MD2001 Week 7 Flashcards
3 classes of hormones
- proteins
- steroids
- amino acid derivatives
what type of hormone secretion is important in embryogenesis?
paracrine secretion is important in this development
pineal gland
gland that secretes melatonin
thymus gland
gland involved in immune system and blood cell count
which type of hormone must be injected to prevent from degradation in gut?
protein hormones must be administered this way
6 hormones secreted by adenohypophysis
- GH
- TSH
- ACTH
- FSH
- LH
- Prolactin
Vasopressin
antidiuretic hormone
what does hypothalamus secrete to stimulate adenohypophysis to secrete FSH?
hypothalamus secretes gonadotropic releasing hormone (GnRH) to stimulate this
glandular cancer
adenoma
protein found in the colloid
thyroglobulin
3 layers of epithelial cells in adrenal cortex
- zona glomerulosa
- zona fasciculata
- zona reticularis
neuroectoderm
neural crest cells
Cushing’s Syndrome
over secretion of cortisol caused by adenoma
exocrine component of the pancreas
pancreatic acini that produce pancreatic amylase
endocrine component of the pancreas
islets of langerhans produce alpha cells (glucagon) and beta cells (insulin)
how many pairs of cranial nerves?
12 pairs of this type of nerve
how many pairs of spinal nerves?
31 pairs of this type of nerve
what area of body is sympathetic?
thoracolumbar is this type of autonomic system
what area of body is parasympathetic?
craniosacral is this type of autonomic system
locations of the ventricles of the brain
lateral - cerebral hemisphere
3rd - diencephalon
4th - brain stem
3 main sulci
- longitudinal
- central
- lateral
collection of cell bodies in CNS not called nuclei
basal ganglia
corpus callosum
axon communicating b/w hemispheres
constituents of the basal ganglia
- caudate nucleus
2. putamen
Broca’s area
area of brain for delivering speech
Wernicke’s area
area of brain for understand speech
role of thalamus
relay station for inputs from subcortical motor nuclei and cerebellum to cerebral motor cortex
role of hypothalamus
maintains water balance, thirst, eating behaviour, GI, body temp, activity of adenohypophysis
roles of superior and inferior colliculi respectively
these parts of midbrain control visual and auditory mechanisms respectively
red nucleus
subcortical motor centre
what surrounds the cerebral aqueduct?
the midbrain surrounds this structure
cerebral aqueduct
connects 3rd to 4th ventricle
roles of pons (2)
- connect forebrain and cerebellum
2. help regulate respiration, hearing, balance
where does pyramidal decussation occur?
this occurs at the medulla oblongata
what is regulated at the medulla oblongata?
respiratory rhythm, HR, BP, cough, sneeze, swallowing, vomiting
what connects cerebellum to brain stem
peduncles connect these two brain structures
role of cerebellum
interprets impulses from motor cortex and coordinates motor activity for smooth, timed movements
anterior white commissure
bundle of nerves that cross at the anterior median fissure
examples of inherited lipid pathway disorders
- Gaucher’s
- Niemann Pick
- Tay-Sachs
- Fabry
molecular structure of fatty acid
carboxyl group + hydrocarbon chain
which fatty acid nomenclature counts the double bond from the carboxyl end?
delta fatty acid nomenclature works this way
amphipathic
having both hydrophilic and hydrophobic parts
types of sterols
- bile acids
- steroid hormones
- vitamins
- cell membranes
structure of a glycerophopholipid
diacylglycerol + phosphate group + head group
common head groups (4)
- choline
- serine
- ethanolamine
- inositol
what membrane lipid reduces fluidity of membrane?
cholesterol does this to the membrane
2 flippase mechanisms
- pore model (hydrophilic structure attracts lipid to flip)
2. slip-pop ( physically flips lipid)
molecular structure of a membrane chain
an alpha helix protein across membrane
molecule structure of a membrane pore
5 alpha helices across membrane
pleckstrin homology domain
a protein domain that helps protein bind to lipid membrane
example of a protein-attached protein
example of this type of protein connection: receptor binding to G protein signalling complex
6 steps of cell-cell communication
- synthesis of signal
- release signalling molecule by exocytosis, diffusion, cell-cell contact
- transport signal to target cell
- detect signal by receptor protein
- change in cellular function triggered by signal
- removal of signal
3 types of exocrine glands
- merocrine
- apocrine
- holocrine
4 types of receptors
- ligand-gated ion channels (ionotropic) *quick
- G-protein-coupled (metabotropic) *quick
- kinase-linked *slow
- nuclear *slow
inositol phospholipid signalling pathway
phospholipase C (PLC) split phospatidylinositol 4, 5-bisphosphate (PIP2) into inositol 1,4,5 triphosphate (IP3) and diacylglycerol (DAG)
3 types of protein kinase C (PKC)
- conventional (requires DAG and Ca2+)
- novel (requires DAG)
- atypical
3 principle eicosanoids (prostanoids)
- prostaglandins
- thromboxanes
- leukotrienes
structure of arachidonic acid
20 C unsaturated fatty acid w/ 4 double bonds
how are leukotrienes made?
phospholipase A2 (PLA2) liberate arachidonic acid, which is then metabolized by lipoxygenases to make this
what is a byproduct of arachidonic acid liberation?
platelet-activating factor a by product of this
thromboxane
- made in platelets
- short lived (as active form A2 lasts only 30s)
- prothrombotic properties
- vasoconstrictor
which eicosanoid is responsible for inflammatory response, thermoregulatory (fever) and pain
prostaglandin are responsible for this
which eicosanoid is responsible for immune response (asthma, allergy, anaphylactic shock)?
