4g

Question 1

Sarcomere

Answer 1

Each myofibril consists of repeating subunits called sarcomeres that are aligned end to end along the length of the myofibril, connected to one another by protein discs called Z discs.

Question 2

Sliding Filiment

Answer 2

A contraction process which shortens all the sarcomeres along the muscle fibre instantaneously.

Question 3

Thin Filiments

Answer 3

Each thin filament (actin) is anchored to a Z disc at one end

Question 4

Types of skeletons

Answer 4

Hydrostatic
Exoskeleton
Endoskeleton

Question 5

Antagonistic Muscle Pairs

Answer 5

Are pairs of muscles with opposing actions ( a flexor and extenser) that compress or pull on its skeleton

Question 6

Cartilage

Answer 6

Flexible support and connections
they cover the end of bones and are the fremwork for the respritory sysem, ear and nose. made from chondrocytes these cells secrete the glycoproteins and collagen that make up most of the matrix of cartilage.

Question 7

Ligaments

Answer 7

Attached to moveable joints.
The parallel orientation of collagen in ligaments gives them tremendous strength
Impacts perpendicular to collagen fibres can easily rupture ligament

Question 8

Bone types and their function

Answer 8

bother are the bodys fremwork
Spongey bone - Open network of bony fibres and is porous and lightweight. holds many blood vessels.
Compact bone - Dense and strong and provides an attachment site for muscle and consists of subunits called osteons.

Question 9

Joint Types

Answer 9

hinge joints
ball and socket joints

Question 10

Osteoblasts

Answer 10

During embryonic development, osteoblasts produce bone within the cartilage skeleton by secreting a collagen matrix that becomes infiltrated with minerals.
As osteoblasts generate new bone, many become trapped in the hardened matrix and mature into osteocytes

Question 11

Osteocytes

Answer 11

Osteocytes are essential to bone health because they coordinate the activity of osteoclasts and osteoblasts, which are constantly breaking down and replacing bone

Question 12

Osteoclasts

Answer 12

Osteoclasts remove excess bone, restoring the bone’s original shape, but often leaving a slight thickening

Question 13

types of vetebrate muscle systems

Answer 13

Cardiac, Skeletal, Smooth

Question 14

Myofibrils

Answer 14

Individual muscle fibres contain parallel cylinders called myofibrils

Question 15

Striated

Answer 15

A regular arrangement of sarcomeres which alternate betweens thick and thin filaments.

Question 16

Feature of cardiac muscle

Answer 16

Striated, brached and smaller than skeletal, they hold one nucleus and are connected via intercalated discs which have gap junctions. In the heart.

Question 17

features of skeletal muscle

Answer 17

Surronds and contracts to move the skeleton. made from striated muscle and alwas have voluntary movement.
These muscles have many nuclei and individual fibres contain parallel cylinders called miyofibrils

Question 18

feature of smooth muscles

Answer 18

Surronds viens and arrteries and lines hollow organs. Not striated, meaning the think and thin fillaments are not striated, they have one nucleus and are connected by gap junctions.

Question 19

Hydroskeleton

Answer 19

A skeleton which uses tubes that control water flow to move the structure.
Worms, cnidarians, and many mollusks.
To squeeze its hydrostatic skeleton the animal uses two sets of antagonistic muscles in its body wall—one circular, the other longitudinal

Question 20

Exoskeleton

Answer 20

Arthropods have external skeleton, they have antagnonistic muscle which attach to the inside of the skeleton for movement.

Question 21

Endoskeleton

Answer 21

Internal skeletons are rigid structures found inside the bodies of echinoderms and chordates.

Question 22

types of osteons (bone cells)

Answer 22

Osteoblasts—bone-forming cells
Osteocytes—mature bone cells
Osteoclasts—bone-dissolving cells

Question 23

How do muscles contract?

Answer 23

Each microfibril is surrounded by a specialised endoplasmic reticulum called a sarcoplasmic reticulum (SR), which are flattened, membrane compartments filled with fluid containing a high concentration of calcium ions.
The plasma membrane that surrounds each muscle fibre forms tubes, called T tubules, that tunnel deep into the inside of the cell at regular intervals.

Question 24

Thick filament

Answer 24

Thick filaments are formed from bundles of myosin proteins

Question 25

Myosin

Answer 25

Each myosin had a bulbous head and a long shaft made from myosin proteins
The myosin head is hinged to the shaft so it can swivel back and forth

Question 26

how do thick and thin fiiments interact

Answer 26

Suspended between the thin filaments are thick filaments (myosin)
Two smaller proteins (troponin and tropomyosin) regulate interaction between the filaments. When the mysodin head flexes it binds to the site of the thin fliliment, this pulls the thin filiments towards the center of the sarcomere, then is detaches untill it is energised (ATP) again.