Lecture 2 & 3

Question 1

what are the 4 different kinds of body cells?

Answer 1

nerve
muscle
epithelial
connective tissue

Question 2

A bit about muscle cells, name the 3 different kinds

Answer 2

skeletal muscle
smooth muscle
cardiac muscle

involuntary control -cardiac, smooth
voluntary control -skeletal
striated -cardiac, skeletal
unstriated -smooth

are used for contraction & generation of force

Question 3

A bit about nerve cells, and the 1 kind.

Answer 3

Neurons.

initiate & transmit electrical impulses
control & regulate muscle contraction, gland secretion, sensory perception, emotions, thoughts etc

Question 4

A bit about epithelial cells

Answer 4

Form basement membranes or a ‘barrier’
seperates body from external enviro
lines hollow organs
forms glands specialised tissue for excretion or gas exchange

Question 5

a bit about connective tissue

Answer 5

can be in the form of RBC’s, WBC’s, bone cells, fibroblasts

forms extracellular matrix -connects, anchors & supports

Question 6

Cells can be organised into (3 things)

Answer 6

tissues
organs
organ systems

Question 7

tissues are…?

Answer 7

collection of cells of the same type

Question 8

organs are…?

Answer 8

collection of two or more types of tissues put together

Question 9

organ systems are…?

Answer 9

collection of organs working together to accomplish a particular task

Question 10

Define homeostasis

Answer 10

maintenance of stable internal conditions for optimum body/cell functioning

Question 11

what does homeostasis regulate or control?

Answer 11

temperature
pH
concentrations of waste products
concentrations of H2O, O2, CO2,salts & 
supply of energy to cells

Question 12

Fluid in the internal environment of the animal are called/description?

Answer 12

Extracellular fluid (ECF) -fluid surrounding cells
intracellular fluid (ICF) -fluid within cells

Question 13

what is the name of the thin layer that seperates the ECF from the ICF?

Answer 13

plasma membrane

Question 14

what does the plasma membrane consist of, and what does it maintain?

Answer 14

consists of phospholipids and proteins in a lipid bilayer w/ other molecules embedded.
maintains different composition of fluids, and exchange of nutrients, ions and waste products

Question 15

explain plasma membrane physiology.

Answer 15

concentrations of K+ & Na+ ions are different on each side of the membrane, causing a membrane potential, which is maintained by a Na+/K+ -ATPase pump (active transport).
Higher [] of Na+ outside cell, higher [] of K+ inside cell.

Pump transports 2 K+ ions inside the cell and 3 Na+ ions outside the cell at the COST of 1 ATP molecule.

Question 16

nerves rely on what to send a message? Muscles also rely on this to contract

Answer 16

membrane potential

Question 17

Describe the distribution of body water

Answer 17

Total BW: 60%

consisting of: ICF (40%), ECF (20%), plasma (5%), interstitial fluid (15%) & transcellular fluid

Question 18

describe diffusion, what rate of diffusion depends on & List 3 types of diffusion

Answer 18

simple, facilitated, ion channels

passive transport =ions move down a gradient
rate depends on [], permeability & SA of membrane, MW, distance, temp.

Question 19

describe osmosis

Answer 19

passive movement of water across a semipermeable membrane from a region of high h2o concentration to a region of low concentration

Question 20

describe osmotic pressure

Answer 20

minimum pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane.

Question 21

a bit about osmotic balance

Answer 21

depends on NaCL &H2O load in body.

maintained by regulating ECF volume & osmorality.

Question 22

ECF osomotic pressure is regulated to…?

Answer 22

prevent swelling or shrinking of cells

Question 23

ECF volume is regulated to…?

Answer 23

maintain blood pressure

Question 24

what is isotonic?

Answer 24

equal concentrations of solutes

Question 25

what is hypertonic? what happens to the cells?

Answer 25

solution has a higher [] of solutes -cells shrink

Question 26

what is hypotonic? what happens to the cells?

Answer 26

solution has a lower [] of solutes -cells swell

Question 27

watar balance in body affects 3 other processes. name these

Answer 27

``` fluid balance (circulatory pressure) electrolyte balance (osmotic balance) acid-base (H3O+ ions) ```

Question 28

Describe how thirst comes about

Answer 28

initial loss of water is from ECF, then ICF. Changes in ECF will influence ICF but only to extent permitted by cellular membranes. Pituitary gland directs kidneys (via ADH hormone) to conserve water=> limited capacity as kidneys must excrete some water. If more water is lost than is drunk or conserved by kidneys, ultimately leads to thirst (triggered by hypothalamus in brain.