A Synopsis of Physiology

267 Pages·1927·6.822 MB·English

by  A. Rendle Short and C. I. Ham (Auth.)

A SYNOPSIS
OF PHYSIOLOGY
A. RENDLE SHORT
M.D., B.S., B.Sc, F.R.O.S. ;
Surgeon to the Bristol Royal Infirmary ; Lecturer in Physiology to the University
of Bristol ; lately Examiner for the first F.R.C.S. ;
AND
C. I. HAM
M.B., B.Ch., M.R.O.S., L.R.C.P. ;
Demonstrator in Physiology to the University of Bristol.
ILLUSTRATED WITH DIAGRAMS
SOME OF WHICH ARE COLOURED
BRISTOL: JOHN WRIGHT & SONS LTD.
LONDON : SIMPKIN, MARSHALL, HAMILTON, KENT & Co. LTD.
TORONTO : THE MACMILLAN CO. OF CANADA LTD.
1927
PRINTED IN ENGLAND BY
JOHN WRIGHT AND SONS LTD., BRISTOL.
P R E F A CE
THIS volume adds another number to the popular series
of synopses of SURGERY, of MEDICINE, and of MIDWIFERY
AND GYNAECOLOGY, issued by the same publishers.
The object of the book is to give a fairly full summary
of modern physiology, particularly human physiology, in a
small compass. It will be necessary for the beginner to
consult also an ordinary text-book of physiology or attend
a good course of lectures, and to use practical text-books
on histology and on chemical and experimental physiology,
if for no other reason than to consult their diagrams. But
he should be able with the aid of this synopsis to extend
his knowledge, or revise it, with a minimum expenditure
of time and trouble. We have aimed to give enough infor-
mation to enable the student to pass the more advanced
examinations, including the First Fellowship ; the less
ambitious candidate may omit the sections printed in
small type.
Practitioners who wish to keep abreast of modern
physiology will find here a means of making a quick survey.
We have taken particular pains to make this a text-book of
human and clinical physiology. Unfortunately, in these
days of specialism, it has often happened that facts of
human physiology which have been part of the everyday
knowledge of the clinician have taken years to get into the
ordinary text-books of physiology, and some facts worked
out on animals appear not to hold good in man.
We are not without hope that this synopsis may also be
of use on the desk of our brethren who lecture to classes
in physiology, as an aide-mémoire.
A. R. S.
CLIFTON, BRISTOL,
October, 1927.
SYNOPSIS OF PHYSIOLOGY
CHAPTER I.
CHEMISTRY.
Proteins.—These are long-linked chains of amino-acids, con-
taining carbon (53 per cent), hydrogen (7 per cent), oxygen (22
per cent), nitrogen (16 per cent), and usually a little sulphur ;
phosphorus less frequently. They are colloid bodies, though
a few can be crystallized (e.g., egg albumen), and will not pass
through an animal membrane unless hydrolysed. Many of
them can be coagulated by heat. They are usually precipitated
by saturation with neutral salts.
AMINO-ACIDS ENTERING INTO PROTEINS.—
MONO-AMINO-ACIDS. — E.g., glycin (amino-acetic acid) ;
alanin (amino-propionic acid) ; leucin (amino-caproic
acid) ; cystin (dithio-amino-propionic acid—i.e., con-
tains the sulphur of the protein molecule).
DI-AMINO-ACIDS.—Act as bases. Ornithin (di-amino-
valeric acid) ; lysin (di-amino-caproic acid) ; arginin
(guanidine-amino-valeric acid). Are called hexone
bases.
DI-CARBOXYLIC ACIDS (i.e., two COOH groups).—Aspartic
acid (amino-succinic acid) ; glutamic acid (amino-
glutaric acid).
AROMATIC AMINO-ACIDS. — Tyrosin (hydroxy-phenyl
amino-propionic acid) ; tryptophan (indol-amino-pro-
pionic acid) ; phenyl-alanin.
Leucin (spheres with radiate structure) and tyrosin
(sheaves) may be found crystalline in the urine in
acute yellow atrophy of the liver. Cystin may be
found as flat hexagons in the urine in patients with
cystinuria—a rare congenital defect, in which the
necessary ferments for handling cystin are absent.
1
2 CHEMISTRY
Proteins, continued.
