CHAPTER 21	INDEXING PRINCIPLES FOR CATEGORY A 
(ANATOMICAL TERMS) 
 
 

21.1		Category A is a collection of MeSH terms for organs, regions,  
tissues and cells in the human and animal body.  They represent the concepts  
most frequently met in anatomy literature.  For organs, tissues and cells   not  
in MeSH, subheadings are available as a means of indexing and retrieving  
specific anatomical concepts. 
 

21.2		The following subheadings are permitted with Category A  terms 
/abnormalities		/microbiology 
 
/anatomy & histology		/parasitology 
/blood supply		/pathology 
/chemistry			/physiology 
/classification (A 11 only)		/physiopathology 
/cytology			/radiation effects 
/drug effects		/radiography 
/embryology			/radionuclide imaging 
/enzymology			/secretion 
/genetics (subcellular  
elements only) 
/growth & development		/surgery 
/immunology		/transplantation 
/injuries	/ultrasonography 
/innervation	/ultrastructure 
/metabolism		/virology 
 
 

21.3		Not every subheading listed in 21.2 is permitted with  every  
Category A term. The subheadings permitted with a particular term can be found  
in the AQ field for that term. 
 

21.4		Index a blood vessel for which there is no MeSH heading  under the  
name of the organ with the subheading /blood supply (IM) and coordinate with the  
type of vessel (NIM). 
 
	Pancreatic artery. 
		PANCREAS /* blood supply 
		ARTERIES 
 

21.4.1	Do not index a vessel which feeds into or branches from a larger  
vessel under the name of the larger vessel even though that term is in MeSH. 
 
Gastric artery.  
	STOMACH / *blood supply  
	ARTERIES (not under HEPATIC ARTERY or CELIAC ARTERY from which the right  
and left gastric arteries originate respectively). 
 

21.4.2	/blood supply refers not only to the vessels themselves supplying an  
organ but also to the circulation through those vessels. If an article discusses  
circulation or the circulatory process, index also under REGIONAL BLOOD FLOW  
(NIM). Do not index under BLOOD CIRCULATION for this heading is reserved for  
general, i.e., systemic circulation. 
 
	Blood circulation of the forearm. 
		FOREARM /* blood supply	 
			REGIONAL BLOOD FLOW / physiol		 
 

21.5		MICROCIRCULATION (A7, G9) refers to either the anatomy   or the  
physiology of microcirculation by virtue of its category assignments. When used  
with a specific organ with /blood supply (IM), MICROCIRCULATION is NIM. 
 
		Microcirculation of the skin. 
			SKIN / *blood supply 
			MICROCIRCULATION / physiol 
 

21.6		A few pre-coordinated circulation headings exist in Category G9, for  
example, LIVER CIRCULATION, RENAL CIRCULATION, and PULMONARY CIRCULATION. These  
are physiological concepts and therefore do not replace LIVER / blood supply,  
KIDNEY / blood supply or LUNG/ blood supply for anatomical aspects of blood  
vessels to these organs. SPLANCHNIC CIRCULATION is the circulation of blood  
through vessels supplying the abdominal viscera. 
 
The effect of ethanol on splanchnic blood flow. 
ETHANOL /* pharmacol 
SPLANCHNIC CIRCULATION /* drug eff 
 
The effect of ethanol on capillaries in the liver. 
ETHANOL /* pharmacol 
CAPILLARIES / drug eff 
LIVER /* blood supply / drug eff 
(not LIVER CIRCULATION / drug eff) 
 
 

21.7		Index a nerve for which there is no MeSH term under the  name of the  
organ with the subheading /innervation. When indicated, index also under a more  
specific nervous system heading such as SYMPATHETIC NERVOUS SYSTEM. Do not,  
however, index under NERVE TISSUE.  Do not index a nerve which feeds into or  
branches from a larger nerve under the larger nerve even though that term is in  
MeSH. 
 
	Gastric nerve. 
	STOMACH / * innerv 
 
	Autonomic innervation of the stomach. 
	STOMACH / * innerv 
	*AUTONOMIC NERVOUS SYSTEM 
 
	Vagal innervation of the stomach. 
	STOMACH / * innerv 
	*VAGUS NERVE 
 
	Saphenous nerve. 
LEG /* innerv (not also PERIPHERAL NERVES) 
 

21.8		Index muscles not in MeSH under the name of the organ (IM) and  
MUSCLE, SKELETAL (IM),  MUSCLE, SMOOTH (IM) or MUSCLES (IM). 
 
