Chapter 5 Flashcards
What are the 3 types of intracellular junctions?
Tight junction, desmosome, and gap junction
Describe a tight junction?
When the membranes of adjacent cells merge and fuse such as those of the digestive tract and blood vessels
Describe a desmosome?
When cells connect via rivets/spot welds such as skin cells
Describe a gap junction?
Cells that are connected by tubular channels such as those of the heart muscle and some of muscle of the digestive tract
What are 3 the types of epithelial tissue by shape?
Squamous, cuboidal, columnar
Describe squamous epithelial tissue?
Flattened, irregular, & scale-like cells
Describe cuboidal epithelial tissue?
Cubed shaped cells
Describe columnar epithelial tissue?
Rectangular cells
Types of epithelial tissue by arrangement?
Simple, stratified, and pseudostratified
Describe simple epithelial tissue?
One layer thick
Describe stratified epithelial tissue?
More than one layer thick
Describe pseudostratified epithelial tissue?
Appears to be more than one layer, but all the cells reach the basement membrane
What are the 7 functions of epithelial tissue?
Cover
Line
Protect
Absorb
Secrete
Filter
Diffuse
What are the 6 characteristics that epithelial tissues have in common?
Basement membrane
Rapidly dividing
Avascular
Sides joined by junctional desmosomes
Minimal matrix-cells tightly packed together
Apical surface
Function and location of simple squamous epithelium?
Diffusion and filtration as in the air sacs of the lungs and the walls of capillaries
Function and location of simple cuboidal epithelium?
Lines follicles of the thyroid gland, covers ovaries, and lines kidney tubules and ducts where it faces the lumen
Two types of simple columnar epithelium?
CIliated and non-ciliated
Function and location of ciliated simple columnar epithelium?
Lines uterine tube where it moves oocyte to the uterus
Function and location of non-ciliated simple columnar epithelium?
Secretes digestive fluid and absorbs nutrients in the digestive tract
Function and location and pseudostratified columnar epithelium?
Commonly have cilia so they can move mucus and captured particles up and out of airways in the passages of the respiratory system
Function and location stratified squamous epithelium?
Form outer layer of skin and line oral cavity, esophagus, vagina, and anal canal
Function and location of stratified cuboidal epithelium?
Lines the ducts of mammary glands, sweat glands, salivary glands, and pancreas
Function and location stratified columnar epithelium?
lines large ducts of exocrine glands and lines male urethra
What is a goblet cell?
Specialized flask-shaped epithelial cell scattered among simple columnar epithelium specialized to secrete mucin which forms mucous
Describe cilia and their function?
Sensory organs that provide movement for substances outside the cell
What is the role of cilia in simple columnar epithelium?
Move oocyte through the uterine tube
Describe microvilli and their function?
Cylindrical processes that increase the surface area of the cell membranes where it is exposed to substances being absorbed
Describe the keratinization process?
In stratified squamous epithelium older cells push outward. During this, they accumulate proteins called keratins. Then the cells harden and die. This produces a tough, dry, protective material.
Process of hardening, dehydration, and keratin accumulation that occurs in epidermal cells as they migrate outward
What is glandular epithelium?
Composed of cells specialized to produce and secrete substances into ducts or into body fluids. Usually found within columnar or cuboidal epithelium.
Two major types of glandular epithelium?
Exocrine and endocrine
Three types of exocrine glands?
Merocrine/eccrine glands, apocrine glands, and holocrine glands
What products do eccrine/merocrine glands secrete?
Secrete fluid products via exocytosis
What products do apocrine glands secrete?
Glands that lose small portions of their glandular cell body
What products do holocrine glands secrete?
Release entire cells
What are the three cell types of connective tissue?
Fibroblasts, mast cells, and macrophages
Describe fibroblasts?
A type of fixed cell that is large and star-shaped
Helps to repair tissue with poor ability to regenerate (i.e. heart) and respond to injury by increasing in number and fiber production
Describe mast cells?
A type of fixed cell that resides near blood vessels
They release heparin which prevents blood clotting and release histamine which stimulates inflammation
Describe macrophages?
A type of wandering cell that originates as a white blood cell
They are scavenger cells that perform phagocytosis to clear foreign particles
What are the three types of CT fibers?
Collagen, elastic, and reticular
Describe collagen fibers?
