- Created by: Hannah
- Created on: 23-04-13 18:26
Suggest why blood films are very thin,clean and gr
So cells can be distinguished from each other under a microscope
clean and grease free so cells stick to the slide
Why is a stain used?
Makes some structures appear darker or different colour
stains nuclei of leucocytes purple so that structures within blood cells show up more clearly-determined by nuclei shape as to whether its a monocyte,lymphocyte or neutrophils
Whys sterile equipment and alcohol based solution
sterile equipment- to stop pathogens/bacteria being introduced into the body
skin cleaned to make sure no pathogens/bacteria on the the skin can enter wound causing infection
Why are blood tests taken from the vein?
vein has less pressure so less bleeding afterwards
vein has a thinner wall so easy to insert the needle
wider and nearer to the surface
outline making and staining a blood film?
add small drop of blood near end of microscope slife
use end of another slide postioned at 30 degrees to smear blood along slide
label slide with paitents details, allow to dry for few minutes so cell stick
fix using alcohol to perserve the cells
add leishmans stain all over the slide and leave for 2 minutes
then wash off with water
Outline a blood test
tie tourniquets around paitents around so vein sticks out
clean area around vein with alcohol based solution
insert sterile needle into vein which is attached to sterile syringe
pull plunger of syringe until right amount of blood has entered the syringe
remove the needle and place cotton wool and pressure for 2 minutes until bleeding stops
Describe the use of haemocytometer?
designed to count eythrocytes
add dilution factor 1 in 200
count all cells following north-west rule
3 or more counts in different squares
calculate a mean
1/0.2 x E x200 = E x 10000
Why is a dilution factor used?
causes red blood cells to burst so leucocytes are more visble as less leucocytes than eythrocytes
Describe structure and function of Erythrocyte?
structure: biconcave discs
no nucleus or organelles- flattened
Function: transport 02 from lungs to tissues and CO2 from tissues to lungs.
does this as its shape means it has a large surface area to volume ratio so more gas exchange can occur between interior cells and surrounding plasma
small and flexible be able to squeeze through capilarries therefore reducing distances for gases to diffuse across
lots of room for haemoglobin which associates reversibly with o2 so more o2 can be carried
other facts: life duration 120 days spleen is where they are destroyed
What is the structure and function of neutrophil?
granular ctyoplasm where nuclues is separated into several lobes
cytoplasm contain lysome enzymes and bacteriducal compounds
function: engulf microorganisms with phagocytosis
What is the structure and function of monocyte?
dark bean shaped nuclues and clear cytoplasm
largest leucocyte twice diameter of rbc
Function: individual monocyte stays in circulatory system for 24 hours or more until it migrates into peripheral tissues to become a macrophage. which is an aggressive macrophage that engulf microorganisms and realeases chemical to stimulate other phagocytes
What is the structure and function of Lymphocyte?
dark nucleus with thin layer of cytoplasm
function: migrate from bloodstream to peripheral to bloodstreamm
two types T cells- cell distruction or control other lymphocytes
B cells- produce antibodies
Outline roles of membrane within and at the surfac
Surface- seperates cell from environment
controls entry and exit of ions and nutrients
phospholipid bilayer to prevent and allow certain molecules to pass through layer
Channel protein- to move molecules through facilated diffusion into the cell e.g water
Contains receptor which allow cell to recognise and respond to specific molecules in environment
glycoproteins- involved in cell recognition and cell adhesion
prevents disruption of process/reactions
reactions take place within and enzymes fuse with membrane
Outline structure and function of platelets?
structure- flattened discs from above and spindle shaped on blood smear
fragmented cytoplasm and no nuclues
contain enzymes and pro-enezymes
held in spleen and other vascular organs
Function: 1) realeases enzymes which initate and control clotting process
2) clumps together at injury site to reduce bleeding
3)contraction of filaments- contain actin and myosin which contract shrinking the clot
Difference between leukocyte and palisade mesophyl
palisade mesophyll has cell wall (structural support and protection and filters)
large permenant vacuole ( contains cell sap and keeps cell rigid)
chloroplasts ( absorb light to produce carbohydrates through photosynthesis)
Whats the function of rough and smooth ER?
Rough- modifies and synthesises new proteins
smooth- lipid and carbohydrate synthesis
Outline function of nucleus and Nucleolus?
nucleus- contains genetic information ( dna) and controls cell activity
nucleolus- ribosomes are made here
ribosomes- invoved in protein synthesis
Whats the function of mitochondria and lyosomes?
mitochondria- involved in aerobic respiration and production of ATP
lyosomes-contains enzymes for intercellular digestion
Whats the function of glogi apparatus?
synthesis of glycoproteins,polysaccharides and hormones
production of lysosomes
Outline production and secretion of proteins (orga
-gene on chromatin codes for protein which is copied to mrna and leaves through nuclear pore
- associates with ribosome on rough r.e.r where protein is packaged and modified into vesicles and transported to glogi apparatus
- glogi apparatus modifies and packages again into more vesicles
- which make their way to cell surface membrane to fuse with and realease antibodies into cell
- requires atp from mitochondria
What type of plant cell doesnt contain chloroplast
- root cell