Anatomy and Physiology Unit 5 Health and Social Care

Objectives  Identify different types of tissue  State where these tissues can be found  Explain the function of different tissue types

What are tissues?  Tissues are groups of similar cells carrying out specific functions.  E.g lung, heart, skin, muscle  Categories of tissues include epithelial, connective, muscle or nervous tissue.  We will be looking at these four types of tissues in detail

Epithelial Tissue  Epithelia forms the linings of surfaces of the body  Eg tubes, ducts from glands, blood vessels, cavities, internal and external surfaces  They are supplied with oxygen and nutrients from deeper tissue by diffusion*.  Diffusion = movement of molecules from a high concentration to low concentration (equilibrium)

Epithelial Tissue Simple Cuboidial, squamous Columnar, ciliated Compound Stratified, keratinised

Simple Epithelia ( squamous, cuboidal, columnar, ciliated) Squamous (‘scaly’)epithelial cells:  Found in the walls of the lung alveoli, blood capillaries  They are flat and fit together closely.  They are delicate and thin Function  Allows materials to pass through (e.g air and blood)  This is via diffusion and osmosis* Osmosis = movement of water molecules from a high concentration to low concentration (equilibrium) through a partially permeable membrane.

Squamous Epithelia cell

Simple Epithelia (squamous, cuboidal, columnar, ciliated) Cuboidal (cube shaped) epithelia cells:  Cube shaped with spherical nuclei  Found in kidney tubules, sweat ducts and glands (e.g thyroid)  Often occur in glandular tissues making secretions Function  Allow material to pass through in a similar way to squamous epithelia o

Cuboidal Epithelial Cell

Simple Epithelia (squamous, cuboidal, columnar, ciliated ) Columnar (column) epithelial cells:  Tall with oval nuclei  Found in the trachea, bronchi and villi in the small intestine Function  Often associated with filaments called cilia and are then called ciliated epithelia  Cilia move in wave like motions  Cilia are commonly associated with goblet cells which secrete mucus in the respiratory and alimentary tracts.  The mucus traps unwanted particles e.g carbon and the cilia transports it away and out of the body.

Columnar Epithelial Cell

Recap of Types All of theses types are ‘simple’ epithelial tissues

Compound Epithelia ( stratified, keratinised) Compound Epithelia  Made up of multiple layers of cells (stratified epithelia) hampering the passage of materials  e.g mouth, tounge oesophogeous Function  Its main function is to protect deeper structures

The Skin: Stratified/Keratinised Epithelium The skin:  Made of stratified / keratinised epithelium  The outside top layer is made of flattened dead cells  This is known as the epidermis  Cells advance from the basement membrane and become filled with a protein called keratin  They are called ‘keratinised’ cells Function  This layer of keratinised cells prevents micro-organisms entering the skin and acts as a waterproof layer

Skin Layer (Stratified, keratinised Epithelium)