BMS130 Lecture Notes - Lecture 9: Esophagus, Jejunum, Blood Sugar
State and describe 5 functions of the respiratory system
1. Olfaction – it provides the passageway in the upper nasal cavity for the airborne
chemicals (odorants) to be detected by the olfactory cells
2. Phonation – houses the vocal cords which enable us to produce a variety of
sounds and hence communicate
3. Cleaning, warming, and humidification of inspired air – dust particles stick to
nasal mucosa and nasal conchae anatomy (i.e. increased surface area) ensures
that air contacts nasal mucosa and hence picks up moisture and heat
4. Conduction of air – series of airways allowing airflow to reach the alveoli from the
nose or mouth
5. Gas exchange – the exchange of CO2 and O2 between the alveoli and the
pulmonary capillaries
6. pH regulation – CO2 is exhaled which helps to prevent the accumulation of H+
ions and hence acidosis
7. Blood pressure regulation – the lungs synthesize angiotensin II which has a
vasoconstrictor effect which ↑s blood pressure
8. Breath holding – acts to increase intra-abdominal pressure which aids in
urination, defecation, childbirth and lifting heavy objects
State and describe 5 functions of the kidneys
1. Blood plasma filtration – the kidneys act as a blood filter to excrete harmful toxic
waste products
2. Regulation of blood volume – by conserving water or eliminating it in the urine
3. Regulation of body fluid osmolarity – the kidneys help regulate the blood levels of
Na+, K+, Ca2+ , Cl- and phosphate ions
4. Regulation of blood pressure – the kidneys secrete renin which helps to increase
blood pressure by activating the renin-angiotensin-aldoster one pathway
5. Production of erythropoietin - erythropoietin stimulates the production of red
blood cells in the red bone marrow
