Membrane Transport, Epithelial Tissues, and Connective Tissues (LECTURE #2) Flashcards
- maintains internal conditions of the cell
- communicates with the other cells
- described by the fluid mosaic model
The Plasma Membrane
The Plasma Membrane is divided into 5 groups:
1. Phospholipids
#2. Cholesterol
#3. Proteins
#4. Glycolipids
#5. Glycoproteins
- describes how the cell membrane is fluid, flexible, and made of many different components or macromolecules
- allows for the membrane to move with the cell and perform various functions, including maintaining homeostasis, facilitating cellular movement, communication, etc
Fluid Mosaic Model
__(1)__ = not solid
__(2)__ = many different types of macromolecules, embedded and attached
(1) = Fluid
(2) = Mosaic
forms a lipid bilayer in the plasma membrane
Phospholipids
maintains fluidity within the plasma membrane
Cholesterol
a group within the plasma membrane that is subdivided into 2 groups
Proteins
There are 2 types of proteins:
__(1)__ = extends through the lipid bilayer
__(2)__ = attaches to the surface
(1) = Integral Proteins
(2) = Peripheral Proteins
- lipids with a carbohydrate attached by a glycosidic (covalent) bond
- maintain the stability of the cell membrane and facilitate cellular recognition (which is very important in regards to immune response and in the connections that allow cells to connect to one another to form tissues)
Glycolipids
protein with a carbohydrate attached
Glycoprotein
allows some substances to pass through, but not others
Selective Permeability
With Selective Permeability;
- __(1)__ and __(2)__ soluble molecules can pass easily
- __(3)__ pass through moderately easily
- __(4)__ soluble molecules do NOT pass through
(1) = gases
(2) = small, fat
(3) = ions
(4) = large, water
What are the 2 types of transport processes?
1. Passive process
#2. Active process
involve substances moving across the cell membranes WITHOUT energy input
(via D I F F U S I O N)
Passive Transport
passive spread of particles, through random motion, from areas of high to low concentration
Diffusion
What are the 2 types of diffusion?
1. Simple diffusion
#2. Facilitated diffusion
pass without the aid of a membrane protein (unassisted)
Simple Diffusion
requires a carrier protein or channel (assisted)
Facilitated Diffusion
- usually refers to passive processes
- allows ions and molecules to move along their concentrated gradients (facilitated diffusion)
- “open” without changing shape
Channels
- similar to channels, BUT, they have a structural change when they move molecules from one side of the plasma membrane to the other
Carriers
the net movement of water through a selectively permeable membrane from an area of LOW solute concentration TO one of HIGHER solute concentration
Osmosis
Water can pass through the membrane in 2 ways:
__(1)__ = slower
__(2)__ = through an A Q U A P O R I N which is faster
(1) = Simple Diffusion
(2) = Facilitated Diffusion
Which type of diffusion provides a quicker path for water to pass through?
Facilitated Diffusion
protein channels in the plasma membrane allowing the passage of water
Aquaporins
a measure of the solution’s ability to change the volume of cells by altering their water content
Tonicity
Tonicity is broken down into 3 groups:
__(1)__ solution
__(2)__ solution
__(3)__ solution
(1) = Isotonic
(2) = Hypertonic
(3) = Hypotonic
interstitial fluid is the same concentration as cytosol
Isotonic Solution
interstitial fluid is less concentrated than cytosol
Hypotonic Solution
_______ = when the cell bursts
Lysis - aka - Hemolysis
interstitial fluid is more concentrated than cytosol
Hypertonic Solution
_______ = when the cell shrinks
Crenation
moves substances AGAINST their concentration gradient
Active Transport
Active Transport is a process that can be divided into 2 groups…
1, Primary
#2. Secondary
uses ATP (from mitochondria) for energy
Primary active trasnport
does NOT use ATP (uses another energy source)
Secondary active transport
Active Transport Process:
__(1)__ pump is found in all cells, which transports 3 __(2)__ OUT, and 2 __(3)__ INTO the cell. As a result, cells have __(4)__ [Na+], and __(5)__ [K+] inside the cell.
(1) = Na+/K+ Pump
(2) = Na+
(3) = K+
(4) = low
(5) = high
There are 2 Secondary Active Transport Mechanisms. What are they?
