Chapter 4: Histology (Part 1)

Nervous Tissue Function

receive, process, and transmit nerve processes; glial cells protect, nourish, and support neurons

What are the three muscle tissues?

Skeletal, Cardiac, Smooth

What cells do nervous tissue have?

Neurons and glial cells

Neurons

nerve cells capable of initiating/conducting electrical activity

Neuroglial (Glial) Cells

cells supporting, nourishing, and protecting neurons

Skeletal Muscle Tissue Location

attached to bones or sometimes skin; forms external urethral and anal sphincters

Smooth Muscle Tissue Location

Walls of hollow internal organs: intestines, stomach, airways, urinary bladder, uterus, blood vessels; eye’s iris

Epithelial Tissue Location and does it have ECM?

lines/covers body surfaces, cavities, and organs; only cells, no ECM

Epithelial Tissue Functions

selective permeability, secretion, physical protection

Epithelial Tissue Characteristics

cellularity, polarity, avascularity, innervation, high regeneration capacity, basement membrane attachment

Connective Tissue (CT) and does it have ECM?

fills/connects body tissue; has ECM

Type of Cell Connections

tight junctions, desmosomes, gap junctions

Tight Junctions

makes spaces between cells impermeable

Desmosomes

increase tissue resistance to mechanical stress

Gap Junctions

allow small substances to pass between cells

Simple Squamous Epithelial Tissue Location and Funciton

alveoli; lining of lumen of blood/lymph vessel, serous membranes of body cavities
allows filtration/diffusion; secretion in serous membranes

Simple Cuboidal Epithelial Tissue Location and Function

kidney tubules, thyroid gland follicles; ovary surface; secretory region and ducts of most glands and small ducts;

absorption/secretion

Simple Columnar Epithelial Tissue Location and Function

inner lining of most of digestive tract
absorption/secretion; secretion of mucin

(Non-keratinized) Stratified Squamous Epithelial Tissue Location and Function

lining of oral cavity, part of larynx/pharynx, esophagus, vagina, and anus
protects underlying tissue from abrasions

Stratified Cuboidal Epithelium Location and Function

ducts of most exocrine glands and ovarian follicles;
protection and secretion

(Ciliated) Pseudostratified Columnar Epithelium Location and Function

lining of larger airways of respiratory tract: nasal cavity, pharynx, parts of larynx, trachea, and bronchi
protection; mucin secretion and cilia move mucus along apical surface of epithelium

Stratified Columnar Epithelium Location and Function

salivary gland ducts; lining parts of male urethra and epididymis (rare)
protection

Transitional Epithelium Location and Functions

lines bladder, ureters, and part of urethra
accommodates urine volume changes in bladder/ureters

Glands Function

secretion: mucin, hormones, enzymes and waste products

Gland Categories

Exocrine and Endocrine

What do Exocrine Glands possess?

ducts and secretory portion (acini)

Endocrine Glands

no ducts, secretes directly into interstitial fluid or bloodstream

Endothelium

lumen lining of blood and lymph vessels

Mesothelium

serous membranes of body cavities

Alveoli

air sacs in lungs