Histology Anatomy 10A. Tissues are sectioned in three ways: Longitudinal section Transverse, cross-...

Histology

Anatomy 10A

Tissues are sectioned in three ways:

Longitudinal section

Transverse, cross-section

Oblique

Category 1: epithelia

• Surface and lining layer(s)

• Characterized by cells close together

• Characterized by no blood vessels

• Described by the number of layers • One, or more than one

• Described by the shape• Flat, square or rectangular

Simple epithelium= 1 layer

Basementmembrane

Stratified epithelium = more than one layer

Types of epithelium based on shape

Squamous = flat

Cuboidal = square

Columnar = rectangular

Simple squamous epithelium

Each cell is like a floor tile- thin and flat, placed very close to the next tile.

3D view 2-D view

Simple cuboidal epithelium

3-D view 2-D view

Each cell is shaped like an ice cube with the nucleus in the center.

Simple columnar epithelium (with microvilli, non-ciliated)

Each cell is tall, rectangular-shaped. Nuclei are organized in rows.

3-D

2-D view

Pseudostratified ciliated columnar epithelia

3-D

22-D view

Cells are many sizes; tallest are ciliated. Nuclei are disorganized, staggered.

Simple colunmar epithelium (with microvilli)

Transitional epithelia

3-D

2-D view

Cells transition in shape from cubes to columns to rounded pillow-like cells.

Stratified squamous epithelia

Cells flattenas they go tothe surface

Stratified squamous epithelia

Epithelia review, compare and contrast

Category 2: connective tissue

• Characterized by scattered cells

• Protein (fibers or globular) in the matrix outside cells

• Matrix can be liquid, semi-solid, or solid

• Found under epithelial layers, never on a surface

Areolar (loose) connective tissue

Adipose

Dense regular (Fibrous) connective tissue

Blood

Hyaline cartilage

Hyaline cartilage

Elastic cartilage

Fibrocartilage

Bone

Category 3: muscles

• Contract

• Found in three places:– Heart (cardiac)– Hollow organs (smooth)– Attached to the skeleton (skeletal)

Skeletal muscle

Skeletal (voluntary) muscle

Cardiac muscle

Smooth muscle

Category 4

Nervous tissue:

Neuron

Neuroglia

Nervous tissue