locomotion Flashcards
what is movement and locomotion
movement and displacement
how does movement help us
- to maintain equilibrium of body
- capture food
- ingestion,defence and locomotion
- peristalsis
- pumping of heart
types of movements
1.amoeboid/psuedopodial: due to the streaming of protoplasm
seen in amoeba,macrophages, wbc,microfilaments
2.cillary movements: surface of cells have small hair like structures. have an oar like movement creating a current
seen in repro(oviduct) and respiratory tracts and paramoecium
3. flagellate: flagella for locomotion as in sperm and protozoa
4.muscular
5.proctosomes(tentacles) in hydra
how does locomotion help us
to get food finding shelter mating protection from predators migration
where is muscle from
specialied tissue fromthe germ layer mesoderm
cells that make muscle
myocytes
no. of muscles in human body
639
unique properties of muscles
contractibility,excitability,extensibility and elasticity
weight of muscles
40-50%of human body weight
biggest muscle in the body
gluteus maximus in the butt
smallest muscle in the body
stapedius in the middle ear
thinner than a cotton thread
muscle is covered by a sheath of connective tissue
epimysium
protects from friction
inside the epimysium, a muscle has many muscle fibres arranged in a bundle called
fasciculi
what is fasciculi surrounded by
perimysium
the muscle fibres in the fasciculi
parallel to eachother and the the muscle fibres in the fasciculi are surrounded by endomyseium
what are muscle bundles bound together by
fascia, it lies above and covers the epimysium
what is tendon
inelastic connective tissue
joins bone to muscle
types of muscles
- skeletal/striped/voluntary
- visceral/smooth/involuntary
- cardiac
striated muscles(14)
cylindrical blunt ends unbranched occur in bundles good blood supply voluntary get impulses from cranial and spinal nerves intercalated disc absent multinucleated a good number of mitochondria abundant myoglobin deep striation quick contraction easily get fatigued
in hindlimbs,forelimbs,bodywall, tongue, pharynx, upper oesophagus
smooth muscles (14)
these are spindle shaped tapering ends unbranched occur single,in sheets and small bundles poor blood supply involuntary controlled by autonomic nervous system intercalcated disc absent uni nucleated few mitochondria poor myoglobin no stripes slow contractions no fatigue
NOT ORGANISED PARALLELY they are present in organs
cardiac muscles(14)
cylindrical blunt ends branched fibres 3d network rich in blood supply involuntary under autonomic nervous system intercalcated discs present uni nucleated mitochondria are abundant abundant myoglobin faint stripes rhythamic contractions never fatigue
only in heart, they are autogenic and myogenic
busiest muscle
eye
number of muscles to smile
17
muscles in the root hairs
goose bumps
anatomical unit of muscle
muscle fibre
what is muscle fibre covered by
sarcolemma( a plasma membrane)
what does the sarcolemma enclose
sarcoplasm which contains many nuclei
what do the muscle fibres contain
parallely arranged myofibrils
alternate dark and light bands
what are formed over the myofibrils
t tubules/transverse tubules
what is a myofibril made up of
2 types of myofilaments thick myofilament(myosin) thin myofilament (actin)
the endoplasmic reticulum in the sarcoplasm
sarcoplasmic reticulum
a storehouse of calcium for muscle contraction
the dark band on myofibril
A band ( anisotropic band)
light band on myofibril
I band(isotropic band)
the centre of A band
a slightly lighter area called the H band or the hensen zone
the M line
a dark line passing through the H zone
centre of I band
dark line passing called the Z line
the part between two successive z lines
sarcomere
what is the sarcomere
structural and functional unit of a myofibril
what does a sarcomere consist of
2 half of I bands and 1 whole A band
what is the dark A band made of
thick myosin and little bit of the thin actin extends into it
what is the light I band made of
only thin actin
what is myoglobin
an oxygen and fe binding protein. found mainly in haemoglobin but in muscles it helps in storing oxygen in the muscles
structure of myosin
the thick myofilament which are made of polymerised protein myosin
monomers of meromyosin make myosin protein
each meromyosin has two parts( globular head with a short arm and tail)
globular head + short arm is the HEAVY MEROMYOSIN
tail is the LIGHT MEROMYOSIN
the globular head is the site for ATP binding and actin . the head also produces ATPase which hydrolysis ATP to produce energy
the myosin molecule forms a tadpole structure. the head and the short arm protrude out of the body and make bridges with actin
the appearance of myosin filament
thick dark and rough surface due the cross bridges and it is free at both ends.
structure of the thin filament(actin)
made up of three proteins(actin,tropomyosin,troponin)
actin: the globular protein which is light weighted molecule. it occurs as monomeric g actin and polymeric F actin. in the presence of magnesium ions,the G actin turns to F actin
tropomyosin: a fibrous molecule. two tropomyosin molecules run closely along the entire length of the actin. at the resting phase, it separates the actin and myosin by binding to the myosin-binding site on the actin
it prevents the formation of cross-bridges.
troponin: at regular intervals of tropomyosin. it makes the active binding sites for myosin on actin filament. it is a trimeric protein
1. troponin I: inhibits actin myosin interaction and binds to other components of troponin
2. troponin T : binding site for tropomyocin
3. Troponin C: binding site for calcium
appearnce of actin filaments
thin, light,smooth due to no cross bridges,free at one end and joined to Z line at other
ration of myosin actin
myosin< actin
3 myosin surround 1 actin
6 actin surround 1 myosin.
what is end plate
nuero muscular junction which recieves impulse from the motor neuron and causes depolarization of the skeletal muscle.
