MBC header

Keratinizing Epithelial Cells

Cells of Wet Stratified Barrier Epithelia

Epithelial Cells Specialized for Exocrine Secretion

Cells Specialized for Secretion of Hormones

Epithelial Absorptive Cells in Gut, Exocrine Glands, and Urogenital Tract

Cells Specialized for Metabolism and Storage

Epithelial Cells Serving Primarily a Barrier Function, Lining the Lung, Gut, Exocrine Glands, and Urogenital Tract

Epithelial Cells Lining Closed Internal Body Cavities

Ciliated Cells with Propulsive Function

Cells Specialized for Secretion of Extracellular Matrix

Contractile Cells

Cells of Blood and Immune System

Sensory Transducers

Autonomic Neurons

Supporting Cells of Sense Organs and of Peripheral Neurons

Neurons and Glial Cells of Central Nervous System

Lens Cells

Pigment Cells

Germ Cells

Nurse Cells

Cells of the Adult Human Body: A Catalogue
How many distinct cell types are there in an adult human being? In other words, how many normal adult ways are there of expressing the human genome? A large textbook of histology will mention about 200 cell types that qualify for individual names. These traditional names are not, like the names of colors, labels for parts of a continuum that has been subdivided arbitrarily: they represent, for the most part, discrete and distinctly different categories. Within a given category there is often some variation - the skeletal muscle fibers that move the eyeball are small, while those that move the leg are big; auditory hair cells in different parts of the ear may be tuned to different frequencies of sound; and so on. But there is no continuum of adult cell types intermediate in character between, say, the muscle cell and the auditory hair cell.
     The traditional histological classification is based on the shape and structure of the cell as seen in the microscope and on its chemical nature as assessed very crudely from its affinities for various stains. Subtler methods reveal new subdivisions within the traditional classification. Thus modern immunology has shown that the old category of "lymphocyte" includes more than 10 quite distinct cell types. Similarly, pharmacological and physiological tests reveal that there are many varieties of smooth muscle cell - those in the wall of the uterus, for example, are highly sensitive to estrogen, and in the later stages of pregnancy to oxytocin, while those in the wall of the gut are not. Another major type of diversity is revealed by embryological experiments of the sort discussed in Chapter 21. These show that, in many cases, apparently similar cells from different regions of the body are nonequivalent, that is, they are inherently different in their developmental capacities and in their effects on other cells. Thus, within categories such as "fibroblast" there are probably many distinct cell types, different chemically in ways that are not easy to perceive directly.
     For these reasons any classification of the cell types in the body must be somewhat arbitrary with respect to the fineness of its subdivisions. Here, we list only the adult human cell types that a histology text would recognize to be different, grouped into families roughly according to function. We have not attempted to subdivide the class of neurons of the central nervous system. Also, where a single cell type such as the keratinocyte is conventionally given a succession of different names as it matures, we give only two entries - one for the differentiating cell and one for the stem cell. With these serious provisos, the 210 varieties of cells in the catalogue represent a more or less exhaustive list of the distinctive ways in which a given mammalian genome can be expressed in the phenotype of a normal cell of the adult body.