	Thigh muscle. 
	*THIGH 
	*MUSCLE, SKELETAL 
 

21.9		Frequently articles are written on muscle as tissue rather than as  
an organ of movement.  In such cases, index under the muscle term (IM) with the  
site, being of secondary importance, as NIM. Often in relation to third-tier  
indexing (20.11), the site might not be picked up at all. 
 
Glucose metabolism in smooth muscle. (Rat ileum  is used.) 
	GLUCOSE / * metab 
	MUSCLE, SMOOTH  / * metab 
	ILEUM  / metab 
	RATS (check tag) 
	ANIMAL (check tag) 
 

21.10		Index MEMBRANES and its indentions in Category A10 as IM for general  
articles; index them as NIM when a specific organ is IM. This is true also for  
EPITHELIUM and its indentions. 
 

21.11		Index cells of an organ under the name of the organ with the  
subheading  
/cytology (IM).  Index the microanatomic structure of organs or cells under the  
organ or cell with the subheading /ultrastructure (IM). 
 
Determination of the size of renal tubular cells. 
KIDNEY TUBULES /* cytol 
CELL SIZE 
 
Fine structure of the middle ear epithelium of the chicken. 
EAR, MIDDLE /* ultrastruct 
EPITHELIUM / ultrastruct  
CHICKENS	 
ANIMAL (check tag) 
 

21.11.1	If subcellular elements of an organ or cell are discussed, index the  
subcellular element IM  or NIM depending on the emphasis of the article. 
 
Comparison of nuclear DNA synthesis in hepatocytes and muscle cells. 
DNA / *biosyn 
CELL NUCLEUS / metab 
LIVER / *metab /cytol 
MUSCLES / *metab / cytol 
COMPARATIVE STUDY (check tag) 
 
A study of protein glycosylation in the Golgi apparatus using fibroblasts. 
GOLGI APPARATUS / *metab 
PROTEINS / *metab  
GLYCOSYLATION 
FIBROBLASTS /metab 
 
Lysosome structure in retinal pigment epithelium. 
LYSOSOMES /* ultrastruct 
PIGMENT EPITHELIUM of EYE /* ultrastruct 
 

21.12		Index the function of an organ under the name of the organ with the  
subheading /physiology. 
 
The physiology of the stomach in digestion. 
STOMACH / *physiol 
DIGESTION / *physiol 
 
Brain function during thinking.  
BRAIN / * physiol  
THINKING / * physiol 
 

21.13		Index the effect of a drug on an organ under the organ with the  
subheading  
/drug effects (IM) and the drug or chemical with the subheading /pharmacology. 
 
The effect of bronchodilators on the lung.		BRONCHODILATOR AGENTS / *  
pharmacol  
	LUNG /* drug eff 
 

21.13.1	Frequently the effect of a drug is on some specific aspect of an  
organ such as its metabolism, function or structure. In these cases, index the  
organ with both /drug effects and a subheading to cover the other aspect. Tend  
to make /drug effects IM particularly in pharmacology journals. If in doubt, if  
the drug is NIM, then the  organ /drug effects will probably be NIM with the  
other subheading on the organ IM. 
 
The effect of LSD on histone acetylation in the brain.  
	LSD / * pharmacol 
	BRAIN / * drug eff / metab  
	HISTONES / * metab  
	ACETYLATION / drug eff 
 
Ultrastructural study of rat hepatocytes in the presence of cortisone.  
	CORTISONE / * pharmacol  
	LIVER / *drug eff /ultrastruct  
	RATS (check tag)  
	ANIMAL (check tag)  
 
Effect of alpha-ketoglutarate on glutamate dehydrogenase activity in rat liver  
mitochondria. 
ALPHA-KETOGLUTARATE /* pharmacol  
MITOCHONDRIA, LIVER / * enzymol / drug eff 		GLUTAMATE DEHYDROGENASE /*  
metab  
RATS (check tag)  
ANIMAL (check tag) 
 
Although /drug effects is allowed with enzymes, it is rarely used except for the  
effect of a drug on the chemical structure of an enzyme. 
 

