Histology

Question 1

o Structural and functional unit of life
o Groups of cells similar in structure and function
o Two or more tissues work together towards a common greater function, each contributing the function of its cell type

Answer 1

Cells
Tissues
Organs

Question 2

o Layers and lining

o Most abundant tissue in body, attachments, protection. Support and protection

Answer 2

Epithelial

Connective

Question 3

o	skeletal (control), smooth (involuntary), cardiac (heart). Movement and control
o	brain and spinal cord. Communication

Answer 3

Muscular

Skeletal

Question 4

PROPERTIES OF A CELL:

Stem cell

Answer 4

o capable of becoming varied cells (unspecialized)

Ex.) hemocytoblast – can become an RBC/WBC or…

Question 5

PROPERTIES OF A CELL:

Totipotent

Answer 5

in the embryo, the original 1-32 cells have the ability to differentiate to ALL of the different types of cells and tissues

Question 6

o able to differentiate into many different cell types (but perhaps not all)
o process of change & specialization. Depends on environment in which cell is found

Answer 6

PROPERTIES OF A CELL:
Multi-potent
Differentiation

Question 7

o Separates intracellular fluids from extracellular fluids
o Plays a dynamic role in cellular activity
o Intracellular: inside the cell
o Extracellular: outside the cell

Answer 7

Plasma Membrane

Question 8

o scheduled or programmed death of a cell

o Ex.) stratified squamous cells of skin slough off

Answer 8

Apoptosis

Question 9

o unscheduled death of cells

o Necrotic: dying tissue

Answer 9

Necrosis

Question 10

o trophe = nourishment)

o Increase in SIZE of cells > tissues > organs

Answer 10

Hypertrophy

Question 11

o Decrease in SIZE of cells > tissues > organs

Answer 11

Atrophy

Question 12

o (plassein = to mold)
o Increase in number of cells
o Can be hormonal, compensatory or pathologic (tumours)
♣ Ex.) calluses, more RBC’s in anemia, uterine cells during pregnancy (estrogen)

Answer 12

Hyperplasia

Question 13

o A change from one cell type to another but LESS differentiated
o Can be reversible if stimulus is removed
o Can become cancerous if not

Answer 13

Metaplasia

Question 14

o	New and abnormal development of cells 
♣	Benign: no harm
♣	Malignant: causes harm 
o	Metastasis: these new cells may dissolve the membrane separating one tissue (ex. skin) from another (ex. blood or lymphatic vessel) and then invade other areas of the body
♣	Ex.) stage 1-4 cancer
♣	Movement of neoplasia cells

Answer 14

Neoplasia

Question 15

Every cell needs…

Answer 15

o To get: nutrients (fats, AA’s, glucose)
o To get rid of: wastes (ammonia, CO2)
o Protection – from changes in its immediate environment
o pH, temperature, concentrations of water and other dissolved substances

Question 16

Body is made up of 3 parts

Answer 16

Cells, intercellular spaces, fluids

Question 17

FIBRES:
(“net”) – fibres that form a mesh or web or net – think ‘filtering’.
o Found in lymph nodes, liver, spleen

Answer 17

Reticulin

Question 18

FIBRES:
stretch, rebounding protein.. C02
o Allows deformations of tissues (Cartilage in ear)

Answer 18

Elastin

Question 19

FIBRES:
25% of all human protein is _____
o Strength in tissues

Answer 19

Collagen

Question 20

o Between cells
o Carries (5 things) O2, CO2, nutrients, other wastes, hormones
o Transparent fluid in lymphatic vessels
o If fluids accumulate in a tissue (between the cells)

Answer 20

Interstitial
Blood
Lymph
Edema

Question 21

• Percent of water in sweat:
Males =
females =
newborns =

Answer 21

60%
55%
75%

Question 22

o Heart pumps - creates pressure in fluid = _______
o As distance increases from the heart, __ decreases
o ____ drives fluid OUT OF blood vessels

Answer 22

Hydrostatic pressure (HP)

Question 23

o _____ is exerted by various proteins in the blood – primarily albumins. ______ = movement of water from low concentration to high concentration
♣ Albumins are made in the liver, normally kept in blood and not excreted by the kidney
o Concentration in the blood tends to stay the same throughout system (unlike HP)
o Higher concentration in blood than in the interstitial space attracts water
o ___ tends to draw water INTO blood vessels

Answer 23

Osmotic Pressure

Question 24

o Hormone that increases permeability of capillaries – fluid leaks out into tissues
o Alters permeability of tissue

Answer 24

Histamine

Question 25

♣ Blocked veins – HP rises behind blockage, drives fluid out
♣ Blocked lymphatic ducts – normal collection of excess fluid is blocked (ex. Elephantiasis)
♣ Low albumin – OP in blood is not sufficient to draw water back into blood – liver or kidney disease
♣ Damage to capillaries – burn or trauma
♣ Normal histamine response to injury (Ex. Bee sting, sprained ankle)

Answer 25

Edema causes