Basic Sciences Stuff Flashcards
Red cell Indices
MCV, MCHC, MCH, RBCmass
MCV: Mean corpuscular volume (MCV) is the average volume of a red blood cell and is calculated by dividing the hematocrit (Hct) by the concentration of red blood cell count.
# MCV =Hct/ [RBC COUNT]
Normal range: 80–100 fL (femtoliter)
MCH: Mean corpuscular hemoglobin is the average amount of hemoglobin (Hb) per red blood cell and is calculated by dividing the hemoglobin by the red blood cell count.
MCH= {Hb} / {RBC}}
Normal range: 27-31 pg/cell
MCHC: Mean corpuscular hemoglobin concentration is the average concentration of hemoglobin per unit volume of red blood cells and is calculated by dividing the hemoglobin by the hematocrit.
MCHC= {Hb} / {Hct}}
Normal range: 32-36 g/dL
Red blood cell distribution width (RDW or RDW-CV or RCDW and RDW-SD) is a measure of the range of variation of red blood cell (RBC) volume, yielding clues about morphology
Iron Profile
Normal reference ranges are:
Serum iron:
= Men: 65 to 176 μg/dL
= Women: 50 to 170 μg/dL
= Newborns: 100 to 250 μg/dL
= Children: 50 to 120 μg/dL
TIBC: 240–450 μg/dL
Transferrin saturation: 20–50%
Serum iron is a medical laboratory test that measures the amount of circulating iron that is bound to transferrin and freely circulate in the blood. Clinicians order this laboratory test when they are concerned about iron deficiency, which can cause anemia and other problems. 65% of the iron in the body is bound up in hemoglobin molecules in red blood cells. About 4% is bound up in myoglobin molecules. Around 30% of the iron in the body is stored as ferritin or hemosiderin in the spleen, the bone marrow and the liver. Small amounts of iron can be found in other molecules in cells throughout the body. None of this iron is directly accessible by testing the serum.
However, some iron is circulating in the serum. Transferrin is a molecule produced by the liver that binds one or two iron(III) ions, i.e. ferric iron, Fe3+; transferrin is essential if stored iron is to be moved and used. Most of the time, about 30% of the available sites on the transferrin molecule are filled. The test for serum iron uses blood drawn from veins to measure the iron ions that are bound to transferrin and circulating in the blood. This test should be done after 12 hours of fasting. The extent to which sites on transferrin molecules are filled by iron ions can be another helpful clinical indicator, known as percent transferrin saturation. Another lab test saturates the sample to measure the total amount of transferrin; this test is called total iron-binding capacity (TIBC). These three tests are generally done at the same time, and taken together are an important part of the diagnostic process for conditions such as anemia, iron deficiency anemia, anemia of chronic disease and haemochromatosis.
C Reactive Proteins
C-reactive protein (CRP) was discovered by Tillett and Francis in 1930. The name CRP arose because it was first identified as a substance in the serum of patients with acute inflammation that reacted with the “c” carbohydrate antigen of the capsule of pneumococcus.
CRP is a pentameric protein synthesized by the liver, whose level rises in response to inflammation. CRP is an acute-phase reactant protein that is primarily induced by the IL-6 action on the gene responsible for the transcription of CRP during the acute phase of an inflammatory/infectious process.
Foot -Muscles-Movements-Nerves
Plantar Flexion:
= downgoing as accelerating car
= Gastrocnemius, Soleus
= Sciatic S1
Foot dorsiflexion:
= Tibialis anterior (L4L5)
= Long foot Extensors (Sciatic, common peroneal nerve)
Foot inversion:
= Tibialis anterior & Posterior (L4, Tibial)
Foot Eversion:
= Peronei (S1, Sciatic, common pero)
Great Toe Extension:
= Extensor Hallucis longus, L5
Peripheral Neuron
There are three types of fibers that carry pain signals to the brain — A-beta, A-delta and C-fibers. The first two are evolutionarily modern fibers that are myelinated (insulated) and carry nerve impulses rapidly to the cortical regions of the brain
The C-fibers are relatively primitive, are unmyelinated and conduct rather slowly to the subcortical part of the brain. The brain perceives a more generalized burning, aching pain sensation, and this pain takes longer to pass.
Types
A beta type: Large, myelinated, Afferent to skin, Light touch, Moving stimuli
A delta type: Small fiber, myelinated, afferent to pain stimuli
C type axons: unmyelinated, afferent (sensory) slow
Sympathetic Post-Ganglionic: unmyelinated
Pituitary Hormones
Anterior pituitary:
= Growth Hormone
= Prolactin
= Thyroid stimulating Hormone (TSH)
= Adrenocorticotropin Hormone (ACTH)
= Follicle stimulating hormone (FSH)
= Leutinizing Hormone (LH)
Posterior Hormone:
= Anti-diuretic Hormone (Vasopressin)
= Oxytocin
= Melanocyte stimulating hormone
Blood pressure formula
= Cardiac Output x SVR (systemic vascular resistance)
ie
= (Heart Rate x Stroke volume) x SVR
Ortbial Apex and Superio Orbital fissure contents:
The orbital apex incorporates the optic canal and the superior orbital fissure. The optic canal transmits the optic nerve (surrounded by meninges) and the ophthalmic artery to the cranial fossa. The superior orbital fissure is anatomically lateral to the optic canal which can be divided into the superior, middle, and inferior portions by the common tendinous ring comprised of the thickened periorbita lining the surface of the orbital bones. The contents of the optic canal and the middle portion of the superior orbital fissure course through the common tendinous ring. The superior portion transmits the lacrimal nerve (CNV1), frontal nerve (CNV1), trochlear nerve (CNIV), superior branch of the ophthalmic vein, and recurrent meningeal artery. The middle portion transmits the nasociliary nerve (CN V1), abducens nerve (CNVI), and the superior and inferior branches of the oculomotor nerve (CNIII). The inferior portion transmits the inferior branch of the ophthalmic vein.
