tissues

Question 1

what is the location and function of 3 types of simple epithelium?

Answer 1

forms lining or body cavities
thin layer for fast absorption, secretion and filtration

squamous - blood vessels

cuboidal - kidney

columnar - gut/ ovary

Question 2

what is the location and function of 3 types of stratified epithelium?

Answer 2

stratified squamous (thick) - for protection, withstands abrasion e.g. skin

stratified cuboidal - exocrine glands

pseudostratified columnar - secretion and movement in the trachea.

Question 3

what is the location and function of transitional epithelium?

Answer 3

permeability barrier and stretchability in the urinary tract

Question 4

describe the membrane that all epithelial tissue lay on

Answer 4

Basement Membrane - which is made up of two lamina:

Basal Lamina - upper layer on which the epithelium sits

Reticular Lamina - lower layer

Question 5

what does apical mean?

Answer 5

side of the epithelium that faces the lumen

Question 6

what are the 4 junctions?

Answer 6

Desmosomes (macula adherens) - firm anchorage

Tight junctions (occluding junctions) - seals intercellular spaces

Gap junctions - cell to cell communication

Hemidesmosomes - connects the basal layer of epithelium to basement membrane

Question 7

what is the difference between endocrine and exocrine glands?

Answer 7

Endocrine glands - glands that are cut off from the surface during epithelium development and they secrete into the bloodstream.

Exocrine glands - glands that are connected to the surface during epithelium development and they secrete into tubes.

Question 8

what are exocrine glands?

Answer 8

glands that remain connected to the surface during epithelium development and they secrete into tubes/ducts.

Question 9

what 2 shape types can exocrine glands be subdivided into?

Answer 9

Simple ( Tubular & Acinar )

Compound ( Tubuloacinar or separate)

Question 10

what 2 product secretion types can exocrine glands be subdivided into?

Answer 10

mucous glands - proteoglycans and water secretion in the trachea and gut

serous glands - protein-rich and water/ enzyme secretion in the pancreas

Question 11

what are the 3 mechanisms of exocrine secretion?

Answer 11

Merocrine - gland stays whole (exocytosis of vesicles) most common type. e.g. sweat glands

Apocrine - pinched off a portion of the gland
e.g. mammary glands

Holocrine - gland dies and becomes secretory product e.g. sebaceous gland

Question 12

what is the pancreas?

Answer 12

an organ that is both an exocrine and an endocrine gland.

Question 13

what is the pancreas made up of?

Answer 13

exocrine glands - pancreatic acini

endocrine glands - islet of Langerhans, excretes insulin and glucagon into the bloodstream

Question 14

what are myoepithelial cells?

Answer 14

they have contractile functions around acini glands, helping them expel their secretions from the lumen.

Question 15

what could happen when things go wrong with the function of epithelial cells? 5

Answer 15

Over/ under proliferation

Over/ under secretion

Loss of cilia or villi

Question 16

what are the abnormal functions of uterine tube glands i.e. mucus production?

Answer 16

chlamydia trachomatis (STD) infects uterine tube - makes mucus thick

infertility

trapping of ovum/sperm

Question 17

what are the abnormal functions of pituitary glands i.e. growth hormone production (GA)

Answer 17

overproduction - gigantism

underproduction - dwarfism

Question 18

what are the 3 types of connective tissue?

Answer 18

Loose - papillary layer of the dermis of the skin

e.g. areolar, adipose

contains permanent and transient cells

Dense regular - in the tendons

Dense irregular - reticular layer of the dermis of the skin

Question 19

connective tissue comprises cells and extracellular matrix, what is the ECM composed of?

Answer 19

Fibres (Collagen & Elastin) - rope-like

Ground substance - jelly-like

Tissue fluid - liquid

Question 20

what 3 fibres make up the extracellular matrix?

Answer 20

collagen - tendons (ordered)

elastin- aorta (wavy)

reticulin - lymph (irregular)

Question 21

what are elastic fibres?

Answer 21

flexible fibres that can stretch 1.5 times their resting length, made up of microfibrils and amorphous (without a defined form) components.

found in sheets rather than fibres, usually in the Aorta.

Question 22

describe the characteristics of collagen

Answer 22

30% of body weight

inelastic, flexible, great tensile strength

Question 23

how is collagen formed?

Answer 23

fibroblasts secrete collagenase and procollagen.

A sum of organised procollagen in a triple-stranded helix shape forms collagen fibrils

A sum of collagen fibrils forms collagen fibres

Question 24

what are the 3 main types of collagen?

Answer 24

type 1 - tendon

type 3- reticulin (lymphatic organs)

type 4 - basal lamina (non-fibrous)

Question 25

What is the ground substance that makes up the ECM?

Answer 25

Proteoglycan = (Core Protein + Glycosaminoglycans)
e.g. Hyaluronic acid

Glycoproteins (laminin, fibronectin.. etc.)

Question 26

what are permanent cells in loose connective tissue? give examples

Answer 26

Permanent cells are cells that develop and remain within the connective tissue

e.g. Fibroblasts, Macrophages, Adipocytes, Mast cells, undifferentiated mesenchyme cells

Question 27

what are transient cells in loose connective tissue?

Answer 27

Transient cells are cells that migrate from the bloodstream into the connective tissue

e.g. white blood cells like neutrophils, monocytes, eosinophils …etc.

Question 28

what are the abnormal functions of connective tissue in different areas?

Answer 28

In blood/bone marrow → Leukaemia
(overproduction of abnormal WBC)

In loose/dense tissue → loss of fibres or abnormal fibres

In cartilage → tears in tendons or bones

In bone → osteoporosis (bone weakening) or osteopetrosis (bone hardening)

Question 29

describe skeletal muscle tissue

Answer 29

striated with a highly ordered arrangement of contractile proteins.

Question 30

describe cardiac muscle tissue

Answer 30

striated, branched, and has a less highly ordered arrangement of contractile proteins.

Question 31

describe smooth muscle tissue

Answer 31

non-striated with a randomly ordered arrangement of contractile proteins.

Question 32

what is nerve tissue?

Answer 32

it’s involved in communication; they receive impulses generate signals and integrate information.

The basic component is neurone

Question 33

what are neurones?

Answer 33

involved in neuronal function in all animals, they generate action potentials and conduce them to other cells.

Made up of four regions:

• Dendrites
• Cell body (soma)
• Axons
• Terminals