21.14		Index the effect of various radiations on an organ under the name of  
the organ with the subheading /radiation effects (IM) and under the specific 
		radiation (IM). 
 
The effect of ultraviolet rays on the skin. 
SKIN /*rad eff 
*ULTRAVIOLET RAYS 
 
The effect of microwaves on the cell membrane. 
CELL MEMBRANE / *rad eff 
*MICROWAVES 
 

21.15		When the radiation affects a specific aspect of an organ or tissue,  
index under both the organ with the subheading /radiation effects and the other  
aspect of the organ (metabolism, structure, etc.) The /radiation effects  
combination will probably be IM, the other combination NIM. 
 
The effect of gamma rays on DNA synthesis in muscle mitochondria. 
MITOCHONDRIA, MUSCLE / * rad eff / metab 
*GAMMA RAYS 
DNA, MITOCHONDRIAL/ *rad eff / biosyn 
 

21.16		Do not coordinate the Category A term with RADIATION, IONIZING or  
RADIATION, NON-IONIZING unless the article is very general and the nature of the  
radiation seems to be the point of the study. See sections 28.11-13 for further  
discussion of radiation. 
 
The effect of irradiation of the liver on subsequent blood coagulation. (the  
author states that ionizing radiation was used) 
	LIVER /*rad eff 
	BLOOD COAGULATION / *rad eff 
	(do not index RADIATION, IONIZING) 
 

21.17		Index articles on the metabolism of a substance by an organ under  
the name of the organ with the subheading /metabolism IM and the name of the  
substance with the subheading /metabolism IM. See 19.8.43 and 19.10.4 for a  
discussion of the coverage of the concept "metabolism". 
 
Glucose metabolism in the kidney. 
	KIDNEY /* metab 
	GLUCOSE /* metab 
 
Turnover of alanine in brain neuroglia. 
	ALANINE /* metab 
	BRAIN /* metab / cytol 
	NEUROGLIA/* metab 
 

21.18		Index the chemistry or chemical composition of an organ or tissue  
under the name of the organ with the subheading /chemistry. Do not add specific  
chemistry terms as coordinates such as NEUROCHEMISTRY  or BIOCHEMISTRY. 
 
The chemical composition of the liver. 
LIVER /*chem 
 
The chemistry of regenerating nerve tissue. 
NERVE TISSUE / * chem / physiol 
*NERVE REGENERATION (do not index also under NEUROCHEMISTRY) 
 

21.18.1	Brain chemistry is an exception to this and is indexed with the  
precoordinated term BRAIN CHEMISTRY. 
 

21.18.2	The presence of a substance in an organ is related to the above  
concept.  Index the substance with the subheading /analysis (IM) and coordinate  
with the organ with the subheading /chemistry (IM). 
 
Collagen content of muscle. 
	MUSCLES /*chem 
	COLLAGEN /*anal 
 
Phospholipid content of the brain. 
	PHOSPHOLIPIDS /*anal 
	*BRAIN CHEMISTRY 
 
 

21.19		Index the secretion of a substance by an organ under the name of the  
organ with the subheading /secretion (IM).  If the substance is also discussed,  
index it with the same subheading. 
 
Do not seek to add routinely the name of every organ naturally secreting  
substances by checking physiology texts to determine the organ heading. Index on  
the basis of the article. Index both the organ and the substance it secretes  
only if the author discusses both. 
 
Circadian rhythm in pituitary secretion. 
	*CIRCADIAN RHYTHM 
	PITUITARY GLAND /* secret 
 
Circadian rhythm in the pituitary secretion of prolactin. 
	PITUITARY GLAND/*secret 
	PROLACTIN /*secret 
	*CIRCADIAN RHYTHM 
 
Circadian rhythm in prolactin secretion. 
	PROLACTIN /*secret 
	*CIRCADIAN RHYTHM 
 

21.20		Index a disease of an organ or tissue under the pre-coordinated  
organ-disease term applicable from Category C (diseases) if it is an exact  
equivalent of the desired concept. 
 
Mouth neoplasms. 
	*MOUTH NEOPLASMS 
	(not MOUTH + NEOPLASMS) 
 
Shoulder fractures. 
	*SHOULDER FRACTURES 
	(not SHOULDER and FRACTURES) 
 
Gastritis. 
	*GASTRITIS 
	(not STOMACH and INFLAMMATION) 
 
21.21 If a pre-coordinated organ disease concept is not in MeSH, index the  
organ IM and add the most specific Category C disease term NIM. See  
section 23.11. 
Diseases of the ciliary body. 
 
