SAQ - POWERPOINT Flashcards
What type of enzymes catalyse phase I reactions
Cytochrome P450 dependent enzymes
What is the length of stores of glycogen and lipids in the body?
12 hours - Glycogen
3 months - Lipids
What binds to unconjugated bilirubin in the blood?
Albumin
Define: Allele?
One of two or more alternative forms of the same gene. Alleles occupy the same loci on homologous chromosomes
What artery provides and anastamosis between the superior and inferior mesenteric arteries?
Marginal artery
Which three muscles make up the abdominal wall?
External oblique
Internal oblique
Transversus abdominus
Where are the bile salts reabsorbed?
Terminal Ileum
What hormones are secreted by the duodenum and what do the stimulate secretion of?
CCK - bile
Secretin - Pancreatic juices
Gastrin - HCl
What is the role of glucagon?
Stimulates the conversion of glycogen to glucose (glycogenolysis) and gluconeogensis
What is the normal BMI range?
18.5 - 25
What is a stroma?
The connective tissue between the base of an organ and a tumour
What dermatomes are at the:
Nipples
Umbilicus
Crotch?
Nipples = T4
Umbilicus = T10
Crotch = L1
What are some notifiable diseases?
Measles Plague Rubella Leprosy Yellow Fever
What do raised serum levels of aminotransferase enzymes indicate and why?
Liver damage as the enzymes may of leaked from the damaged hepatocytes
What causes lactose intolerance?
Lactase deficiency
Three functions of salvia ?
Lubrication to assist in swallowing
Moistens mouth and tongue to facilitate speech
Initiates carbohydrate digestion
Maintains neural pH in the mouth, buffering mouth acid
What is another name for oxyntic cells?
Parietal cells
What effect does secretin have on gastrin and pancreatic secretion?
Regulates duodenal pH by reducing gastric acid from parietal cells, increases pancreatic bicarbonate secretion
What cells secrete cholecytoskinin and secretin and where are they located?
Duodenum (enteroendocrine - CCK)
S cells - secretin
What are the folds of the stomach known as?
Rugae
Where are the haustra found?
Large intestine between the tanae coli
The haustra are small pouches caused by sacculation
What cells secrete gastrin?
G cells in the pylorus
Where are the pacemaker cells in the stomach and what is its basic electric rhythm?
Interstital cells of Cajal are located along the greater curvature in the body of stomach
3 contractions per minute
Where are the crypts of Librkuhn located?
Small intestinal mucosa
State three factors that stimulate bile secretion by the liver?
Vagus stimualtion
Secretin
Presence of bile salts
Where are the islets of Langerhans found and what do they produce?
Pancreatic Endocrine cells
Insulin = Beta cells
Glucagon = Alpha cells
Stomatosatin = Delta cells
Pancreatic polypeptide = PP cells
Also amylin
What are the three types of jaundice?
Haemolytic jaundice: Caused by the destruction of RBCs
Obstructive jaudice: Caused by a blockage in the pathway where bilirubin is make in liver cells and where bile goes into duodenum
Hepatic jaundice: Damage to liver cells
Why is urine dark coloured and stools light in obstructive jaundice?
Plasma excess of water soluble conjugated bilirubin turns urine dark
Lack of sterocobilinogen causes pale faeces
Where do the thoracic duct and lymphatic ducts drain into systemic circulation?
Left and right brachiocephalic veins
Define phase I reactions?
Biotransform substancess
Aim is to make the drug more hydrophilic so that it can be excreted by the kidneys, easier to conjugate
Oxidation/Reduction
Microsomal enzymes mainly phase I e.g. Cytochrome P450
Define phase II reactions?
Glucuronidation
Conjugation to water soluble substance that can be excreted in urine by kidneys
What cartilage is responsible for altering tension on the vocal cords?
Arytenoid cartilage
What muscles are involved in respiration?
Diaphragm, intercostal and abdominal muscles
External intercostals and diaphragm only during quiet breathing
What is the costodiaphragmatic recess?
The largest of the pleural recesses, lying between the diaphragm and the thoracic wall into which the basal border of the lung encroaches during inspiration.
Where are the alveoli first found in the respiratory tract?
Respiratory bronchioles
What type of molecules is the blood brain barrier permeable to?
