Chapter 4 Flashcards
what is histology defined as
The study of tissue
Name the four types of tissues studied and an example of each
Epithelial: GI tract, glands, outer lay of the skin
Connective: bones, joints of cartilage, blood, fat, tendons and ligaments
Muscle: heart, stomach/intestines, skeletal muscles
Nervous: brain and spinal cord, nerves of the body, sensory organs
Describe the three components of Extracellular matrix:
Collagen
Elastin
Reticular
Collagen - proteins arranged in twisted in bundles like fibers, often called white fibers. This is the most abundant component in the body, strength
Elastin - proteins that create elastic fibers, which returns to its original length after being stretched. This is found in ‘stretchy’ tissues like cartilage of the ear and the walls of the arteries. This is sometimes called yellow fibers
Reticular - very thing collagen fibers highly branched proteins that form delicate supporting nutrients.
Epithelial tissue:
Epithelial tissue consists of tightly packed cells that form a continuous layer, they cover the surfaces and line the body cavities. epithelial tissue are characterized by extremely limited amounts of Extracellular matrix.
The functions of epithelial tissue
Protection
Sensory functions
Secretion
Absorption
Excretion
Define membranous and glandular
Membranous: the ‘covering or lining’ covers the body and some of its parts, lines serous cavities, blood, lymphatic vessel, respiratory, digestive, and gentiurinary tracts.
Glandular: ‘glands’ they are grouped in solid cords or hollow follicles and tubules to form secretory units of endocrine and exocrine glands.
Basement membrane
Thin glue-like connections between a sheet of epithelial cells and the underlying fibrous connective tissue.
- a noncellular layer directly beneath the epithelial tissue.
The basement membrane is composed of what
Composed of proteins secreted by epithelial cells and connective tissues. the structured support for overlying cells and attaches to underlying tissues.
Example of a basement membrane
An example of basement membranes is a blister. Blisters are like the basement membrane coming undone
Cell shapes:
Squamous
Cuboidal
Columnar
Psuedostratfied
Squamous - “scaly,” flat, plate - like
Cuboidal - cube-shaped, more cytoplasm than squamous
Columnar - column shaped, additional height
Psuedostratfied - one layer column like cells pseudo = fake
the three layers of the cells described:
Simple
Stratified
Transitional
Simple - straight with one layer
Stratified - many layers
Transitional - multiple layers that can stretch
Describe what a goblet cell is
Large, secretory vesicles that give an appearance of a goblet. Vesicles that contain mucus, which is produced in great quantities and secretes onto the surface of the epithelial membranes.
The goblet cell can assist in absorption of materials
Where is a goblet cell usually found
Usually appears in conjunction with the cilia or microvilli. (Typically is found in or near the Psuedostratified)
Cillia
Microscopic cell extensions of the cell. Sensory organs of a cell to detect changes, such as the presence of certain chemicals outside of the cell. Also assist in movement on surface material.
Microvilli
Much shorter and more numerous than the cilia. Greatly increase the surface area of the cells. this assists in absorbing nutrients and fluid.
Transitional layers are what
Unique arrangements of differing cell shapes in a stratified or layered epithelial sheet. They are able to stretch and change forms
What is keratinized stratified squamous epithelium
Keratinized stratified squamous epithelium has the presence of tough keratin fibers in the squamous cell and contributes to the enhancement of productive qualities
Example of keratinized stratified squamous epithelium
Skin
What is nonkeratinized stratified squamous epithelium
Nonkeratinized stratified, squamous epithelium is free service is moist and it contains no keratin. It works with thick and thin.
Describe the two types of glandular epithelium
Exocrine
Endocrine
Exocrine glands- discharge their secretion products into ducts
Endocrine glands - often are called ductless glans, and discharge their secretion (hormones) directly into blood or interstitial fluid.
The four types of connective tissue
Fibrous, bone, cartilage, blood
Fibrous connective tissue
(Loose fibrous) arealor
Adipose -> fat tissue
Reticular
Dense
Aerolar - surrounds the internal organs, muscles, and blood vessels. It refers to bubbles that appear during dissection. Widely distributed
Adipose - contains adipocytes (fat cells), stores any excess calories for fuel and energy for the body
Reticular: web like/net like makes up internal framework of soft organs (liver, spleen, lymph)
Dense: Regular -> collagenous, common in ligaments and tendons. Irregular -> common in deeper layers of the skin (dermis) is supportive
Bone
Most rigid connective tissue, consists of inorganic salts (calcium and phosphorous) and protein fibers