Keratinizing Epithelial CellsTop
keratinocyte of epidermis (= differentiating epidermal cell)
basal cell of epidermis (stem cell)
keratinocyte of fingernails and toenails
basal cell of nail bed (stem cell)
hair shaft cells
hair-root sheath cells
 of Huxley's layer
 of Henle's layer
hair matrix cell (stem cell)
Cells of Wet Stratified Barrier EpitheliaTop
surface epithelial cell of stratified squamous epithelium of cornea, tongue, oral
 cavity, esophagus, anal canal, distal urethra, vagina
basal cell of these epithelia (stem cell)
cell of urinary epithelium (lining bladder and urinary ducts)
Epithelial Cells Specialized for Exocrine SecretionTop
cells of salivary gland
 mucous cell (secretion rich in polysaccharide)
 serous cell (secretion rich in glycoprotein enzymes)
cell of von Ebner's gland in tongue (secretion to wash over taste buds)
cell of mammary gland, secreting milk
cell of lacrimal gland, secreting tears
cell of ceruminous gland of ear, secreting wax
cell of eccrine sweat gland, secreting glycoproteins (dark cell)
cell of eccrine sweat gland, secreting small molecules (clear cell)
cell of apocrine sweat gland (odoriferous secretion, sex-hormone sensitive)
cell of gland of Moll in eyelid (specialized sweat gland)
cell of sebaceous gland, secreting lipid-rich sebum
cell of Bowman's gland in nose (secretion to wash over olfactory epithelium)
cell of Brunner's gland in duodenum, secreting alkaline solution of mucus and
cell of seminal vesicle, secreting components of seminal fluid, including fructose
 (as fuel for swimming sperm)
cell of prostate gland, secreting other components of seminal fluid
cell of bulbourethral gland, secreting mucus
cell of Bartholin's gland, secreting vaginal lubricant
cell of gland of Littre, secreting mucus
cell of endometrium of uterus, secreting mainly carbohydrates
isolated goblet cell of respiratory and digestive tracts, secreting mucus
mucous cell of lining of stomach
zymogenic cell of gastric gland, secreting pepsinogen
oxyntic cell of gastric gland, secreting HCl
acinar cell of pancreas, secreting digestive enzymes and bicarbonate
Paneth cell of small intestine, secreting lysozyme
type II pneumocyte of lung, secreting surfactant
Clara cell of lung (function unknown)
Cells Specialized for Secretion of HormonesTop
cells of anterior pituitary, secreting
 growth hormone
 follicle-stimulating hormone
 luteinizing hormone
 adrenocorticotropic hormone
 thyroid-stimulating hormone
cell of intermediate pituitary, secreting
 melanocyte-stimulating hormone
cells of posterior pitutiary, secreting
cells of gut and respiratory tract, secreting
cells of thyroid gland, secreting
 thyroid hormone
cells of parathyroid gland, secreting
 parathyroid hormone
 oxyphil cell (function unknown)
cells of adrenal gland, secreting
steroid hormones
cells of gonads, secreting
 testosterone (Leydig cell of testis)
 estrogen (theca interna cell of ovarian follicle)
 progesterone (corpus luteum cell of ruptured ovarian follicle)
cells of juxtaglomerular apparatus of kidney
juxtaglomerular cell (secreting renin)
 macula densa cell
peripolar cell
mesangial cell
{(uncertain but probably related in function; possibly involved in secretion of erythropoietin)
Epithelial Absorptive Cells in Gut, Exocrine Glands, and Urogenital TractTop
brush border cell of intestine (with microvilli)
striated duct cell of exocrine glands
gall bladder epithelial cell
brush border cell of proximal tubule of kidney
distal tubule cell of kidney
nonciliated cell of ductulus efferens
epididymal principal cell
epididymal basal cell
Cells Specialized for Metabolism and StorageTop
hepatocyte (liver cell)
fat cells
 white fat
 brown fat
 lipocyte of liver
Epithelial Cells Serving Primarily a Barrier Function, Lining the Lung, Gut, Exocrine Glands, and Urogenital TractTop
type I pneumocyte (lining air space of lung)
pancreatic duct cell (centroacinar cell)
nonstriated duct cell of sweat gland, salivary gland, mammary gland, etc.
parietal cell of kidney glomerulus
podocyte of kidney glomerulus
cell of thin segment of loop of Henle (in kidney)
collecting duct cell (in kidney)
duct cell of seminal vesicle, prostate gland, etc. (various)
Epithelial Cells Lining Closed Internal Body CavitiesTop
