Body Logistics (1-3) Flashcards
homeostasis definition
physiological process by which internal systems of the body are amitnaied at dynamic equilibrium despite variations in factors both intrinsic and extrinsic that impinges upon that ssytems
examples of negative feedback
temperature
pH
Water
examples of positive feedback
Child birth
Blood clotting
Homeostatic mechanism
variable–> sensory –> control centre–> effector
1) stimulus proceeds change in variable
2) changes detected by receptor
3) inout information sent along afferent pathway to
4) output: information sent along efferent pathways
5) response of effector feeds back to influence magnitude of stimulus and return variable to homeostasis
normal temp range
36.5-37.5
hypothermia
<35
- shivering
- cold, pale skin
- slurred speech
hyperthermia
> 38
- excessive sweating
- clammy skin
- thirst
- tachypnea
- tachycardia
where to measure body temp
mouth ear armpit rectums temporal
FEVER IS BETWEEN
37.5- 38.2
therapeutic hypothermia
- comatose cardiac arrest- neuroprotective
- neonatal encephalopathy
therapeutic hyperthermia
tumours
how does infection pyrexia
infection produces pyrogens –> stimulate IL1 production by macrophage –> increase set point of hypothalamus –> heat generation initiated –> 38.5
rigor
heat accompanied by shivering
febrile seizure
seizure associated with high temperature without any serious underlying health issue
- affects 6 months - 5 years
normal pH
7.35 to 7.45
arterial blood pH vs venous
7.45 and 7.35
pH =
-log[H+]
small change in [H+]
big change in pH
death related pH
<6.8/ >8.0
acidosis
<7.35
- headaches, confusion, fatigue, tremors, coma
metabolic acidosis
lactic acid build up
respiratory acidosis
hypoventilation
osmolarity
conc of solutes per litre (mOsm/L)
osmolality
conc of solutes per kg (most/kg)
types of solution
hypotonic
isotonic
hypertonic
hypotonic
osmolarity higher in cells, net movement of water into cells
isotonic
osmolarity equal on both sides- no net movement of water
hypertonic
osmolarity higher in solution, net movement of water out of cells
total body mass of females
45% solids
55% fluids
total body mass of males
40% solids
60% fluids
how much of fluids is ICF
2/3
how much of fluids is ECF
1/3
how much fluid found in interstitial fluid (ECF)
80%
how much fluid found in plasma (ECF)
20%
when blood is centrifued
plasma at top, white blood cells in middle and RBC a the bottom
starling forces
hydrostatic pressure and oncotic pressure
oedema
abornul fluid accumulation in interstitial
oedema causes
- increased HP
- decreased OP in capillaries
- increased OP in interstitial
- impaired lymphatic drainage
symptoms of dehydration in adults
dry mouth, thirsty, fatigue, low urine output, conc urine
symptoms of dehydration in children
sunken eye, sunk fontanelles and cold skin
symptoms of dehydration in elderly
confusion, low BP
water intoxication causes
decrease in Na+ in blood plasma
decreases [Na+] in blood plasma
muscle weakness
seizure
coma
unconsciousness
which cells can be seen with naked eye
Oocyte (200um)
smallest organelle seen with light microscope
mitochondria
smallest organelle seen with electron microscope
ribosome
definition of tissue
an aggregate of cells of a particular kind which work together to carry out specific functions
importance of histology
- visualise connects and architecture of cells
- distinguish between certain pathologies (benign or malignant)
common biopsy techniques
1) Curettage
- scraping method for uterine tissue
2) Needle aspiration
- bone marrow, synovial fluid, thyroid tissue
3) Transvascular
- Venepuncture, ABG analysis
tissue fixing purpose
preservation of biological tissues from decay due to autolysis or putrefaction
two types of tissue fixing
- paraffin-embedded tissue section
- frozen section
paraffin-embedded tissue section
- formalin- preserve tissue, prevent rotting
- melted paraffin wax- embedded tissue for slicing
- microtome- slice tissue to thin clices
- H&E sraining
frozen section
- surgical specimen frozen to -20 and -30 degrees
- cyrostat- slice tissue
- H&E staining
fixation artifacts
changes brought about in tissues as a result of human activity
1m =
x1000 = 1um
1um=
x1000= 1nm
artefact: tissue shrinkage occurs when
left in fixative too long–> dehydrated
artefact= formalin pigments
produced in acidic conditions
H&E staining
Haematoxylin binds to DNA/RNA (binds to acid)
Eiosin: cytoplasm, extracellular matrix (binds to rpptoeins
H
stain blue
E
