Week 2 Flashcards
What are the levels of organization
(1) organism, (2) system, (3) organ, (4) tissue, (5) cell, (6) organelle, (7) macromolecule, (8) molecule,( 9) atom
(large to small)
what is three main types of cell-cell connection?
tight junctions
- “leak-proof” barrier
desmosomes
- “sticky” glycoproteins, stick cells together
gap junctions
- protein channels, allow communication between cells
what are the 4 tissue types
epithelial, muscle, nervous, connective
explain secondary active transport
uses one concentration gradient as energy source for transport of something else
cotransport or symport- to go in same direction
counter-transport or anitport- to go in when other goes out
explain osmosis
diffusion of water down its concentration gradient (passive transport)
explain facilitated diffusion
Large water soluble molecules that use carrier protein (passive transport)
explain simple diffusion
When small lipid soluble molecules can pass through gaps in the phospholipid bilayer or small water soluble may diffuse through channel proteins (passive transport)
what are the 2 main transport types and describe them
Passive (diffusion)
- no energy required
- movement down concentration gradient
- eg.simple diffusion, facilitated diffusion, osmosis
Active
- requires energy
- movement against concentration gradient
- “typical” (across membrane) or exocytosis and endocytosis (vesicular transport)
what is a gradient?
A full difference between two adjoining regions higher in one area and lower and another
Relates to the movement across a membrane
what is diffusion?
net movement down a concentration gradient
what is exocytosis?
a type of vesicular transport that migrates to cells membrane and fuses to expel contents
what is endocytosis?
a type of vesicular transport
there is phagocytosis (solid particle engulfed) pinocytosis (dissolved particles engulfed e.g. liquid) and receptor mediated endocytosis which is specific
explain primary active transport
- can go against concentration gradient
- Na+ out K+ in ( sodium-potassium pump)
describe muscle tissue
- can contract and is responsible for movement
- three types are CARDIAC (striated, one nucleus/cell, under involuntary control), SMOOTH (not striated,one nucleus/ cell , under involuntary control) and SKELETAL (striated, many nuclei/cell, under voluntary control)
location: heart, attached to bones, hollow visceral organs
Describe nervous tissue
able to conduction action potential (an electrical signal)
made up of neurons (nerve cells) plus neuroglia (support cells)
Location: spinal cord, brain, nerves
describe epithelial tissue
location: lining chambers, tubes and surfaces
characteristics: little extra cellular matrix, has connective tissue under, nutrients from diffusion, replaces itself
functions: absorb and secrete, protection, barrier
Describe connective tissue
supports, protects, gives structure, stores fat
types are CT proper (loose and dense), CT fluid, (blood and lymph) CT supporting (bone and cartilage)
simple cuboidal epithelium
structure: Single, cube shaped, may have cilia or micro villi
function: secrete and absorb
location: in kidney tubules, thyroid gland, salivary gland
Simple squamous epithelium
Structure: single, thin layer of flat cells
Function: Allows passage of materials by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae. (Reduces distance and time of diffusion
Location: lining of lung aveoli and capilaries, lining of heart, blood vessels
Simple columnar epithelium
Structure: one layer, tall cells
Function: Absorption; secretion of in tubes and across large surfaces
Location: nonciliated type lines most of the digestive tract (stomach to anal canal), Eg. Intestines
Stratified squamous epithelium
Structure: Many layers of cells, apical cells appear flat: nuclei visible in apical layer non keratinized
Function: protects underlying tissues in areas subject to abrasion
Location: skin, lining of mouth, throat,esophagus, rectum, anus, vagina
Stratified cuboidal epithelium
Structure: Many layers, cube shaped spherical nuclei
Function: secretion and absorption in ducts and tubes
Location: Kidney tubules; ducts and secretory portions of small glands, ovary surface. Eg. Salivary gland, thyroid gland
Stratified columnar epithelium
Structure: many layers tall (apical)
Function: Protect and secrete
Location: male urethra, some ducks, larynx (only portions)
Transitional epithelium
Structure: multiple layers, appear puffy and cuboidal when relaxed but flat when stretched (cuboidal to Sqaumaous)
function: stretches readily and permits distension of urinary organ by contained urine
Location: lines the ureters, urinary bladder, and part of the urethra
Pseudostratified ciliated columnar epithelium
Structure: some looks layered but all cells contact basement membrane; nuclei do not line up neatly
Function: protects, secretes and moves material through passageways
Location: Lines nasal cavity, trachea, bronchioles, bronchi
Explain endocrine glands
They are ductless and produce hormones
Explain exocrine glands
Release secretions on body surface or body cavities
Unicellular: produce mucin, protect and lubricate
Multicellular: many types, made up of duct and secretory portion
Describe multicellular exocrine glands
Simple: duct no branches
Compound: branched duct tubular or acinar
Modes of secretion:
Merocrine- AKA. Eccrine exocytosis (cells are not altered)
Eg. Sweat glands, salivary glands, pancreas
Holocrine- acucumulate to rupture, while cell reaplaced
Eg. Oil glands
Apocrine- accumulate to pinch off
Eg. Not sure if in humans
Types of Connective tissue
Location: everywhere
types: CT proper – Areolar, adipose,reticular, dense regular, dense irregular, elastic.
