CELL PHYSIOLOGY

Physiology: study of biological fx of human body

Cell physiology: the scientific study of physiological processes operating within and among cells, and intracellular communication & behavior, in the context of larger systems & whole organisms 

A single drop of blood = 5000k RBC, 5~10k WBC, 200~300k platelets

Chemical level

matter: atoms held together by chemical bonds

elements: building blocks of matter

inorganic: water

organic: carbs, lipids, proteins, NA, ATP

major elements: CHON

minor elements: Ca, P, K, S, Na, Cl, Mg, I, Fe

trace elements: copper (+Fe = RBC) zinc (immunity, mitosis, healing, taste, smell)

basic level

atoms: smallest unit

molecule: >2 atoms

ions: atoms gives up/gain e

compound: substance contains atoms of >2 differ elements

cations: H, Na, K, NH4, Mg, Ca, Fe

anions: F, Cl, I, OH, HCO3, O, SO4, PO4

Cellular level: basic structural & smallest fx units

Tissue level: grp of cell similar fx -epithelial, connective, muscle, nervous

Organ level: structure >2 primary tissue

System level: grp of organ work together carry out specific fx

Organ-system level

Organisma level

Homeostasis = equilibrium - internal environment

dynamic condition 

acidosis

alkalosis

maintain volume & composition of body fluids

body fluids = dilute, watery solutions - dissolved chemicals inside/outside cell

ICF - within cells

ECF - outside cells

e.g. interstitial fluid btwn cells & tissues

Control of homeostasis 

homeostasis being disrupted:

physical insults - intense heat, dehydration - lack of O2

changes in internal environment - drop in BG due to lack of food

physiological stress - demands of work/school - gastritis 

disruptions - mild & temporary - intense & prolonged

hemorrhage 

toxicity 

Internal factors regulate homeostasis:

concentration of nutrient molecules

concentration of O2 & CO2

concentration of waste products

pH

concentration of water, salt & other electrolytes

11 body systems

Feedback: a cycle of events - status of body condition is monitored, evaluated, changed, re-monitored, re-evaluated 

Components of feedback: 

receptor -sends input

control center -set point within controlled condition, evaluate input receives from receptor, generate output commands 

effector -receives output, produce response 

Negative feedback: reverse a change in a controlled condition

regulation of BP

Positive feedback: strengthen or reinforce a change 

normal childbirth 

Body fluid compartments

water 60%, 18% protein, 7% mineral, 15% fats = body weight

fat = 10% water

soft tissues & internal organs = 70-80% water

Total Body Water male > female

before 10 years old, TBW male = female 

2/3 ICF (K, PO)

1/3 ECF (Na Cl) = 80% interstitial fluid, 20% plasma (plasma protein), negligible transcellular fluid & lymph

cellular plasma membrane + sodium-potassium pump (active transport Na out K in): barrier btwn ICF & ECF

cell protein in ICF cannot permeate membrane 

blood vessel wall: barrier btwn plasma & interstitial fluid (passive transport water & plasma constituent thro capillary wall) 

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