*CILIARY BODY 
 
UVEAL DISEASES 
 
(Ciliary Body is indented in Category A under UVEA and there is a term UVEAL  
DISEASES in Category Cll). 
 

21.21.1	If the intended coordinate is more specific than the pre-coordinated  
organ/disease term, index under the organ (IM) and the pre-coordinated disease  
(IM). 
Ciliary body neoplasms. 
	*CILIARY BODY 
	*UVEAL NEOPLASMS 
 

21.21.2	The above instructions represent general principles of indexing  
organ/diseases not in MeSH. The matter of IM or NIM sometimes changes in certain  
circumstances. Always check the Annotated MeSH for guidelines on IM or NIM with  
specific headings.  See also section 23 for detailed instructions on indexing  
diseases. 
 

21.22		The term "pathology" is taken to mean the structural or  
morphological changes in organs, tissues and cells in disease states. It is not  
meant by MeSH as a synonym for "disease" nor as a substitute for a pre- 
coordinated organ/disease heading lacking in MeSH. 
 

21.22.1	Examine the term "pathology" as used by an author.  If the author  
means by "pathology" what INDEX MEDICUS means - a description of non-normal  
organs, tissues and cells or a description of their structure in disease states  
then use the subheading /pathology with the organ.  If, on the other hand, the  
author is using  an expression such as "lung pathology" to mean lung disease,  
the correct heading is LUNG DISEASES, not LUNG /pathology. 
 

21.23		Index the pathology of an organ under the name of the organ with the  
 
subheading /pathology (IM). 
 
Pathology of the liver.  
 
	LIVER /* pathol 
 

21.24		Index the pathology of an organ in a disease of that organ under the  
name of the organ with the subheading /pathology (IM) and the name of the  
disease with the subheading /pathology (IM). 
 
The structure of the liver in hepatitis.  
	LIVER /* pathol  
	HEPATITIS /* pathol 
 
The hepatocyte in liver diseases.  
	LIVER /* pathol  
	LIVER DISEASES /* pathol 
 

21.25		Index the pathology of an organ in a disease unrelated to that organ  
under the name of the organ with the subheading /pathology (IM) and the name of  
the disease with the subheading /pathology (IM). 
 
Kidney pathology in stomach diseases.  
	KIDNEY /* pathol  
	STOMACH DISEASES /* pathol 
 

21.26	Use the subheading /pathology to cover the anatomy, histology, or cytology  
of an organ in a disease state. Use the subheading /ultrastructure to cover  
pathological ultrastructure or ultrastructure in a disease state. 
 
Stomach tissue in hepatitis. 
	STOMACH /* pathol 
	HEPATITIS / * pathol 
 
Liver and kidney cells in encephalitis.  
	LIVER /* pathol  
	KIDNEY / * pathol  
	ENCEPHALITIS /* pathol 
 
The ultrastructure of the kidney in kidney disease.  
KIDNEY /*ultrastruct  
KIDNEY DISEASES /* pathol (/ultrastructure is permitted only with diseases in  
Category C4 - Neoplasms) 
 

21.27	The physiopathology of an organ must be distinguished from its physiology  
and pathology.  Physiology is the normal function of an organ; pathology is the  
structure of an organ in a disease state or non-normal structure of an organ.  
Physiopathology is the disordered function of an organ in a disease state. 
 

21.28	Index the physiopathology of an organ under the name of the organ with the  
subheading /physiopathology (IM) and the name of the disease with the subheading  
/physiopathology (IM). 
 
The physiopathology of the pancreas. 
	PANCREAS / * physiopathol 
 
The function of the pancreas in pancreatitis.  
	PANCREAS /* physiopathol 
	PANCREATITIS / * physiopathol 
 
Abnormal function of the liver in colitis. 
	LIVER/* physiopathol 
	COLITIS /* physiopathol 
 

21.29		As with the term "pathology" (21.22.1), examine the     term  
"physiopathology" used by an author. If  the author   means by "physiopathology"  
what INDEX MEDICUS means - the disordered function of an organ in a disease -  
then use the subheading /physiopathology with the organ.  If, on the other hand,  
the author is using an  expression such as "lung physiopathology" to mean lung   
diseases, then use the term LUNG DISEASES, not LUNG  /physiopathology. 
 