Vitamin B12
cyanacobalamine, water soluble
Essential ie not made in body
co-factor in DNA synthesis
Absorbed in distal ileum
Deficiency causes: fatigue, High MCV anemia, paraesthesia, Headache. Sore red tongue, SACD if long standing
Pernicious anemia (Antiparietal cell and Anti Intrinsic factor antibodies)
Post Gastrectomy (IF secreted here)
Post Ileal resect (B12 absorbed here)
Intrinsic factor deficiency
Malabsorption: coeliac, Sprue
Pure vegan diet
Rx - always replace before folate, iron or transferrin because neuropathies will occur otherwise.
IM Dose alternate days x 2 weeks
then every 3 months for life
Anti-diuretic Hormone, Vasopressin
secreted by hypothalamus and stored in posterior pituitary
acts on collecting ducts through AVP RECEPTORs which inserts aquaporine channels leading to more water absorption. (anti diuresis action)
- Defect in AVR2 or Vasopressin 2
- Defect in aquaporin 2 channels
both these will leads to nephrogenic Diabetes insipidus due to low action of ADH - more diuresis and severe dehydration, Hypernatremia due to Na retention and water loss.
Aldosterone
Hormone secreted by adreenal zona glomerulosa in response to angiotensin II and K.
Acts on distal tubules of nephron via H-K-channel leading to
Na retention - hence water retention
H loss
K loss
excess causes Hypertension(Na gain)
Spironolactone - aldosternone antagonist drug competively inhibits Na-K exchange channel leading to H2O loss > Na loss and K retention ie hyperkalemia
Conn’s syndrome
aldosterone secreting tumor of adrenal - excess Aldosterone leads to Na retention, water retention, High resistant HTN, hypokalemia. There is mild metabolic alkalosis due to low K and increased blood volume.
Antinuclear Antibodies, ANA
can be Cytoplasmic or nuclear ANA
may be - Homogenous-Speckled-Nuclear-Centromere
1:160 is high titre
checked by ELISA, Immunofluoroscence
Speckled ANA: Ro, La, U1-RNP
Nuclear, Centromere: = Scleroderma
ENA: Extractable nuclear antigens
Anti ds-DNA: SLE
Anti Phospholipid: APLS
Anti-Topoisomerase-1(Scl-70): Systemic sclerosis
Anti Ro, La: Sjogren’s ie keratoconjunctivitis sicca
Anti Jo1, Mi2: Polymyositis
ANCA-Anti-neutrophillic-cytoplasmic antibody
c-ANCA (proteinase-3, PR3) = Vasculitis
p-ANCA (myeloperoxidase, MPO) = Vasculitis
C for cytoplasmic, p for perinuclear, fluoroscopic patterns
- Granulomatosis with polyangitis (Wegner’s)
- Eosinophillic granulomatosis with polyangitis (Churg Strauss syn)
- Microscopic polyangitis
Liver screen
Liver function tests
Hepatitis B & C screen
Immunoglobulins
Anti mitochondrial antibody
Anti smooth muscle antibody
Anti Liver Kidney microsomal AB
Anti nuclear antibody
Ferritin levels
Alfa 1 anyitrypsine levels
Coagulation profile
Gamma GTT
Alfa fetoprotein
Caeruloplasmin
Ultrasound liver
Alfa fetoprotein
AFP is a major plasma protein produced by the yolk sac and the fetal liver during fetal development. It is thought to be the fetal analog of serum albumin. AFP binds to copper, nickel, fatty acids and bilirubin and is found in monomeric, dimeric and trimeric forms.
The function of AFP in adult humans is unknown. AFP is the most abundant plasma protein found in the human fetus. Maternal plasma levels peak near the end of the first trimester, and begin decreasing prenatally at that time, then decrease rapidly after birth. Normal adult levels in the newborn are usually reached by the age of 8 to 12 months.
