45%-75%

increases and decreases based on percent of body weight that is fat, which has very little water content. Discluding fat, water percentage is constant in across most people

21 year old white male

70kg

weight x aprx %

_____________________ = ~L

100

male - 61%

female - 51%

insensible perspiration vs pure sweating

qualities

insensible perspiration: pure water, passive evaporation, entire skin surface, and continuous

pure sweating: electolyte solution, active secretion, sweat glands, activated by heavy work or high T

Intracellular Fluid (ICF): 2/3 of body water, 40% of body mass

Extracellular Fluid (EFC): 1/3 of body water, 20% of body mass

major: plasma, interstitial fluid (ISF)

minor: lymph, trancellular fluid

plasma: 55%

Erythrocytes: 45%

the aggregates of fluid volumes secreted by specific cells into a number of body cavities lined by epithelial cells having specialized functions. Ex: synnovial fluid in joints

localized changes do not effect water balance

Body Water Composition

All Compartments

Indicator Dilution Method:

Determining fluid comparment volume steps

1. introduce a known quatity (Q) of indicator into vein

2. allow time to equilibrate

3. remove known volume of blood and centrifuge to obtain plasma

4. measure concentration (C) in unit volume of plasma

5. calculate: V=Q/C

Plasma Volume: evans blue

Total ECF: inulin, sucrose, mannitol

Total Body Water: antipyridine, D2O, T2O

High in K+, Mg++

Low in Na+, Cl-

High in Na+, Cl-

Low in K+

8.6g NaCl

.3g KCl

.3g KCl2

+H20 to 1L

amount of solute present in a unit of volume of solution

expressed in g/L

molarity of an ion x valency of ion

ex: Na+ has 1Eq/mol

1. muscle cells

2. neurons

3.epithelial cells

4. connective tissue cells

1. muscle tissue

2. nervous tissue

3. epithelial tissue

4. connective tissue

1. skeletal: voluntary muscles, perform motor actions connected to skin and bone

2. cardiac: found only in the heart, allows heart to contract sending blood around body

3. smooth: surround blood vessels, gi tract etc. help with transport in body

1. cuboidal (cube shaped)

2. collumnar (ellongated)

3. squamous (flattened)

4. ciliated

1. loose: found in network between cells and fibers enderlying epithelial cells

2. dense: tendons and ligaments

3. bone, cartilage, adipose tissue and blood

an increase or decrease in a regulated variable brings responses that tend to move variables in opposite directions.

**see book for negative feedback diagram**

accelerates a process, with no obvious means of stopping. Creates an "explosive" system.

**responsible for birth (paturation)

1. muscle

2. gland

a type of chemical messanger secreted into the blood by cells of the endocrine system

the response of the glands in a reflex

can effect many cells all over the body at once

initiated by a change in the environment, induces an alteration of cell activity with the goal of counteracting the stimulus

-unlike a reflex, only happens immediately surrounding the stimulant

1. hormones

2. neutransmitters

3. paracrine/autocrine substances

chemical messangers released from ending of a neuron onto other neurons, muscles, and gland cells

**not released into blood

1. gap junctions

2. juxtacrine

the improved functioning of an already existing homeostatic system

reversable

acclimatization very realy in life at a critical period of development of a structure or response

irreversable

cycles of approximately 24 hours. Includes waking, sleeping, body T, hormone conc. and exretion of ions in urine.

different from feedforward as it anticipates changes in the environment

1. positive balance: gain exceeds loss

2. negative balance: loss exceeds gain

3. stable balance: gain equals loss

**take 4-5 days for a steady positve/negative balance to reach a steady balance.

see balance diagram in book