Summary Biol 2220 - Exam 2 study guide

Anatomy and Physiology
BIO 2220
Dr. Cummings
Exam 2
Lecture Objectives

Tissues
Discuss the classifications of epithelial tissues—how and why they are classified as they are—
and the functions of each.
 Covering/lining
o Numbers of layers
 Simple = one layer; absorption and filtration; not a lot of friction
 Stratified = more than one layer of cells; exposed to friction; Naming is
based on shape of cells on apical surface
 Pseudostratified = only one layer, but looks like more than one, aren’t
exposed to a lot of movement; named by shape of cells on apical surface
o Shape
 Squamous
 Cuboidal
 Columnar
 Transitional
- Dome shaped cells
- Line hollow cavities
o Urinary bladder  dome shaped when bladder is empty,
flatten when bladder fills
 Glandular
o Number of cells
 Unicellular
 Multicellular
o Functional
 Merocrine
- Cells produce secretory product  packaged into a vescicle by
Golgi  released into duct by exocytosis product travels; cell
has not been damaged, stays active; salivary, sweat, pancreas
 Holocrine
- Cell produces product and stores it as an inclusion  cell
sloughed off into duct  bursts and releases contents  cell
dies; cell has died and is replaced by mitosis; sebaceous glands
Differentiate glandular epithelium from covering and lining epithelium.
 Covering and lining – all free body surfaces, anything exposed to the environment
 Glandular – one or more cells that produce and secrete a specific product

Define gland, and explain the difference between exocrine and endocrine glands.
 Gland – cell or group of cells of specialized epithelium that secrete substances into
ducts, onto surfaces or into the blood

, o Exocrine: secrete into a duct
 Sweat glands, gall bladder
o Endocrine: ductless, secrete hormones which travel in the bloodstream
 Thyroid
o The pancreas has an endocrine portion and an exocrine portion

List the different classes of connective tissue, and identify the structural elements possessed by
all classes.
 All connective comes from the mesenchyme (embryonic origin)
 All connective tissue possess cells and fibers embedded in a background of matrix
 Connective tissue proper
o Areolar, dense regular, elastic
 Cartilage
o Elastic cartilage, hyaline, fibrocartilage
 Bone
o Spongy and compact
 Blood

Compare and contrast the structure, location, and function of the three types of muscle tissue.
 Skeletal
o Striated
o Multiple nuclei
 Cells merge during embryonic development, nuclei are pushed toward
edges
o Voluntary
 Cardiac
o Striated
o Only one nucleus
o Involuntary
o Intercalated discs
 Communication junction between neighboring cells
 Channel proteins are fused with a gap junction  connexon
 Allows for heart cells to beat together
 Smooth
o No striations
o Only one nucleus
o Stretched nucleus
o Involuntary

Identify the criteria used to classify muscle tissue.
 Classification criteria
o Striations
o Nervous control
o Number of nuclei

,  Cells modified for contraction
 Provide movement and/or heat
 Sarcolemma = plasma membrane of a muscle cell; modified lipid bilayer
 Sarcoplasm = cytoplasm of a muscle cell

Identify the functional and supportive components of nervous tissue.
 Neurons
o Detect stimuli
o Stimulus energy  electrical energy (impulses)
o 50% of the tissue are neurons
 Neuroglia
o Other 50% of nervous tissue
o “Nerve glue”
o Supports and connects neurons

Membranes
Describe the structure and function of cutaneous, mucous, serous, and synovial membranes.
 Cutaneous – skin
o Keratinized stratified squamous epithelium
 Keratinized = accumulated protein keratin
 Cells start to protein keratin, cellular inclusion in squamous epithelium
cells
 Top layer is dead and full of keratin
o Attached to dense irregular connective tissue (underneath)
o Exposed to air
o “dry”
o Basale = germinal cells that are dividing
 Mucous – body cavities that are open to the external environment
o Most contain stratified squamous or simple columnar epithelium
o Attached to areolar connective tissue
o Line body cavities that are open to the exterior
o Moist  secretes mucus
o Absorption and secretion
 Serous – lining the insides of the body that are not open to the external environment
o Simple squamous epithelium resting on areolar connective tissue
o Line closed ventral body cavities
o Moist  secretes serous fluid
o Where leaked blood accumulates
o Hyaluronic acid = carbohydrate-rich secretion, water-based
 Combines with fluid from capillaries to produce a viscous fluid that
provides lubrication
 Allows cavity to slip around organs when moving to keep organs stable
o Double layered membrane
 Parietal = body cavity