vascular endothelial cells of blood vessels and lymphatics
synovial cell (lining joint cavities, secreting largely hyaluronic acid)
serosal cell (lining peritoneal, pleural, and pericardial cavities)
squamous cell lining perilymphatic space of ear
cells lining endolymphatic space of ear
 squamous cell
 columnar cells of endolymphatic sac
  with microvilli
  without microvilli
 "dark" cell
 vestibular membrane cell
 stria vascularis basal cell
 stria vascularis marginal cell
 cell of Claudius
 cell of Boettcher
choroid plexus cell (secreting cerebrospinal fluid)
squamous cell of pia-arachnoid
cells of ciliary epithelium of eye
corneal "endothelial" cell
Ciliated Cells with Propulsive FunctionTop
of respiratory tract
of oviduct and of endometrium of uterus (in female)
of rete testis and ductulus efferens (in male)
of central nervous system (ependymal cell lining brain cavities)
Cells Specialized for Secretion of Extracellular MatrixTop
 ameloblast (secreting enamel of tooth)
 planum semilunatum cell of vestibular apparatus of ear
  (secreting proteoglycan)
 interdental cell of organ of Corti (secreting tectorial "membrane" covering
 hair cells of organ of Corti)
nonepithelial (connective tissue)
 fibroblasts (various-of loose connective tissue, of cornea, of
  tendon, of reticular tissue of bone marrow, etc.)
 pericyte of blood capillary
 nucleus pulposus cell of intervertebral disc
 cementoblast/cementocyte (secreting bonelike cementum of
  root of tooth)
 odontoblast/odontocyte (secreting dentin of tooth)
  of hyaline cartilage
  of fibrocartilage
  of elastic cartilage
 osteoprogenitor cell (stem cell of osteoblasts)
 hyalocyte of vitreous body of eye
 stellate cell of perilymphatic space of ear
Contractile CellsTop
skeletal muscle cells
 red (slow)
 white (fast)
 muscle spindle-nuclear bag
 muscle spindle-nuclear chain
 satellite cell (stem cell)
heart muscle cells
 Purkinje fiber
smooth muscle cells (various)
myoepithelial cells
 of iris
 of exocrine glands
Cells of Blood and Immune SystemTop
red blood cell
macrophages and related cells
 connective-tissue macrophage (various)
 Langerhans cell (in epidermis)
 osteoclast (in bone)
 dendritic cell (in lymphoid tissues)
 microglial cell (in central nervous system)
mast cell
T lymphocyte
 helper T cell
 suppressor T cell
 killer T cell
B lymphocyte
killer cell
stem cells and committed progenitors for the blood and
 immune system (various)
Sensory TransducersTop
  blue sensitive
  green sensitive
  red sensitive
 inner hair cell of organ of Corti
 outer hair cell of organ of Corti
acceleration and gravity
 type I hair cell of vestibular apparatus of ear
 type II hair cell of vestibular apparatus of ear
 type II taste bud cell
 olfactory neuron
basal cell of olfactory epithelium (stem cell for olfactory neurons)
blood pH
 carotid body cell
  type I
  type II
 Merkel cell of epidermis
 primary sensory neurons specialized for touch (various)
 primary sensory neurons specialized for temperature
  cold sensitive
  heat sensitive
 primary sensory neurons specialized for pain (various)
configurations and forces in musculoskeletal system
 proprioceptive primary sensory neurons (various)
Autonomic NeuronsTop
cholinergic (various)
adrenergic (various)
peptidergic (various)
Supporting Cells of Sense Organs and of Peripheral NeuronsTop
supporting cells of organ of Corti
inner pillar cell
 outer pillar cell
 inner phalangeal cell
 outer phalangeal cell
 border cell
 Hensen cell
supporting cell of vestibular apparatus
supporting cell of taste bud (type I taste bud cell)
supporting cell of olfactory epithelium
Schwann cell
satellite cell (encapsulating peripheral nerve cell bodies)
enteric glial cell
Neurons and Glial Cells of Central Nervous SystemTop
neurons (huge variety of types-still poorly classified)
glial cells
 astrocyte (various)
Lens CellsTop
anterior lens epithelial cell
lens fiber (crystallin-containing cell)
Pigment CellsTop
retinal pigmented epithelial cell
Germ CellsTop
spermatogonium (stem cell for spermatocyte)
Nurse CellsTop
ovarian follicle cell
Sertoli cell (in testis)
thymus epithelial cell

© 1994 by Bruce Alberts, Dennis Bray, Julian Lewis, Martin Raff, Keith Roberts, and James D. Watson.