HISTOLOGY

Question 1

Where is a 9+2 pair arrangement of microtubules seen?

Answer 1

in cilia and flagella

Question 2

neat packing of circles with 9+2 arrangement represent:

Answer 2

cilia

Question 3

on periphery of cell are

Answer 3

actin filaments

Question 4

outline epithelial tissue/cells

Answer 4

form surfaces in and on body
protection and secretion
very little space between cells
strong attachments between cells
polarised to have a free apical surface
adhere to basement membrane
avascualar (no blood supply)

Question 5

what are tight junctions

Answer 5

seal adjacent epithelial cells in a narrow band just beneath apical surface

Question 6

what are zonula adherens

Answer 6

more basal than tight junctions. they link cytoplasmic face with actin cytoskeleton

Question 7

what are desmosomes

Answer 7

link to the intermediate cytoskeleton to give mechanical strength to tissues

Question 8

what are gap junctions

Answer 8

connect cytoplasm of 2 cells to help with diffusion of molecules

Question 9

hemidesmosomes

Answer 9

attach a cell to the extracellular matrix

Question 10

outline cross section of skin

Answer 10

keratin: dead keratinocytes flaky
epidermis: full of keratinoctyes, sits on basement membrane
dermis: dense irregular CT
hypodermis: adipose tissue loose CT

Question 11

what is the basement membrane made of

Answer 11

fibres

Question 12

-blast

Answer 12

immature/growing

Question 13

-cyte

Answer 13

mature/decomposition

Question 14

functions of connective tissue

Answer 14

structural support and storage

Question 15

what are 4 main types of connective tissue

Answer 15

adipose
bone
blood
collagen

Question 16

outline collagen

Answer 16

• the most common fibre
• strong and inelastic
• arranges parallel or irregularly

Question 17

outline elastic fibres

Answer 17

consist of fibrillin and elastin
elastic
synthesised by fibroblasts, smooth muscle, chondrocytes
wavy shape

Question 18

outline reticular fibres

Answer 18

• delicate supporting mesh or framework

- allows adherance attachment of surrounding cells

Question 19

outline cartilage

Answer 19

• hard/strong

- 3 types: hyaline, elastic, fibrocartilage

Question 20

outline hyaline cartilage

Answer 20

most common
glass-like
found in articular surfaces of joints, respiratory cartilages, epiphyseal growth plates, C-shaped rings of cartilage in trachea

Question 21

outline elastic cartilage

Answer 21

yellowish
consists of a matrix of elastic fibres
found in external ear, epiglottis, auditory tube

Question 22

outline fibrocartilage

Answer 22

whitish
tensile strong bundles of collagen fibres
blends with adjacent tissue
found in intervertebral discs, link between tendon-bone, menisci of knee joint, symphysis pubis

Question 23

outline bone

Answer 23

3 types of cells: osteoblasts, osteoclasts and osteocytes.
rigid form of CT
develops mainly by endochondral ossification
2 types: compact and spongy

Question 24

what is endochondral ossification

Answer 24

where cartilage turns into bone

Question 25

outline compact bone

Answer 25

solid mass of calcified tissue outside encases spongy bone contains osteons

Question 26

What is an osteon

Answer 26

concentric lamallae that hold blood vessels, nerves, loose CT in bone. They have a haversian canal in the centre with osteocytes and their cytoplasmic processes.

Question 27

outline spongy bone

Answer 27

3d lattice of branching spicules or trabaculae that form a meshwork with bone marrow and fat. in pictures bone marrow is thicker than spongy bone

Question 28

outline adipose tissue

Answer 28

stores fat as adipose cells white blobs in pictures loose CT

Question 29

outline blood

Answer 29

The extracellular matrix is plasma and the cells are red/white blood cells and platelets. red=erythrocytes white=leukocytes

Question 30

specialised tissue

Answer 30

blood, bone marrow

Question 31

loose CT

Answer 31

storage properties, packing materials between cells and other tissue, many cells

Question 32

dense CT

Answer 32

Dominated by fibres and is used for strength/structure. Fewer cells. regular and irregular are based on the way collagen fibres are arranged.

