Lecture #7 Chapter 5 Flashcards
What is histology?
The study of tissues
What is a cell?
The structural and functional unit of an organism
What is a tissue?
A group of cells that performs a specialized function
What is the biological organization of an organism?
Atom – molecule – macromolecule – organelle – cells – tissues – organ – organ system – organism
What are the three types of intercellular junctions?
Tight junction, desmosome, and gap junction
Why are cells packed with intercellular junctions?
To connect their cell membranes and allow them to interact
What is a tight junction?
When membranes of adjacent cells converge and fuse such as in the digestive tract
What is a desmosome?
Rivets/spot welds such as skin cells
What is a gap junction?
Junctions interconnected by tubular channels such as heart muscles
What is the function of intracellular junctions?
Communication
What are the four major types of tissue?
Epithelial, connective, muscle, and nervous tissue
What is the function of nervous tissue?
Internal communication
What are three examples of nervous tissue?
Brain, spinal cord, and nerves
What is the function of muscle tissue?
Contracts to cause movement
What are the three types of muscle tissue?
Skeletal which attaches bones, cardiac which is the muscles of the heart, and smooth which is the muscle walls of hollow organs
What are the 6 functions of epithelial tissue?
Covers, lines, protects, absorbs, secretes, and filters/diffusers
Forms boundaries between different environments
What are the three functions of connective tissue?
Supports, protects, and binds other tissues together
What are three examples of connective tissue?
Bones, tendons, and fat
What are six characteristics that the different epithelial tissues have in common?
A basement membrane which anchors it to the lower surface, sides joined by junctional desmosomes, a minimal matrix with tightly packed cells, avascular, rapidly dividing, and always containing an apical surface
What are the three classifications of epithelial tissue based on shape?
Squamous which is flattened irregular scale like cells, cuboidal which is cubed shaped cells, and columnar which is rectangular cells
What are the three classifications of epithelial tissue based on arrangement?
Simple which is one layer thick, stratified which is more than one layer, and pseudostratified which appears to be more than one layer but where all the cells reach the basement membrane
What is the function/characteristics of simple squamous epithelium?
It is thin and delicate so easily damaged but common outside of diffusion and filtration. Such as air sacs in the lungs were carbon dioxide and oxygen are exchanged
What is a lumen?
A hollow channel
What is the function of simple cuboidal epithelium?
It lines follicles of the thyroid gland, covers ovaries, lines kidney tubules and ducts. It faces the lumen
What are two types of simple columnar epithelium?
Ciliated or non-ciliated
What is the function of ciliated simple columnar epithelium?
It can move the oocyte through the uterine tube
What is the function of non-ciliated simple columnar epithelium?
Lines the digestive track, secretes digestive fluids, and absorbs nutrients
What can connective tissue be thought of as?
Packing tissue
What are characteristics and functions of pseudostratified columnar epithelium?
They commonly have cilia in line the passages of the respiratory system. This allows the cilia to move mucus and captured particles up and out of airways
Why are characteristics/functions of stratified squamous epithelium?
Cells near the surface are flattened the most, it is relatively strong, and comprises the epidermidis and lines the oral cavity and a esophagus
What does stratified cuboidal epithelium do?
Lines the ducts of mammary glands, sweat glands, salivary glands, and pancreas
What is the role of stratified columnar epithelium?
Found in part of the male urethra and lining of the large ducts of exocrine glands
What is transitional epithelium?
Many layers of cubed shaped and elongated cells that are stretchable
What are the five functions of connective tissue?
Binds/Connects, protects, supports, stores energy reserves, and body defense/immunity
What are the four common characteristics of connective tissue?
Abundance of matrix between cells, fibers, vascularity, and a variety of cell types
What are the three structural elements of connective tissue?
Ground substance which is unstructured material that fills space between cells, fibers, and cells
What are the three types of connective tissue fibers?
Collagen, elastic fibers, and reticular
What are characteristics of collagen?
The strongest and most abundant type of fiber which is tough and provides high tensile strength
What are the characteristics of elastic fibers?
Networks of long, thin, elastin fibers that allow for stretch and recoil