WHY IS HOMEOSTASIS IMPORTANT IN THE BODY

Because we would not survive if conditions were to vary greatly. Conditions are kept at optimum for enzyme activity.

DESCRIBE THE PROCESS OF INHALATION.

It is an active process.

  • The diaphragm contracts and flattens, while at the same time the intercostal muscles contract
  • Lifting the ribcage up and out
  • These movements cause an increase in the volume of the thorax cavity
  • Which causes a decrease in pressure which forces air into the lungs 

NAME A BREATHING DISORDER 

Asthma 

STATE A CAUSE AND TREATMENT 

cause:It is an allergic reaction to a trigger/ allergen in the environment. Eg dust

Treatment: Inhaler, this contains bronchiole dilator 

WHAT IS A PULSE 

A pressure wave caused by the contraction in the artery wall.

NAME A STRUCTURE FOUND IN CELLS IN WHICH CARBON DIOXIDE IS PRODUCED

Mitochondria 

GIVE A FEATURE OF A CAPILLARY WHICH ALLOWS RAPID UPTAKE OF CARBON DIOXIDE 

One cell thick 

WHY ARE CO2 LEVELS USUALLY HIGHER IN VENOUS BLOOD THAN IN ARTERIAL BLOOD 

Venous blood has collected CO2 from respiration. Arterial blood has been cleared of CO2 in the lungs.

GIVE AN EXCEPTION TO THIS.

The pulmonary vein has been cleared of CO2 in the lungs. 

BRIEFLY OUTLINE THE ROLE OF CO2 IN THE CONTROL OF THE BREATHING RATE

The medulla oblongata picks up any rises in CO2 levels. It measures the CO2 concentration in the blood.If an increase has been detected. An impulse is sent. The diaphragm begins contracting. Breathing is deeper and faster. 

GIVE 2 FEATURES OF THE ALVEOLI WHICH ALLOW FOR EFFICIENT GAS EXCHANGE

  • Moist inner surface: allows O2 to dissolve and diffuse quickly 
  • One cell thick: Rapid diffusion 
  • Large surface area
  • Dense and close network of capillaries 

DRAW LARGE DIAGRAM OF HUMAN BREATHING SYSTEM

STATE THE FUNCTION OF THE FOLLOWING 

EPIGLOTTIS: is a flap of cartilage which prevents food from entering the trachea

LARYNX: Voicebox, to make sound