Tissues

Question 1

epithelial tissue

Answer 1

covers exposed tissues
lines internal passageways and chambers
produces glandular secretions
layers of cells form linings, membranes and glands

Question 2

layers

Answer 2

simple= single layer of cells
stratified= multiple layers

Question 3

shape

Answer 3

squamous- flattened cell/ squashed
cuboidal- cube shaped, found in glands
columnar- long and narrow, longer than they are wide
transitional- cells that can change shape

Question 4

epithelial cell structure

Answer 4

bottom= basal surface and basement membrane
contain organelles eg nucleus and mitochondria
cells connected by cell junctions
apical surface is open to external world eg lungs
specific adaptations on some cells eg microvilli/ cillia

Question 5

simple squamous epithelia

Answer 5

eg linings of blood vessels and alveoli
provide smooth surface
reduces friction
help with absorption and secretion- shorter pathway for gases/ nutrients

Question 6

stratified squamous epithelia

Answer 6

eg skin
lots of layers
provides physical protection against pathogens, abrasion and chemical attack

Question 7

simple cuboidal epithelium

Answer 7

eg lining of ducts and glands
allows some protection
secretion of products into glands/ ducts and absorption

Question 8

stratified cuboidal epithelium

Answer 8

lining of some glands eg sweat glands
protection, secretion and absorption

Question 9

transitional epithelia

Answer 9

eg lining of urinary bladder
able to expand/ enlarge and recoil/shrink depending on contents of bladder
relaxed epithelium = empty bladder
stretched epithelium (shrunk so smaller) = full bladder

Question 10

simple columnar epithelia

Answer 10

eg lining of stomach and intestine
have microvilli
tall cells so substances can pass through
protection, secretion, absorption

Question 11

pseudostratified cilliated columnar epithelia

Answer 11

eg lining of nasal cavity, trachea and bronchi
partly layered as all cells are connected to basement membrane
cilliated with hair at the top
mucus producing cells which have cilia to clear/ move mucus

Question 12

stratified columnar epithelia

Answer 12

eg small areas of the pharynx (mouth)
several layers of cells
provides protection- moves food around

Question 13

exocrine glands

Answer 13

excrete out of the body eg sweat glands
can be simple or compound
simple- one duct
compound- multiple ducts

Question 14

glandular secretion- merocrine

Answer 14

cells produce product in golgi appartus
vesicles containing product move up towards cell surface membrane
discharged from cell surface
product is released from exocrine cell by exocytosis

Question 15

apocrine secretion

Answer 15

product accumalates in apical portion (top of cell) of cytoplasm
this portion of the cell is shed- cytoplasm breaks off, releasing vesicles with product
cells regrow and cytoplasm can be shed again

Question 16

holocrine secretion

Answer 16

gland cell is destroyed in the process
cell division occurs at the base, cell becomes packed with secretory vesicles, cell increases in size and bursts; releasing the cytoplasmic contents

Question 17

connective tissue

Answer 17

supports and protects
contains;
cells eg fibroblasts, macrophage, adipocytes
fibres eg collagen, elastic, reticular
ground substance eg blood, lymph, cartilage

develops from mesenchymal stem cells + can differentiate into different types of cell

Question 18

loose connective tissue

Answer 18

provide padding/ connection between tissues
adipose- deep to the skin eg kidneys, buttocks
adipocytes (fat cells)
provides padding and cushion, insulates and stores energy

reticular- found in liver, kidney, spleen
reticular fibres- 3D branched to connect structures
provides supportive network

Question 19

dense connective tissue

Answer 19

regular- lots of collagen fibres parallel to each other, creates rope like structure
provides firm attachment, can transfer forces, conducts pull of muscles
eg tendons and ligaments

irregular- collagen fibres in different directions to form a sheet/ layers of protection
provides strength to resist forces from different directions
eg in deep dermis + capsules of visceral organs

elastic- elastic fibres instead of collagen so stretchier than collagen, allows more expansion and contraction
stabilises and cushions shocks
eg elastic ligament

high proportion of protein fibres

Question 20

connective tissue- cartilage

Answer 20

hyaline cartilage-
provides support with jelly like matrix with pits called lacunae with chondrocytes (cartilage cells)
and reinforced with collagen fibres
quite strong
eg between rib and sternum/ nose

elastic cartilage- elastic fibres instead of collagen
can tolerate distortion without damage, returns to original shape
matrix and lacunae is the same
eg ears

fibrocartilage- fibrous matrix and more collagen fibres
resists compression, prevents bone to bone contact
more strength
eg in joints

Question 21

tissue membranes

Answer 21

all contain epithelial cells and a layer of connective tissue

mucous membrane-
outer epithelial layer, cells producing mucus
communicates with exterior of the body eg openings to lungs

Serous membrane- fluid on top/ surface which reduces friction, layer of squamous cells
lines body cavities

Cutaneous membrane (skin)- several layers
covers the body surface

Synovial membrane- lines joint cavities
produces synovial fluid

Question 22

fasciae

Answer 22

superficial- layer underneath skin/ organs
adipose and areolar tissue
deep- tougher and stronger, dense connective tissue, surrounding organs
subserous fascia- connective tissue under serous membranes
maintains integrity of cavity

Question 23

muscle tissue

Answer 23

Skeletal muscle tissue- fibres are striped/ striated
very large
under voluntary control- controlled via nerve (motor neuron)

Cardiac muscle tissue- smaller cells than skeletal, cells connected by intercalated discs- electrical activity
Involuntary control- controlled by pacemaker cells
Interconnected disks

Smooth muscle tissue- organs/ blood vessels, smaller, no stripes
pacesetter- electrical activity but slower
mostly under hormonal control

Question 24

neural tissue

Answer 24

neuron cell- cell body, axon, dendrites connect with other neurones

neuroglia- supporting cells
maintain physical structure of tissues,
repair tissue network after injury
perform phagocytosis, provide nutrients to neurons, regulate the composition of intestinal fluid surrounding neurons

Question 25

bone

Answer 25

ostoecytes- bone cells
matrix- made up of mineral and collagen fibres
toughest tissue