Antiporters and Symporters
carry 2 substances across the membrane in OPPOSITE directions
Antiporters
carry 2 substances across the membrane in the SAME direction
Symporters
connect adjacent cells mechanically
Intercellular Junctions
found where a leakproof seal is needed between cells (ex. bladder, stomach)
Tight Junctions
pores (connexons) that allow small substances (like ions) to pass between cells
Gap Junctions
the hemichannel supplied by a cell on one side of the junction
Connexons
provide resistance to mechanisms stress at a single point
Anchoring Junctions (Desmosomes)
- tightly packed cells
- no blood vessels
- form surface layers
Epithelial Tissue
- loosely packed, lots of extracellular matrix
- lots of blood vessels
- covered by other tissues
Connective Tissue
- line surfaces
- form protective barriers
- secrete mucous and hormones
- sense
- absorb
Epithelium
all epithelia have a __(1)__ surface and an __(2)__ surface
(1) = free apical
(2) = attached basal
Naming Epithelia according to SHAPE:
Simple __(1)__ Epithelium
Simple __(2)__ Epithelium
Simple __(3)__ Epithelium
(1) = Squamous
(2) = Cuboidal
(3) = Columnar
flat, wide “paving stone” cells
Simple Squamous Epithelium
cells that are as tall as they are wide
Simple Cuboidal Epithelium
cells taller than they are wide
Simple Columnar Epithelium
Naming Epithelia according to ARRANGEMENT:
__(1)__ Columnar Epithelium
__(2)__ Columnar Epithelium
__(3)__ Columnar Epithelium
(1) = Simple
(2) = Pseudostratified
(3) = Stratified
- 1 layer
- all cells are I N C O N T A C T with the basement membrane
Simple Columnar Epithelium
APPEARS to have layers, BUT, in reality, all cells go from the A P E X to the base
Pseudostratified Columnar Epithelium
- 2 or more layers
- ONLY the B A S A L layer is in contact with the basement membrane
Stratified Columnar Epithelium
STRUCTURE =
- single layer of flat (squamous) cells
FUNCTION =
- filtration
- diffusion
LOCATION =
- air sacs of lungs
- lining of the blood vessels, heart, lymphatic vessels, and all capillaries
Simple Squamous
STRUCTURE =
- single layer of cuboidal cells
FUNCTION =
- secretion
- absorption
LOCATION =
- lining tubules of the kidneys and glands
Simple Cuboidal
STRUCTURE =
- single layer of columnar cells
- NO CILIA ON THE MICROVILLI
FUNCTION =
- secretion
- absorption
LOCATION =
- line the gastrointestinal (GI) tract, and the gallbladder
Simple Columnar, Nonciliated
STRUCTURE =
- single layer of columnar cells
- microvilli HAVE cilia
FUNCTION =
- move mucous and foreign particles
LOCATION =
- line the bronchioles and the fallopian tubes
Simple Columnar, Ciliated
STRUCTURE =
- single layer of columnar cells
- nuclei at different levels
FUNCTION =
- secrete mucous
- absorption
- protection
LOCATION =
- upper respiratory tract
- male urethra
Pseudostratified Columnar
STRUCTURE =
- multiple layers of thin cells
FUNCTION =
- protect against strong friction forces and UV radiation
LOCATION =
- skin
- tongue
- mouth
- esophagus
- vagina
- cervix
Stratified Squamous
STRUCTURE =
- multiple layers of cuboidal cells
FUNCTION =
- protection
- SOME secretion
- SOME absorption
LOCATION =
- sweat glands
- part of the male urethra
Stratified Cuboidal
STRUCTURE =
- irregularly shaped basal layers
- apical layer has columnar cells
FUNCTION =
- protection
- secretion
LOCATION =
- some glands
Overall? Quite RARE.
Stratified Columnar
STRUCTURE =
appearance varies…
- changes shape depending on the state of stretch
FUNCTION =
- allows for stretch to hold variable amounts of liquid
LOCATION =
- urinary bladder
Transitional
an epithelial tissue involved in the production and release of different secretory hormones (ex. sweat, saliva, mucous, digestive enzymes, hormones, etc)
Glandular Epithelium
function for secretion
are categorized into 2 groups
Epithelial Glands
secrete contents directly INTO the blood
Endocrine Glands
secrete into a lumen or duct, then empty ONTO a surface (ex. skin)
Exocrine Glands
__(1)__ Tissues perform many different functions:
- __(2)__ tissues together
- __(3)__ and __(4)__ tissue
- protect and insulate __(5)__
- __(6)__ reserves and __(7)__ responses
- store __(8)__ and __(9)__
(1) = Connective
(2) = bind
(3) = support
(4) = strengthen
(5) = internal organs
(6) = energy
(7) = immune
(8) = adipocytes
(9) = calcium
__(1)__ Tissue is highly __(2)__ and suppled with many __(3)__ (exceptions are cartilage and tendons where there are little to no nerves).
(1) = Connective
(2) = vascular
(3) = nerves
In __(1)__ Tissues, cells are __(2)__ and surrounded by an __(3)__ (which consists of protein fibers and ground substance - this ground substance may be fluid, gelatinous, or solid).
