Body logistics (7-12) Flashcards
how are exocrine glands classified
shape
simple/ compound
type of secretion
exocrine glands shape
- tubular
- acinar
tubular
elongated
acinar
grape shape
simple exocrine glands
drain to one duct
compound exocrine glands
multiple ducts drain to common duct
structure of a gland
duct portion at the top where products secreted
secretory portion- main, lower body of the duct
types of exocrine secretion
serous
mucous
serous
watery proteinaceous fluids
- lubrications
mucous
mucus rich in glycoprotein
a common unicellular gland
goblet cell
goblet cell
simple columnar epithelial cells that secrete mucus
where are goblet cells found
- upper resp tract
- jejunum, colon
function of goblet cell (unicellular)
- lubrication
- protection
- trap dust and microbes
parotid salivary gland is the
biggest salivary gland
parotid gland secretion type
serous- salivary amylase
what innervates the parotid salivary gland
parasympathetic innervation
function of parotid salivary glands
- secrete enzyme- digest food
- secret serous- lubricates bolus
duct system in parotid glands
Acinar (where serous and mucous membranes are found)–> intercalated duct –> striated duct –> interlobular duct –> principle duct
submandibular gland found
a salivary gland found on the jaw
secretion type of submandibular glands
serous, mucous and mix (demilune)
stimulation of submandibular
parasympathetic- watery saliva (enzyme)
sympathetic- thick saliva (mucus)
where are myoepithelial cells found
role in normal mammary glands
- wraps around the edges of luminal acinar cells (where serous produced)
role of myoepithelial cells
able to contract- expelling luminal continents from acinar e.g. milk
features of myoepithelial cells
flattened nuclei- diff to see in histology
what give myoepithelial cells the ability to contract
actin and mysoin filaments
anatomical location of the ,liver
upper right abdomen- below diaphragm
histological features of liver
parenchymal and non parenchymal cells
- hepatocytes
- kupffer cell
- stellate cells
hepatocyte role
storage of iron, fat soluble vitamins and glycogen
synthesis of protein, bile, cholesterol
breakdown of hormones, drugs and toxins
kupffer cells
ingest pathogens
recycle RBC
stellate cells
vitamine A storage
types of muscle tissue
skeletal
cardiac
smooth
myoglobin present in
skeletal and cardiac muscle
which muscle type. has voluntary control
skeletal
which muscle has involuntary control
cardiac and smooth
nerve muscle communication in skeletal muscle
direct
nerve-muscle communication in cardiac
indirect
nuclei arrangement ins skeletal muscle
right on the periphery
nuclei arrangment in cardiac and smooth
central
which muscle is striated
skeletal and cardiac
1 muscle fibre =
1 striated muscle cell
- many myofibrils
- nucleus on periphery
- T tubules
- mitochondria (sacrosome)
- sarcolemma
- sarcoplasm
- SR
a band
dark- thick myosin filament and slight cross over with thin actin
- stays same size during contraction
I bands
light- thin actin filament
- get smaller
z disc
middle of the I band
- get closer during contraction
M band
in the middle of the sarcomere
myofibrils forms
muscle fibre
muscle fibers form
muscle fascicles
muscle fascicles form
skeletal muscle
muscle contraction at the NMJ
1) Nervous impulse arrive at NMJ
2) Ach released into synaptic cleft- binds to each receptors on the post-synaptic membrane
3) depolarisation of sarcolemma
4) voltage-gates Na+ channels opens nd sodium enters the cell
5) depolarisations reads across the sarcolemma and down into the T tubules
6) Voltage gated ca channels of terminal cisternae open
7) calcium released into sarcoplasm
8) Ca binds to TnC (subunit of troponin)- contractile cycle intitiated
myasthenia gravis is what type of disease
autoimmune
summary of myasthenia gravis
antibodies block NAch receptors- reducing sympathetic transmission–> muscle weakeness
symptoms of myasthenia gravis
- ptosis, diplopia
- fatigue at end of day
- loss of breathing control (myasthenia crisis)
treatment of MG
- immunosuppressive drugs
- acetylcholinesterase inhibitor
botulism and the NMJ
clostridium botulinum produces botulinum Toxin A
- block NT release at motor end plate
clinical use of botulinum A
muscle spasms, wrinkles
organophosphate poisoning
inhibits Ach esterase–> continuous Ach activity at NMJ
symptoms of organophosphate poisoning
cholinergic toxidrome
cholinergic toxidrome Muscarinic symptoms
S- salivation L- Lacrimation U- urination D- defecation G- GI cramping E- emesis
cholinergic toxidrome nicotinic symptoms
M- muscle cramps T- tacky cardia W- weakness T- twitching F- fasciculations
sliding filement model
1) myosin head hydrolyses App to ADP + P, reorientates itself and reenergises
2) Myosin heads bid to actin- cross bridges forms, P is released
