Lab 2 Tissues

Hierarchy in the Human Body

Cell

Tissue

Organ

Organ system

Organism

Epithelial Tissue Characteristic

1. Cellualrity and Specialized contacts

2. Polarity - apical(top) or basal(bottom)

3. Supported by connective tissue (attached to basement membrane)

4. Avascularity (no blood vessels/ nutrients need to diffuse to epithelial tissue)

5. Regeneration (replacement of cells lost due to friction)

Classification of Epithelia

1. Basis of Arrangement(or number of layers), such as simple 1 layer of stratified multiple layers

2. Cell Shape such as squamous(flat), cuboidal(cube-shaped), or columnar(column-shaped)

• glands formed by epithelial cells

Exocrine glands vs Endocrine Glands

Exocrine glands secrete substances through ducts to the outside of the body or into body cavities, while endocrine glands release hormones directly into the bloodstream to regulate various bodily functions.

What Tissue?

Simple squamous epithelium

Function: allows material to pass diffusion and filtration in sites where protection isn’t important and secretes lubricating substances.

Location: air sacs of lungs, lining of heart and blood vessels, and ventral body cavity

What Tissue?

Simple Cuboidal epithelium

Function: secretion and absorption

Location: kidney tubules and ovary surface

What Tissue?

Simple columnar epithelium

Function: absorption and secretion of mucus, enzymes, and other substances

Location: Nonciliated digestive tract, gallbladder, excretory ducts, uterine tubes, some parts of uterus

What Tissue?

Pseudostratified columnar epithelium

Function: secretes substances particualry mucus and propels mucus by ciliary action.

Location: Nonciliated in males sperm carrying ducts, ciliated lines in trachea, upper respiratory tract

What Tissue?

Stratified squamous epithelium

Function: protects underlying tissues in areas subjected to abrasion

Location: nonkeratinized type forms moist linings of esophagus, mouth, and vagina, keratinized type forms the epidermis of the skin, a dry membrane.

What Tissue?

Stratified cuboidal epithelium

Function: protection

Location: largest ducts of sweat glands, mammary glands, and salivary glands

What Tissue?

Stratified Columnar epithelium

Function: protection and secretion

Location: rare in body, small amounts in male urethra and large ducts of some glands

What Tissue?

Transitional epithelium

Function: Stretches readily and permits distention of urinary organ by contained urine

Location: Lines ureters, urinary bladder, and part of urethra

Connective Tissue Characteristics

• rich blood supply

• composed of many cell types

• has nonliving material(extracellular matrix) found between cells; matrix produced by cells and composed of

  • Ground substance: interstitial fluid, cell adhesion proteins, and proteoglycans

  • Fibers: collagen, elastic, and reticular fibers

Connective tissue functions to

• protect tissues/organs

• support tissues/organs

• bind together other tissues

Loose connective tissue, areolar vs adipose vs reticular

Areolar: cushions/protects body

Adipose: insulates body and food storage

Reticular: fine collagen fibers

Dense Connective Tissue, elastic vs normal

Elastic: bronchial tubes, large arteries

Normal: in ligaments and tendons

• regular: in tendons/ligaments

• irregular - in dermis of skin, submucosa of digestive tract

What Tissue?

Embryonic Connective Tissue: Mesenchyme

Function: gives rise to other connective tissue

Location: primary embryo

What tissue?

Connective Tissue Proper: Loose connective tissue, areolar

Function: Wraps and cushions organs; important role in inflammation; holds and conveys tissue fluid

Location: epithelia of body, mucous membranes, surrounds capillaries, packages organs

What tissue?

Connective Proper Tissue: loose connective tissue, adipose

Function: provides reserve fuel; insulates against heat loss; supports and protects organs

Location: under skin; around kidneys and eyeballs; within abdomen; in breast

What tissue?

Connective tissue proper: loose connective tissue, reticular

Function: Fibers form soft internal Skelton (stroma) that supports other cell types like white blood cells, mast cells, and macrophages

Location: Lymphoid organs

What tissue?

Connective tissue proper: dense connective tissue, dense regular

Function: attaches muscles to bone or other muscles, attaches bones to bones, withstands great stress

Location: tendons, most ligaments, aponeuroses

What tissue?

Connective tissue proper: dense connective tissue, dense irregular

Function: able to withstand tension exerted in many directions, provides structural strength

Location: Fibrous capsules of organs and joints, dermis of skin

What tissue?

Connective tissue proper: dense connective tissue, elastic

Function: allows recoil of tissue following stretching, maintains pulsatile flow of blood through arteries

Location: Walls of large arteries, certain ligaments associated with the vertebral column

Three Types of Cartilage

A. Hyaline

B. Elastic

C. Fibrocartilage

What type of cartilage?

Hyaline

Function: supports and reinforces, serves as resilient cushion, resist stress

Location: most of the embryonic skeleton, covers the ends of long bones in joint cavities, nose

What cartilage?

Elastic

Function: maintains shape of structure while allowing flexibility

Location: supports external ear, epiglottis

What cartilage?

Fibrocartilage

Function: Tensile strength with ability to absorb compressive shock

Location: intervertebral discs, disc of knee joints

What is it?

Bone

Function: supports and protects, provides levers for muscles to act on, stores calcium and other minerals

Location: Bone

What is it?

Blood

Function: Transport of respiratory gases, nutrients, waste, and other substances

Location: blood vessels

Three types of muscle tissue?

• Skeletal: voluntary muscle that is striated

• Cardiac Muscle: involuntary muscle found in heart

• Smooth Muscle: involuntary visceral muscle that lines the walls of hollow organs

What type of muscle?

Skeletal Muscle

Function: voluntary movement, locomotion, facial expressions

Location: attached to bones or occasionally to skin

What type of muscle?

Cardiac Muscle

Function: as it contracts, it propels blood into circulation, involuntary control

Location: Walls of heart

What muscle?

Smooth Muscle

Function: propels substances or objects along internal pathways, involuntary control

Location: mostly in the walls of hollow organs

What type of tissue?

Nervous tissue

Function: neurons transmit electrical signals from sensory receptors and to effectors, supporting cell support and neuron protection

Location: Brain, spinal cord, nerves