Histology: The Cell and Organisation of Tissues
08 February 2016 17:16
• Cell membrane:
Bilipid layer, fluid mosaic model.
Phospholipids can move in relation to each other.
Semipermeable
Breaks and tears are sealed quickly.
Proteins can become embedded.
• Centriole:
Pairs, arranged perpendicular to each other.
Found near nucleus (centrosome, cell centre)
Organises micro tubular network within cell and cilia.
• Rough Endoplasmic Reticulum:
Network of tubules, vesicles and flattened cisternae.
Protein synthesis, modification of newly synthesised protein by glycosylation (reaction in
which carbohydrate is attached to hydroxyl).
• Smooth Endoplasmic Reticulum:
Lipid biosynthesis, protein processing and intracellular transport by packaging of products into
vesicles.
• Golgi Apparatus:
Modification by addition of sugars.
Proteolysis (breakdown of proteins into smaller polypeptides or amino acids, catalysed by
cellular enzymes – proteases).
Sorting and packaging of macromolecules into vesicles for transport within cell and for
secretion.
• Microtubules:
Hollow fibres present in all cell except red blood cells.
Formed from 2 protein sub units, α and β tubulin, join to form protofilament chains.
Arranged in groups of 13.
Functions – intracellular transport, form cell cytoskeleton, form centrioles.
• Microfilaments:
Composed of actin.
Form crosslinked mesh which provides mechanical support to cell membrane.
Form bundles which extend beyond the cell membrane to form microvilli.
Actin interacts with myosin to generate motion.
• Microvilli:
Small projections found on apical surfaces of most epithelial cells.
Number and shape correlates with the absorptive capacity of the cell.
Function – increase surface area of the cell.
Tissue Types:
Tissue Nature
Type
Epitheliu Forms sheets of cells.
m Squamous (flat) cells - skin
Glandular cells – form glands, synthesize, secrete and absorb
Transitional cells – lining kidney, bladder and urological tract. Can stretch and recoil to
accommodate variable volumes of urine.
Connecti Supports and links other tissues.
ve Adipose – adipocytes (fat cells/ store fat), energy reserve, insulation and involved in
peripheral synthesis of some hormones.
Fibrous connective tissue – fibroblasts make collagen (protein secreted out of cells into
spaces between organs). Forms extracellular matrix, flexible but tough tissue, helps to
hold soft organs in place within the body. Tendons are example.
Week 1 Page 1
, hold soft organs in place within the body. Tendons are example.
Bone Bone is laid down by osteoblasts onto a preformed structure of cartilage or fibrous tissue
by ossification.
Osteoclasts ‘remodel’ the bone in response to weight or other forces. Consists of a large
amount of extra-cellular calcified connective tissue with mature bone cells (osteocytes)
Cartilage in it.
Chondrocytes (cells) synthesize and secrete the extra-cellular matrix material
(glycoaminoglycans) which make up cartilage.
Chondroblasts form areas of cartilage by their increase in number which lay down the
cartilage matrix. Once laid down, chondroblasts become less active and now termed
3 types of cartilage, classified depending on fibrous proteins:
chondrocytes.
• Hyaline cartilage - Type II collagen. Created as a temporary skeleton for the formation
of bone, and is found in joints and the lungs.
•Fibrocartilage - Type I & Type II collagen. Is found in intervertebral discs and tendon
attachment to bones.
•Elastic cartilage - Type II collagen and elastic fibres. Found in the ear, epiglottis and
Blood larynx.
Blood cells and plasma.
Muscle Contractile tissues.
Nervous Nerves, ganglia and CNS.
Week 1 Page 2
, Introduction to the Living Cell
08 February 2016 21:28
Cells: Fundamental unit of all things living on earth.
Surrounded by plasma membrane.
Exchange molecules with their surroundings e.g. sugars, amino acids and ions.
Hereditary information is stored as DNA.
Number of cells in human body: 3.72x10 13 (37 trillion).
Small cell: (mycoplasma genetalium, image) 0.3µm (10 -6), 10-14g.
3 main domains:
Bacteria
Archaea
Eukaryotes
Taxonomy: academic discipline of defining groups of biological organisms on the basis of shared characteristics.
Phylogenetics: study of evolutionary relationships among groups of organisms.
Catabolic = exergonic
Anabolic = endergonic
Composition of Human Body:
Molecule % of Mass
Water 65
Protein 20
Lipids 12
Inorganics 1.5
RNA 1
Organics 0.4
DNA 0.1
Homeostasis: ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological
processes.
Properties shared by all cells:
Order
Metabolism
Evolution
Reproduction
Homeostasis
Growth
98% of cells in the body turnover every year.
Week 1 Page 3
, 98% of cells in the body turnover every year.
