Unit 1 Flashcards
What are the 6 levels of organization?
- Chemical
- Cellular
- Tissue
- Organ
- Organ System
- Organismal
What is integument?
- Includes skin, hair, nails, etc.
- forms the border between the organism and the environment (can be internal and external)
- site of many sensory receptors
- highly variable composite organ (layers)
Functions of Integument (9)
- prevents entrance of pathogens
- resists mechanical injury
- aids in gas exchange
- aids in thermoregulation
- supports sensory receptors
- gives rise to teeth
- produces secretory glands
- balances salt/water
-provides basis for claws, horns, etc.
AND MORE!!!
Tissue
collection of cells and extracellular material that perform a specific or limited range of functions
4 Types of Tissue
- Epithelial
- Connection
- Muscle
- Nervous
Epithelial Tissue
An avascular layer of cells covering internal or external surfaces
(surfaces of the body, lines internal cavities/passageways, forms certain glands)
- has high rates of growth (common for cancer)
Role of Epithelial Tissue (4)
- Physical Protection
- Permeability Control
- Sensation Trigger
- Specialized Secretions
ecto-
“outer”
meso-
“middle”
endo-
“inner”
Anatomy
“to cut apart” ~ a process
- ideals with the structural organization of living things
- tied to developmental, embryological, histological, and historical studies
“form dictates function dictates form”
Aspects of Biology Dictated by Surface Area to Volume Ratio
- neurons
- digestion (intestines)
- hibernation
- baby heads
- cutaneous breathing
- intestinal villi
Modulators of Diffusion
- distance
- particle size
- temperature
- concentration gradient
Why are baby heads so big?
Need big brain to survive so the size of the brain is optimizes in the least possible surface area
- increase exchange
- birthing now is as simple as it can be
Surface Area (SA) to Volume (V) Ratio does what?
Facilitates rate of exchange
- As V increases, relative SA decreases therefore substrate for exchange in reactions decreases
- want a higher SA:V ratio ~ occurs with smaller volume (ex: alveoli)
How to maximize exchange rate?
- Want thin layers (less distance to travel across)
- Concentration gradient
- Pressure gradient (b/c diffusion occurs too slow)
Pressure-Volume Relationships
If V increase, Pressure decreases
If V decreases, Pressure increases
3 Types of Epithelial Tissue (shapes)
Squamous
Cuboidal
Columnar
Layer Naming
Single Layer - Simple
Multiple Layers - Stratified
Columnar can also be “pseudostratified”
lumen
“inside”
vascular
“blood supply”
basal
“basement” or “bottom”
apical
“outermost” surface
Role of Simple Squamous Epithelial Tissue
Lining surfaces