(1) = Connective
(2) = scattered
(3) = extracellular matrix
What are the 5 cells that compose Connective Tissue?
1. fibroblasts
#2. chondrocytes
#3. adipocytes
#4. osteocytes
#5. white blood cells
- make up the majority of cells within connective tissue
- secrete protein fibers
Fibroblasts
found in cartilaginous connective tissue
Chondrocytes
store fats
Adipocytes
make bone
Osteocytes
found in blood
White Blood Cells
What are the 3 common fibers secreted by connective tissue?
1. Collagen fibers
#2. Elastin fibers
#3. Reticular fibers
- strong
- resist pulling
- NOT stiff
Collagen Fibers
strong, BUT CAN stretch
Elastin Fibers
- supportive
- mesh-like
Reticular Fibers
- Mesenchyme
- Mucous connective tissue
EMBRYONIC Connective Tissue
- Loose connective tissue
- Dense connective tissue
- Cartilage
- Bone
- Liquid
MATURE Connective Tissue
Loose Connective Tissue is divided in 3 categories:
1. Areolar connective tissue
#2. Adipose connective tissue
#3. Reticular connective tissue
Most abundant in the body!
STRUCTURE =
- viscous (sticky) ground substances
- lots of blood vessels
FUNCTION =
- strength
- protection
- support
LOCATION =
- attach skin to underlying tissues
- packing between muscles, nerves, etc
Areolar Connective Tissue
STRUCTURE =
- closely packed adipocytes
FUNCTION =
- reduces heat loss
- padding
- source of energy
LOCATION =
- subcutaneous (under the skin) layer
- surrounds organs
Adipose Connective Tissue
STRUCTURE =
- network of interlacing reticular fibers
- viscous ground substance
FUNCTION =
- forms a scaffolding (stroma, which is the supportive tissue of an epithelial organ, tumor, gonad, etc) to lymphatic organs (spleen and lymph nodes)
LOCATION =
- spleen
- lymph nodes
- bone marrow
Reticular Connective Tissue
Dense Connective Tissue is divided into 3 categories:
1. Dense Irregular connective tissue
#2. Dense Regular connective tissue
#3. Elastic connective tissue
STRUCTURE =
- fibroblasts and collagen fibers are RANDOMLY arranged
FUNCTION =
- provides strength from forces pulling in MULTIPLE directions
LOCATION =
- fascia
- periosteum
- dermis of skin
Dense Irregular Connective Tissue
STRUCTURE =
- fibroblasts and collagen fibers are REGULARLY arranged
FUNCTION =
- provides strength from forces pulling along ONE axis
LOCATION =
- tendons
- ligaments
Dense Regular Connective Tissue
STRUCTURE =
- fibroblasts
- freely branching elastic fibers
FUNCTION =
- allows stretching
LOCATION =
- lung tissue
- walls of elastic arteries
Elastic Connective Tissue
- collagen and elastic fibers in a gel-like substance
- has poor blood supply
- repair is slow
Cartilage
Cartilage is divided into 3 groups:
1. Hyaline cartilage
#2. Fibrocartilage
#3. Elastic cartilage
STRUCTURE =
- chondrocytes with collagen fibers and a gel-like substance
FUNCTION =
- provides a smooth surface for joint movement
LOCATION =
- end of long bones
- parts of ribs, nose, and trachea
Hyaline Cartilage
STRUCTURE =
- thick bundles of collagen fibers
FUNCTION =
- provides strength
- joint structures
- shock absorption
LOCATION =
- intervertebral discs
- menisci
Fibrocartilage
STRUCTURE =
- chondrocytes with elastic fibers
FUNCTION =
- strength
- elasticity
LOCATION =
- epiglottis
- external ear
Elastic Cartilage
a connective tissue with a calcified extracellular matrix
Bone
atypical liquid connective tissues
Blood & Lymph
used for movement
Muscular Tissues
Muscular Tissues are classified into 3 groups:
__(1)__ - heart
__(2)__ - movement of skeleton
__(3)__ - blood vessels and visceral
(1) = Cardiac
(2) = Skeletal
(3) = Smooth
generate electrical signals for communication
Nervous Tissues
consist of EPITHELEAL tissue and the CONNECTIVE tissue to which it is attached
Epithelial Membranes
- aka “Mucosa”
- composed of an epithelium and lamina propria that lines the body tracts (ex. respiratory) that open to the external environment
Mucous Membrane
a mesothelial tissue that lines certain internal cavities of the body, forming a smooth, transparent, two-layered membrane lubricated by a fluid derived from serum
Serous Membrane
- aka “skin”
- a soft covering that shields the underlying organs
Cutaneous Membrane
a specialized connective tissue that lines the inner surface of capsules of synovial joints and tendon sheaths
Synovial Membrane