Small ions and water molecules can cross the blood-brain barrier through ion channels e.g. K+ and Na+
However, hydrogen ions CANNOT cross BBB
Glucose, O2 and CO2 are transported across
Small lipophilic molecules that can be transported passively across the cell.
Three ways that CO2 is transported in the blood?
Bound to haemoglobin - carboaminohaemoglobin
HCO3-
Dissolved in plasma
What is chloride shift and why do we need it ?
As CO2 enters an RBC, some of it is converted into H2CO3 which dissociates into HCO3-
This diffuses out leaving the H+ and the Cl- moves into to keep the cell neutral
Name three type of receptor involved in ventilation and what affect their stimulation has?
- Juxtapulmonary receptors (J receptors): Chemical stimulated. Close to blood capillaries in alveolar/bronchial walls, decrease blood pressure and heart rate
- Stretch receptors: Pressure stimulated, smooth muscle in bronchial walls, Shorter and shallower breathing
- Irritant receptors: throughout respiratory tract, causes coughing in upper respiratory tract and increased respiration in lower respiratory tract
What is normal blood pH range?
7.35 to 7.45
When does phyisological shunting occur?
Adequate perfusion
No ventilation
Caused by COPD, asthma lung collapse and Type 2 respiratory failure
Describe FEV1?
Forced Expiratory Volume in one second
A normal FEV1 is where the result is 80% or greater than the predicted value
Describe FVC?
Forced Vital Capacity, the total amount of air forcibly expired
Less reproducible than FEV1
A normal FVC is where the result is 80% or greater than the predicted value
A low FVC is airways restriction
What is the significance FEV1/FVC ratio?
If the ratio of FEV1/FVC is below 0.7 = airways obstruction
If the ratio is above 0.7 but the FVC is low = airway restriction
Describe type 1 respiratory failure?
pO2 = low pCO2 = low OR normal
Pulmonary embolism morst common cause
Describe type 2 respiratory failure?
pO2 = low pCO2 = high
Hypoventilation causes Type 2
What is physiological deadspace?
Ventilation but no perfusion
It is the sum of the anatomical dead space (nose, trachea bronchi) plus alveolar dead space (can be caused by pulmonary embolism)
What are the types of T lymphocytes and their role?
CD4 helper cells = Recognise antigens and release cytokines that activate CD8 cytotoxic cells
CD8 cytotoxic cells kill infected cells
How do you calculate maximum heart rate?
220-age
What should be administered in a hypoglcaemic emergency?
15 to 20g of carbohydrates orally
If this is not possible then glucagon can be administered by injection
What is the function of screening?
It is designed to detect people who probably have a disease from those who do not from those that are likely to have it.
Not diagnostic, further tests and investigation is required
Which cancers commonly metastasise to the bones?
Bronchus, breast, thyroid, kidney and prostate
What is a gene?
A segment of DNA that codes for a protein
Give an example of an autosomal dominant condition?
Huntingdon’s disease
Where are the four heart sounds listened to?
Mitral - 5th ic space along mid clavicular line
Tricuspid - 4th ic space right sternal margin
Pulmonary - 2nd ic space left sternal margin
Aortic - 2nd ic space right sternal edge
Where is the dorsalis pedis pulse located?
First interosseus space on the dorsum of the foot
What is the last rib to directly link to the sternum?
7th
Ribs 1-7 = true ribs as they attach to sternum
Ribs 8-10 = false ribs as they attach to 7th costal cartilage
Ribs 11-12 = Floating ribs
What is the level of:
Angle of Louis (sternal angle)
Xiphi Sternum?
Angle of Louis = T4
Xiphi Sternum = T9/10
The right coronary artery splits into?
Right acute marginal artery
Right posterior descending artery
The left coronary artery splits into?
Left anterior descending - diagonal artery
Circumflex - Left marginal
What supplies the SAN?
Right marginal 60% of people
Circumflex 40% of people
Surface markings of the oblique and horizontal fissures?
Oblique:
2nd rib posteriorly
4th rib mid axillary
6th rib mid clavicular
Horizontal fissure runs along the 4th intercostal space
What is the infundibulum?
Also known as conus arteriousus
Non contractile inflow portion of ventricle, develops from the bulbus cordis
What is the significant of the moderator band in the right ventricle?
