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Flashcards in Chapter 5 - Tissues Deck (32)
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1

what creates tissue

cells. The combination of different cell types, with similar structures and functions, creates tissue.

2

The four basic tissue types

epithelial
connective
nervous
muscle

3

describe: Epithelial tissue

epithelia and glands:
covers the surface of the skin and organs
forms the inner lining of body cavities
lines hollow organs
makes up glands

anchored to connective tissue by a 'basement membrane'

classified according to shape of their cells and number of cell layers

4

describe: Connective tissue

widely distributed throughout the body, filling internal spaces. Binds, Supports and protects body structures.

5

describe: Nervous tissue

carry information from one part of the body to another via electrical impulses. found in:
the brain and spinal cord (CNS)
the nerves (PNS)

6

describe: Muscle tissue

specialised for contraction and include
skeletal muscles(attached to bones, used for movement of the body)
the heart
muscular walls of hollow organs

cardiac (involuntary)
smooth ( involuntary)
Striated (voluntary)

7

describe: Epithelium

an avascular layer of cells that forms a barrier, providing protection and regulating permeability.

8

describe: Glands

are secretory structures derived from epithelia

9

functions of Epithelia - physical protection

abrasion, dehydration, destruction from biologic or chemical agents.
Tightly interlocked epithelial cells of the circulatory system reduce friction between the blood and the walls of the blood vessels.

10

functions of Epithelia - Absorption

examples of epithelia that absorb or secrete substances are those that line the kidney tubules and intestine. In the intestine certain epithelia absorb nutrients from the digestion of food.

11

functions of Epithelia - Filtration

Some epithelia have tiny motile cilia that propel substance along free surfaces, as part of filtration. These include epithelia lining the trachea and other air passages.

A thin supporting sheet adjacent to the basal surface of an epithelium is called the 'basal lamina', which acts as a selective filter. It determines which molecules can diffuse from underlying connective tissue can enter the epithelium.

12

functions of Epithelia - Excretion

In the kidneys epithelia excrete waste products and also reabsorb needed material form the urine.
In the skin, the epithelia of sweat glands excrete sweat.

13

functions of Epithelia - Sensation

Most epithelia are very sensitive to stimulation because they have a large sensory nerve supply. Sensory stimuli penetrate specialised epithelia. Such tissue is found in the eyes, ears, skin, nose and on the tongue.

14

functions of Epithelia - Specialised secretions

Epithelial cells that produce secretions are called gland cells. Cells of this type are scattered among other cells in an epithelium. Most or all of the epithelial cells in a glandular epithelium produce secretions, which are either discharged onto the surface of the epithelium or released into the surrounding interstitial fluid and blood. These secretions include enzymes, hormones and lubricating fluids.

15

functions of Epithelia - Permeability

Any substance entering or leaving the body must cross and epithelium, so the epithelia control permeability. Some epithelia are relatively impermeable, whereas others are crossed easily by compounds of various sizes. In response to stimuli, the epithelial barrier may be modified and regulated. Hormones can effect ion and nutrient transport through epithelial cells. Physical stress can also alter the structure and properties of epithelia. An example is the formation of calluses on the hands after repeated manual labour.

16

functions of Epithelia - Regeneration

Epithelia have a strong ability to regenerate because they are often exposed to friction, acids, bacteria, smoke and other environmental substances or factors. They begin to reproduce quickly when their apical-basal polarity and lateral contacts are destroyed. Epithelia can replace lost cells (due to cell division) for as long as they receive enough nutrition.

17

the 8 functions of epithelia

physical protection
absorption
filtration
excretion
sensation
specialised secretions
permeability
regeneration

18

variations of epithelium cells

squamous
cuboidal
columnar

simple (one layer)
Stratified (multiple layers)
psuedostratified (looks like multiple layers but all cells connect to base - only columnar)

glands - transitional. endocrine, exocrine (compound or simple)

19

what is fluid connective tissue

a distinctive population of cells suspended in a water matrix. This contains dissolved proteins.

They transport materials between interior body cells and other cells that exchange substances with the external environment, maintaining a stable internal environment.

20

Name the two type of fluid connective tissue

Blood
Lymph

21

What formed elements does blood contain

Red blood cells
White blood cells
Platelets

these are suspended in a liquid extracellular matrix known as blood plasma.

22

Lymph

Lymph forms as interstitial fluid entering the lymphatic vessels, which return the lymph to the cardiovascular system.

23

what is blood

the formed elements (red blood cells, white blood cells and platelets) and blood plasma make up blood.

24

what are the three types of muscle tissue

Skeletal muscle tissue
Smooth muscle tissue
Cardiac muscle tissue

25

characteristics of Skeletal Muscle Tissue

known as voluntary muscle tissue as it is controlled by conscious effort, contracting when stimulated by nerve cells.
attaches to bones.
composed of long thread like cells that have light and dark markings called striations.
The cells are multi nucleated.
Skeletal muscle cells are also called 'muscle fibers'.
Long and cylindrical containing many peripherally located nuclei.

26

characteristics of Smooth Muscle Tissue

Composed of elongated, spindle shaped cells in muscles not under voluntary control.
shorter then striated fibers.
one nucleus per spindle shaped fiber.
also called ; 'non-striated involuntary muscles' or 'unstriated muscles'.
they can divide, regenerating after being injured.
composes hollow internal organ walls (intestines, stomach, bladder, blood vessels, uterus)
cannot be controlled by conscious effort.
moves food through the digestive tract, empties the bladder and constricts blood vessels by contracting or relaxing.

27

characteristics of Cardiac Muscle tissue

also called 'myocardium'
thick contractile middle layer of the heart wall.
Composed of fibers with cross striations, branching frequently and are interconnected, forming a network.
Contains less connective tissue then skeletal muscle and is usually uninucleated.
Its involuntary and makes up most of the heart.
Relies on pacemaker cells for regular contraction.
Cardiac muscle cells are branched and fit together tightly at junctions known as intercalated discs.

28

basic structure of neural tissue

Nervous tissues contain two basic types of cells:
1. Neurons
and several kinds of supporting cells, collectively called:
2. Neuroglia or Glial cells

29

role of Neural Tissue

specialised for the conduction of electrical impulses from one region of the body to another.
Neurons transmit impulses along axons to other Neurons, muscles or glands.
They respond to stimuli via processes called dendrites.
Neurons co-ordinate, integrate and regulate a wide variety of functions in the body.

30

where do you find nervous tissue

Brain
Peripheral nerves
Spinal chord