A+P Flashcards
***Four Types of Human Tissue
(1) Muscle Tissue
(2) Nervous Tissue
(3) Epithelial tissue
(4) Connective Tissue
Functions/characteristics of Muscle Tissue
(a) Generates the physical force to make the body structures move
(b) Arranged in bundles
(c) Contractile cells that provide the ability to move the body in three dimensions
(d) Well supplied with blood vessels (lots of energy & waste requirements).
Functions/characteristics
of Nervous Tissue
(a) Detects changes inside/outside the body
(b) Initiates & transmits nerve impulses that coordinate body
*** Functions/characteristics of Epithelial tissue
(a) Integumentary System
(b) Epithelium:
(c) Epithelial Tissue:
Functions/characteristics
of Connective Tissue
(a) Protects and supports the body and its organs
(b) Binds organs together
(c) Stores energy reserves as fat
(d) Provides immunity
1) Skin, Hair, Nails
2) Accessory Structures
Integumentary System
1) Medical term for skin and main portion of the integumentary system.
Epithelium:
1) Covers body surfaces; lines body cavities, hollow organs and ducts (tubes); and forms glands
(c) Epithelial Tissue:
(1) They provide contact or adhesion between neighboring cells or between a cell and extracellular matrix.
(2) They maintain paracellular barrier of epithelia (barrier in between cells) and control transport of materials or signals between cells (paracellular transport).
(3) Cell junctions are dense in epithelial tissues because the tissue needs to maintain both
strength and integrity in a wide variety of conditions.
Cell Junction
Form barrier against water and antigens passing between individual epithelial cells
Tight Junctions
Cell-cell adhesions continuously assembled & disassembled so cells can respond changes in their microenvironment.
Adherens Junctions
Form stable adhesive junctions between cells.
Desmosomes
Allows various molecules & electrical signals to pass freely between cells
Gap Junctions
Facilitate the stable adhesion of basal epithelial cells to the underlying basement membrane.
Hemidesmosomes
***Epithelial tissue is broadly categorized as either:
(a) Covering and lining epithelium
(b) Glandular epithelium
Covering and lining epithelium:
(a) Covers external surfaces of the body and some internal organs
(b) Lines body cavities, blood vessels, and ducts
(c) Lines interior of respiratory, GI, urinary and reproductive systems
(d) Integral part of sense organs for hearing, vision and touch
Secreting portion of the glands, such as sweat glands
Glandular epithelium
***Most superficial layer of cells
Apical
***Deepest layer of the cell
Basal
- **(a) Thin extracellular structure composed mostly of protein fibers
- **(b) Located between the epithelium and underlying connective tissue layer
- **(c) Helps to bind and support the epithelium
Basement membrane
2 ways of classifying epithelial tissue:
Morphology
Stratification
Classification of epithelial cells based on shape
Morphology
Classification of epithelial cells based on number of layers
Stratification
***Shaped like pancakes
Squamous
***Shaped like the tesseract in Captain America
Cuboidal
***Shaped like the column block in Tetris
Columnar
***Changes shape like the T-1000 in T2: Judgement Day
Transitional
- **(1) Thin, flat shape allows rapid passage of substances through them
(2) Can be keratinized or non-keratinized; “wet” or “dry” depending on their location in the body
(3) Found in areas such as the lining of the esophagus, mouth and cervix
Squamous Epithelium
(1) Tall as they are wide and shaped like cubes or hexagons
(2) Frequently have microvilli at apical surface
(3) Function in either secretion or absorption
(4) Found in areas such as the salivary glands and thyroid follicles
Cuboidal Epithelium
(1) Taller than they are wide
(2) Protect underlying tissues
(3) Apical surfaces may have cilia or microvilli
(4) Often specialized for secretion and absorption
(5) Lines most organs of the GI tract, respiratory tract, and fallopian tubes
Columnar epithelium
(1) Able to change shape from flat to cuboidal and back depending on tension & distention of tissue.
* **(2) Useful for organs such as the urinary bladder, when it is stretching (distend) to a larger size and then as it collapses to a smaller size.
Transitional Epithelium
**(1) A single layer of cells that functions in a diffusion, osmosis, filtration, secretion and absorption.
**(2) Secretion: production and release of substances
**(3) Absorption: intake of fluids or other substances
**(4) Osmosis: movement of water across a semipermeable membrane from an area of lower
solute concentration to an area of higher solute concentration.
***(5) Diffusion: movement of particles from an area of high concentration to an area of low Concentration
Simple Epithelium
- **(1) Pseudo (false) stratified (layered)
- **(2) It is simple epithelium that appears be stratified because the nuclei lie at different levels & not all cells reach the apical surface.
- **(3) However, it is still simple epithelium because all the cells rest on the basement membrane.
