CIE A Level Biology (9700) 2019-2021

Revision Notes

9.1.3 Recognising Tissues

Recognising Tissues in the Gas Exchange System

Cartilage

Cartilage micrograph, downloadable AS & A Level Biology revision notes

Cartilage micrograph

 

Cartilage SEM, downloadable AS & A Level Biology revision notes

Cartilage – electron micrograph

 

  • The cartilage in the trachea has a ‘glassy’ appearance due to its translucent protoplasm
  • It contains no nerves or blood vessels

Ciliated epithelium

Ciliated Epithelium Photo Micrograph, downloadable AS & A Level Biology revision notes

Ciliated epithelium – photomicrograph

 

Ciliated Epithelium Electron Micrograph, downloadable AS & A Level Biology revision notes

Ciliated epithelium – electron micrograph

 

  • Ciliated epithelial cells are distinctive due to their narrow cell bodies and hair-like cilia located along the apical layer
  • The cilia are tiny projections which greatly increase the surface area of the cell

Goblet cells

Goblet Cell Light Micrograph, downloadable AS & A Level Biology revision notes

Goblet cell – light micrograph

 

Goblet Cells Electron Micrograph, downloadable AS & A Level Biology revision notes

Goblet cells – electron micrograph

 

  • Goblet cells can be found scattered among the ciliated epithelium of the trachea and bronchi
  • They are distinctive in the epithelium due to their lack of cilia (although they still have some microvilli projecting outwards)
  • The nucleus is found towards the basal (bottom) layer of the cell, with a large Golgi apparatus and mucus granules found towards the apical layer

Squamous epithelium

Squamous Epithelium Light Micrograph, downloadable AS & A Level Biology revision notes

Squamous epithelium – light micrograph

 

Squamous Epithelium Electron Micrograph, downloadable AS & A Level Biology revision notes

Squamous epithelium – electron micrograph

 

  • Squamous epithelium is made of thin, flat squamous cells

Smooth muscle

Smooth Muscle Light MIcrograph, downloadable AS & A Level Biology revision notes

Smooth muscle – light micrograph

 

10. Smooth Muscle Electron Micrograph, downloadable AS & A Level Biology revision notes

Smooth muscle – electron micrograph

 

  • The cells of smooth muscle are tightly packed and are found beneath the ciliated epithelium
  • Unlike skeletal muscles, they are not striated and so don’t show any cross stripes under a microscope

Capillaries

Capillary Photomicrograph, downloadable AS & A Level Biology revision notes

Capillary – photomicrograph

 

Capillary Electron Micrograph, downloadable AS & A Level Biology revision notes

Capillary – electron micrograph

 

  • Capillaries are distinctive from other blood cells due to their tiny diameter (~4 μm)
  • Their walls consist of a single layer of epithelial cells

Author: Jenna

Jenna studied at Cardiff University before training to become a science teacher at the University of Bath specialising in Biology (although she loves teaching all three sciences at GCSE level!). Teaching is her passion, and with 10 years experience teaching across a wide range of specifications – from GCSE and A Level Biology in the UK to IGCSE and IB Biology internationally – she knows what is required to pass those Biology exams.
Close

Join Save My Exams

Download all our Revision Notes as PDFs

Try a Free Sample of our revision notes as a printable PDF.

Join Now
Go to Top