Mechanisms of Mind and Body: Anatomy and Physiology Basics for Care Workers

Mind and body mechanisms（こころとからだのしくみ）· Material

こころとからだのしくみ · Updated 30 October 2026

The こころとからだのしくみ field is the basic-science field: how the brain, nerves, muscles, and organs work, and how their mechanisms change and affect care. Its favourite exam questions are very distinctive: the order of the stages of swallowing （嚥下）, the differences between フレイル・サルコペニア・ロコモ, and how the autonomic nerves work.

The brain, nerves, and autonomic nerves

The cerebrum （大脳） is divided into the frontal lobe （前頭葉） for movement and personality, the temporal lobe （側頭葉） for hearing and language, the parietal lobe （頭頂葉） for sensation, and the occipital lobe （後頭葉） for vision. The brainstem （脳幹） controls vital functions such as breathing and heartbeat, while the cerebellum （小脳） maintains balance and coordination.

The autonomic nerves （自律神経） work unconsciously in two opposing directions: the 交感神経, which activate the body (heart pounding, blood pressure rising) during activity and tension, and the 副交感神経, which dominate during rest and digestion (heart calm, bowels active). The balance between the two is disturbed by stress and aging.

• 脳幹: the centre of breathing and circulation; 小脳: balance
• 交感神経 = active mode; 副交感神経 = rest-and-digest mode
• The temporal lobe is related to language — this links to aphasia

The five stages of swallowing

Swallowing （嚥下） proceeds in five sequential stages: 先行期 (recognizing food by sight and smell), 準備期 (chewing and forming a bolus with the tongue and saliva), 口腔期 (the tongue pushes the bolus into the throat), 咽頭期 (the swallowing reflex closes the airway and opens the esophagus), and 食道期 (peristaltic movement carries the bolus to the stomach).

The most common problem in older adults occurs at the pharyngeal stage: the swallowing reflex and cough reflex weaken, so food enters the airway （誤嚥）. That is why sitting upright when eating, an appropriate pace, and oral care before and after meals are at the core of preventing aspiration pneumonia （誤嚥性肺炎）.

• Order: 先行期 → 準備期 → 口腔期 → 咽頭期 → 食道期
• 誤嚥 occurs mainly when the pharyngeal-stage reflexes weaken
• Prevention: upright position, oral care, appropriate pace

Frailty, sarcopenia, and locomotive syndrome

Three terms for declining function in older adults that you must distinguish: フレイル (frailty) is overall frailty — physical, psychological, and social — which can still improve with intervention; サルコペニア is specifically the loss of muscle mass and strength; ロコモティブシンドローム (ロコモ) is a disorder of the locomotor organs (bones, joints, muscles, nerves) that increases the risk of needing care.

The three are interrelated and form a cycle: muscles weaken → activity declines → appetite and social interaction decline → frailty worsens. The intervention is a combination of exercise, adequate protein intake, and social participation.

• フレイル: broad frailty (physical–psychological–social), still reversible
• サルコペニア: focuses on muscle mass and strength
• ロコモ: focuses on the locomotor organs and fall risk

Homeostasis: temperature, fluids, blood sugar, immunity

The body maintains the stability of its internal environment （ホメオスタシス/恒常性） through the cooperation of nerves and hormones: temperature is kept at around 36–37 degrees, fluids and salts are regulated by the kidneys, and blood sugar is regulated by insulin from the beta cells of the islets of Langerhans in the pancreas （膵臓）, which lowers it, and glucagon, which raises it.

The immune system （免疫） protects the body from germs; in older adults the immune response weakens （免疫老化）, so infections occur easily, fever sometimes does not appear, and recovery slows. Other hormones often tested: the thyroid hormone （甲状腺ホルモン）, which regulates metabolism, and the parathyroid hormone, which regulates blood calcium.

• インスリン from the pancreas’s β cells lowers blood sugar
• Homeostasis = the cooperation of the autonomic nerves and hormones
• Older adults’ immunity weakens: a serious infection can occur without fever

Key terms

Frequently tested points

• The order of the swallowing stages is a classic question: 先行期・準備期・口腔期・咽頭期・食道期.
• Distinguish フレイル (overall) from サルコペニア (muscle) and ロコモ (locomotor organs).
• 交感神経 speed up the heart; 副交感神経 slow it down and activate digestion.
• Insulin is produced by the β cells of the islets of Langerhans in the pancreas — not by the liver.

Independent study material for the Japanese national Certified Care Worker exam (介護福祉士国家試験). Official terms and rules may change — always cross-check with the latest official sources.