Biology Tissues Overview

Tissues

• Tissues are categorized based on their structure and function.
• Epithelial tissues are classified into squamous, cuboidal, and columnar.
• Connective tissues include blood, bone, cartilage, and adipose tissue.
• Muscle tissue is categorized into skeletal, smooth, and cardiac.
• Nervous tissue is composed of neurons and allows for signal transmission.

Simple vs. Complex Tissues in Plants

• Simple tissues are made up of one type of cell.
• Complex tissues are made up of different types of cells.

Plant Tissues Based on Cell Wall

• Parenchyma tissues have thin cell walls and are involved in storage, photosynthesis, and gas exchange.
• Collenchyma tissues have unevenly thickened cell walls providing support and flexibility to growing plant parts.
• Sclerenchyma tissues have thick and rigid cell walls for structural support and protection.

Stomata Function

• Stomata are small pores on the surface of leaves that regulate gas exchange and transpiration.

Types of Muscle Fibers

• Skeletal muscle fibers are striated, voluntary, and attached to bones for movement.
• Smooth muscle fibers are unstriated, involuntary, and found in internal organs like the digestive tract.
• Cardiac muscle fibers are striated, involuntary, and found only in the heart.

Cardiac Muscle Function

• Cardiac muscle is responsible for the rhythmic contractions of the heart, pumping blood throughout the body.

Muscle Tissue Comparison

• Skeletal muscle is attached to bones and responsible for voluntary movement.
• Smooth muscle is found in internal organs and responsible for involuntary movements like digestion.
• Cardiac muscle is found only in the heart and responsible for rhythmic contractions to pump blood.

Neuron Structure

• Neurons are composed of a cell body, dendrites, and an axon.
• Dendrites receive signals from other neurons.
• The axon transmits signals to other neurons or target cells.

Tissue Types

• Skin is composed of epithelial tissue.
• Plant bark is made up of complex tissue, including cork and parenchyma.
• Bone is a type of connective tissue.
• Kidney tubule lining is composed of epithelial tissue.
• Vascular bundles are complex tissues in plants, containing xylem and phloem.

Parenchyma Tissue Regions

• Parenchyma tissues are found in various regions of plants, including the cortex, pith, and mesophyll.

Epidermis Function

• The epidermis is the outermost layer of plant tissues, protecting the plant from environmental stress.

Bark (Cork) as Protective Tissue

• Bark acts as a protective layer to prevent water loss, protect from herbivores, and resist infection.

Permanent Tissue Table