Tissues

Question 1

What are the 4 types of tissue?

Answer 1

Nerve
Epithelial
Connective
Muscle

Question 2

What are nerve tissues used for?

Answer 2

Projecting electrical signals across the body for communication

Question 3

What do muscle tissues do?

Answer 3

Contract and generate a force

Question 4

What is the purpose of epithelial tissue?

Answer 4

Covers surfaces and seperates compartments

Question 5

How does epithelial tissue stick and cover surfaces?

Answer 5

Through the use of junctions giving minimal contact inhibition

Question 6

What type of junction is a desmosome?

Answer 6

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

Question 7

What type of junction is a tight junction?

Answer 7

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

Question 8

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

Answer 8

Yes, to form strong water tight seals/junctions

Question 9

What is a gap junction?

Answer 9

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

Question 10

What do all epithelial cells sit on?

Answer 10

A basement membrane

Question 11

What is the basement membrane made of?

Answer 11

Basal lamina and Reticular lamina

Question 12

What is a hemi-desmisome?

Answer 12

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

Question 13

What does the function of epithelial cells depend on?

Answer 13

The cell itself and not the ECM

Question 14

What is the function of the cilla?

Answer 14

Movement due to finger like tublin projections

Question 15

What is the function of microvilli?

Answer 15

Absorption via finger like projections made from actin

Question 16

What are the three types of simple epithelial structures?

How many cells thick are they?

Answer 16

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

Question 17

What is a stratified epithelium?

Answer 17

Same types as simple but with multiple layers of cells

Question 18

What is a pseudostratified epithelium?

Answer 18

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

Question 19

What are the epithelial components of the liver?

Answer 19

Hepatocytes

Arranged in rows between blood vessels

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

Question 20

What are the epithelial components of the kidney?

Answer 20

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

Question 21

How are endo/exocrine glands develped?

Difference between exo and endo?

Answer 21

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

Question 22

What are the two simple exocrine glands?

Answer 22

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

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

Question 23

What is the compound exocrine gland?

Answer 23

Tubuloacinar - mix of two simple and has a varied function

Question 24

Example of an exocrine gland?

Answer 24

Serous gland - secretes water solutions that are protein rich

Mucous glands - secrete mucus rich in proteoglycans

Question 25

What do endocrine glands tend to secrete?

Answer 25

Steroids and proteins into bloodstream

Question 26

Describe a outcome of abnormal function of glands

Answer 26

over/under proliferation or loss of cillary beat

Question 27

Example of abnormal gland function

Answer 27

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

Question 28

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

Answer 28

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

Question 29

What is ground substance CT?

Answer 29

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

Question 30

What is Loose CT?

Answer 30

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

Question 31

What is dense CT?

Answer 31

Thick, lines up and very regular - tendons

Question 32

What is tissue fluid?

Answer 32

Fluid in ECM

Question 33

Consequences of abnormal CT?

Answer 33

Blood/Bone Marrow - overproliferation of WBC causes Leukaemia

Loose/Dense - Loss/abnormal fibres

Cartilage - Tears

Bone - Osteoporosis