Mer Scott
Test por , creado hace más de 1 año

Objectives: Define ‘homeostasis’ and explain why extracellular fluid (ECF) composition is regulated in multicellular organisms. • Define ‘osmosis’, ‘osmolarity’ and ‘tonicity’ and understand their relevance to cell volume • Understand the basis of the cell’s ‘resting membrane potential’ and appreciate its physiological significance.

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Mer Scott
Creado por Mer Scott hace más de 7 años
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L2+L3 Homeostasis: Principles and Control

Pregunta 1 de 14

1

The homeostatic theory states that every mechanism of the body exists to the constancy of the body's fluid environment.

Arrastra y suelta para completar el texto.

    regulatory
    maintain
    internal
    external

Explicación

Pregunta 2 de 14

1

(Select the correct statements.)
ECF composition is regulated in multicellular organisms because:

Selecciona una o más de las siguientes respuestas posibles:

  • 1/3 of total body water is in the ECF.

  • Cell membranes are semi-permeable and the concentration of components in the ECF influences the ICF, and so the internal environment of cells.

Explicación

Pregunta 3 de 14

1

Rellena los espacios en blanco para completar el texto.

Fill in the normal reference ranges.
- Core body temperature = - degrees celsius.
- Fraction of body water content in ICF = , and so ECF = . (4/5 of this is fluid, 1/5 of this is .)
- Na+ conc. in ECF = - mmol/L.
- Ca++ conc. in plasma = - mmol/L
- Glucose conc. in blood = - mmol/L while fasting, 3.5 - mmol/L non fasting.
- K+ conc. in ECF = - mmol/L.

Explicación

Pregunta 4 de 14

1

Osmosis is the movement of water toward a region of concentration of , or from a high water concentration to a low water concentration.
is a measure of the total number of solute per of solution. For body cells this is 275 - 300 mosmol/L, in the ECF and ICF.
refers to the effect that a solution's osmolarity has on cell .

Arrastra y suelta para completar el texto.

    high
    low
    solute
    particles
    litre
    Tonicity
    volume
    Osmolarity

Explicación

Pregunta 5 de 14

1

Normal RMP (resting membrane potential) is:

Selecciona una de las siguientes respuestas posibles:

  • -70mV, if the outside of the cell is taken as 0.

  • -70mV, if the inside of the cell is taken as 0.

Explicación

Pregunta 6 de 14

1

The main determinant of RMP (resting membrane potential) is:

Selecciona una de las siguientes respuestas posibles:

  • K+, as it has the highest permeability of ions.

  • Ca++, as it controls electrical impulses and therefore contractions in muscles.

Explicación

Pregunta 7 de 14

1

The RMP of cells remains constant.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 8 de 14

1

Which statement about reference (normal) ranges is incorrect?

Selecciona una de las siguientes respuestas posibles:

  • Reference range values are specific to age group, and values within two standard deviations of the mean are considered normal.

  • By chance, 5% of tests outside this range are from healthy people.

  • Intra-individual variation is normal, but inter-individual is not.

  • Both inter-individual and intra-individual variation are normal.

Explicación

Pregunta 9 de 14

1

Choose the correct statements about feedback systems.

Selecciona una o más de las siguientes respuestas posibles:

  • Positive feedback systems are the most helpful to maintaining homeostasis.

  • Negative feedback systems oppose change to regulated variables.

  • Feed-forward system responses can be behavioural or physiological.

  • The sensor and integrator of a system can be the same cell.

  • A good example of a negative feedback system is childbirth, specifically oxytocin release due to stretch which triggers more contractions.

Explicación

Pregunta 10 de 14

1

Choose the two physiological communication pathways, and their appropriate timings.

Selecciona una de las siguientes respuestas posibles:

  • Neuronal for quick responses, hormonal for slow responses.

  • Neuronal for slow responses, hormonal for quick responses.

  • Feed-forward for quick responses, feedback for slow responses.

Explicación

Pregunta 11 de 14

1

Which method of heat loss is still effective when the environment is hotter than the body.

Selecciona una de las siguientes respuestas posibles:

  • Evaporation

  • Radiation

  • Convection

  • Conduction

Explicación

Pregunta 12 de 14

1

allows more blood to the skin and so allows more heat . diverts more blood to the visceral organs and so aids heat .

Arrastra y suelta para completar el texto.

    Vasodilation
    Piloerection
    loss
    retention

Explicación

Pregunta 13 de 14

1

In anatomical position the palms face backward.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 14 de 14

1

Which statement is false?

Selecciona una de las siguientes respuestas posibles:

  • Anterior is opposite to superior.

  • Inferior means below something, superior means above something.

  • Medial means closer to the saggital median line, lateral means further away from it.

  • Distal is opposite to proximal.

  • Superficial means closer to the surface.

Explicación

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