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
What are the functions of the skin?
Protection - UV light, Mechanical stress
Sensation - touch, pressure, pain, temperature
Thermoregulation - hairs, sweat glands, blood vessels, adipose tissue
Metabolic functions - Vitamine D synthesis
Sexual signalling - Visual features, sex pheromone production
What are the apendages of the skin?
Hair, hair folicles
Sweat glands
Subaceous glands
What are the properties of the epidermis?
Apical outermost layer
Stratefied squamous epithelia
keratinised
What are the epidermal layers?
Stratum cornea
Straum granulosum
Stratum spinosum
Stratum Basal
What is the extra layer of the epidermis in the palms of hands and soles of feet?
Stratum lucidum between cornea and granulosum
What are the properties of the dermis?
Connective tissue Hair folicles sensory receptors Sweat glands Subaceous glands Blood vessels
What are the properties of the hypodermis?
Adipose tissue
What are the function of eccrine glands (sweat glands)?
Secrete water to the skin surface which then cools the body by evaportation
What is the funciton of apocrine glands?
Secrete substances whcih produce a sent
WHat does the subaceous gland do?
keeps the skin moist by secreting an oily substance to the surface
What is connective tissue?
Tissue of mesodermal origin providing structural support and metabolic support for the other tissues and organs in the body.
What is connetive tissue made up of?
Made up of fibres, ground susbtance and cells
What are the types of connective tissue?
Loose connective tissue
Dense connective tissue
Cartilage and bone
What are the components of loose connective tissue?
Hydrate ground substance Collagen fibres Elastin fibres Fibroblasts Immune system cells Blood vessels Adipose tissue
What is the function of loose connective tissue?
Surrounds blood vessels and underlies all epithelia.
site of exhcange between capillary and tissues (metabolic)
Provides environment for exchange of nutrients and waste products between tissues and the blood
What are the components of dense connective tissue?
Fibroblasts collagen elastin reticular fibres Sparse ground substance Some immune cells
What is the function of dense connective tissue?
Provides tough physical support and protection in ligaments, tendons and the dermis of the skin.
Has both regular and irregular forms depedning on the shape and order of collagen fibres
What is gound substance?
Amorphous fluid which surrounds the fibres and cells which is highly hydrated
What are the components of gound substance?
Hyaluronic acid - provides strength
Heparan sulphate
keratan sulphate
What types of fibres are present in connective tissue and what are their functions?
Collagen fibres - provide high tensile strength
Elastin fibres - provide ability to stretch and recoil bac to its original shape
Reticular fibres - provides a scaffolding for cells
What are the functions of the 2 types of adipose tissue?
White - storage of triglycerides as energy reserve and for metabolic roles
Brown - Metabolises triglycerides for heat under NS control
What are the funcitons of chondroblasts and osteoclasts?
Chondroblasts - Secrete the elastin and collagen fibres appropriate to the cartilage type GAGs that bind to water
Osteoclasts - secrete the organic osteoid matrix and collagen fibres, the matrix being mineralised later to form bone
What is cartilage?
Avascular connective tissue found on all articular surfaces of all synovial joints.
Forms the flexible skeleton of the nose, larynx, pinna of the ear and costal cartilages of the ribs
Highly hydrated meaning it can withstand compressive foces to provide almost frictionless surface
What are the different types of cartilage?
Hyaline
Elastin
Fibrous
What is the structure of Hyaline cartilage?
Highly hydrated ground substance of 3 GAGs (hyaluronic acid, chondroitin sulphate, keratan sulphate)
High density of collagen fibres
What is the function of hyaline cartilage?
Support movable joints between bones due to its frictionless surface and high strength capacity to act as a shock absorber
Where would hyaline cartilage be found?
At ends of bones in free moving joints. at ends of ribs Nose Pharynx Trachea
What is articular cartilage?
Specialised form of hyaline cartilage on the articulating surfaces of bone without nervese/vasculature
Smooth surfaced with a low friction coefficient & collagen fibres orientated parallel to the surface of the bone allowing bones to glide over each other
What is the structure of elastic cartilage?
Structurally similar to hyaline cartilage but also consists of many elastic fibres lying in a solid matrix
What is the function of elastic cartilage?
Due to its strength and elasticity, elastic cartilage is used to maintain shapes of structures such as the external ear
Where would elastic cartilage be found?
Larynx
Pinna of the ear
What is the structure of fibrous cartilage?
The type of collagen is type 1 compared to other cartilage types having type II cartilage
What is the function of fibrous cartilage?
Very tough and strong and is found predominantly in the intervertebral disks and at the intersections of ligaments and tendons
What is orceine?
Type of stain for elastic fibres
What are the cells present in cartilage?
Chondroblasts - At outer edge of cartilage and secrete ECM
Chondrocytes - Make matrix and maintain the cartilage ECM
What is the functional significance of the perichondrium?
Functions in growth and repair of cartilage
What is bone?
Living tissue which is a form of dense irregular connective tissue containing large amounts of collagen and a mineralised ECM
What are the different types of bone?
Compact bone - Corticle/lamellar
Spongy boen - Cancellous bone
Woven bone - type of cancellous bone
What are the functions of bone?
Mechanical support / movement
Calcium homeostasis
Haematopoeisis
What is osteoporosis?
Metabolic bone disease
Leads to skeletal fragility and an increased risk of fracture
What are the various cells in bones and what are their functions?
Osteoblasts - Cells that form bone
Osteocytes - A cell that lies in fully formed bone occupying a lacuna contained in a calcified matrix
Osteoclasts - role in bone remodelling and errode old/damaged bone to then be developed into woven bone and further remodelled into corticle or cancellous bone
What is an osteon?
Osteons (haverisan system) consist of concentric layers of osteocytes surrounding a central canal containing blood vessels, nerves and a lining of osteoblasts
What is woven bone?
Developing boind or bone formed directly after fractures where the collagen fibres are arranged in a random orientation
What is corticle/lamellar bone?
80% of adult bone where osteoblasts have laid down the matrix in concentric rings forming osteons and the haversian systems
Forms the peripheral aspect of all bone
What is cancellous bone?
Marrow bone which has spaces containing haematopoietic cells (red marrow) or fat (yellow marrow)
Hollow interior is supported by trabuclea
What are trabuclea?
Boney struts arranged along stress lines
What happens if bones lose thier blood supply?
Death of tissue - avascular necrosis
What are the components of ground substance of bone?
GAGs
Hydroxyapartite crystals
Calcium sulphate