Question 33

3 types of muscle tissue

Answer 33

skeletal, cardiac and smooth

Question 34

outline skeletal muscle

Answer 34

serves for movement, strength, support and heat generation | muscle fibre is made up of many myofibrils

Question 35

build up of muscle fibres

Answer 35

myofibril (regions of actin and myosin filaments) muscle fibre fascicle skeletal muscle

Question 36

cytoplasm, plasma membrane, ER muscle called

Answer 36

sarcoplasm sarcolemma sarcoplasmic reticulum

Question 37

epimysium, perimysium, endomysium

Answer 37

epi surrounds entrie muscle peri surronds fascicles endo surrounds muscle fibres

Question 38

explain the structure of myofibrils

Answer 38

I band are made of actin and are on ends A band made of myosin and actin in middle Z lines are sarcomeres between bands sarcoplasmic reticulum surrounds myofibrils and stores calcium causing contractions transverse tubules connect sarcolemma and sarcoplasmic reticulum vascular supply

Question 39

describe nuclei of skeletal muscle

Answer 39

many nuclei on peripheral due to hypertrophy and muscle cells joining and growing together.

Question 40

outline cardiac muscle

Answer 40

also has A I and Z bands cells are joined by intercalated disks: adherens-type junctions, desmosomes and gap junctions abundant mitochondria central not peripheral 1-2 nuclei

Question 41

outline smooth muscles

Answer 41

walls of hollow organs no striations but still have actin and myosin filaments for contractions by re-organisation "fusiform" tapered shape centrally located nucleus

Question 42

what are the 2 main parts of nervous tissue

Answer 42

central nervous system (brain, spinal cord) | peripheral nervous system

Question 43

all nervous tissue is composed of

Answer 43

neurons (nerve cells), supporting cells and blood vessels

Question 44

outline neurons

Answer 44

receive information from internal/external sources via dendrites process signals conduct nerve impulses (actin potentials) away from neurons

Question 45

what are the components of a neuron

Answer 45

``` cell body or soma (top part) cytoplasm=perikaryon dendrites (branches) 1 axon (long thing) mitochondria golgi and RER= nissl bodies microtubules and filaments lipofuscin-undigested materials from lysosomes ```

Question 46

outline dendrites

Answer 46

conduct electric signals towards cell body, branch profusely, similar to cell body without golgi

Question 47

outline axons

Answer 47

up to 1m long conduct nerve impulses around body lacks protein synthesising organelles

Question 48

motor (efferent) neurons sensory (afferent) neurons interneurons

Answer 48

- effector organs - receive stimuli from sources - establish relationships between other neurons

Question 49

what are glial cells

Answer 49

supporting cells that attach to neurons and help with homeostasis, scar formation, moping up neurotransmitters

Question 50

what are the glial cells in the CNS

Answer 50

astrocytes (star like) microglia oligodendrocytes

Question 51

what are the glial cells in the PNS

Answer 51

schwann cells

Question 52

what do oligodendrocytes and schwann cells do

Answer 52

attach to axon and produce myelin sheath. this helps with protection, increase speed of signal transduction

Question 53

build up of nervous systems

Answer 53

nerve fibers fascicle bigger cluster

Question 54

epineurium, perineurium, endoneurium

Answer 54

whole outside outside of fascicle outside of nerve fibres these contain mast cells (immune), blood vessels and fibroblasts

Question 55

what are ganglia

Answer 55

bundles of nerve cells that act as a relay station. they are in the PNS only and act between 2 muscle layers

Question 56

where does CNS have blood vessels

Answer 56

the blood-brain barrier

Question 57

grey matter | white matter

Answer 57

neurons and glial cells, lots of cells, inside | myelinated fibres, outside