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UNIT 1

Cholera

Transmitted through drinking contaminated water

Bacteria releases exotoxins

One part of the bacteria binds to intestinal epithelial cells

Other part stimulates the facilitated diusion of chloride

ions into the lumen

ater potential of lumen decreases

ater mo!es into the lumen b" osmosis

#iarrhoea

The epithelial cells that line the small intestine are adapted for

the absorption of glucose$ %xplain how&

'illi and micro!illi for larger diusion area

(embrane bound maltase to breakdown maltose into alpha

glucose

(itochondria for )T* +Na,-lucose pump.

Co transport of sodium ions and glucose

/tructure of cell membrane

0luid (osaic +proteins can mo!e about within the

phospholipid bila"er.

Bila"er

Cholesterol for uidit"

%xtrinsic and Intrinsic proteins

-l"coproteins

2"drophilic head and h"drophobic fatt" acid tails

*roteins3 channel4 carrier4 en5"mes4 receptors4 antigens

Ner!ous coordination of cardiac c"cle

2eart muscle is m"ogenic

/)N initiates electrical impulse down the atrium causing

contraction

/tops at )' node to allow all the blood to trickle into the

!entricles

%lectrical impulse the tra!els down the bundles of 2is

Contracts from base up

*hagoc"tosis

Bacteria produces toxins which the phagoc"te detects

+chemotaxis.

The phagoc"te binds to the bacteria

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Bacteria is enclosed in a phagosome

2"drol"tic en5"mes from l"sosomes break down

bacteria

Bacteria is engulfed and digested b" phagoc"te

'entilation

#iaphram contracts and attens

Thorax !olume increases

#ecrease in pressure

)ir mo!es in from high to low pressure

T and B cells

)ntigen presenting cell presents antigen

Complimentar" T cell selected

T cell undergoes mitosis to form T helper4 T killer and T

memor" cells

T helper cells then complimentar" bind to antigen presented

b" B cells

T cells release chemicals which stimulate cell di!ision of B

cells

B cell undergoes mitosis to form plasma cells and memor"

cells

Tuberculosis

*rimar" infection

6 Transmitted b" an aerosol into the lungs

6 Bacteria attack al!eoli cells

6 /car tissue forms6 7ess diusion due to thicker tissue

6 Bacteria engulfed b" phagoc"tes

6 Trapped in tubercle to pre!ent bacteria from replicating

/econdar" infection

6 Bacteria acti!ated and start replicating

6 8eplicate in blood and damage organs

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Cardiac c"cle

#iastole9 /7 'al!es closed: )' !al!es open: blood enters

atria and trickle into !entricles

)trial /"stole9 when atria full: contract: blood pressure in

atria increases and blood passes through )' !al!es into!entricles

'entricular /"stole9 !entricle full: !entricles contract: blood

pressure increases and )' !al!es close: blood pushes past

/7 !al!es

%7)/TIC 8%COI7 INC8%)/%/ *8%//U8% IN )O8T) (O8% T2)N

'%NT8IC7%/: /%(I7UN)8 ')7'%/ C7O/%

2ow are the lungs adapted to allow e;cient gas exchange&

Numerous al!eoli walls and man" capillar" 9 large surface

area 9 faster rate of diusion

Thin al!eoli and capillar" walls 9 short diusion distance

'entilation +bringing in air with low ox"gen concentration.

and circulation +replacing blood with high ox"gen

concentration. 9 maintains a diusion gradient$

Cell fractionation

Ice cold 9 reduce en5"me acti!it"

Buer 9 maintain constant ph

Isotonic 9 pre!ent osmosis

O8/

-lucose and sodium ions

Co transport channel proteins transport Na< and glucose

ater potential of intestinal cells lowered

ater mo!es into cells b" osmosis

2ow are the products of digestion of starch broken down&

Na< glucose cotransport channel proteins in the membrane

of the epithelial cells

Na< pump acti!el" transports Na< ions from the epithelial

cells into the blood

Na< concentration gradient maintained between lumen and

blood

-lucose inside epithelial cells mo!es into blood b"

facilitated diusion

%mph"sema

al!eoli break down

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less surface area

lots of elastic tissue

al!eoli cannot recoil

reduced diusion gradient

less ox"gen diuses into the blood

less respiration,)T*

Breathing di;cult"

al!eoli do not inate full"

breathing no longer passi!e

conc$ -radient and rate of diusion reduced

8eduction in e;cienc" of gas exchange

walls of al!eoli thicken

longer diusion pathwa"

scarred =brosis tissue

reduced surface area

)sthma

attack narrows airwa"

air in al!eoli not e;cientl" replaced

dierence in conc$ lower4 so rate of diusion lower

%ect of training on resting heart rate

cardiac output 9 stroke !olume x heart rate

increased si5e of heart muscle

increased stroke !olume

cardiac output is the same

lower heart rate

Testing for reducing sugars

Benedict and heat 9 blue to red precipitate

Non>reducing sugars

heat sugar with 2Cl4 neutralise with NaO24 benedict?s test