Anatomy Flashcards
What is histology?
The study of the microanatomy of cells and the integration of their visual appearance to their structure and function
What are the 4 main tissues?
Epithelial
Connective
Muscles
Nervous
Define anabolic
Small molecules combine to form 1 big one
Define catabolic
1 big molecule breas down into smaller molecules
What are the destinations of proteins synthesised by RER associated and free ribosomes?
RER associated -Synthesise proteins for secretion and addition to cell membranes such as channel/transporter proteins, excreted proteins such as hormones will be used outside of the cell
Free- Synthesise proteins to be used within the cell
What is the main histological preparation process?
- Carry out biopsy - collection of tissue from the specimine
- Sample placed in fixative fluid
- Sample dehydrate in a series of alcohol baths with anincreasing concentration (50, 70, 95, 100)
- Cells then placed into a paraffin bloc
- Paraffin bloc is heated and the cells absorb the wax as the bloc melts. As it cools the cells are embedded into the wax
- sample is sliced along the paraffin bloc approx 7um
- Sample is stained to see the tissue structure
- The sample can now be placed on a slide and viewed under a microscope
What is the main standard stain?
H&E Haematoxylin and Eosine
Haematoxylin - Basic stain
Stains nucleus purple due to the acidic nature of DNA
Eosine - Acidic stain
Stains cytoplams pink due to the basic nature of the proteins present and many other components
Why do you dehydrate the histological preparation sample?
Prevents water from the sample reacting with the stain or dehydration chemicals
What colour does the nucleus, cytoplasm and connective tissue appear after staining with HvG
HvG - Haematoxylin and Van Gieson
Nucleus - grey/blue
Cytoplasm - Green/yellow
Connective tissue - red (collagen)
How are epithelial tissues classifiied?
Number of cell layers - 1 layer = simple… 2 layers = Stratefied
Shape of cells - Squamous, cuboidal, columnar
Specialisation - Microvilli, cilia, keratinisation, Goblet cells
What is the apical and basal layer?
Apical - Top layer facing the lumen
Basal - Bottom layer facing the connective tissue
Where would simple columnar epithelia be found and what would be its funciton?
Found - Gall bladder, small intestine
Use - Absorption of substances
Where would simple cuboidal epithelia be found and what would be its function?
Found -Collecting tubes of kidney, small excretory ducts and pancreas
Use - exretory, secretory or absorptive functions
Where would simple squamous epithelia be found and what would be its function?
Found - alveoli, blood vessels, lining/body cavities
Use - selective diffusion, absorption, secretion
What would simle columnar ciliated epithelia be found and what would be its funciton?
Found - Fallopian tubes
Use - Ciliary action aids transport of the ovum from the ovary
What would stratefied squamous epithelia be found and what would be its function?
Found - Ora cavity, pharynx, eosophagus, anal canal, uterine, cervix and vagina
Use - Protective function due to large number of cells
Where would pseudostratefied columnar ciliated epithelia be found and what would be its function?
Found - Respiratory tract and in nose and sinuses
Use - Cilia move mucus around respiratory tract
What are some functions of epithelia tissue?
Interface between internal and external environment
Selective diffusion, absorption and secretion
Form glands
What are the importance of intracellular contacts/Junctions?
Maintain cell polarity
Maintain tissue integrity (retaining flexibility)
Medaitors of metabolic and information exchange
Define vascular and Avascular?
Vascular - Blood vessles present
Avascular - lacks blood vessels
Epithelia are avascular
What is the function of tight Junctions?
Limit paracellular transport
Help maintain cell polarity
What is the anatomical classification of muscles?
Skeletal muscle - Attaches to bones
Cardiac muscle - the heart
Smooth/visceral muscle - internal organs and vessels
What is the histological classification of muscles?
Straited - Skeletal /cardiac
Smooth - Visceral
What is the physiological classification of muscles?
Voluntary - Skeletal
Involuntary - Smooth/cardiac
What are the components of microfilaments of muscle?
Thin - Actin, troponin, tropomyosin
Thick - Mysoin
What are the different sections of a sarcomere?
A band - Mysoin filaments, actin filaments
I band - Actin filaments
H zone - Only myosin
Z line - end of sarcomere
What happens to parts of a sarcomere upon muscle contraction?
H band disappears
I band Shortens
What are the different sections of connective tissue associated within mucles?
Epimysium - Encases all fascicles (bundles of muscle fibres) forming complete muscle
Perimysium - Encircles around a group of muscle fibres forming fascicles
Endomysium - Surrounds muscle cells within a muscle fibre
What are some histological properties of skeletal muscle?
Striated Multinucleated peripheral nucleus Flattened nucleus No branching Elongated fibres No intercalating discs T-tubules system Innervated by a single motor axon
What are some histological properties of Cardiac muscle?
Striated Central nucleus Shape of nucleus is normal branching of muscle fibres Shape of fibres is fibrous Intercalating discs present T-tubules system Innervated by sympathetic nervous system
What are some histological properties of smooth mucsle?
Non-striated Central nucleus Nucleus shape is normal No branching Fibres are spirally shaped Has Gap Junctions No T-tubules system Innervated by the sympathetic nervous system
What are the 3 layers of the skin?
Epidermis - Provides a protective barrier with the outside environment
Dermis - Support and blood vessels, also contains hair folicules and sweat glands
Hypodermis (subcutis) - Adipose tissue