TESTS FOR PROTEIN.—
HEAT COAGULATION.
PRECIPITATION BY ALCOHOL, SALICYL-SULPHONIC ACID,
OR ESBACH'S REAGENT.
HELLER'S TEST.—Pour on to strong HN0 : white ring
3
at junction.
XANTHOPROTEIC TEST.—Add strong HN0 ; white pre-
3
cipitate, turned yellow on heating. Add ammonia :
turns orange. Due to aromatic amines.
MILLON'S TEST.—Add Millon's reagent (nitrates of mer-
cury) : white precipitate, turned red on boiling. Due
to tyrosin.
PIOTROWSKI'S TEST.—Add KOH and trace of CuS0 :
4
violet colour.
HOPKINS-ADAMKIEWICZ TEST.—Add a little glyoxylic
acid, and pour strong H S0 down side of tube : purple
2 4
colour. Due to tryptophan.
[MOLISCH'S TEST.—Add a little alcoholic solution of a-naphthol, then
strong H2S04 : violet colour, turned yellow by NaOH. Due to
sugar in the protein molecule.
NINHYDRIN TEST.—Boil with ninhydrin: blue colour on cooling.
Given by proteins and amino-acids.]
VARIETIES OF PROTEIN.—
[PROTAMINES.—Elementary proteins ; found in fish-roe. Consist
mainly of di-amino-acids ; no sulphur, usually no tyrosin. Yield
protones like peptones. Do not show heat coagulation.
HISTONES.—Tissue proteins. Contain more amino-acids ; are coagu-
lated by heat ; precipitated from acid solution by ammonia. E.g.,
globin of haemoglobin.]
SCLEROPROTEINS.—E.g., gelatin, collagen (in fibrous tissue
or cartilage), elastin (of elastic tissue), keratin (of skin,
hair, horn—rich in cystin). Gelatin is obtained by
boiling collagen or the ossein of bone. It does not
contain any aromatic amino-acids, and will not
give the Millon or glyoxylic tests. Will support life
for a time, if given with aromatic amino-acids and
vitamins, not without.
CONJUGATED PROTEINS (i.e., united with other sub-
stances).—Examples are :—
Glucoproteins, conjugated with glucose, as mucin.
Chromoproteins, coloured, as oxyhaemoglobin.
Nucleoproteins, in which the protein is united with
nuclein, which contains nucleic acid and a protein.
CARBOHYDRATES 3
Nucleic acid yields :—
Sugars -f Purin -f Pyrimidine bases -f H P0
3 4
(hexoses or (guanin, (cytosin, uracil,
pentose) adenin) thy mine)
Nucleoprotein is contained in cell nuclei.
Obtained by mincing with NaCl and pouring
into water ; the nucleoprotein rises to the
top as a sticky mass, soluble in alkali.
Precipitated by acid.
PHOSPHOPROTEINS.—Probably esters of phosphoric acid
with protein. E.g., vitellin (of eggs) ; caseinogen, 0-8
per cent of phosphorus (in milk) ; casein (in cheese).
Unlike nucleoproteins, they do not contain purins, and
are easily decomposed by NaOH.
NATIVE PROTEINS.—Animal proteins include albumins and
globulins (rich in glycin, insoluble in water). These
contain sulphur, and most of the amino-acids found in
proteins. Coagulated by heat. Albumin is precipitated
by full saturation with Am S0 ; globulin by half-
:2 4
saturation, or by saturation with MgSo .
4
[Vegetable proteins include :—
Phy to-albumins and, Phy to-globulins.—In cereals. Contain
C, H, O, N, S. Coagulated by heat.
Gliadins.—Also in cereals. Soluble in alcohol. Make dough
sticky. Zein of maize contains no lysin or tryptophan.
Glutelins.—Insoluble in alcohol. Gluten of wheat contains
glutelin and gliadin.] i
DERIVED PROTEINS.—E.g., proteoses, peptones. See pp.
72, 73.
Carbohydrates.—These are ketones or aldehydes, contain-
ing carbon, and oxygen-hydrogen in the ratio of 1:2. The
monosaecharides have the formula C H O (glucose, laevulose,
e 12 e
galactose) ; the disaccharides C H O (saccharose, maltose,
12 22 n
lactose) ; the polysaccharides (C H O )„ (starch, glycogen,
e 10 5
dextrin, cellulose). Pentoses contain 5 carbon atoms.
