Midterm Flashcards
4 types of tissues
Epithelial, Connective, Muscular, Nervous
Types of intercellular junctions
Tight, adherens, desmosomes, hemidesmosomes, gap
Tight intercellular junction
Inhibit passage of substance between cells and prevents leakage from the organs such as stomach and urinary bladder
Adherens junction
Helps resist separation during contractile activities like peristalsis in the GI tract
Desmosomes junction
Prevents epithelial cells from getting separated under tension and cardiac muscle cells from pulling apart during contraction
Hemidesmosomes junction
Helps anchor cells to the basement membrane
Gap junction
Seen in nerve and muscle cells where the cells transmit electrical signals
Epithelial tissue
Cells (many) are densely packed with little to no ECM
Tissue is avascular
They form covering and lining layer and not covered by other tissues
Provides protection, carries out filtration, secretion, absorption, and excretion
Connective tissue
Fewer cells separated by lots of ECM
Most connective tissues are highly vascular
They bind cells within tissues and compartmentalizes organs like skeletal muscles
It protects, supports, and strengthens other body tissues and insulate internal organs
On what basis are the covering and lining epithelia classified?
- Arrangement of cell layers, and
- Shape of their cells
Cell layers
Simple, Pseudostratified, and Stratified
Shape of cells
Squamous, Cuboidal, and Columnar
Simple squamous
one row of flat cells – Endothelium, Mesothelium, Alveoli (air sacs)
stratified squamous
multilayered – non-keratinized (mouth); keratinized (epidermis of skin)
Simple cuboidal
one layer of cube-like cells - kidneys), stratified cuboidal (sweat glands)
Simple columnar
one row of tall, column-like cells - GI tract organs like stomach and intestines
pseudostratified columnar
may be ciliated like in the respiratory tract organs like trachea, stratified columnar (rare – male urethra)
Endocrine glands
ductless and secrete hormones into the interstitial fluid and then transported in the blood. E.g., Pituitary gland, Thyroid gland, Adrenal gland
Exocrine glands
have ducts to carry their secretions on to the body surface. E.g., Salivary gland, Sweat gland, Mammary glands
Simple tubular
Large intestinal glands
Simple branched tubular
Gastric glands of the stomach
Simple coiled tubular
Sweat glands
Simple acinar
Penile urethral glands
Simple branched acinar
Sebaceous glands