Supporting CT - cartilage, bone
Fluid CT - Blood, lymph
Three main elements of connective tissue
Ground substance: “space filler” fluid helps connective tissue stick (part of ECM)
Fibres: Collagen (most abundant, strong) , elastic (long and thin, elastin proteins), reticular (shorter, sign, branch, support)
Cells: Can secrete the fibres and ground substance
Areolar tissue
CT proper: loose
Structure: gel like, three fibre types
function: cushions, holds body fluid, helps to fight infection (houses macrophages)
location: around most organs and get pillories
e.g.Under dermis, digestive tract
Adipose tissue
CT proper: loose
structure: adipocytes closely packed with large fat droplets
function: stores energy, insulation, supports and protects
location: under skin, around eyes, breast, butt
Reticular tissue
CT proper: loose
structure: network of reticular fibres
function: provide “skeleton” to support other cell types
location: lymphoid organs
e.g. spleen, lymph nodes, bone marrow
Dense regular tissue
CTproper: dense
Structure: Parallel collagen fibers; some elastin
Fibroblast = main cell type
Location: tendons, most ligaments
Function: provides very high tensile strength when pulled in one direction
Dense Irregular tissue
CT proper: dense
Structure: Irregularly arranged collagen fibers, some elastin
Fibroblast = main cell type
Location: in dermis of skin, submucosa of gut, fibrous capsules of joints, etc.
Function: can withstand pulling in many directions (not just one)
Elastic tissue
CT proper: dense
structure: Similar to dense regular or irregular CT, but with LOTS of elastic fibers
Location: supporting ligaments in spinal column and penis, plus transitional epithelium
Also in walls of some large blood vessels (e.g., aorta)
Function: Strong, but also allows for flexibility (stretch and recoil)
Blood
Fluid CT
Structure: Many types of blood cells, surrounded by a fluid matrix (plasma)
Functions: Transport of nutrients, wastes, etc.
Also: lymph (another type of fluid CT)
Hyaline cartilage Connective tissue
Structure: EYES, lots of collagen
Functions: support, cushioning
Example locations: embryonic skeleton, ends of long bones (=articular cartilages), costal cartilages of ribs; also in parts of your nose, trachea, and larynx
Elastic Cartilage connective tissue
Structure:Similar to hyaline cartilage, but with more elastic fibers
Function: Can hold its shape and be very flexible
location: In your external ear and your epiglottis
Fibrocatilage connective tissue (fibrous)
Structure: Similar to hyaline cartilage, but matrix is less firm
Lots of collagen fibers; different arrangement than in hyaline cartilage
Function: Good for absorbing shock.
Location: Intervertebral discs, pubic symphysis, menisci of knee joint
Compact bone connective tissue
Structure: Hardness (mineralized matrix) to resist compression stress,many collagen fibres
Function: provide support and protection
Location: diaphysis of long bones/ surfaces
Spongy bone connective tissue
Structure: strong, mineralize fibres with spaces for bone marrow
Function: with stand stress from many directions, red s is a way of skeleton and forms framework,develops blood cells in bone marrow
Location: forms happy faces of long bones and inside flat irregular bones