stain red
fat cannot be seen
dissolves in formaldehyde
RBC and H&E
white in middle- no protein or DNA
immunofluorescence
antibody labelled with fluorescent makers
immunohistochemistry
antibody labelled with fluorescent marker
- antibody bind to antigen- fluorophor emits visibile light
Types of light microscope
- phase contrast
- dark field
- confocal microscopy
Phase contrast microscope mechanism
- converts phase shift light (invisible) through transparent specimen to brightness changes in image
- no staining required
dark field microscope mechanism
- illuminate sample with light that will not be collected by objective lens
- form dark background
- no staining required
confocal microscopy microscope mechanism
- capture multiple 2D images at diff depths to reconstruct 3D structures
- use with Immunofluorescence
limit of resolution
smallest distance by which two objects can be distinguished
advantages of electron microscope
- higher magnification (x500,000)
- higher resolution (0.25nm)
disadvantage of electron microscope
difficult to use, expensive, dead sample, heavy metal staining
advantage of light
- low skill
- alive samples
- takes short amount of time
specimens used in paraffin-embedded tissue section
fixed tissue
specimens use in frozen section
fresh tissue
making time of paraffin-embedded tissue section
24-48hours
making time of frozen section
10-20 mins
saving time of paraffin-embedded tissue section
permanent
saving time of frozen section
months
morphology under microscopy: embedded tissue section
clarity
morphology under microscope: frozen section
opacity
application of paraffin embedded tissue
pathological diagnosis
application iof frozen section
intraoperative consultation
cell adherence system (4)
- cell-cell adhesion molecules
(tight and adhesion junction) - extracellular matrix protein
( basement membrane, GAGs, fibrous protein-n collagen) - scaffolding
(internal cytoskeleton) - close proximity
(each layer packed closely together- pressure affect)
cell adherence systems on the lateral surface
- tight junctions
- adheren junction
- desmosome
- gap junction
- cell adhesion moelcules
tight junctions
prevent movement of large molecules into deeper tissue.
adherence junction
join actin bundle, stabilising tissue
desmosomes
join intermediate filaments- providing mechanical strength
- cardiac muscle and bladder tissue
gap junctions
allows movement of small molecules
cell adhesion molecules (3)
1) Integrin
2) selectin
3) CAM
cell adherence systems on the basal surface
- focal adhesion
- hemi-desmosme
- integrin
- membrane proteoglycan
focal adhesion
anchors actin filaments to basal lamina
hemi-desmosomes
anchors intermediate filaments to basal lamina
integrin
anchors actin filament to extracellular matrix
- signal transduction from ECM to cell
membrane proteoglycan
major component of ECM, binds cations and water- regulates movement of molecules through matrix
mucosa made up of
epithelium + lamina propria + muscularis mucosa (ELM
layers of a blood vessel
- epithelium
- lamina propria
- sub mucosa
- muscular propria
- adventitia
basement membrane
thin acellular layer where epithelial cells are anchored
- basal lamina and reticular lamina
role of mucosa in GI tract
secrete mucous and absorption
role of submucosa in GI tract
lymphatic vessels, arteries, veins and nerves
structure of muscularis external in GI tract
- inner circular
- outer longitudinal
serosa of the GI tract
blood& and lymph vessel
- continuous with mesenteries
urinary tract composed of
ureters, bladder and urethra
ureter structure
- Mucosa (transitional epithelial cells)
- lamina propria
- muscular (inner longitudinal and outer circular)
bladder and urethra structure
- muscosa (b-transitional and u-squamous epithelium)
- lamina propria
- muscularis (detrusor muscle)
- adventitia
portions of the respiratory tract are either ….. or….
conducting or respiratory
conducting portions
nasal cavity –> terminal bronchioles
respiratory portions
respiratory bronchioles –> alveoli
structure of trachea and primary bronchi
- Mucosa (EL)
- submucosa
- cartilage (perichondrium)
structure of secondary and tertiary bronchi
similar as tracheostomy’s but cartilage not present as full ring
- supported by smooth muscle
Alveolus structure
- epithelium (simple squamous) attached to basal lamina
- Type 1 pneumocytes
- Type 2 pneumocytes
- collage, elastic fibres etc
Type 1 pneumocytes
gas exchange
Type 2 pneumocytes
produce surfactant
