Introduction Flashcards
What are the levels of organization?
- chemical or molecular level
- cellular level
- tissue level
- organ level
- system level
- organism level
What is homeostasis?
the maintenance of dynamic equilibrium of internal environment of the body.
Ex: body temperature, acid-base balance, fluid balance, hormonal, nutrient, oxygen levels
What does homeostatic autoregulation (intrinsic regulation) do?
adjust automatically in response to some environmental changes
What is homeostatic extrinsic regualtion?
nervous and endocrine systems adjust the activities of many systems simultaneously
What is negative feedback?
a corrective mechanism that opposes or negates a variation from normal limits
What is positive feedback?
a mechanism that increases a deviation from normal limits after an initial stimulus
What is cell physiology include?
cellular environment, movement of substance through cell membranes
What are the fluids of the cellular environment?
intracellular fluid and extracellular fluid
What does extracellular fluid consist of?
interstitial fluid, blood and lymph
What percentage of water is muscle?
75%
What percentage of fat is water?
10%
What does acid release?
H+
What do bases release?
OH-
What is the normal body pH of mammals?
7.35-7.5
What is osmolarity?
the total solute concentration in an aqueous solution.
What is an isotonic solution?
equal inside and outside of cells (0.9% NaCl)
What is the cell membrane made up of?
phospholipid bilayer
What are the two parts of a phospholipid?
hydrophilic head on the outside and hydrophobic fatty acids tails on the inside.
Why is a phospholipid bilayer useful?
It allows proteins suspended in the bilayer to easily move through it.
What are the 4 kinds of passive transport?
diffusion, osmosis, filtration, facilitated diffusion
What are the 3 types of active transport?
active transport, endocytosis, exocytosis
What are the 3 types of endocytosis?
phagocytosis, pinocytosis, receptor mediated
How does diffusion move?
down a concentration gradient
What are the factors influencing diffusion rates?
Distance, gradient size, molecular size, temperature, electrical forces, lipid solubility, membrane channels
What are the main molecules of diffusion?
water, O2, CO2, steroids, Cl-, urea
What is osmosis?
The diffusion of water across the cell membrane
What is osmotic pressure equal?
the force of a concentration gradient of water equals the force (hydrostatic pressure) needed to block osmosis
What does a cell in an isotonic solution do?
no size change
What does a cell in a hypotonic solution do?
cells swell to burst
What do cells in a hypertonic solution do?
cells shrink
What is filtration?
the passing of water and permeable solutes through a membrane by the force of hydrostatic pressure
What is hydrostatic pressure?
The force, weight, of a fluid pushing against a surface, such as blood pressure
What is facilitated diffusion?
Is passive, includes channel mediated and carrier mediated
What is involved in channel mediated diffusion?
only water and ions
What is active transport?
The movement of substance against a concentration gradient
What does active transport require?
energy, such as ATP
What is an example of active transport?
sodium-potassium exchange pump
What is secondary active transport?
When Na+ concentration gradient drives glucose transport and ATP energy pumps Na+ back out
What is phagocytosis?
When a cell engulfs solid material
What is pinocytosis?
When a cell engulfs liquid
What does endocytosis require?
energy, making it active transport
What is transmembrane potential?
Unequal charge across the cell membrane
What is the charge of the inside and outside of the cell membrane?
inside the cell membrane is slightly negative, outside is slightly positive
What are the four basic tissue types?
epithelial, connective, muscle, neural
What is epithelial tissue?
Layers of cells covering internal or external surface
What are glands?
structures that produce secretion
What are the characteristics of epithelial tissue?
cellularity, polarity, attachment, avascularity, regeneration
What are the two types of glandular epithelia?
endocrine and exocrine
What do endocrine glands do?
release hormones into interstitial fluid and blood, do not have ducts
What do exocrine glands do?
produce secretions onto epithelial surfaces through ducts (with the exception of goblet cells)
What are the functions of epithelial tissue?
physical protection, control permeability, sensory functions, absorbs nutrients, secretions of hormones and mucus, excretion of sweat and urine
What are the functions of connective tissue?
largest tissue, connect epithelium to the rest of the body (basal lamina), provide structure (bone), store energy (fat), transport materials (blood, have no contact with environment (sterile)
What are the characteristics of connective tissue?
specialized cells, matrix (extracellular components) – collagenous fiber - reticular fibers - elastic fibers, vasculated (direct blood supply)
What makes up a body membrane?
epithelia and connective tissues
What do membranes do?
line body cavities, separate organs, and cover surfaces
What are the four types of mucous membranes?
mucous membranes (mucosae), serous membranes (serosaw), cutaneous membranes (integument, skin), synovial membranes
What is muscle tissue specialized for?
contraction
What are the three types of muscle tissues and their qualities?
skeletal muscle (striated, voluntary), cardiac muscle (involuntary, striated), smooth muscle (non-striated, involuntary)
What is nervous tissue specialized for?
the conduction of electrical impulses from one region of the body to another
What does nervous tissue include?
brain, spinal cord, and peripheral nerves
