Histology notes banana

What is the function of epithelial tissue

Lining tissue that forms the boundary between our body and the external environment

Protection, absorption, filtration, secretion

What does epithelial tissue functions include

Respiratory tract

What do epithelial tissues line

Top surface of an epithelial tissue, apical

What is the free surface

Bottom edge or base of an epithelial cell

What is the basal surface

basement membrane

What is the membrane underneath the basal surface

Avascular

What are epithelial tissues

Simple epithelial

Only one layer of cells

Stratified epithelial

More than one layer of cells

Simple squamous epithelium

Single, flat layer

Function of squamous epithelium

Rapid diffusion of materials

Blood vessels and lung tissues

Where is simple squamous found?

Simple cuboidal epithelium

Single layer of cubed-shaped cells

Function of simple cuboidal

Secretion and absorption of substances

Tissue of the kidney

Where is simple cuboidal found

What is simple columnar?

Single layer of tall, closely packed cells

What is cilia

What are goblet cells

Secretion of mucus for protection and absorption of substances

What is the function of simple columnar?

Lining of the digestive tract

Where is simple columnar found

Areolar

Lots of ground substances, holds H20 and salts

Stratified cuboidal epithelium

More than one layer of cuboidal cells

Rare in the body

Stratified cuboidal is

Salivary and mammary glands

Where are stratified cuboidal epithelium found?

Stratified columnar epithelium

Free surface is lined with columnar cells

no, it is Rare

Is stratified columnar common in body?

larynx and male urethra

Where is the stratified columnar found

Nuclei are found at different levels, so it appears stratified, though it is not

What is pseudo-stratified epithelium

secretion and absorption

What is the function of pseudo-stratified

Most of the upper respiratory tract

Where is pseudo-stratified found

free surface cells vary in appearance based on stretching of the tissue

What is transitional epithelium

Where is transitional epithelium found?

Lining of the urinary bladder

Gland made of group of cells that secrete a fluid substance

What is a glandular epithelium

Complexity, how substances are secreted

Two ways glands are classified

Has ducts and secrete a variety of product

Exocrine glands

sweat glands

Example of exocrine gland

ductless glands that secrete hormones through the bloodstream

Endocrine gland

Thyroid gland

Example of endocrine gland

Cells excrete the products (substances) by exocytosis

Merocrine gland

Sweat glands

Example of Merocrine gland

A portion of the cell pinches off with the secreted products

Apocrine gland

Holocrine gland

Cells rupture and spill products into the duct

Sebaceous (oil) glands in skin

Example of holocrine gland

secrete hormones into the blood, to be delivered over longer distances. Packed tightly with capillaries

What are the characteristics of endocrine glands

thryoid, thymus, adrenal glands, pancreas

Examples of endocrine glands

Provides support and bind other tissues together, insulation, protection

Functions of connective tissue

Formed from one type of stem cell, vary in degree of vascularity, mostly composed of extracellular matrix

Characteristics all connective tissues share

Watery or gel-like substance secreted by cells

What is the ground substance of connective tissue?

Fibers or threads such as collagen, elastic or reticular

What is in connective tissue

Areolar, Adipose, Reticular

Examples of Loose connective tissue

Regular, irregular, elastic

Examples of Dense connective tissue

Mostly open space, holds water and salts, found under epithelium and around organs

Areolar

Comprised of fat cells (adipocytes) has large vacuoles that contain fat/oil, insulates and warms body, provides nutrients to other cells

Adipose

Contains reticular fibers, create a stiff framework that support other cells

Reticular

Collagen fibers arranged in one direction, provides
tensile strength like a rope, Found in tendons and ligaments

Regular

Collagen fibers arranged in many directions, provide strength in multiple directions, found in capsules around organs

Irregular is

Elastic

Provides flexible cushioning, found between vertebrae and in arteries

nerves or blood vessles

Cartilage doesn’t have

Hyaline, Fibrocartilage, elastic

Types of Cartilage

Glassy looking, firm ground substance, has lacuna, few collagen fibers

Hyaline

Where is the Hylaine cartilage found

larynx, bridge of nose, and ribs

contains lots of collagen, mostly running parallel

Fibro-cartilage

Invertebral spaces

Where is fibro-cartilage found

Highly flexible, more elastic fibers

Elastic Cartilage

outer ear and tip of nose

Where is elastic cartilage found

Calcified ground substance

Bone

Spongy and compact

Two types of bone

Osteocytes secrete ground substances, fibers, collagen, fluids and becomes calcified and hard

Characteristics of bone tissue

Detect foreign substances

Mast cells

Granules that secrete inflammatory chemicals

What do mast cells contain

Blob-like cells that engulf invading substances or organisms

Macrophages

red blood cells carry oxygen, white blood cells provide immune response

Blood cells

Vascular

What is blood tissue also called

Contracts involuntarily, non-striated

Smooth muscle tissue

Walls of stomach, uterus, intestines, bladder, arteries, veins and eyes

Where is smooth tissue found

Contracts involuntarily striated, activated by brain or hormones

Cardiac tissue

heart muscle

Where is cardiac found

Skeletal tissue

contracts voluntarily striated, connected to bones of the skeleton

somatic nervous system

skeletal tissue is controlled by

Neurons

Makes up 10% of all nerve cells

Neuroglia

Makes up 90% of all nerve cells