3.1A Cells and Tissues

Factors that influence differentiation

1. cytoplasm content

2. environmental conditions

3. neighbouring cells

• mitosis ensures that daughter cells receive identical sets of chromosomes

• but the content of cytoplasm may differ in each daughter cell (eg. one cell may have more or less storage vacuoles)

1. Cytoplasm Content

2. Environmental Conditions• cell specialization can be affected by temperature or presence or absence of certain nutrients

• Example:

• on Siamese cats, only cells that develop at cool temperatures produce dark hair colour

• tips of cat’s feet, tail, ears and nose are usually cooler

3. Neighbouring Cells

• when cells are close to one another, the substances produced by one cell can diffuse through a neighbouring cells’ membrane

• the substances can change how the info in the DNA of the second cell gets expressed

• in this chick embryo, neighbouring cells influence the development of the eye in a specific location

Abnormal Cell Development• production of abnormal cells is often linked to environmental conditions present during cell development

• these conditions include:

• the presence of chemical contaminants

• temperature changes

• diseases, and parasites

Types of Tissues• groups of similarly specialized cells form tissues

tissue - a cluster of similar cells that share the same specialized structure and function

• there are four main tissues:

1. epithelial

2. muscle

3. nervous

4. connective

Epithelial Tissue• provides a covering (skin, the linings of the various passages inside the body)

Muscle Tissue• includes voluntary muscles that move the skeleton, and smooth muscle, such as the muscles that surround the stomach

Nervous Tissue• made up of nerve cells (neurons) and is used to carry "messages" to and from various parts of the body

Connective Tissue• supports other tissues and binds them together (bone, blood, and lymph tissues)

Section 3.1 Review

Concepts to be reviewed:

• the factors affecting cell specialization (cytoplasm contents, environmental factors, and neighbouring cell secretions)• the four types of tissues (muscle, epithelial, nervous, and connective)

Homework

• Complete 3.1A Homework Worksheet

VIDEO: Introduction to Anatomy & Physiology: Crash Course A&P #1https://www.youtube.com/watch?v=uBGl2BujkPQ

VIDEO: Tissues, Part 1: Crash Course A&P #2https://www.youtube.com/watch?v=i5tR3csCWYo

VIDEO: Tissues, Part 2 - Epithelial Tissue: Crash Course A&P #3https://www.youtube.com/watch?v=lUe_RI_m-Vg

VIDEO: Tissues, Part 3 - Connective Tissues: Crash Course A&P #4https://www.youtube.com/watch?v=D-SzmURNBH0

VIDEO: Tissues, Part 4 - Types of Connective Tissues: Crash Course A&P #5 https://www.youtube.com/watch?v=Jvtb0a2RXaY