Again, like /pathology (21.22),  /physiopathology is not meant to be used as a  
substitute for a pre-coordinated organ/diseases heading  not in MeSH. 
 

21.30		Index wounds or injuries of an organ under the name of the organ  
with the subheading /injuries (IM).  The word "trauma" or "traumatic" appears in  
titles and means our term "injuries".  In foreign titles do not translate  
"traumatism" in various cognate forms as "trauma" or "traumatism": translate as  
"injury". 
 
Stomach wounds. 
	STOMACH /* inj 
 

21.31		Since wounds and injuries are so frequent in medicine, MeSH has  
supplied many specific types of wounds and injuries and pre-coordinated injury  
concepts.  Always prefer an applicable pre-coordinate to the organ with the  
subheading /injuries. 
 
Head wounds. 
	*HEAD INJURIES (not HEAD /* inj) 
 

21.32		Index specific types of injuries under the name of the organ with  
the subheading /injuries (IM) and the specific type of wound or injury from  
Category C21.  See Section 23.23+. 
 
Stab wounds of the uterus. 
	UTERUS /* inj 
	*WOUNDS, STAB 
 
Penetrating injuries of the neck. 
	NECK /* inj 
	*WOUNDS, PENETRATING 
 
Chemical burns of the esophagus. 
	ESOPHAGUS /* inj 
	*BURNS, CHEMICAL 
 
Electric burns of the hand. 
	*HAND INJURIES 
	*BURNS, ELECTRIC 
 
Fractures of the fibula. 
	FIBULA /* inj 
	*FRACTURES 
 
Ununited fractures of the arm. 
*ARM INJURIES 
		*FRACTURES, UNUNITED 
 

21.33		The concept "abnormalities" refers to structural congenital (rather  
than acquired) conditions appearing  variously in the literature as "deformity",  
"anomaly", "malformation".  The main heading ABNORMALITIES and the subheading  
/abnormalities will include the absence of organs, aplasia, agenesis, atresia,  
duplications of single organs, triplication of double organs and other anomalous  
or teratological states. 
 

21.34		Index structural abnormalities of an organ under the subheading  
/abnormalities (IM) or under a specific abnormality heading from Category C16.  
See section 23.20+. 
 
Abnormalities of the pancreas. 
	PANCREAS /* abnorm 
 
Agenesis of the lung. 
	LUNG /*abnorm 
 
Mouth abnormalities. 
	*MOUTH ABNORMALITIES (not MOUTH /*abnorm 
 
Heart abnormalities. 
	*HEART DEFECTS, CONGENITAL 
 
Abnormalities of the tricuspid valve. 
	TRICUSPID VALVE /* abnorm 
(do not index also under HEART DEFECTS,CONGENITAL) 
 

21.35		Index the x-ray examination of an organ under the name of the organ  
with the subheading /radiography.  In Category E1, however, are many pre- 
coordinated radiography terms (AORTOGRAPHY for AORTA/radiography) and many  
specific radiographic techniques (PNEUMORADIOGRAPHY, etc.). If a specific pre- 
coordinated radiography term is in MeSH, use that term instead of the organ with  
the subheading /radiography. 
 
X-ray of the liver. 
	LIVER /* radiogr 
 
Pancreas radiography. 
	PANCREAS /* radiogr 
 
Gallbladder x-ray. 
	*CHOLECYSTOGRAPHY 
 
Radiography of veins. 
	*PHLEBOGRAPHY 
 
Radiography of the femoral vein. 
	FEMORAL VEIN /*radiogr 
    (not also PHLEBOGRAPHY) 
 

21.36		Index specific x-ray techniques for various organs under the name of  
the organ with the subheading /radiography (IM) and the specific technique (IM). 
 
Microradiography of the pancreas. 
	PANCREAS /* radiogr 
	*MICRORADIOGRAPHY 
 

21.37		Although the widest application of the x-ray of an organ is in  
diagnosis, do not interpret an article or a discussion on the radiography of an  
organ as the diagnosis of a disease. 
 