(a) Cells that extend to the apical surface may contain cilia - **(4) One specialized type of pseudostratified cell are goblet cells, which secrete mucus and are an integral part of mucous membranes.
Pseudostratified Epithelium
(1) Cilia provide two forms of locomotion depending on the cell:
(a) Movement of the cell itself (like bacteria) or some parasites ***
(b) Movement of particles or substances across or around the cell
(2) In mammals, cilia help remove contaminants or move particles by moving fluids over the cell layers.
(a) The lining of the nasopharynx and the trachea are covered in cilia to remove mucus, bacteria, and other debris from the lungs.
(b) Fallopian tubes are lined with cilia to assist in helping fertilization by moving the egg towards the uterus.
Ciliated Epithelial Cells
1) increase the surface area of a cell by multiplying the area from 2 dimensions to 3
dimensions. **
(2) on cellular surfaces enable the absorption and secretion of far more nutrients/material because they expand the active surface area by orders of magnitude.
(3) Other uses:
(a) Help anchor sperm to the egg and allow for easier fertilization.
(b) In white blood cells, ___ act as an anchoring point and aid in the migration of white blood cells.
(c) ___on other cell surfaces may sweep unwanted materials toward an absorptive area of the cell.
Microvilli on Epithelial Cells
a highly-insoluble fibrous protein with water-proofing qualities & high friction resistance.
Keratin
Epithelial cells infused with keratin in the stratum basale of the epidermis are called
Keratinocytes
Keratinocytes lose their nucleus and organelles to make room for keratin. Are they still living
No
Keratinized or non-keratinized:
(a) Found on wet/interior surfaces exposed to considerable wear & tear.
(b) Found in the lining of mouth cavity, tongue, pharynx, esophagus and vagina.
Non-keratinized epithelium
Keratinized or non-keratinized:
(a) Found on dry/outer surfaces where resistance to both friction & water is needed.
(b) Outer epidermis consists of keratinocytes that provide protection against water, friction,
abrasion, and microorganisms.
Keratinized stratified epithelium
(1) Supports & physically connects other tissues/cells together to form the organs of the body.
Connective Tissue
↑ cells ↓ extracellular space (matrix)
Epithelial
↓ cells ↑ extracellular space (matrix)
Connective
Connective tissues typically have three components:
(a) Resident Cells
(b) Extracellular Matrix (ECM)
(c) Protein fibers
extracellular material produced by the connective tissue cells embedded within it
Matrix
Major component of the matrix is
ground substance crisscrossed by protein fibers
CT CELLS
(1) Most common cells in connective tissue
(2) Produce & maintain most of the tissue’s extracellular components
(3) Synthesizes & secretes collagen** and elastin
(4) Major component of the reparative capacity of connective tissue
Fibroblasts
CT CELLS
(1) AKA fat cells or adipose cells or adipose tissue
(2) Specialized for cytoplasmic storage of lipid as neutral fats, or less commonly for production of heat. ***
(3) Large population of adipocytes (adipose connective tissue) serves to cushion and insulate the skin and other organs.
Adipocytes
CT CELLS
(1) Components of loose connective tissues, often located near small blood vessels in the skin.
(2) Function in localized release of compounds important to inflammatory response, innate immunity, and tissue repair.***
Mast Cells
CT CELLS
(1) Abundant (25% of all protein in body) ***
(2) Very strong and resistant to shear forces
(3) Key element of all connective tissues, as well as epithelial basement membranes
Collagen Fibers
CT CELLS
(1) Composed of elastin
(2) Strength and elasticity
(3) Have rubberlike properties that allow tissue containing these fibers to be stretched or distended and return to their original shape.
Elastic Fibers
CT CELLS
(1) Compromised of glycogen and glycoprotein (2) Provide strength and support in the walls of small blood vessels **
(3) Stroma supporting framework of many soft organs; most notably the immune system, liver, endocrine glands, spleen, lymph nodes
Reticular Fibers
(1) Line entire GI, respiratory, reproductive, and much of the urinary system.
(2) Epithelial layer secretes mucous (mucin) via goblet cells.
Mucous Membranes
Mucous Membrane functions:
(a) General: Prevents cavities from drying out
(b) Resp: traps particles in the respiratory tract
(c) GI: lubricates and absorbs food as it moves through the tract, secretes digestive enzymes
(d) Derm: helps bind the epithelium to underlying structures
Lines body cavity that doesn’t open directly to exterior & covers organs that lie within the cavity.
Serous Membranes
Serous Membranes
Attached to cavity wall
Parietal
Serous Membranes
Part that covers and attaches to the organs
Visceral
Serous Membranes
Secretes serous fluid and provides lubrication for organ movement
Mesothelium
Serous Membranes
Lining thoracic cavity and covering the lungs.
Pleura
Serous Membranes
Lining the heart cavity and covering the heart.
Pericardium