Human Bio

to find the magnification of the structure (how much bigger than real life):

size of structure in the picture

real size of the image

to find the real size of the structure imaged:

size of the structure in the image

magnification

1000 um = 1mm

• always measure in mm

• convert to um by multiplying by 1000

• or adding '000'

Cardiac Output

the volume of blood pumped out of the left ventricle in one minute

usually 4 - 8

Stroke Volume

the volume of blood pumped out of the left ventricle in one cardiac cycle

usually 60 - 80

CARDIAC OUTPUT = STROKE VOLUME X HEART RATE

PULSE RATE

the expansion and elastic recoil of the wall of the artery as blood leaves the heart under pressure

CAN BE MEASURED WITH TWO FINGERS ON THE NECK OR WRIST

AMOUNT OF PULSES PER MINUTE = HEART RATE

Tissue

'a group of specialised cells that carry out the same function'

can be seen in squamous epithilial tissue which contains cililated epithelium cells that are specialised and all carry out the same function

Organ

'a group of different tissues carrying out different functions'

within the lungs, there is squamous epithilial tissue and ciliated epithelial tissue that carry out different functions, yet they are grouped together to form the lungs

Squamous Epithelial

• a tissue formed from squamous epithelium cells

• the tissue forms the wall of the alveoli

• the tissue is flat and thin so that diffusion rate can be at its most efficient

Ciliated Epithelial Tissue

contains goblet cells - these produce mucus which contains a glycoprotein and traps bacteria and dirt

contains ciliated cells- these have cilia on their surface which are microscopic hairs that beat rhythmically to remove the mucus produced by the goblet cells that contains dirt and bacteria. This mucus is moved up the trachea to the throat where it can be swallowed and destroyed by hydrochloric acod in stomach

CILIATED CELLS LINE THE BRONCHIOLES

WHILST BOTH CILIATED CELLS AND GOBLET CELLS LINE THE TRACHEA AND BRONCHI

CAUSES

blockage of the bronci or trachea (food etc.)

suppression of the respiratory system by drugs 

a respiratory condition such as asthma

WHEN SOMEONE IS NOT BREATHING BUT HAS A PULSE

• roll them onto their back
• lift chin to open the airway
• ensure nothing is blocking the airway e.g. vomit
• pinch the nose shut
• place your mouth over patient's mouth, forming a seal
• breath slowly into mouth
• watch chest to see if it rises
• pause between each breath to allow air to flow through the body

• CONTINUE IF NOT BREATHING BUT STILL HAS PULSE

A BREATH EVERY 5 SECONDS

FOR CHILDREN

• don't tilt back head as far
• give a breath every 3 seconds, not 5
• check for a pulse after 20 breaths, not 2 (about a minute)

• make a seal over the whole of a baby's mouth and nose

surface area = 'the amount of cells exposed to the environment'

volume = 'the cells that are occupied within the organism'

surface area to volume ratio

HIGHER RATIO = MORE EFFICIENT DIFFUSION

this means more materials will be exchanged at an efficient rate if an organism has a large surface area compared to it volume

formed by squamous epithelial tissue

• thin = shorter diffusion distance
• steep concentration gradient by good ventililation and a good supply of oxygenated blood
• large surface area provided by folding = more area for diffusion to occur across