3) myosin head tilts towards the centre of the sarcomere, ADP is released
4) New ATO binds to myosin head- cross bridge detach from actin
Skeletal muscle histology
- peripheral
- striated
- 3 contractile cell types
name the 3 contractile cell types of skeletal muscle
- Slow twitch- type 1
- fast twitch
- -> Type 2A
- -> Type 2B
Type 1 skeletal fibres
slow twitch
- rich capillary supply
- aerobic
- high myoglobin levels
- many mitochondria
- many cytochromes
- red
- fatigue resistant
- endurance type activities
- standing/ walking
Type 2A muscle fibres
fast twitch
- rich capillary supply
- aerobic
- high myoglobin
- many intermediate mitochondrial numbers
- many cytochromes
- red to pink
- moderate fatigue resistance
- assists type 1 and type 2B actiivites
- standing/ walking
Type 2B muscle fibres
fast twitch
- poor capillary supply
- anaerobic
- low myoglobin levels
- few mitochondria
- few cytochromes
- white
- rapidly fatigues
- strengths/ anaerobic type activities
- e.g. sprinting
which muscle fibres are red/ pink
Type 1 and Type 2A
- myoglobin
which muscle fibres are white
Type 2B- fastest twitch
- no myoglobin
cardiac muscle histology
Nuclei- central and large
- striations
- intercalated discs
- branching
- sarcomere not fully developed
- no T tubules
- 1 contractile cell tyope
Purkunje fibres
no contractile machinery
- many glycogen and gap junctions
purkunje fibres in the heart allow
rapid conduct- ventricles contract in synchronous manner
smooth muscle hisotlogy
Nuclei- central and large
- fusiform (spindle-like shape that is wide in the middle and tapers at both ends)
- non striated
- no T tubules
- 1 contractile cell type
muscle hypertrophy
repeated exercise –> microtears of muscle fibres–> new and extra myofibrils added
muscle atrophy
caused byL immobilisartion, denervation of muscle and muscular dystrophy
- wasting of muscle tissue due to lack of use
Duchenne muscular dystrophy inheritance
X-linked recessive
- dystrophin gene mutation
pathophysiology of Duchenne muscular dystrophy
- absence of dystrophin
- excess calcium enter muscle cell
- calcium uptakes by mitochondria
- water drawn into mitochondria- burst
- rhabdomyolysis
- CK and myoglobin released into plasma
rhabdomyolysis
rhabdomyolysis is a condition in which damaged skeletal muscle breaks down rapidly
symptoms of Duchenne muscular dystrophy
- shoulders arms held backwards
- belly sticks out
- thin, weak thighs
- poor balance
definition of connective tissue
tissue that connects, supports, binds or separates other tissues or organs
structures of connective tissues
Cells, fibres and ground substance
which cells make up connective tissue
- fibroblasts
- adipocytes
- reticular cells
which fibres make up connective tissue
collagen, elastin, reticular fibres
what makes up ground substance
- Viscous clear substance with slippery feel (high water content)
- Composed of proteoglycans called GAGs e.g. hyaluronic acids
what makes up the ECM in connective tissue
ground substance and fibers
function of connective tissue
- binding
- supporting
- protecting
- insulating
- separation of tissue
fibroblasts secrete
procollagen
myofibroblast
wound contractionwo
adipocte
fat storage
mesenchymal stem cells
replenish cells
mast cells
histamine release
macrophages
APCs
types of fibres found in ECM of connective tissue
collagen
reticular
elastic
collagen has
high tensile strength and flexibility
how many types of collagen
5
type I collagen
most common (90%) - tendons, ligaments, dermis
type II collagen
hyaline and elastic cartilage
type III collagen
lymphoid tissues and organs
RETICULIN
type IV collagen
basement membrane- epithelial tissue
Type V
skin, placenta
elastic fibres in connective tissue
elastin and fibrillin
features of ECM- ground substance
gel like extracellular space that contains proteoglycans
proteoglycan
core protein with covalently bonded glycosaminoglycans (GAGs)
GAG
very hydrophilic
- permits rapid diffusion
- resist compression
loose connective tissue function
holds vessels
- permits migration
- stabilities organs
composition of loose connective tissue
- highly cellular
- sparse fibres
- abundant ground substance
distribution of loose connective tissue
capillaries, lamina propria
- around glands
dense connective tissue can be
regular and irregular
dense connective tissue general composition
few cells
- abundant fibres- collagen
irregular dense connective tissue
- contains fibroblasts
- Collagen I fibres in all directions
- resists stress in all directions
examples of irregular dense connective tissue
- deep layers of the dermis
- submucosa of intestine
regular dense connective tissue
- cotnains fbroplastas
- collagen 1 fibres in parallel
- resists stress in only one direction
examples of regular dense connective tissue
- tendons
- ligaments
- aponeuroses