leukotrienes are responsible for this
types of coding mutations (3)
- nonsense/frameshift
- point
- silent
polymorphisms
minor changes in DNA sequence present in >1% of pop
what enzyme attaches amino acid to tRNA?
aminoacyl-tRNA synthetase
what on tRNA attaches to the codon sequence on mRNA?
anticodon attaches these two things
where on tRNA does the amino acid attach on to?
it attaches on to the 3’ -OH terminal adenosine of tRNA
what difference in ribosomes allows antibiotics to target only bacterial ribosomes?
different sedimentation coefficient (S) b/w eukaryotic (80S) and prokaryotic (70S) ribosomes specific target of this
3 steps in DNA translation
- initiation
- elongation
- termination
start codon
methionine (AUG)
kozak consensus sequence
methionine and surrounding sequence where translation begins
explain elongation in DNA translation
tRNA binds to ribosome at A-site and peptide bonds form b/w amino acids. Large subunit translocates, followed by small. tRNA exits at E-site
polysome
multiple ribosomes working on mRNA
signal-recognition particle (SRP)
bind to signal sequence on protein and brings protein to destination
example of result of too much protein modification
Tau- hyperphosphorylation causing neurofibrillary tangles in dementia is an example of this
examples of SSIs
- pus
- induration
- dehiscence
- lymphadenitis
- abscess
- necrosis
- gas gangrene
- sepsis
causes of SSIs
- contamination of incision by microbiota
- damage to tissue or blood vessel
- presence of foreign bodies
- reduced efficacy of inflammatory response
classification of surgical wounds
class I: clean (elective surgery, R, GI, GU not involved) class II: clean/contaminated (emergency case, uncomplicated R, GI, or GU surgery) class III: contaminated (outside objects contact, spillage from GI) class IV: dirty (purulent inflammation, foreign object lodged)
prophylaxis
action taken to prevent disease
preoperative care
- shower
- don’t shave
- give antibiotic prophylaxis
- don’t routinely use nasal decontamination
- don’t routinely use mechanical bowel prep
intraoperative care
- clean hands
- sterile gear
- clean site
- maintain patient homeostasis
- careful handling of tissue
- don’t use irrigation
- cover incision w/ appropriate dressing
- short length surgery
disinfectants for site of surgery (2)
- alcohol chlorhexidine
2. povidone iodine
occlusive dressings (2)
- hydrocolloid
2. polyurethane films
postoperative care
- use aseptic or non-touch technique to change/remove dressings
- use sterile saline for wound cleansing
- don’t use topical antimicrobial agents
- keep stay short
3 levels of presentation of prosthetic joint infection
- early: less than a month (fulminant w/ wound sepsis)
- delayed: less than a year (indolent, low grade infection)
- late onset: over 2 years (septic arthritis)
examples of specimens that can be taken for microbiology test
- midstream urine (UTI)
- pus (wound)
- CSF (meningitis)
- blood (pyrexia)
- sputum (pneumonia)
3 types of molecular diagnostics
- smear (rapid, cheap, not sensitive or specific, requires considerable expertise)
- culture (more sensitive, detailed)
- MALDI (rapid)
serological diagnosis
diagnostic identification of antibodies in the serum.
examples of molecular techniques
- DNA hybridization (slow)
- nucleic acid amplification testing (fast): PCR, ligase chain reaction, automated DNA amplification, real time PCR
ability of a test to detect all of the try positives; # of positives obtained/total # of positives
sensitivity
ability of a test to identify number of true negatives; # of negatives obtained/# of true negatives
specificity
lining of the uterus
endometrium
vesico-uterine pounch
recess of peritoneum b/w bladder and uterus
introitus
an entrance
urethral meatus
opening of the urethra
4 propositions to describe features of homeostasis
- mechanisms act to maintain constancy of body
- any change is met w/ factors that resist this change
- regulating system that determines homeostatic state consists of numerous mechanisms
- homeostasis is not by chance, but a result of organized self-government
average body temp.
normal: 37 degrees C
what part of brain controls thermoregulation?
hypothalamus controls this
steps to the baroreceptor reflex
- baroreceptors sense arterial pressure
- brain medulla vasomotor centre detects error
- sympathetic nervous system affects blood vessels/heart
- arterial pressure changes
players in glucose homeostasis
glucose sensor = special pancreatic cells
controller = autonomic nervous system
effectors = pancreatic cells in islets of Langerhans (a - glucagon, b - insulin)
normal blood glucose levels
normal: 4-8mmol/L
feedback gain equation
correction divided by error (amount over/under shot by change)
4 points in physiological control systems
- what is the variable being maintained?
- where are the receptors that detect change?
- where is the integrating centre and what are the afferent and efferent pathways
- what are the effectors?
5 principals of homeostatic control
- primarily operate through neg. feedback
- stability is achieved through balancing inputs and outputs
- unable to maintain complete constancy of internal environment (range of normal values)
- unable to maintain every system constant (hierarchy of importance)
- set point of some control systems can be reset
factors affecting body core temperature
- time of day
- stage of menstrual cycle
- activity level
- age
main receptors responsible for body temp control (3)
- hypothalamus
- receptors in skin
- deep receptors in spinal cord, abdominal viscera, great veins
main effectors of thermal regulation
too hot: vasodilation, sweating, decrease in heat production
too cold: vasoconstriction, piloerection, increase in thermogenesis, shivering
pyrogen
a substance, typically produced by a bacterium, which produces fever
what class of molecules are released by pyrogens that cause fever?
cytokines
colestyramine
sequesters bile acids