TESTS.—
REDUCING TESTS.—Many of them reduce copper sul-
phate, thus :—
Trommels Test.—Strong KOH, a few drops of
CuS0 ; add sugar ; heat : red or yellow precipi-
4
tate of cuprous oxide or hydrate.
Fehling's Test.—NaOH, a few drops of CuS0 ,
4
Rochelle salt (to keep black copper oxide from
4 CHEMISTRY
Carbohydrates—Tests for, continued.
coming down) ; boil ; if clear, add sugar : pre-
cipitate as above.
[Nylander's Test.—To sugar solution add bismuth subnitrate
and Rochelle salt and NaOH ; boil : black precipitate of
bismuth.]
The reducing sugars include glucose, laevulose, mal-
tose, lactose, galactose, but not the starches or
saccharose.
FERMENTATION TESTS.—Some sugars are acted on by
yeast, yielding alcohol and C0 . Shown by frothing
2
after keeping warm for some hours. Such are glucose,
saccharose, laevulose, and usually maltose. Some
yeasts ferment lactose, not all.
POLARIMETRY TESTS.—Most sugars and starches rotate
polarized light rays to the right. Laevulose rotates
them to the left. When saccharose is converted into
glucose and laevulose, the mixture rotates the ray to
the left, because laevulose is more active than glucose.
PHENYL-HYDRAZINE TESTS.—To sugar solution add
phenyl-hydrazine hydrochloride and sodium acetate ;
heat on water-bath ; cool : yellow crystals called
osazones come down, either at once (glucose), or very
slowly (lactose). Identify by microscope, or melting
point (put in capillary tube, strap to thermometer,
heat in strong H S0 ).
2 4
Glucosazone,—Yellow sheaves ; Μ.Ρ. 205° C.
Maltosazone. — Stellate clusters of broad-bladed
crystals ; Μ.Ρ. 206° C.
Lactosazone.—Tufts of slender crystals ; Μ.Ρ. 200° C.
THE MONOSACCHARIDES.-—
GLUCOSE (dextrose, grape sugar). —In fruit, honey, blood,
urine of diabetics. Very soluble in water and alcohol.
Quantity estimated Jby Fehling method : run solution
into boiling Fehling till blue colour goes. Or, faetfer.
ra&iirtoi?oilin£B (anhydrous Na C0 ,
2 3
CuSÖ , sodium citrate, and potassium thiocyanate
4
and ferrocyanide) : a white precipitate forms, and the
disappearance of the blue colour is easier to read.
LÉVULOSE (fructose).—Obtained by 'inverting' sac-
charose.
GALACTOSE.—Obtained by splitting up lactose. Enters
into certain galactosides (cerebrins) found in brain.
FATS AND LIPOIDS 5
THE DISACCHARIDES.—
SACCHAROSE (cane sugar, sucrose). —In cane and beet
sugar. 'Inverted' by yeast, ferments, or boiling with
acids ; yields glucose and laevulose. Does not reduce
copper salts.
MALTOSE.—Prepared by action of malt or ferments on
starch. Reduces Fehling's ; has two-thirds the reducing
power of glucose ; estimated quantitatively thus. On
hydrolysis, yields two molecules of glucose.
LACTOSE.—In milk. Yields glucose and galactose. Has
seven-tenths the reducing power of glucose. Souring
of milk is due to its conversion into lactic acid by
bacteria.
THE POLYSACCHARIDES.—On boiling with acids yield
glucose. Give colour with iodine (starch gives blue ; glyco-
gen and dextrin red-brown), discharged by heat, returning
on cooling.
STARCH.—In many vegetable cells, e.g., rice, potato,
bread. Ptyalin and amylopsin turn it into maltose.
Soluble in hot water, giving opalescent colloidal solution.
GLYCOGEN.—In liver and muscle and placenta. Precipi-
tated by basic lead acetate. Gives opalescent solution
in water ; precipitated by 55 per cent alcohol. For
method of preparation, see p. 125.
DEXTRIN.—First stage in action of ferments on starch.
Gummy. Clear solution in water ; precipitated by
85 per cent alcohol. Not precipitated by basic lead
acetate.
CELLULOSE.—In cell-walls of vegetable cells ; it forms
stringy fibres. Insoluble. Converted into glucose by
long boiling with acids. Broken up by certain bacteria.