Dacryocystography (x-ray of the lacrimal apparatus) 
	LACRIMAL APPARATUS /*radiogr 
	(not LACRIMAL APPARATUS DISEASES /*diag 		nor  
	LACRIMAL APPARATUS DISEASES /*radiogr) 
 
It is possible to discuss the x-ray, x-raying or x-ray image of an organ without  
discussing its application to the x-ray or radiographic diagnosis of a disease. 
 

21.38		Index the radionuclide imaging or ultrasonography of an organ under  
the name of the organ with the subheading /radionuclide imaging or  
/ultrasonography.  Follow the procedures outlined above for radiography. 
 
Determination of kidney size by renal scintigraphy. 
KIDNEY / *radionuclide 
 
Ultrasonography of the liver in liver cirrhosis. 
LIVER / *ultrasonogr 
LIVER CIRRHOSIS /* ultrasonogr 
 

21.39		Index foreign bodies of an organ under the name of the organ (IM),  
without a subheading, and FOREIGN BODIES (IM). There are so many objects and so  
much matter available as foreign bodies that no attempt in a medical thesaurus  
can be made to supply their names. The indexer, therefore, is seldom able to  
name the foreign body as a coordinate. 
 
Foreign bodies of the nose. 
	*NOSE 
	*FOREIGN BODIES 
	 
Foreign bodies of the eye. 
	*EYE FOREIGN BODIES 
 

21.40		Index the presence of bacteria or fungi  or Archaea in an organ  
under the name of the organ with the subheading /microbiology (IM) and the name  
of the organism with the subheading /isolation & purification (IM).  Index the  
presence of a virus in an organ under the name of the organ with the subheading  
/ virology (IM) and the name of the virus with the subheading / isolation &  
purification (IM).   
 
The presence of Klebsiella in the liver.  
	LIVER /*microbiol  
	KLEBSIELLA /*isol 
 
The isolation of Candida albicans from the skin.  
	SKIN /* microbiol  
	CANDIDA ALBICANS /*isol 
 
Detection of methanogens in the rumen of the cow. 
	METHANOGENS /* isol 
	RUMEN / * microbiol 
	CATTLE / * microbiol 
	ANIMAL ( check tag)  
 
Detection of rotaviruses in the intestines.  
	INTESTINES /* virology  
	ROTAVIRUS /* isol 
 

21.41		Distinguish the presence of a microorganism in an organ from an  
infection of that organ.  It is possible for an author to write about the  
presence of a microbe in body tissue without writing about an infection.  For  
indexing purposes we make that distinction, although clinically the presence of  
an organism very often indicates an infection. See also section 22.11.1 for  
indexing infected cell lines or cultured cells.  
 
The presence of Salmonella in the liver.  
LIVER /* microbiol  
SALMONELLA /* isol (not LIVER DISEASES and SALMONELLA INFECTIONS) 
 

21.42		Index the presence of parasites in organs, tissues, and body fluids  
under the name of the organ with the subheading /parasitology (IM) and the name  
of the parasite from Category B1 (IM). 
 
The presence of Dracunculus in the eye.  
DRACUNCULUS /* isol  
EYE /* parasitol  
(not DRACUNCULOSIS and EYE INFECTIONS, PARASITIC) 
 

21.43		Distinguish the presence of a parasite in an organ from an infection  
of that organ. An author may discuss the presence of a parasite in an organ  
without discussing an infection by that organism.  In many cases, however, an  
infection is discussed. 
 

21.44		Use the subheading /parasitology and not /microbiology with an organ  
for protozoa in an organ. 
 

21.45		Index the surgery of an organ under the name of the organ with the  
subheading /surgery (IM).  Category E4 contains surgical procedures. Index under  
the Category E4 term instead of the organ/surgery if it is more specific. 
 
Surgery of the stomach. 
	STOMACH /* surg 
 
Excision of the stomach. 
	*GASTRECTOMY 
 
Surgery of the heart. 
	*CARDIAC SURGICAL PROCEDURES 
	(not HEART / surg) 
 

21.46		Index the surgery of an organ in a disease of that organ treated  
surgically under the name of the organ with the subheading /surgery and the name  
of the disease with the subheading /surgery. The title of the article and the  
amount of discussion in the text will determine whether the organ/surgery  
combination is IM or NIM. 
 