Carries the right AV bundle
Surface markings of:
Bifurcation of trachea Upper oesophageal sphincter Bifurcation of the aorta Coeliac artery Superior Mesenteric artery Inferior Mesenteric Artery SVC entering right atrium
Bifurcation of trachea = T4
Upper oesophageal sphincter = C6
Coeliac artery = T12
Superior mesenteric artery = L1
Inferior mesenteric artery = L3
SVC entering right atrium= 3rd right costal cartilage
What is an auricle ?
Auricles are wrinkled pouch like structures attached to the atria that aim to increase the capacity of the atria
What level are the thyroid and cricoid cartilages?
C4 and C5 respectively
What are the three pharyngeal constrictor muscles?
Superior, middle and inferior constrictor muscles
Split into cricopharyngeal and thyropharyngeal
What are the cartilages of the larynx?
Epiglottis
Thyroid
Cricoid
Arytenoid x 2
Cuneiform x 2
Corniculate x 2
Under which ribs does the spleen sit?
9, 10 and 11
Which peritoneal organs are connected by a mesentery?
Part of the duodenum, remainder of small intestine, transverse colon, sigmoid colon
Which organs are retroperitoneal?
S: Suprarenal (adrenal)glands
A: Aortia/IVC
D: Duodenum (except proximal 2cm)
P: Pancreas (except tail) U: Ureters C: Colon K: Kidneys E: Eesophagus R: Rectum
What are Kupffer cells?
A form of macrophage, derived from circulating blood monocytes that partly line the hepatic sinusoids
What are sinusoids?
Small blood vessels in the liver that receive O2 rich blood from the hepatic portal artery and nutrient rich blood from the hepatic portal vein allowing diffusion into hepatocyte through the space of Disse
What is the role of transferrin?
Transports iron from the breakdown of RBCs in the spleen, through the blood to the bone marrow to be incorporated into the new RBCs
What is the precursor that all blood cells are developed from?
Pluripotent haematopoietic stem cells
From which cells are platelets derived?
Megakaryocytes
How is (a) glucose/galactose and (b) fructose absorbed in the small intestine?
(a) secondary active transport with Na+
(b) Facilitated diffusion through GLUT 5
How are (a) amino acids and (b) di/tripeptides absorbed in the small intestine?
(a) active transport with Na+
(b) Secondary active transport with H+
Diffusion into blood stream
How are short chain fatty acids absorbed in the small intestine?
Simple diffusion in and out
How are fats absorbed in the small intestine?
After emulsification and transport in micelles, micelles release long chain lipids and monoglycerides to diffuse across the intestinal lining
They aggregate in chylomicrons which pass into the lymph drainage system through thoracic duct into the blood stream
What organs does an ERCP look at?
Liver, gall bladder pancreas, bile ducts and pancreas
Name two differences between the mitral valve and tricuspid valve
2 vs 3 cusps
2 vs 1 papillary muscles per cusps
What is the rough inside surface of the right auricle known as?
Muscular pectinae
What three areas does the phrenic nerve innervate?
Motor: Diaphragm
Sensory: Diaphragm peritoneum
Sensory: Pericardium
What do the adenoids consist of and what condition can they contribute to?
Lymphoid tissue
Swelling causes obstruction and obstructive sleep apnoea
What innervates the muscles of the pharynx?
Pharyngeal plexus (IX and X)
Cricopharyngeus - external laryngeal nerve
What innervates the intrinsic muscles of the larynx?
Recurrent laryngeal nerve
EXCEPT
Cricothyroid - extenteral laryngeal
Describe the course of the left recurrent laryngeal nerve?
Left recurrent laryngeal nerve is a branch of the vagus and hooks under the arch of the aorta
Describe the course of the right recurrent laryngeal nerve?
Right recurrent laryngeal nerve loops under the right subclavian and it is a branch of the vagus
Describe the arrangement of vessels and nerves at the Hilum of the lung?
Artery bronchus vein superior to inferior
Phrenic to vagus anterior to posterior
The caudate and quadrate lobes are anatomically and physiologically on which side of the liver?
Anatomically - right
Physiologically - left
Functional division is from the IVC to the gall bladder
Between which muscles are the intercostal vascular bundles situated?
The internal and the innermost intercostal muscles?