Fats and Lipoids.—
FATS.—Consist of fatty acids and glycerin. Greasy sub-
stances, insoluble in water or cold alcohol, soluble in ether,
chloroform, hot alcohol. Capable of saponification—i.e.,
conversion into glycerin and soaps (alkali salts of fatty acids,
soluble in water)—by boiling with strong alkalis. Capable
also of emulsification—i.e., resolution into tiny drops held
in milky suspension ; requires an alkali, and shaking ;
aided by bile, and mucin.
The principal fats are olein, palmitin, stearin.
β CHEMISTRY
Fats and Lipoids, continued.
OLEIN.—M.P. 5° C. Oleic acid is C H COOH. Is
17 33
unsaturated. Gives black colour (Os0 ) with osmic
2
acid. Absorbs iodine.
PALMITIN.—M.P. 45° C. Palmitic acid is C H COOH.
15 31
Saturated.
STEARIN.—M.P. about 60° C. Stearic acid is C H COOH.
17 35
Saturated.
Body fats, or milk fats, contain mixtures of the above.
They are analysed by the melting point, the saponifi-
cation value (i.e., amount of alkali needed to saponify),
and iodine value (which estimates the olein).
Histologically, fats are stained by osmic acid, Sudan III,
or Scharlach R ; acid fats by Nile blue.
LIPOCHROMES (luteins).—Fatty pigments—e.g., in corpus
luteum.
LIPOIDS.—Fatty substances. There are three main groups :—
CHOLESTERIN.—C H OH. An alcohol of the terpene
27 45
series. Found in nervous tissue, blood, red blood-
corpuscles, gall-stones. Probably forms the semi-
permeable membrane of red corpuscles ; is shed out
by inflamed mucous surfaces. For tests, etc., see p. 81.
CEREBRINS.—Are galactosides in nervous tissue.
PHOSPHATIDES OR PHOSPHOLIPINS.—The principal one is
lecithin, which is a compound of cholin, fatty acid
(oleic, stearic), glycerin, and H P0 . It is a waxy
3 4
substance, soluble in alcohol and ether, found in nervous
tissue, red corpuscles, and bile. Turns black with osmic
acid. Cholin is a nitrogenous base, found in cerebro-
spinal fluid if degeneration of nervous tissue has occurred.
Gives crystals with platinum chloride. Causes fall of
blood-pressure if injected.
[Other phosphatides are kephalin and sphingotnyelin. The first
is insoluble in alcohol ; the latter contains no glycerin.]
7
CHAPTER IL·
BLOOD, LYMPH, AND CEREBROSPINAL
FLUID.
THE BLOOD.
Reaction of Blood.—
REACTION OF ANY FLUID.—Depends on the relative pro-
portions of hydrogen (H) and hydroxyl (OH) ions. When
these are equal, fluid is neutral.
EXPRESSION OF REACTION.—Expressed in terms of
H-ion concentration. In a neutral solution, product of H
and OH ions is a constant—namely, 10-u : hence the
H-ion concentration is 10-7, or 00000001 grm. per litre.
This is expressed as pH, obtained by taking the logarithm
of the reciprocal of the number expressing the H-ion con-
centration. Thus for a neutral solution the pH is 7.
Figures less than 7 express acid reactions, over 7 alkaline
ones. 'Strong' acids completely dissociate, and so give a
low figure—e.g., } normal HN0 has pH = 3.
τιΰπ 3
DETERMINATION OF THE H-ION CONCENTRATION
IN THE BLOOD.—
1. ELECTROLYTIC METHOD.—Measurement of difference
in electrical potential between an electrode sur-
rounded by blood and one in solution of known
H-ion concentration.
2. COLORIMETRIC METHOD.—Indicators such as neutral red
and phenolphthalein are used, which give different
colours with different concentrations of H-ions.
Examination must be made at body temperature
and in an atmosphere containing same amount of
C0 as the tissues. Dialysed plasma is tested against
2
mixtures of phosphate of known pH.
The pH of blood is 7-39, i.e., slightly alkaline. The reaction
of blood is dependent on the relative amounts of C0
2
and sodium bicarbonate.
CONSTANCY OF REACTION OF BLOOD.—Although, as a
result of metabolism, acids are constantly added to the