The strongest and most abundent type of fiber that provides high tensile strength
Describe elastic fibers?
Networks of long, thin, elastin fibers that allow for stretch and recoil
Describe reticular fibers?
Short, fine, highly branched collagenous fibers with different chemistry than collagen fibers that form supportive networks that offer “give”
What is the difference between “blast” cells and “cyte” cells?
Blast cells are immature (baby) cells that are mitotically active and secrete ground substance and fibers
Cyte cells are mature and maintain matrix
What are the different cells in CT?
Fibro (CT proper), Chondro (cartilage), and Osteo (bone)
Chondrocytes vs chondroblasts?
Chondrocytes are mature cartilage cells that perform maintenance while chondroblast are immature cells that secrete extracellular matrix
What are the 3 types of cartilage?
Hyaline cartilage
Fibrocartilage
Elastic cartilage
Describe hyaline cartilage?
Most common type of cartilage found on the ends of bones in joints and throughout the skeleton
Chondrocytes in spaces called lacunae with invisible fibers present
Describe elastic cartilage?
Provides the framework for external ears and parts of the larynx
Chrondrocytes in spaces called lacunae with visible elastic fibers
Describe fibrocartilage?
A very tough tissue that acts as a shock absorber with many collagen fibers
Chondrocytes in lacunae with visible dense collagen fibers
Describe the structure of compact bone?
Osteoblasts deposit bony matrix in layers called lamellae (rings of a tree). These layers form concentric patterns around longitudinal tubes called the central/Haversian canal which contain blood vessels. Osteocytes (osteoblast trapped in lacunae) are evenly spaced throughout the lamellae. Osteocytes are connected by canaliculi so nutrients can pass through. All this forms a cylindrical unit called an osteon which is the functional unit of compact bone.
Describe the structure of spongy bone?
Consists of branching plates called trabeculae which is bone matrix deposited around osteocytes connecting them
How does connective tissue help in immunity?
White blood cells, which are a type of connective tissue, are wondering cells that pass through capillaries and attack unknown substances throughout the body. (Phagocytosis)
What are the epithelial membranes?
Cutaneous, mucous, serous, and synovial
Describe the cutaneous membrane?
The skin
Describe the mucous membrane?
Lines cavitites and tubes that open to the outside of the body such as the oral and nasal cavities, and the tubes of the digestive, respiratory, urinary, and reproductive systems
Describe the serous membrane?
A membrane that lines body cavities that do not open to the outside. They reduce friction between organs and cavity walls by secreting a watery serous fluid. Made up simple squamous and areolar tissue.
What are the different serous membranes?
Parietal pleura-lines the thorax
Parietal peritoneum-lines the abdomen
Visceral pleura-lines organs in the thorax
Visceral peritoneum-lines organs in the abdomen
Describe the synovial membrane?
Composed of connective tissue that lines joints
What are the three types of muscle tissue?
Skeletal
Cardiac
Smooth
Describe skeletal muscle?
Multinucleated cell made of long, non-branching, striated fibers
Attached to the skeleton for voluntary movement
Describe cardiac muscle?
Branching, striated cells joined by intercalated discs and with a centrally located nucleous
Makes up the wall of the heart and is involuntary
Describe smooth muscle?
Smooth, non-striated, elngated, spindle shaped cells witha centrally located nucleus
Makes up the walls of internal organs and blood vessels and is invuluntary
What is the function of nerve tissue?
Able to detect changes in the environment and initiate responses
What are the two catagories of nerve tissue?
Neurons and neuroglia
Describe neurons?
A nerve cell or conducting cell
Describe neuroglia?
Protective and suppoting cells
What are the 4 types of neuroglia in the CNS?
Astrocytes
Oligodendrocytes
Microglia
Ependymal cell
What athe the 2 types of neuroglia in the PNS?
Satellite cell (ganglionic gliocyte)
Schwann cell (neurolemmocyte)
3 funcitons of astrocytes?
Support, ionic buffering, and blood-brain-barrier
Function of oligodendrocytes?
Form myelin
Function of microglia?
Phagocytes cellular debris
Function of ependymal cell?
Line ventricles
Characteristic of ependymal cell?
ciliated
Function of satellite cells?
Support
Function of Schwan cells?
Form myelin
