Tissues 2 Flashcards
What are cum glands?
Collections of secretory epithelial cells (mostly)
Single celled or multicellular
What are the two types of glands?
Exocrine (secrete into tubes), and
Endocrine (secrete into blood)
Development of exocrine and endocrine glands?
Exocrine- epithelium dips down and maintains connection to surface
Endocrine- cuts off from the surface
Shapes of exocrine glands?
Simple- tubular (longer horseshoe shape) and acinar (shorter)
Compound- (more complex) tubuloacinar
Give the two examples of exocrine glands?
Mucous and serous glands
Describe mucous glands?
-secretion rich in proteoglycans
-secretion and water gives mucus
e.g. mucous glands of trachea and gastrointestinal
Describe serous glands?
-watery, with enzymes
-protein rich secretion
-e.g. exocrine pancreas
Merocrine gland secretion method?
-remain whole glands
-vesicles get secreted out by exocytosis into lumen of secretory unit
-most exocrine glands secrete this way
Apocrine gland secretion method?
-apex of cell and secretion gets secreted into lumen
Holocrine gland secretion method?
-whole cell becomes secreted
-cell regenerated by mitosis and cytokinesis
Where would you find merocrine gland secretion?
sweat, salivary glands , pancreas
Where would you find apocrine gland secretion?
breast glands
Where would you find holocrine gland secretion?
sebaceous glands for e.g. hair follicle
What cells help exocrine secretions come out?
-myoepithelial cells
-single cell, muscular type cells
-squeeze the acinus
How do endocrine glands secrete?
-proteinaceous in secretion
Pancreas glands?
-pancreas has both exocrine and endocrine secretions
-endocrine secrets insulin and glucagon
Abnormal functions of epithelial cells?
-over-proliferation
under-proliferation
over-secretion
under-secretion
loss of cilia / ciliary beat
Abnormal functions of pituitary glands?
Growth hormone
Over production – pituitary gigantism
Under production – pituitary dwarfism
Abnormal functions of uterine tube?
Mucous glands (single cell glands)
Chlamydia trachomatis (STD)
Thick mucus
Ovum/sperm trapped – infertility
What are the different types of connective tissue?
Blood / bone marrow
Mucous
Reticular
Loose
Dense - regular
Dense - irregular
Cartilage
Bone
Adipose (fat)
What makes up collective tissue?
-cells and ECM
-collective has fewer cells than epithelial
What makes up ECM?
- fibres (ropelike)
- ground substance ( jelly like)
-tissue fluid (liquid)
What makes up fibres?
-mainly collagen - reticulin (more irregularly arranged)
-elastin - form in sheets and wavy
What do collagen fibres look like?
-Collagen fibres look like skeletal muscle with striations
-periodicity of collagen fibres
What percent of body weight is collagen?
30%
What are characteristics of collagen?
-inelastic but flexible
-strong
-great tensile strength
How many types of collagen is there?
19+ types
What type of collagen is in tendons?
type 1
What type of collagen is reticulin?
type 3
What type of collagen in basal lamina? (non fibrous)
type 4
How does collagen form?
-form from cells known as fibroblasts
-fibroblasts blast out fibres
-collagenase enzyme secreted too by fibroblasts
-winds procollagen (secreted by fibroblasts) into triple stranded helix
-collagen fibril formed
-collagen fibre
Describe some characteristics of elastic fibres?
-tend to find in most blood vessels
-consists of protein elastin
-can stretch 1.5 x resting length and can return to normal shape
-microfibrils and amorphous component
-generally found in sheets rather than fibres
-yellow in colour (aorta)
What is ground substance of ECM composed of?
-semi solid gel
-proteoglycons (protein core and carb attached)
for r.g. Hyaluronic acid
Glycoprotein ( carb with protein attached) -more protein
What are the permanent cells in loose connective tissue?
Fibroblasts
Macrophages
Adipocytes
Mast cells
Undifferentiated mesenchyme cells
What are the transient cells in loose connective tissue?
white blood cells
What are the two types of dense connective tissue?
dense - regular
dense - irregular
Where might you find dense regular and irregular?
regular- tendon
irregular- dermis
Describe dense regular and irregular?
regular- cells in parallel rows, needs to pull in one direction, strong
irregular- more elastic
-can move in more directions
Abnormal functions of connective tissue?
Blood / bone marrow - leukaemia (too many WBC)
Loose / dense - loss/abnormal fibres
(epidermolysis bullosa)
Cartilage - tear
Bone – osteoporosis (rigid) /petrosis (thick)
What does a benign tumor look like?
not spread through basal lamina
What does a malignant tumour look like?
penetrated through basal lamina
How does tumor spread?
-cells grow as benign tumor in epithelium
-cells become invasive and enter capillary (malignant)
-cells adhere to blood vessel wall in liver
-escape from blood vessel to form micromestasis
-colonize liver forming full blown metastasis