Liver surgery in dicrocoeliasis of the liver. 
	LIVER /* surg 
	DICROCOELIASIS /* surg 
	LIVER DISEASES, PARASITIC /* surg 
 

21.47		BLOOD and PLASMA are both in Categories A12 and A15 but are  
used relatively infrequently as main headings since /blood is available as a  
subheading for diseases, drugs, many animals and some physiological states.  Use  
the main heading BLOOD, when an author discusses blood as a substance.  Plasma  
is used somewhat more often since it figures in blood transfusions.  When used   
correctly BLOOD and PLASMA are IM. 
 
A new culture medium for anaerobes containing calf blood. 
	*CULTURE MEDIA 
	*BLOOD 
	BACTERIA, ANAEROBIC /* growth 
	CATTLE (check tag) 
	ANIMAL (check tag) 
 
Levels of calcium in human blood. 
	CALCIUM /*blood 
	HUMAN (check tag)  
		not 
	BLOOD /* chem 
	CALCIUM /* anal 
 

21.48		HEART and MYOCARDIUM are often used interchangeably by authors.   
Differentiate between these two terms in the following way: if the organ is  
viewed as a pump, use HEART, if viewed as tissue, use MYOCARDIUM. 
 

21.48.1	The subheadings that are permitted with Category A terms are listed  
below to show which may be used with HEART and which with MYOCARDIUM. Main  
heading/subheading combinations which are not allowed are also listed. 
 
	/abnormalities		=	HEART DEFECTS, CONGENITAL 
	/anatomy & histology	=	HEART /anatomy & histology 
	/blood supply		=	CORONARY VESSELS 
	/chemistry		=	MYOCARDIUM /chemistry 
	/cytology		=	MYOCARDIUM /cytology 
	/drug effects		=	HEART /drug effects 
	/embryology		=	HEART /embryology 
	/enzymology		=	MYOCARDIUM /enzymology 
	/growth & development=	HEART /growth & development 
	/immunology		=	MYOCARDIUM /immunology 
	/injuries		=	HEART INJURIES 
	/innervation		=	HEART /innervation 
	/metabolism		=	MYOCARDIUM /metabolism 
	/microbiology		=	HEART /microbiology 
	/parasitology		=	HEART /parasitology 
	/pathology		=	MYOCARDIUM /pathology 
	/physiology		=	HEART /physiology 
	/physiopathology	=	HEART /physiopathology 
	/radiation effects	=	HEART /radiation effects 
	/radiography		=	HEART /radiography 
	/radionuclide imaging	=	HEART /radionuclide imaging 
	/secretion		=	do not use 
	/surgery	=	CARDIAC SURGICAL PROCEDURES 
	/transplantation	=HEART TRANSPLANTATION 
	/ultrasonography	=	ECHOCARDIOGRAPHY 
	/ultrastructure	=	MYOCARDIUM /ultrastructure 
	/virology		=	HEART / virology 	 
 

21.49		Foreign bodies of the heart are indexed under FOREIGN BODIES (IM)  
and HEART, not HEART DISEASES. 
 

21.50		The heart in pregnancy will most frequently be indexed under HEART,  
probably with the subheading /physiology and PREGNANCY /physiology (IM). 
 

21.51		HEART ATRIUM and HEART VENTRICLE are MeSH headings but the nature of  
most articles on the heart requires viewing it as an entity, i.e., as HEART or  
MYOCARDIUM. For this reason HEART ATRIUM and HEART VENTRICLE will probably not  
be IM terms but merely NIM coordinates. MeSH has been annotated at HEART ATRIUM  
and HEART VENTRICLE. In addition to HEART ATRIUM and HEART VENTRICLE, there are  
specific ventricular function and atrial and ventricular disease terms in  
Categories G9 and C14. 
 

21.52		PAPILLARY MUSCLES is often seen in articles on muscle experiments  
using the papillary muscles as test tissue. When this is the case, index under  
the main heading MUSCLES (with an appropriate subheading) as IM and make  
PAPILLARY MUSCLES (with the same subheading)NIM.  Under third-tier indexing  
(20.11), it is possible that PAPILLARY MUSCLES may not be picked up at all.  In  
any event do not index under HEART or MYOCARDIUM. 
 
If, however, the point of the article is the papillary muscles as part of the  
anatomy of the heart, PAPILLARY MUSCLES must be the term used. 
 