Week 1 Page 4
08 February 2016 17:16
• Cell membrane:
Bilipid layer, fluid mosaic model.
Phospholipids can move in relation to each other.
Semipermeable
Breaks and tears are sealed quickly.
Proteins can become embedded.
• Centriole:
Pairs, arranged perpendicular to each other.
Found near nucleus (centrosome, cell centre)
Organises micro tubular network within cell and cilia.
• Rough Endoplasmic Reticulum:
Network of tubules, vesicles and flattened cisternae.
Protein synthesis, modification of newly synthesised protein by glycosylation (reaction in
which carbohydrate is attached to hydroxyl).
• Smooth Endoplasmic Reticulum:
Lipid biosynthesis, protein processing and intracellular transport by packaging of products into
vesicles.
• Golgi Apparatus:
Modification by addition of sugars.
Proteolysis (breakdown of proteins into smaller polypeptides or amino acids, catalysed by
cellular enzymes – proteases).
Sorting and packaging of macromolecules into vesicles for transport within cell and for
secretion.
• Microtubules:
Hollow fibres present in all cell except red blood cells.
Formed from 2 protein sub units, α and β tubulin, join to form protofilament chains.
Arranged in groups of 13.
Functions – intracellular transport, form cell cytoskeleton, form centrioles.
• Microfilaments:
Composed of actin.
Form crosslinked mesh which provides mechanical support to cell membrane.
Form bundles which extend beyond the cell membrane to form microvilli.
Actin interacts with myosin to generate motion.
• Microvilli:
Small projections found on apical surfaces of most epithelial cells.
Number and shape correlates with the absorptive capacity of the cell.
Function – increase surface area of the cell.
Tissue Types:
Tissue Nature
Type
Epitheliu Forms sheets of cells.
m Squamous (flat) cells - skin
Glandular cells – form glands, synthesize, secrete and absorb
Transitional cells – lining kidney, bladder and urological tract. Can stretch and recoil to
accommodate variable volumes of urine.
Connecti Supports and links other tissues.
ve Adipose – adipocytes (fat cells/ store fat), energy reserve, insulation and involved in
peripheral synthesis of some hormones.
Fibrous connective tissue – fibroblasts make collagen (protein secreted out of cells into
spaces between organs). Forms extracellular matrix, flexible but tough tissue, helps to
hold soft organs in place within the body. Tendons are example.
Week 1 Page 1
, hold soft organs in place within the body. Tendons are example.
Bone Bone is laid down by osteoblasts onto a preformed structure of cartilage or fibrous tissue
by ossification.
Osteoclasts ‘remodel’ the bone in response to weight or other forces. Consists of a large
amount of extra-cellular calcified connective tissue with mature bone cells (osteocytes)
Cartilage in it.
Chondrocytes (cells) synthesize and secrete the extra-cellular matrix material
(glycoaminoglycans) which make up cartilage.
Chondroblasts form areas of cartilage by their increase in number which lay down the
cartilage matrix. Once laid down, chondroblasts become less active and now termed
3 types of cartilage, classified depending on fibrous proteins:
chondrocytes.
• Hyaline cartilage - Type II collagen. Created as a temporary skeleton for the formation
of bone, and is found in joints and the lungs.
•Fibrocartilage - Type I & Type II collagen. Is found in intervertebral discs and tendon
attachment to bones.
•Elastic cartilage - Type II collagen and elastic fibres. Found in the ear, epiglottis and
Blood larynx.
Blood cells and plasma.
Muscle Contractile tissues.
Nervous Nerves, ganglia and CNS.
Week 1 Page 2
, Introduction to the Living Cell
08 February 2016 21:28
Cells: Fundamental unit of all things living on earth.
Surrounded by plasma membrane.
Exchange molecules with their surroundings e.g. sugars, amino acids and ions.
Hereditary information is stored as DNA.
Number of cells in human body: 3.72x10 13 (37 trillion).
Small cell: (mycoplasma genetalium, image) 0.3µm (10 -6), 10-14g.
3 main domains:
Bacteria
Archaea
Eukaryotes
Taxonomy: academic discipline of defining groups of biological organisms on the basis of shared characteristics.
Phylogenetics: study of evolutionary relationships among groups of organisms.
Catabolic = exergonic
Anabolic = endergonic
Composition of Human Body:
Molecule % of Mass
Water 65
Protein 20
Lipids 12
Inorganics 1.5
RNA 1
Organics 0.4
DNA 0.1
Homeostasis: ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological
processes.
Properties shared by all cells:
Order
Metabolism
Evolution
Reproduction
Homeostasis
Growth
98% of cells in the body turnover every year.
Week 1 Page 3
, 98% of cells in the body turnover every year.
Week 1 Page 4
