IBDP Biology Chapter 6 Notes



Expert teachers have specially curated these notes to simplify and enlighten concepts given in IB Biology HL. The notes are comprehensive and are sufficient to study the chapter in-depth, and one need not look for other resources beyond the notes provided on our website, which can be accessed for free. The notes for Human Physiology IBDP HL are available on our official website and can be downloaded for free. You are one click away from obtaining all that you need to score well in IB Biology HL. 

The material made available on Tychr’s website is available for all IBDP subjects. It is specially curated after an extensive amount of effort to ensure that the notes are in consonance with the IB curriculum and are an amalgamation from various textbooks prescribed by the IBO. Students often face a challenge understanding concepts, especially concepts that are new and tricky. These IB Biology Notes will help the student cover the chapter on Human Physiology entirely while explaining each concept in a detailed and easy way.

This unit consists of various subunits spanning the expanse of Human Physiology. We start with digestion, i.e. the enzyme-mediated breakdown of ingested macromolecules into smaller molecular forms in the alimentary canal. Digestion is coupled with peristaltic and followed by absorption via the gut mucosa. Then we discuss the blood system and heart. The heart is the four-chambered muscular organ that pumps blood into arteries and receives blood from veins. Heart has two sides, right and left, dealing with pulmonary and systemic circulation, respectively. Stroke volume is the amount of blood pumped by the left ventricle after each contraction. The cardiac cycle is the flow of events that occurs in the chambers of the heart to receive and supply blood consisting of systoles (contraction) and diastolic (relaxation).

Alternatively, we study immune defences (primary and secondary), and antibody interaction wherein antibodies interact with the pathogen’s antigen, which leads to the deactivation of the pathogen. Antibiotics hinder pathogens by disfiguring their cell wall or stopping their metabolism. The respiratory system mediates gas exchange. Here we dive into the structure of alveoli and how muscles help in ventilation ( inspiration and expiration). Neurons are the cells of the nervous system designed to transmit information in the form of electrical impulses.

The action potential is the nerve impulse and consists of depolarisation and repolarisation. We end the discussion with hormones, mainly focussing on sex hormones and the interplay of female sex hormones through the menstrual cycle and IVF.