Animal Husbandry WAEC

Homeostasis

Visão Geral

Take a West African Dwarf goat out of its pen at six in the morning in Jos, when the Harmattan air is barely fifteen degrees, and again at two in the afternoon, when the sun over the same pen is fierce enough to make a herdsman sweat through his shirt. Measure the goat's own body temperature both times and it barely moves. The outside world swings wildly. The inside of the animal does not, and that quiet stability is not an accident: it is the animal's body actively fighting to hold its internal conditions steady, every second of the day.

In this lesson you will learn what homeostasis means, the general negative-feedback mechanism that every homeostatic correction follows, and how the nervous system and the endocrine system, the two systems you have already met, each play a distinct part in keeping the correction working. Body temperature will be your running example throughout, because thermoregulation is the homeostatic mechanism every stockman meets first and relies on to keep animals alive, growing and productive.

Objetivos

  1. Define homeostasis
  2. Explain the role of the nervous system in homeostasis
  3. Explain the role of the endocrine system in homeostasis
  4. Explain the importance of homeostasis to a farm animal
  5. Give examples of homeostatic mechanisms in farm animals

Nota de Aula

A trader moving cattle from Sokoto to Lagos crosses cool highland mornings and blistering midday heat, yet none of the animals arrives with a body temperature anywhere near either extreme. A broiler in a poorly ventilated shed near Kano, by contrast, pants continuously and gains weight slowly. Both animals run the same machinery; one is winning the fight to stay stable, the other is losing it. Homeostasis is the name for that fight.

Avaliação da Lição

Parabéns por concluir a lição em Homeostasis. Agora que você explorou o conceitos e ideias-chave, é hora de colocar seu conhecimento à prova. Esta seção oferece uma variedade de práticas perguntas destinadas a reforçar sua compreensão e ajudá-lo a avaliar sua compreensão do material.

Irá encontrar uma mistura de tipos de perguntas, incluindo perguntas de escolha múltipla, perguntas de resposta curta e perguntas de redação. Cada pergunta é cuidadosamente elaborada para avaliar diferentes aspetos do seu conhecimento e competências de pensamento crítico.

Use esta secção de avaliação como uma oportunidade para reforçar a tua compreensão do tema e identificar quaisquer áreas onde possas precisar de estudo adicional. Não te deixes desencorajar pelos desafios que encontrares; em vez disso, vê-os como oportunidades de crescimento e melhoria.

  1. Homeostasis is best defined as: A. Keeping every body condition permanently fixed at one value B. Maintaining a stable internal environment within a narrow normal range despite external change C. The process by which an animal grows larger over time D. The exchange of gases between an animal and its surroundings Answer: B
  2. Arrange in the correct order: (i) effector (ii) receptor (iii) control centre (iv) stimulus. A. iv, ii, iii, i B. ii, iv, i, iii C. iv, iii, ii, i D. i, ii, iii, iv Answer: A
  3. Which brain region acts as the body's thermostat, comparing body temperature against the normal range? A. Cerebellum B. Hypothalamus C. Spinal cord D. Adrenal medulla Answer: B
  4. Which of the following is a nervous, rather than a hormonal, response to a sudden rise in body temperature? A. A gradual fall in thyroxine output over several days B. Widening of skin blood vessels within seconds C. A rise in insulin output after a meal D. A slow rise in growth hormone over several weeks Answer: B
  5. The hormone chiefly responsible for the LONGER-TERM adjustment of metabolic rate during sustained cold weather is: A. Insulin B. Adrenaline C. Thyroxine D. Progesterone Answer: C