Fundamentals of Anatomy & Physiology: A & P Chapter 3 Flashcards
College: First year, College: Second year, College: Third year, College: Fourth year
Cell
smallest living unit
In human body:
~75 trillion cells
~200 different types
2μm-1m (average 50μm)
Metabolic turnover
lets your body grow, change, and adapt to new conditions and activities Your body recycles and renews all of its chemical components at intervals ranging from minutes to years
Cellular Organization
1. shapes, 2. function, 3.plasma membrane, 4.cytoplasm, 5.cytosol, 6.organelles, 7.interstitial fluid
shapes
Different cells have different shapes
function
Unique morphology is related to function
plasma membrane
All cells surrounded by plasma membrane:
–Separates cells from the environment
cytoplasm
Plasma membrane “holds in” the cytoplasm
cytosol/organelles
Cytoplasm consists of cytosol (fluid) and organelles (structures)
interstitial fluid
Body cells surrounded by interstitial fluid
– Interstitial fluid = fluid outside the membrane
Cell Types
Different cells have different shapes and their unique morphology is related to unique function
Somatic cells
all body cells except sex cells
Common Characteristics of All Eukaryotic Cells
-Cells are the building blocks of all plants and animals
- All cells come from the division of preexisting cells
-Cells are the smallest units that perform all vital physiological functions
-Each cell maintains homeostasis at the cellular level
The Plasma membrane-Functions
-Physical barrier to maintain homeostasis: separates intracellular fluid (cytosol) from extracellular fluid (iterstitial fluid)
-different conditions in each
-Regulates exchange with extracellular environment
-Provides sensitivity: cell communication and
signaling
-Provides structural support: attachment site
to hold tissues together
The Plasma Membrane-Components
1.Phospholipids 2.Cholesterol 3.Carbohydrates
Phospholipids
self assemble into bilayer
Cholesterol
resist osmotic lysis
Carbohydrates
linked to other molecules as proteoglycans, glycoproteins, and glycolipids (carb part protrudes from extracellular side creating outer carb layer called glycocalyx)
Functions of glycocalyx
-lubrication & protection
-anchoring & locomotion
-binding specificity (acts as
receptor)
-self recognition
Proteins
1/2 mass of plasma membrane
integral proteins
span width of membrane
peripheral proteins
adhere to inner or outer surface
Functions of membrane proteins
1.anchoring proteins 2.recognition proteins
3.enzymes 4.receptors 5.carrier proteins 5.channels
anchoring proteins
attachment
recognition proteins
self identification by immune system
enzymes
catalyze reactions in cytosol or extra cellular fluid
receptors
bind ligands for signaling, or import/export
carrier proteins
transport solutes in/out
channels
move ions & H2O in/out