3.5 The Nervous and Circulatory Systems in Cosmetology

3.5 The Nervous and Circulatory Systems in Cosmetology

The NIC theory outline asks candidates to identify the functions of the nervous system and the circulatory system. These two systems explain why massage feels the way it does, why a scalp treatment increases blood flow to the follicle, and why certain clients must not receive deep manipulation at all.

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The nervous system: three divisions

The sympathetic division drives the fight-or-flight response; the parasympathetic division promotes rest and recovery. A slow, rhythmic effleurage shifts a client toward parasympathetic dominance, which is the physiological basis of a "relaxing" facial or scalp massage.

Nerve types

• Sensory (afferent) nerves carry impulses from sense receptors to the brain — touch, cold, heat, pressure, pain.
• Motor (efferent) nerves carry impulses from the brain to muscles and glands.
• A reflex is an automatic response to a stimulus that does not require the brain — the impulse travels to the spinal cord and back. A client jerking away from an unexpectedly hot towel is a reflex, not a decision.

The neuron is the basic unit: a cell body, dendrites that receive impulses, and an axon that sends them onward.

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Cranial nerves the cosmetologist works with

There are 12 pairs of cranial nerves. Three matter directly.

Fifth cranial nerve — trifacial or trigeminal. The chief sensory nerve of the face, and it also supplies the muscles of chewing. It has three branches:

Seventh cranial nerve — the facial nerve. The chief motor nerve of the face. It emerges near the lower part of the ear and branches to the facial muscles, so it is the nerve responsible for expression. Its named branches are the posterior auricular, temporal, zygomatic, buccal, mandibular and cervical.

Eleventh cranial nerve — the accessory nerve. Supplies motor fibres to the muscles of the neck and back.

A clean way to hold the pair on exam day: five is what you feel; seven is what you show.

Cervical nerves originate at the spinal cord and supply the neck and scalp: the greater occipital (back of the head and scalp), lesser occipital (behind the ear), greater auricular (side of the neck, ear and face), cervical cutaneous (front and side of the neck), and the smaller occipital.

Nerves of the arm and hand — worked directly in a manicure massage:

• Ulnar nerve — little-finger side of the arm and palm.
• Radial nerve — thumb side of the arm and back of the hand.
• Median nerve — the middle of the forearm and hand; this is the nerve compressed in carpal tunnel syndrome.
• Digital nerves — the fingers.

Nerves of the leg and foot — worked in a pedicure massage:

• Tibial nerve and its branches supply the sole and underside of the toes.
• Common peroneal nerve, dividing into deep and superficial peroneal branches, supplies the front of the leg and the top of the foot.
• Saphenous nerve — inside of the leg and foot; sural nerve — outside and back of the leg and foot; dorsal nerve — the top of the foot.

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The circulatory system

The circulatory system has two parts: the blood-vascular system (heart, arteries, veins, capillaries) and the lymph-vascular system, which drains interstitial fluid, filters it through lymph nodes and returns it to the bloodstream.

The heart is a muscular cone-shaped organ about the size of a closed fist, enclosed in a membrane called the pericardium. It has four chambers: the right and left atria (upper, receiving) and the right and left ventricles (lower, pumping). Valves prevent backflow. A normal resting adult heart beats about 60 to 100 times per minute.

Valves are the reason limb massage runs toward the heart and the reason varicose veins develop when valves fail.

Blood is a sticky, salty fluid, normally about 8 to 10 pints in an adult, roughly 8% of body weight.

Blood's jobs: carry oxygen, nutrients, hormones and enzymes to cells; carry carbon dioxide and waste away; regulate body temperature; clot to seal injury; and protect through white cells and antibodies.

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The vessels of the head, face and limbs

Arteries

• The common carotid artery divides into the internal and external carotid.
  • Internal carotid — supplies the brain, eye, eyelid, forehead, nose and internal ear.
  • External carotid — supplies the face, scalp, skin and neck. Its branches include the facial artery (lower face), superficial temporal artery (side of the head, ear and scalp), occipital artery (back of the scalp), and posterior auricular artery (behind and above the ear).
• Arm and hand: the ulnar artery supplies the little-finger side; the radial artery supplies the thumb side — this is the pulse point at the wrist.
• Leg and foot: the popliteal artery behind the knee divides into the anterior tibial (continuing as the dorsalis pedis on the top of the foot) and the posterior tibial, which supplies the ankle and sole.

Veins

• The internal and external jugular veins return blood from the head, face and neck to the heart. Veins in this region generally parallel the arteries and take the same names.

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Why this matters at the chair

• Scalp treatments and shampoo massage increase local blood flow through the branches of the external carotid, which is the mechanism behind the "stimulating scalp treatment" claim. The effect is real but local and temporary.
• Facial massage works over the paths of the fifth and seventh cranial nerves; slow, even pressure along those paths produces the parasympathetic response clients pay for.
• Limb massage always moves toward the heart because venous valves only open one way.
• Absolute cautions: deep manipulation is contraindicated over varicose veins, in any client with a history of deep vein thrombosis, in uncontrolled hypertension, and in advanced diabetes where neuropathy blunts the client's ability to report pain and fragile skin tears easily. Refer to a physician rather than improvising.