Biology - 9201 OxfordAQA

Control Of Water And Ion Content Of The Body

Resumen

Drink a large glass of water and your bladder will remind you about it within the hour. Spend that same hour running about in the sun and it stays quiet. Nothing you did consciously produced either result. Two organs roughly the size of your clenched fist took the decision for you, sampling the blood that poured through them and adjusting, minute by minute, how much water they were willing to let go.

This lesson follows water, dissolved ions and waste nitrogen through the body. You will sort the routes that lose water without asking permission from the single route that is genuinely controlled, watch the liver convert a poison it has just made into something safe enough to carry in the blood, take a healthy kidney apart into its two jobs of filtering and reabsorbing, and finish with the hormone that decides whether the urine you produce today is pale and plentiful or dark and scarce.

Objetivos

  1. Water leaves the body via the lungs when we breathe out and the skin when we sweat. Excess water is removed via the kidneys in the urine.
  2. Urea and ions are lost via the skin when we sweat. Excess ions are removed via the kidneys in the urine.
  3. In the liver: excess amino acids are deaminated to form ammonia, which is converted into urea for excretion; poisonous substances are detoxified, and the breakdown products are excreted in the urine via the kidneys; old blood cells are broken down and the iron is stored.
  4. In a healthy kidney: the blood is filtered; all the glucose is reabsorbed; the dissolved ions needed by the body are reabsorbed; as much water as the body needs is reabsorbed; urea, excess ions and excess water are released as urine.
  5. If the water content of the blood is too low, the pituitary gland releases a hormone called ADH into the blood. This causes the kidneys to reabsorb more water and results in a more concentrated urine.
  6. If the water content of the blood is too high, less ADH is released into the blood. Less water is reabsorbed in the kidneys, resulting in a more dilute urine.
  7. The production of ADH is controlled by a negative feedback mechanism.

Mapa mental

Este tema esta esquematizado para ver como se conectan las ideas.

Abre el mapa mental en la app

Tarjetas

Practica rapida de memoria sobre lo que se evalua en este tema.

Practica estas tarjetas en la app

Nota de la lección

Every organism on land faces the same arithmetic. Water and dissolved ions arrive with food and drink; they leave by several doors at once; and the concentration of the body fluids has to stay inside a narrow band, because cells sitting in a liquid that is too dilute swell and cells sitting in one that is too concentrated shrink. What separates an animal that copes with a hot afternoon from one that does not is having at least one exit whose size can be turned up and turned down at will. In humans that adjustable exit is the kidney, and almost everything in this topic exists to serve it.

Apunte completo disponible en la aplicacion Green Bridge

Instala la aplicacion Green Bridge CBT en tu movil u ordenador para acceder a toda la biblioteca IGCSE: examenes anteriores, criterios de correccion, mapas mentales, tarjetas de estudio y lecciones en audio.

Notas de lección completas con diagramas
Asistente de aprendizaje con IA
Simulacros cronometrados que se corrigen en cuanto terminas
Disponible en Android, Windows, macOS y Linux App para iOS proximamente

Evaluación de la lección

Felicitaciones por completar la lección del Control Of Water And Ion Content Of The Body. Ahora que has explorado el conceptos e ideas clave, es hora de poner a prueba tus conocimientos. Esta sección ofrece una variedad de prácticas Preguntas diseñadas para reforzar su comprensión y ayudarle a evaluar su comprensión del material.

Te encontrarás con una variedad de tipos de preguntas, incluyendo preguntas de opción múltiple, preguntas de respuesta corta y preguntas de ensayo. Cada pregunta está cuidadosamente diseñada para evaluar diferentes aspectos de tu conocimiento y habilidades de pensamiento crítico.

Utiliza esta sección de evaluación como una oportunidad para reforzar tu comprensión del tema e identificar cualquier área en la que puedas necesitar un estudio adicional. No te desanimes por los desafíos que encuentres; en su lugar, míralos como oportunidades para el crecimiento y la mejora.

  1. Which substance is filtered out of the blood in a healthy kidney but is absent from the urine that reaches the bladder? A. Water B. Urea C. Glucose D. Sodium ions Answer: C
  2. In which organ is ammonia converted into urea? A. The kidney B. The liver C. The bladder D. The pituitary gland Answer: B
  3. Which gland releases ADH into the blood? A. The pancreas B. The thyroid gland C. The pituitary gland D. The adrenal gland Answer: C
  4. The water content of a person's blood rises above its normal level. What happens next? A. More ADH is released and the urine becomes more concentrated B. Less ADH is released and the urine becomes more dilute C. More ADH is released and the urine becomes more dilute D. Less ADH is released and the urine becomes more concentrated Answer: B
  5. What happens during deamination? A. Glucose is converted into glycogen for storage B. The nitrogen-bearing group is removed from an amino acid the body cannot use C. Water is reabsorbed from the kidney tubule into the blood D. Old red blood cells are broken down and their iron is stored Answer: B

Resuelve estas preguntas en la aplicacion

Resuelve estas preguntas en la aplicacion

Practica preguntas simuladas

¿Quieres practicar preguntas simuladas sobre Control Of Water And Ion Content Of The Body? Descarga la aplicación Green Bridge CBT para acceder a preguntas simuladas y evaluaciones completas sobre este tema.

Descarga la aplicación en Google Playstore.

Todo lo que necesitas para destacar en JAMB, WAEC y NECO.

Green Bridge CBT Mobile App
Asistente de Chat de Aprendizaje Personalizado con IA
Más de 200.000 preguntas de examen de IGCSE, JAMB, WAEC y NECO.
Más de 1200 notas de lecciones
Soporte sin conexión: Aprende en cualquier momento y lugar.
Horario del Puente Verde
Resúmenes de Literatura y Preguntas Potenciales
Controla tu rendimiento y progreso.
Explicaciones detalladas para un aprendizaje integral