The Human Nervous System
Gbogbo ọrọ náà
Touch something scalding and your arm is already moving before you have decided anything. You did not choose it, you could not have stopped it, and the pain arrives afterwards like a report filed late. That tiny gap between the injury and the feeling is the most revealing thing your body does all day, because it shows that a decision was taken somewhere other than in your thoughts.
This lesson follows a single signal from the skin of a fingertip to the muscle that pulls the hand clear. You will meet the three kinds of neurone and learn which direction each one carries traffic, see what actually crosses the tiny gap between one nerve cell and the next, and take apart a pain-withdrawal reflex step by step. By the end you will be able to take any piece of behaviour an examiner puts in front of you, however unfamiliar the animal or the situation, and lay it out as stimulus, receptor, coordinator, effector, response.
Ebumnobi
- The nervous system enables humans to react to their surroundings and to coordinate their behaviour.
- Information from receptors passes along cells (neurones) as impulses to the central nervous system (CNS). The CNS is the brain and spinal cord. The brain coordinates the response.
- Reflex actions are automatic and rapid. They often involve sensory, relay and motor neurones.
- In a simple reflex action such as a pain-withdrawal reflex: impulses from a receptor pass along a sensory neurone to the CNS; at a junction (synapse) between a sensory neurone and a relay neurone in the CNS, a chemical is released that causes an impulse to be sent along a relay neurone; a chemical is then released at the synapse between a relay neurone and motor neurone in the CNS, causing impulses to be sent along a motor neurone to the effector; the effector is either a muscle or a gland: a muscle responds by contracting and a gland responds by releasing (secreting) chemical substances.
- Effectors include muscles and glands. Students should be able, when provided with appropriate information, to analyse a particular given example of behaviour in terms of: stimulus → receptor → coordinator → effector → response
Maapụ uche
E seela isiokwu a ka ị hụ otu echiche si ejikọta.
Mepee maapụ uche na ngwa
Akwụkwọ Ọmụmụ
Ndetu Nkuzi Zuru Ezu di na Ngwa Green Bridge
Nweta ngwa Green Bridge CBT na ekwenti gi ma o bu kompiuta maka ulo akwukwo IGCSE zuru oke: akwukwo ule ndi gara aga, usoro nyocha, eserese uche, kaadi omumu na nkuzi olu.
Nnyocha Ọmụmụ
Ekele diri gi maka imecha ihe karịrị na The Human Nervous System. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.
Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.
Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.
- Which two structures make up the central nervous system? A. The brain and the nerves B. The brain and the spinal cord C. The spinal cord and the nerves D. The receptors and the effectors Answer: B
- Which type of neurone carries impulses from the central nervous system to a muscle? A. Sensory neurone B. Relay neurone C. Motor neurone D. Receptor neurone Answer: C
- What crosses the gap at a synapse? A. An electrical impulse B. A chemical C. A nerve fibre D. A red blood cell Answer: B
- Which of the following is an effector? A. A pain receptor in the skin B. A relay neurone in the spinal cord C. A salivary gland D. The spinal cord Answer: C
- Why is a pain-withdrawal reflex faster than a voluntary movement? A. Its impulses travel at a higher speed B. Its pathway passes through fewer synapses C. It uses hormones instead of neurones D. It does not need an effector Answer: B
Rue ajuju ndi a n'ime ngwa ahu
Rue ajuju ndi a n'ime ngwa ahu
Akwụkwọ A Na-atụ Aro
Meecha Ajụjụ Ule Ọmarịcha
Ị chọrọ ime ajụjụ ule ọmarịcha gbasara The Human Nervous System? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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