to a decrease in oxaloacetate which halts the Krebs cycle thus reducing ATP production and leading to cell death.
VLDL
Very low density lipoproteins carry tiglycerides to adipocytes.
Bile Metabolism
In the spleen, haem is broken down into biliverdin via haem oxygenase. Biliverdin is converted to unconjugated bilirubin by biliverdin reductase.
Unconjugated bilirubin is bound to albumin and transported to the liver.
Gluocrinidation occurs to form conjugated bilirubin via UDP Glucoronyltransferase.
Urobilinogen is produced by intestinal bacteria and can be excreted in urine (making it dark)
Further colonic bacteria produce stercobilinogen which contributes to the dark colour of stools.
Alcohol metabolism
Ethanol is converted to Acetaldehyde by alcohol dehydrogenase.
Acetaldehyde is converted to Acetate by aldehyde dehydrogenase which can then be converted to carbon dioxide and water.
Ketogenesis
The production of beta-hydroxybutyrate from acetyl-CoA.
Micturition
The bladder fills with urine and stimulates stretch receptors in the wall.
Pelvic splanchnic (S2-4) parasympathetic nerves, cause contraction of the detrusor smooth muscle.
Hypogastric sympathetic nerve (T12-L2) is inhibited.
The external urethral sphincter relaxes when voiding.
Pudendal (S2-4).
The equation for Glomerular filtration rate
Gf= Kf(Pgc-Pbs-piGc)
What is the difference between primary and secondary bone?
Primary (Woven) bone is disorganised.
Secondary (Spongy) bone is organised but made at a much slower rate.
What is the difference between cortical and trabecular bone?
Cortical is compact and dense with space for blood vessels and cells.
Trabecular is spongy and has many spaces which are filled with bone marrow.
What is endochondral ossification?
Chondrocytes produce a cartilaginous precursor which has osteoid laid onto by osteoblasts.
This occurs in long bone where it occurs at the epiphysis (the growth plate)
Intramembranous ossification
Occurs when osteoid is initially deposited onto mesenchymal stem cells. Forms flat bones such as the ones in the cranium.
How do osteoblasts and osteoclasts communicate with each other?
Osteoclasts are promoted by RANKL which is secreted by osteoblasts and promotes monocytes to differentiate to osteoclasts. Increases in the presence of oestrogen.
OPG- osteoprotegerin inhibits osteoclast activity.
What does Wolff’s law state?
That bone adapts to the loads which it is placed under.
Sources of Vitamin D3
Diet and formed in the skin by UVB from 7-cholecalciferol.
Functional classification of joints
Synarthroses- immobile fibrous joints
Amphiarthroses- slightly mobile cartilagenous joints
Diarthroses- mobile synovial joints
Types of synovial joint
Ball and socket, hinge, condyloid, pivot, saddle, gliding.
What is collagen formed from?
Triple helix molecules called tropocollagen form cross-links between lysine and hydrolysine.
How do ligaments vary from tendons?
Ligaments are bone to bone and contain low levels of Type I collagen, and high elastin with random fibre organisation.
Types of attachment?
Fibrous- intramembranous- Sharpey’s fibres.
Fibrocartilagenous- endochondral
Differences between osteoporosis, penia and malacia
Osteoporosis is decreased bone density below 2.5 SD below the mean, penia is more than 1 below the mean.
Osteomalacia is decreased mineral content.
Pulmonary receptors
Stretch receptors
RASR- in airway
SASR- prevent overinflation of the lungs with the Hering-Breuer reflex.
C-fibres respond to chemical and mechanical stimuli and afferent via the Vagus nerve CNX to initiate the cough reflex.
Layers for gas exchange
Surfactant, Type I pneumocytes, Basement membrane, interstitial space, basement membrane, endothelia, erythrocyte.
Daltons law
p1+p2+p3…=Pt
Boyles Law
P1V1=P2V2
Henry’s Law
The concentration of a gas in solution is proportional to its partial pressure.
Laplaces law
P=2T/R (This explains surfactant action)
Poiseulles law
Q=R4
Cytoskeleton
Filamentous proteins brace the inside of the cell to maintain its structure.
Microfilaments
5nm- Actin forms bracing mesh on the inside of the cell.
Intermediate Filaments
10nm- spread tensile forces through tissues.
Microtubules
25nm- Tubulin is found in all cells except erythrocytes which don’t have a nucleus and do not carry out mitosis.
Osmolality
Number of dissolved particles per Kg of fluid
Co-Enzymes
Cannot directly catalyse reactions but they can activate enzymes, and form covalent bonds such as CoA or accept electrons such as NAD
Aldose vs Ketose
Aldose- aldehyde at C1
Ketose- ketone at C2
Start and Stop Codons
Start= AUG, Stop= UGA, UAG, UAA
Mendels second law
Independent assortment- genes sort independently regardless of the genes.
Dominant Negative Effect
Gene product adversely affects normal wild-type gene product within the same cell.
Factors which decrease the rate of glycolysis
Citrate, ATP, low pH (PFK-1 is pH dependent)
Fatty Acid Oxidation
A fatty acid is combined with ATP and CoA to form Acyl-COA which is converted to acylcarnitine via the addition of carnitine so it can cross the mitochondrial membrane.
2C are removed sequentially, removing NADH, FADH2, AcetylCoA hence yielding vast amounts of energy.
Name an Endogenous source of ROS
ETC
Haber Weiss
O2 + H2O2 + H+ –> O2 + H2O +OH-
Fenton
Fe2+ + H2O2 –> Fe3+ + OH- + Oh
Alcian blue
Stains GAG blue
PAS
Sugars magenta
Toluidine blue
Nuclei, ribosomes and cytoplasm are dark blue and GAG blue
Borders of the Heart
Right - RA
Inf- L&R V
Left- LV
Superior- Atria and great vessels
What occurs in platelet activation?
The platelets change shape to become spiculated due to thrombin positive feedback.
Aortic Sac
Forms the Aorta and Pulmonary artery
Bulbus Cordis
RV
Primitive ventricle
LV
Primitive atrium
LA and RA
Sinus Venosus
RA, VC, Coronary sinus