Measurement of AFP is generally used in two clinical contexts. First, it is measured in pregnant women through the analysis of maternal blood or amniotic fluid as a screening test for certain developmental abnormalities, such as aneuploidy. Second, serum AFP level is elevated in people with certain tumors, and so it is used as a biomarker to follow these diseases. Some of these diseases are listed below:
Developmental birth defects associated with elevated AFP
Omphalocele
Gastroschisis
Neural tube defects: ↑ α-fetoprotein in amniotic fluid & maternal serum
Tumors associated with elevated AFP
Hepatocellular carcinoma
Metastatic disease affecting the liver
Nonseminomatous germ cell tumors
Yolk sac tumor
Other conditions associated with elevated AFP
Ataxia telangiectasia: elevated AFP is used as one factor in diagnosis
A peptide derived from AFP that is referred to as AFPep is claimed to possess anti-cancer properties.
In the treatment of testicular cancer it is paramount to differentiate seminomatous and nonseminomatous tumors. This is typically done pathologically after removal of the testicle and confirmed by tumor markers. However, if the pathology is pure seminoma, if the AFP is elevated, the tumor is treated as a nonseminomatous tumor because it contains yolk sac (nonseminomatous) components.
Alfa 1 Antitrypsin
Alpha-1 antitrypsin or α1-antitrypsin (A1AT, α1AT, A1A, or AAT) is a protein belonging to the serpin superfamily. It is encoded in humans by the SERPINA1 gene. A protease inhibitor, it is also known as alpha1–proteinase inhibitor (A1PI) or alpha1-antiproteinase (A1AP) because it inhibits various proteases (not just trypsin). In older biomedical literature it was sometimes called serum trypsin inhibitor (STI, dated terminology), because its capability as a trypsin inhibitor was a salient feature of its early study. As a type of enzyme inhibitor, it protects tissues from enzymes of inflammatory cells, especially neutrophil elastase, and has a reference range in blood of 0.9–2.3 g/L (in the US the reference range is expressed as mg/dL or micromoles), but the concentration can rise manyfold upon acute inflammation.
When the blood contains inadequate amounts of A1AT or functionally defective A1AT (such as in alpha-1 antitrypsin deficiency), neutrophil elastase is excessively free to break down elastin, degrading the elasticity of the lungs, which results in respiratory complications, such as chronic obstructive pulmonary disease, in adults. Normally, A1AT leaves its site of origin, the liver, and joins the systemic circulation; defective A1AT can fail to do so, building up in the liver, which results in cirrhosis in either adults or children
Gastric Hormones
Gastrin: secreted by G cells of gastric antrum, increased by vagus stimulation and reduced by Low PH and somatostatin. Increases HCl production, pepsinogen, motility and Intrinsic factor levels
Cholecystokinin: secreted by I cell of proximal small intestine. Secretion stimulated by TG and protein meals. Increases pancreatic secretions, causes GB contraction releasing bile, increases satiety and reduces gastric emptying.
Secretin: by S cells in proximal small intestine. Stimulated by acidic chyme and Fatty acids in it. Increased HCO3 rich pancreatic secretions and reduces gastric acid secretion.
Vasoactive Intestinal Peptide: produced by pancreas and small intestine, also increased by neural input. Increased pancreatic and intestinal secretions, reduces gastric acid production. Excess VIP causes secretory diarrhea as in VIPomas.
SomatoStatin: produced by D cells in stomach and pancreas. Secretion stimulated by Fatty acids, glucose and bile. Inhibitory action, reduces acid/ pepsin/ gastrin and insulin secretion and production.
Spinal Pathways
Descending- Motor:
= Pyramidal tracts: Anterior cortico-spinal and Lateral cortico-spinal
= Extra-Pyramidal: Rubrospinal, Reticulospinal, Olivospinal, Vestibulospinal
—————————
Ascending Sensory:
= Dorsal columns-Medial Leminiscus system: Gracile fasciculus, Cuneate fasciculus
= Spino-cerebellar: Anterior, Posterior
= Spino-Thalamic: Anterior, Lateral
Cranial Nerves: Sensory/Motor
Some Say Marry Money But My Brother Says Big Brains Matter Most
S = sensory
M = Motor
M = Mixed
1-12 each word in sequence
Retro-peritoneal structures
SAD PUCKER:
- Supra renal glands
- Aorta
- Duodenum except 1st part
- Pancreas except tail
- Ureters
- Colon (ascending, descending)
- Kidneys
- Esophagus
- Rectum
Testosterone
It is responsible for development of internal genitalia and spermatogenesis. IT IS converted to dihydro-testesterone by enzyme 5 alfa-reductase which is more active form and responsible for development of male secondary sexual characters. Absence of this enzyme or DHT receptor leads to testicular feminization.
Melatonin
Synthesized from serotonin and secreted by pineal gland, causes sleep
Stimulation of release:
= Exposure to darkness
= Retino-Hypothalamic nerves
= Due to Norepinephrine released by post-ganglionic sympathetic nerves (nervi conarnii)
which innervates pineal gland
Rheumatoid Factor
an IgM antibody against patient own IgG Fc
Detected by Rose waaler Assay using sheep rbc agglutination or by Latex agglutination
70-80% positive in Rheumatoid arthritis
Also can be present in:
- Sjogren’s syndrome (100%)
- Felty’s syndrome (100%)
- Infective endocarditis
- SLE
- Systemic sclerosis
- General population
Rarely: TB, HSV, EBV, Leprosy infections