Calcium metabolism in muscle tissue. (Materials and methods indicates papillary  
muscles were used.) 
	CALCIUM / * metab 
	MUSCLES / * metab 
	PAPILLARY MUSCLES / metab 
 
Papillary muscle function in ischemic heart disease. 
	PAPILLARY MUSCLES /*physiopathol 
	ISCHEMIC HEART DISEASE /* physiopathol 
 

21.53		In articles on the human product of conception, EMBRYO will be used  
with reference to the first two months of pregnancy while FETUS will be used  
from the third month of pregnancy on.  In articles on animals, follow the term  
used by the author, but remember FETUS is for mammals only. 
 

21.54		EMBRYOLOGY is to be reserved for the discipline or embryologist  
only.  Distinguish between EMBRYO and /embryology with organs in this way: if  
the article is on the embryo itself as an entity, as a whole or as tissue, use  
the heading EMBRYO.  Use /embryology attached to an organ for the embryonic  
development or embryological aspects of that organ only. 
 
The effect of gamma rays on the mouse embryo. 
	EMBRYO /* rad eff 
	*GAMMA RAYS 
	MICE (check tag) 
	ANIMAL (check tag) 
 
The effect of gamma rays on the embryonic mouse liver. 
	LIVER / *embryol / *rad eff 
	MICE  (check tag) 
	ANIMAL (check tag) 
 
The effect of retinoic acid on Xenopus laevis embryos. 
RETINOIC ACID / *pharmacol 
EMBRYO, NON-MAMMALIAN / *drug eff 
XENOPUS LAEVIS 
ANIMAL (check tag)   
 

21.55		In articles on the fetus, check the tag PREGNANCY only if the  
maternal aspect is discussed in the article. 
 

21.56		Organs or tissue from organs are frequently used in research as  
representative of a particular type of tissue.  For example, in studies of  
smooth muscle, the ileum is often used as a test tissue. When the organ is used  
in this manner, index under the specific tissue type (IM) and the organ (NIM) or  
not at all if it is third tier. 
 
The effect of pH on potassium ion transport in ileal muscle of the guinea pig.  
	PH  
	MUSCLE, SMOOTH /* metab  
	ILEUM /  metab  
	ION TRANSPORT  
	POTASSIUM /* metab  
	GUINEA PIGS (check tag)  
	ANIMAL (check tag) 
 
The function of the ileum in enteritis in humans.  
	ILEUM / * physiopathol  
	ENTERITIS /* physiopathol  
	HUMAN (check tag) 
 

21.57		CELLS, CULTURED including CELL LINE and all the terms treed under it  
in Category All are almost always NIM without a subheading because the concept  
almost always figures in an article as the vehicle in research. 
 
Index a cell line that is not in MeSH under CELL LINE, the check tag ANIMAL or  
HUMAN, the organ or tissue source if it is in the title or statement of purpose,  
and the specific animal for animal cell lines if it can be determined from the  
article.  These terms will be NIM in most cases. If, however, the point of the  
article is the cell line then the term CELL LINE as well as the terms for the  
source will be IM. If a cell line is used to study a particular  organ, the  
organ will be indexed IM probably with a subheading. 
 
A study of cell differentiation using a rat liver cell line.  
*CELL DIFFERENTIATION  
CELL LINE  
LIVER  
RATS (check tag)  
ANIMAL (check tag) (here the liver cell line is used to study the process of  
cell differentiation in general.) 
 
 
Comparison of cell differentiation in liver and kidney. (author indicates the  
study was done using rat liver and kidney cell lines)  
CELL LINE  
CELL DIFFERENTIATION  
LIVER /* cytol  
KIDNEY /*cytol  
ANIMAL (check tag)  
RATS (check tag)  
COMPARATIVE STUDY (check tag) (here the tissues LIVER and KIDNEY are the point  
of the article and are IM) 
 
Description of a new mouse adipocyte cell line. 
*CELL LINE  
ADIPOCYTES /* cytol 
*MICE  
ANIMAL (check tag) (here the cell line is the point of the article.) 
 
Follow the same policy for indexing CELLS, CULTURED and the specific cell  
culture terms treed under it such as TUMOR CELLS, CULTURED, CELL LINE,  
TRANSFORMED, etc.  See section  
24.4.5+ for a discussion of cultured tumor cells. 
 
The same principles apply to the indexing of TISSUE CULTURE (Category E5).  See  
also above 21.56.