Bma Illustrated Medical Dictionary

These are the vestibulocochlear nerve

(hearing and balance), olfactory nerve

(smell), and optic nerve (vision). Other

cranial nerves carry impulses that move

muscles of the head and neck area. These

are the oculomotor, trochlear, and abdu-

cent nerves(movements of the eye),

spinal accessory nerve(head and shoul-

der movements), and hypoglossal nerve

(tongue movements).

Some cranial nerves have both senso-

ry and motor functions. These are the

facial nerve(facial expressions, taste,

and the secretion of saliva and tears)

trigeminal nerve(facial sensation and

jaw movements) and glossopharyngeal

nerve (taste and swallowing move-

ments). The vagus nervehas branches to

all the main digestive organs, the heart,

and the lungs, and is a major compo-

nent of the parasympathetic nervous

system, which is concerned with main-

taining the body’s automatic functions.

All but 2 of the cranial nerve pairs con-

nect with nuclei in the brainstem(the

olfactory and optic nerves link directly

with parts of the cerebrum). The nerves

emerge through openings in the cranium;

many then soon divide into branches.

crackA popular term for a form of cocaine.

cradle capA condition common in

babies in which thick, yellow scales oc-

cur in patches over the scalp. It is a form

of seborrhoeic dermatitis,. which may

also occur on the face, neck, behind the

ears, and in the nappy area.

Cradle cap is harmless as long as the

skin does not become infected. The

condition can be treated by daily use of

a simple shampoo. Alternatively, warm

olive oil or arachis oil may be rubbed

into the baby’s scalp and left on

overnight in order to loosen and soften

the scales, which can be washed off the

following day. A mild ointment that

contains an antibiotic drugand a corti-

costeroid drugmay be prescribed if the

skin becomes inflamed.

crampA painful spasm in a muscle

caused by excessive and prolonged con-

traction of the muscle fibres. Cramps

often occur as a result of increased

muscular activity, which causes a build-

up of lactic acidand other chemicals in

the muscles, and small areas of muscle-

fibre damage. Repetitive movements,

such as writing (see cramp, writer’s) or

sitting or lying in an awkward position

may also cause cramp. Cramp may fol-

low profuse sweating because loss of

sodium salts disrupts muscle cell activi-

ty. Massaging or stretching the muscles

involved may bring relief. A drug con-

taining calciumor quininemay be given

for recurrent night cramps.

Recurrent, sudden pain in a muscle

that is not associated with hardness of

the muscle may be caused by peripheral

vasculardisease. In this case, the condi-

tion should be investigated and treated

by a doctor.

cramp, writer’sPainful spasm in the

muscles of the hand caused by repeti-

tive movements, which makes writing or

typing impossible.

cranial nervesTwelve pairs of nerves

that emerge directly from the underside

of the brain. Each of the nerves has a

number as well as a name. The numbers

indicate the sequence in which the

nerves emerge from the brain.

The main function of some cranial

nerves is to deliver sensory information

from the ears, nose, and eyes to the brain.

CRACK CRANIAL NERVES

C

CRANIAL NERVES

Facial

nerve

(7)

Vagus

nerve

(10)

Trigeminal

nerve (5)

Vestibulocochlear

nerve (8)

Glossopharyngeal

(9)and hypoglossal

nerves (12)

Spinal

accessory

nerve (11)

BRAIN FROM BELOW

Olfactory

nerve (1)

Oculomotor (3),

trochlear (4), and

abducent nerves (6)

Optic

nerve (2)