occipital lobe   

(ok-sip�i-tul)
posterior lobe of the brain.

Body system terms : Nervous system

oesophagus   

(ee-sof�ah-gus)
tube-like passageway which connects the pharynx to the stomach.

Body system terms : Digestive system

oestrogen   

(ees'tro-jen)
the female sex hormone which controls development of the female characteristics and induces changes in the uterus that precede ovulation.

Body system terms : Endocrine system

-oid   

(-oyd)
resemblance
e.g. lipoid = fat-like.

General terms : Suffixes

olfactory receptors   

(ol-fak�tor-ee)
nerves in the upper part of the nasal cavity concerned with the sense of smell.

Body system terms : Respiratory system

-ology   

(-ol-o-jee)
study of
e.g. morphology = the study of the structure of organisms.

General terms : Suffixes

-oma   

(-oh-mah)
tumour
e.g. adenoma = glandular tumour.

General terms : Suffixes

oophoritis   

(oh-off-or-eye'tis)
inflammation of an ovary.

Diseases & procedures : Diseases

openings of ureters   

narrow slit into the base of the bladder where the ureters open.

Body system terms : Urinary system

ophthalm-   

(off-thalm-)
(to do with an) eye.

General terms : Root words

optic nerve   

(op�tik)
second cranial nerve, concerned with sight; connects the retina to the brain.

Body system terms : The eyes

orbit   

bony cavity in the cranium which contains the eyeball and associated structures.

Body system terms : The eyes

orchidectomy   

(orki-dekt'oh-mee)
surgical removal of a testicle (testis).

Diseases & procedures : Procedures

orchidopexy   

(or'kid-oh-pek-si)
an operation to bring down an undescended testis into the scrotum.

Diseases & procedures : Procedures

organ of Corti   

(kor'tee)
the true organ of hearing consisting of hair cells and their nerve fibres.

Body system terms : The ears

orifice   

(or�i-fis)
an opening.

Body system terms : Digestive system

origin   

point of attachment of a muscle to a bone that remains relatively fixed during contraction of the muscle; see also insertion.

Body system terms : Musculoskeletal system

-osis   

(-oh-sis)
process, disease, condition
e.g. dermatosis = any skin disease.

General terms : Suffixes

ost-, osteo-   

(ost-, ost-ee-oh-)
(to do with) bone.

General terms : Root words

osteoarthritis   

(os-tee-oh-ar-thry'tis)
a joint disease characterised by degeneration of the cartilage that lines the joint.

Diseases & procedures : Diseases

otitis media   

(oh-ty'tis med-ee'ah)
inflammation of the middle ear.

Diseases & procedures : Diseases

outer canthus   

(kan'thus)
the angle at the outer end of the eye between the eyelids.

Body system terms : The eyes

outer ear   

the auricle or pinna; consists of elastic cartilage covered by skin; the lobule at the lower end is a small mass of fatty tissue.

Body system terms : The ears

oval window   

the membrane between the middle and inner ear.

Body system terms : The ears

ovarian follicles   

(oh-vair'ee-un fol�lik-uls)
blister-like formations on the ovary which rupture when they ripen and release the egg cell of reproduction.

Body system terms : Endocrine system

ovaries   

(oh'ver-eez)
female reproductive organs which release ova (eggs), oestrogen and progesterone.

Body system terms : Endocrine system

ovary   

(oh�var-ee)
one of the two female glands which produce the ovum for reproduction.

Body system terms : Reproductive system

ovulation   

(ov-yoo-lay�shun)
discharge of the egg from the ovary.

Body system terms : Reproductive system

ovum   

(oh'vum)
female egg cell of reproduction.

Body system terms : Reproductive system

ovum   

(oh�vum)
egg cell; plural: ova.

Body system terms : Endocrine system

oxygen   

(ok�si-jen)
colourless, odourless gas essential to the life of human tissue cells.

Body system terms : Respiratory system

oxygenated   

(ok�si-jen-ay-ted)
carrying oxygen.

Body system terms : Blood, and the circulatory system