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Flashcards in Tissues Deck (33):
1

What are the 4 types of tissue?

Nerve
Epithelial
Connective
Muscle

2

What are nerve tissues used for?

Projecting electrical signals across the body for communication

3

What do muscle tissues do?

Contract and generate a force

4

What is the purpose of epithelial tissue?

Covers surfaces and seperates compartments

5

How does epithelial tissue stick and cover surfaces?

Through the use of junctions giving minimal contact inhibition

6

What type of junction is a desmosome?

Its an adhering junction that gives strong links, but isn't water tight

7

What type of junction is a tight junction?

Two cell membranes sticking together forming a water tight seal. Not very strong

8

Can tight junctions be used with desmosomes? If yes why?

Yes, to form strong water tight seals/junctions

9

What is a gap junction?

Like a tight junction - two cell membranes stick and form a seal, but this one is permeable to allow channels between two cells

10

What do all epithelial cells sit on?

A basement membrane

11

What is the basement membrane made of?

Basal lamina and Reticular lamina

12

What is a hemi-desmisome?

A junction in contact with the basal lamina and the extracellular matrix rather than between two cells

13

What does the function of epithelial cells depend on?

The cell itself and not the ECM

14

What is the function of the cilla?

Movement due to finger like tublin projections

15

What is the function of microvilli?

Absorption via finger like projections made from actin

16

What are the three types of simple epithelial structures?

How many cells thick are they?

Squamous - very thin, good for diffusion

Cuboidal - thicker cells with a lining of nephrons, good for secretion, absorption/pumping

Columnar - similar to cuboidal but higher, lines digestive tract and when cillated, moves mucas

17

What is a stratified epithelium?

Same types as simple but with multiple layers of cells

18

What is a pseudostratified epithelium?

Cells look layered, but isn't as every cell makes contact with the BL, in a tetris sort of structure

19

What are the epithelial components of the liver?

Hepatocytes

Arranged in rows between blood vessels

Multiple functions - secretion
Supporting epithelial cells line the blood vessels and bile ducts

20

What are the epithelial components of the kidney?

Epithelial cells are arranged into nephrons

Multiple functions - filtration of blood, partial absorption of filtrate

Support epithelial cells line blood vessels and renal pelvis which receives toxic urine

21

How are endo/exocrine glands develped?

Difference between exo and endo?

Cell proliferates inwards past the BL and underlining connective tissue into the cell.

Exo froms a tube to secrete outwards - e.g sweat

Endo just spreads hormones inside the body via blood

22

What are the two simple exocrine glands?

Tubular - long thin, straight invagination into cell. Secretes watery things

Acinar - round grape like shape, secretes thicker substances like mucas

23

What is the compound exocrine gland?

Tubuloacinar - mix of two simple and has a varied function

24

Example of an exocrine gland?

Serous gland - secretes water solutions that are protein rich

Mucous glands - secrete mucus rich in proteoglycans

25

What do endocrine glands tend to secrete?

Steroids and proteins into bloodstream

26

Describe a outcome of abnormal function of glands

over/under proliferation or loss of cillary beat

27

Example of abnormal gland function

Pituitary gland - releases growth hormones so over proliferation causes pituitary gigantism and under causes pituitary dwarfism

28

What does fibrous CT do? What is it made of and what makes it elastic? Colour?

Gives support
Made of collagen, is flexible with very high tensile strength

Elastic fibers have protein elastin, microfibrils and an amorphous component. Has a yellow colour

29

What is ground substance CT?

Jelly substance made of;

1. Proteoglycans - consists of GAGS and a protein core.
2. Hyaluronic Acid
3. Glycoproteins - signaling molecules telling body what part is what

Makes up the ECM

30

What is Loose CT?

Fixed cells - fibroblasts, macrophages, adipocytes, mast cells
Transient cells - blood cells

31

What is dense CT?

Thick, lines up and very regular - tendons

32

What is tissue fluid?

Fluid in ECM

33

Consequences of abnormal CT?

Blood/Bone Marrow - overproliferation of WBC causes Leukaemia

Loose/Dense - Loss/abnormal fibres

Cartilage - Tears

Bone - Osteoporosis