Histology Flashcards
What is histology?
Study of tissues and their functions
How are epithelium classified?
The number of cell layers and the shape of cells in the top layer are used to classify epithelium
What are the 3 types of neurons?
Motor neuron
- impulses from CNS to muscles and glands
Interneuron
- Interprets input from sensory & end responses to motor
neurons
Sensory neuron
- receive info from environment & transmits to CNS
How many levels of tissue structure is there?
Tissues are organised at 4 different levels
What is the composition of bone?
Bone is composed of bone cells
- (osteoprogenitor cells, osteoblasts, osteocytes and
osteoclasts)
suspended in a matrix consisting of collagen fibres and minerals
Describe the features of skeletal muscle
- voluntary contraction
- striated - striations perpendicular to muscle fibres
- found attached to bones
- organised in myofibrils
- nuclei peripherally located
- banding pattern formed from one cell to another when
observed longitudinally
What are the 4 different levels of Tissue structure?
- Tissue structure - combination of cells
2. Cellular structure - organisation of organelles to aid cell
function
- Subcellular - detailed analysis of organelles and
inclusions - Histochemical - molecular analysis of cell structure
How does tissue development occur?
All tissues of the body develop from the 3 primary cell layers that form the embryo
What is the structure of loose connective tissue proper?
Many cell types & fibres in a gelatinous matrix found in skin and surrounding
blood vessels, nerves & organs with empty spaces present and organised
randomly
What is the composition of neuroglia?
Neuroglia made up of astrocytes, oligodendrocytes, ependymal cells &
microglia in the CNS
Schwann + stem cells in PNS
What are the 3 types of cartilage?
Hyaline Cartilage
- soft, weakest most abundant
- found at end of long bones, ears and nose
Elastic Cartilage
- maintains shape & is flexible
- branching elastic fibres distinguish it from hyaline
Fibrous Cartilage
- Strongest type, has dense collagen and little matrix
- found in pelvis, skull and vertebral discs
What are the 3 primary cell layers tissues develop from?
- Ectoderm –> nervous tissue and epithelial tissue
- Mesoderm –> epithelial, connective and muscle tissue
- Endoderm –> epithelial tissue
What are the 2 types of epithelial tissues?
- Covering and lining epithelia
2. Glandular epithelium (endocrine & exocrine)
What are the types of bone development?
Membranous - flat bones, clavicle or mandible
Endochondral - limb and vertebral column bones
What are the two classifications of connective tissue proper?
Loose connective
Dense connective
What is histopathology?
The study of tissues affected by disease
Name the different epithelium classifications
- simple squamos
- simple cuboidal (in renal collecting ducts)
- simple columnar
- transitional
- pseudostratified columnar (in trachae lining)
- stratified cuboidal (mammary gland duct lining)
- stratified squamous
What is the connective tissue matrix composed of?
- Ground substance: proteins & polysaccharides
- Fibres: reticular collagen and elastic
Describe muscle tissue
The principle functional unit is muscle fibre
There are stem cells present to develop into new muscle fibres
What are the different types of mature bone?
Compact - Cocentric, circular layers organised in lacunae
and a central canal
Trabecular - Slender , interlacing parallel lamellae with
marrow in the spaces
Describe the structure of epithelial tissue
Has apical and basal layers
(basal layer interacts with basement membrane)
The basement membrane separates the epithelila layer from the underlying connective tissue
What are cells?
Living, self sufficient entities that can form more complex structures (tissues) surrounded by a membrane
What is the composition of neurons?
Neurons are made up of a cell body, axon and dendrites
What are the two main groups of connective tissue
- Connective tissue proper
2. Specialised connective tissue
Describe the structural features of cardiac muscle
- involuntary contraction
- striated
- branched with intercalated discs
- cells smaller than skeletal muscle
- nuclei centrally located
What is the significance of transitional epithelium?
The top layer can change from one type to another
What are the different cell types within connective tissue?
- fibrobalsts
- macrophages
- mast cells
- adipocytes
What are tissues?
Interwoven masses of cells and extracellular material
What is the composition of epithelial tissues?
Made of cells arranged in a continuous hseet with one or more layers
What are the 2 main functional cell types nerve tissue consists of?
- Neurons: convert electrical stimuli to impulses
- Neuroglia: collection of different cell types with
supportive roles
What are the 4 main tissue types?
- Epithelial tissues
- Connective tissues
- Nerve tissues
- Muscle tissues
What is the significance of nerve tissue?
Constitutes both the CNS and PNS
What are pseudostratified epithelium?
When the epitheliums cells are all anchored to the basement membrane (one cell layer) but not all the cells reach the apical surface
The nuclei don’t align, making it look as though it’s not one layer
- the shape of the top layer of cells can be columnar, cuboidal or squamous
Describe the structural features of smooth muscle
- involuntary contraction
- not striated
- spinde shaped
- cells vary in size and have a fusiform
- nuclei in different positions
- found in blood vessels and GI tract
Describe Dense connective tissue proper
Bundles of parallel collagen fibres & fibroblasts found in tendons and ligaments in a packed organisation with no spaces between cells as they are elongated
What is Cartilage composed of?
Cartilage is made of 2 main components:
- collagen & elastin fibres embedded in glycoproteins
matrix
- Chandrocytes
What does stratified epithelium mean?
2 or more cell layers
What is meant by simple epithelium?
Epithelium of one cell layer