the impulse can be electrical,chemical,thermal,mechanical, hormonal
who gave mechanism of muscle contraction.
sliding filament theory by hugh huxley and jean hanson
the sliding filament theory
it the theory where the chemical energy from impulses is converted into mechanical energy of muscle contractions
the myosin head always wants to bind with the actin filament, but the actin filament is always bound to tropomyosin and troponin
luckily, the troponin can be bought over by ca ions and ATP
the action potential is generated via the motor neurons from the CNS. the action potential via acetylcholine reaches the sarcolemma.
it then spreads from the sarcolemma to the t tubules. then impulse then stimulates the sarcoplasmic reticulum to release calcium ions into the sarcoplasm
troponin c of the actin binds with the calcium ions and hence change its shape, the shape change causes the troponin t- tropomyosin complex to move away from the actin.
the myosin binding site is free on actin which then causes the globular head of myosin to release ATPase which breaks the ATP to ADP and inorganic phosphate.
it causes the head to stretch and then causes it to bind with actin.
te actin contracts and it moves closer to H line. the MYOSIN DOES NOT MOVE.
with the help of phosphocreatine, ADP turns back to ATP and the actin-myosin link is broken,
the calcium ions move back into the sarcoplasmic reticulum( with the help of calcium binding proteins called calsequestrin), therefore causing actin to come back to its normal state and the actin moves away from the H zone
the enzyme AchE( acetylcholinesterase) causes the breakdown of acetylcholine in the synaptic cleft,therefore killing the impulse.
muscle twitch
quick isolated contraction of a muscle, to a single stimulus of threshold value.
muscle fatigue
muscle fatigue is when repeated contraction of the skeletal muscles anaerobically causes accumulation of lactic acid in the muscles.
the glycogen present in the body breaks down anaerobically to produce lactic acid. its accumulation can cause pain and fatigue.
the lactic acid then diffuses into the blood.
4/5th of it is converted back to glycogen and the other 1/5th into carbon dioxide and water (Cori’s cycle)
rigor mortis
the complete rigidity of the body after death, due to depletion of ATP and phosphocreatine.
muscle spasm
sudden, involuntary movement in one or more muscles. People may also call it a charley horse or a muscle cramp or twitch.
occur due to stress, dehydration and exercise or tiredness.
during a muscle contraction, the muscle can shorten by
1/3 to 1/2 of its length
red muscle vs white muscle fibres
red white
1.smaller diameter larger diameter
2.red due to haem- myoglobin is absent
protein myoglobin
3.more mitochondria less
4.more capillaries less
5.less sarcoplasmic more
reticulum
6. aerobic oxidation anaerobic, collect lactic acid
7. slow long fast short contractions
contractions.
where can you find red muscle fibres
extensor muscles, flight muscles of kites
where can you find white muscle fibres
eyeball, flight muscles of a sparrow
contraction of smooth muscles
slow lasts much longer
troponin absent, they have a protein called calmodulin that binds calcium to the cytosol
where do smooth muscles get impulses from
autonomic nervous system
contraction of cardiac muscles
gap junctions allow muscle contraction to spread from one fibre to another.
long refractory period and lactic acid produced is used to make ATP
what constitutes the skeletal system
bones and cartilage
exoskeletal system
the skeleton is external. it is made up of dead tissues.
present in both vertebrates and invertebrates
endoskeleton
present inside the body
made up of cartilage and bones in
vertebrates
present in both vertebrates and invertebrates, to make a framework and protect
bones in a child and adult
300 and 206 respectively
the two skeletal systems in man
axial and appendicular
axial skeletal system parts
total 80
skull 29
vertebral column 26
ribs 24
sternum 1
runs along the middle longitude of body
of the 29 skull bones what makes them
facial 14
cranium 8
ear ossicles 6
hyoid bone 1
cranium
frontal(1) anterior part of the skull, forms the forehead
parietal(2) greater portion, the sides and roof of the skull
temporal(2) inferior lateral part, forms part of the cranial floor
occipital(1) posterior part, the base of the cranium
sphenoid(1) middle part holds all the bones of the cranium together. saddle-shaped sella turcica enclosing the pituitary gland
ethmoid(1) sponge-like appearance, located on the midline of the anterior part of cranial floor. the cribiform plate forms the roof of the nasal cavity through which olfactory nerve passes.
perpendicular plate forms the superior portion of the nasal septum.
why is the skull called dicondylic
due to the presence of two occipital condyles in the skull (occipital bone).The condyles connect the skull with Atlas
large opening at the base of the skull through which the spinal cord passes
foramen magnum
the facial bones
nasal bone 2 bridge of the nose
maxillae 2 upper jaw
zygomatic 2 prominences of the cheek
lacrimal 2 thin bone containing lacrimal sac
palatine 2 posterior part of the hard palate and form floor and lateral wall of the nasal cavity
inferior nasal conchae 2 inferior lateral wall of nasal cavity
vomer 1 inferior portion of nasal septum
mandible 1 movable lower jaw, strongest facial bone
which bone doesn’t articulate with any other bone
hyoid bone
backbone
the vertebral column, present mid-dorsal region of body
invertebral discs
present between two adjacent vertebrae, they are pads of cartilage ,provides flexibility
the 26 vertebrae
cervical 7 thoracic 12 lumbar 5 sacral 1 coccyx 1
in a child, the sacral bones are 5 and coccyx is 4 , therefore total 33 vertebrae. they fuse in adults, therefore 26
