Karteikarten
Muscles and Movement - Topic 7
Karten in diesem Stapel (17)
- 1What are the three types of muscles?Striated muscle
Smooth muscle
Cardiac muscle - 2Describe Striated muscleAlso known as skeletal/ voluntary muscle and is attached the skeleton involved in movement
Contracts rapidly and fatigues quickly
Is striped under a microscope
Under the control of the voluntary nervous system - 3Describe smooth muscle and where it is foundSmooth muscle is found in the gut and in blood vessels
It contracts slowly and fatigues slowly
Its under the control of the involuntary nervous system
Not striped under a microscope - 4Describe Cardiac MuscleIs found only in the heart
It contracts spontaneously and never fatigues
It is striated and fibres are joined by cross connection - 5What are muscle fibres made up of ?Made up of myofibrils lying parallel to each other that contain individual units called the sarcomere. The sarcomere is made up of proteins actin and myosin. The myofibrils cytoplasm is called the sarcoplasm and contains many mitochondria and there are a network of membranes running through called sarcoplasmic reticulum to store and release calcium ions
- 6What is myoglobin?Found in muscle cells, its like haemoglobin but has one chain instead of four.
It has a higher affinity of oxygen so takes up oxygen readily - 7What are slow twitch fibres?Also known as oxidative or red muscle fibres
Adapted for steady action over a period of time and maintain body posture
Contract slowly and stay in tetanus
Has rich blood supply
Lots of mitochondria
Lots of myoglobin
Rely as glucose as a fuel supplied by blood vessels to continue to produce ATP. - 8What is fast twitch muscles fibres?Often known as white or glycolytic fibres
Contract rapidly suitable for sudden bursts of activity
Often function anaerobically because fatigues quickly
Low mitochondria and low myoglobin
Contains many myofibrils packed in
contain rich glycogen stores to convert to glucose
Contain relatively high levels of creatine phosphate use to form ATP from ADP - 9What is myosin made up of?Myosin is made up of two polypeptide chains wrapped around each other.
Each ending in large globular bounded with ADP an inorganic phosphate
A myosin filament is made up of many of these bundled together - 10What is Actin made up of?Actin filament made up of two chains of actin monomers joined together like beads on a necklace
Actin provides the binding sites for myosin to join
Tropomyosin is wrapped around the actin filament and when relaxed it covers myosin bonding site
Tropomyosin has troponin attached. - 11Draw a sarcomere when relaxed and contracted
- 12Explain the Sliding Filament Theory1) Calcium ions bind to troponin and changes shape, pulling tropomyosin, exposing myosin binding sites
2) Myosin head binds to binding sites forming an actomyosin bridge
3) ADP and Pi are released from myosin head, causing it to change shape
4) Myosin head bends forwards, pulling the actin filament along myosin, shortening sarcomere
5) Free ATP binds to head, breaking the bond between actin + myosin
6) Activates ATPase in myosin head
7) Hydrolyses ATP, which provides energy needed to return myosin head
8) Calcium ions get pumped back into sarcoplasmic recticulum if not stimulated again
9) Troponin and tropomyosin returns to normal
10) Muscle fully relaxed - 13Tissues of the Skeletal Systems: Describe bone properties and what is made up of.Bone is made up of bone cells embedded in a matrix of collagen and calcium salts
Bone is strong under compression
Is relatively light, but is strong and hard - 14Tissues of the Skeletal Systems: Cartilage.Cartilage is hard and flexible
Made up of cells called chondrocytes within organic matrix
Cartilage is elastic
Able to withstand compressive forces
Good shock absorber
Found between bones - 15What are the two types of Cartilage?1)Hyaline: found at the end of bones and in nose, air passageways and parts of the ear)
2) White Fibrous Cartilage: Found between bones and in the joints
great tensile strength + less flexible
Made of bundles of densely packed collagen in the matrix - 16Tissues of the Skeletal Systems: What are tendons?Tendons join the muscle to the bone
Made up entirely white fibrous tissue and consists of bundles of collagen fibres
Provides little shock absorption for when muscle overstretches - 17Tissues of the Skeletal Systems: What are ligaments?They hold bones together + keep them in correct alignment
Found both around joint as a capsule and within joint itself
Made up of yellow elastic tissue for strength + elasticity