Tissue Types and Characteristics in Anatomy

Epithelial

Covers and lines the body, passageways, and forms glands.

Connective

Found throughout the body and helps connect tissues.

Muscle

Found in skeletal muscles, walls of hollow organs, in the heart, and other locations.

Nervous

Primary component of the brain, spinal cord, and peripheral nerves.

Cellularity

Tightly packed cells; minimal ECM between cells.

Polarity

Apical and basal surface.

Attachment to a basement membrane

Thin layer but composed substances that act like 'glue.'

Avascularity

Lacks blood vessels.

Extensive innervation

Contains nerves to detect changes in the environment.

High regeneration capacity

Frequent cell division from deepest epithelial cells (stem cells).

One layer epithelium

We say it is simple.

Two or more layers epithelium

We say it is stratified.

Flat cell shape

We call it squamous, and its nucleus is also flat.

Cube-like cell shape

We then call it cuboidal, and its nucleus is round.

Column-like cell shape

We then call it columnar, and its nucleus is elongated.

Column-like appearance with multiple layers

We call those pseudostratified.

Simple squamous epithelium

Thin barrier, rapid filtration and diffusion; air sacs in lungs.

Simple cuboidal epithelium

Absorption and secretion; lining of kidney tubules.

Ciliated simple columnar epithelium

Secretion of mucus and movement by cilia; lining of uterine tubes.

Nonciliated simple columnar epithelium

Absorption and secretion; lining of most digestive organs.

Pseudostratified ciliated columnar epithelium

Secretion of mucus and movement by cilia; lining of airways.

Stratified squamous keratinized epithelium

Protection of underlying tissue; epidermis of skin.

Stratified squamous nonkeratinized epithelium

Protection of underlying tissue; lining of MAVE.

Stratified cuboidal epithelium

Protection and secretion; ducts of most exocrine glands.

Stratified columnar epithelium

Protection; rare - lining of part of male urethra.

Transitional epithelium

Accommodates volume change; lining of urinary bladder.

Glands

Can be either individual or multicellular; their goal is to secrete substances.

Label A

The part that secretes substances.

Label B

The area where secreted substances travel.

Exocrine glands classification

Can be classified anatomically and physiologically.

Anatomical classification

Based on whether the glands have branches.

Unbranched glands

Are referred to as simple.

Branched glands

Are referred to as compound.

Physiological classification

Based on how their substances are secreted.

Molecular material

Produced by connective tissue cells.

Types of connective tissue

Include loose connective tissue, dense connective tissue, and specialized connective tissue.

Protein fibers

Found in connective tissue.

Loose connective tissue types

Include areolar, adipose, and reticular connective tissue.

Areolar connective tissue

Binds skin and some epithelial to deeper tissue.

Adipose connective tissue

Stores lipids, an energy fuel source.

Reticular connective tissue

Creates a meshwork of 'nets' to filter.

Dense connective tissue types

Include regular, irregular, and elastic connective tissue.

Regular dense connective tissue

Resists stress in one direction.

Irregular dense connective tissue

Resists stresses in all directions.

Elastic dense connective tissue

Can stretch, but more importantly, it also recoils.

Types of cartilage

Include hyaline, fibrocartilage, and elastic cartilage.

Hyaline cartilage

Provides a nearly frictionless surface for bones.

Fibrocartilage

Weight-bearing and resists compression.

Elastic cartilage

Maintains shape of structure; stretches and recoils.

Superficial fascia

Also called the subcutaneous layer.

Superficial fascia composition

Composed of both loose and dense connective tissue.

Dermis

Deep to the epidermis, composed of two layers.

Papillary layer

Immediately deep to the stratum corneum and made of loose connective tissue.

Functions of the skin

The 8 functions of the skin include protection, sensation, temperature regulation, excretion, secretion, vitamin D synthesis, immune defense, and water resistance.

Nail plate

The hard, visible part of the nail.

Nail bed

The skin beneath the nail plate.

Nail matrix

The tissue under the base of the nail that produces cells that become the nail plate.

Zones of hair

The three zones along the length of hair are the bulb, shaft, and root.

Sudoriferous glands

Sweat glands that can be divided into eccrine glands and apocrine glands.

Repetitive stress

Can stimulate cell division in the stratum basale.

Sebaceous glands

Oil glands that can be classified as holocrine glands.

Skeletal muscle unit

The smallest functional unit of skeletal muscle is the sarcomere, composed of repeating myofibril structures.

Cell repair methods

Cells can be repaired through regeneration (replacement of damaged/dead cells) or fibrosis (filling a gap with scar tissue).

Somatic neurons

Nerve cells that transmit nerve signals from the brain or spinal cord to control skeletal muscle activity.

Neuromuscular junction

The connection point where the neuron meets the muscle fiber.

Characteristics of neurons

The 5 characteristics of neurons include excitability, conductivity, secretion, longevity, and amitotic nature.

Nervous tissue cells

Neurons are nervous tissue cells that collect information, process it, and initiate responses.

Glial cells of the central nervous system

The 4 glial cells include astrocytes, oligodendrocytes, microglia, and ependymal cells.

Glial cells of the peripheral nervous system

The 2 glial cells include Schwann cells and satellite cells.

Myelination process

The process by which part of an axon is wrapped in myelin is called myelination.

Myelin composition

Myelin is an insulating cover made of mostly lipids and some proteins.

Myelinating cells in CNS

In the central nervous system, the cells that myelinate axons are called oligodendrocytes.

Myelinating cells in PNS

In the peripheral nervous system, the cells that myelinate axons are called Schwann cells.