Topic 7 Flashcards
How do movements work?
- Produced by the coordinated action of several muscles
- Where the muscles shorten
- Pull on the bone and move the joint
What are agnostic muscles?
- Since muscles can only pull not push
- Two muscles are needed to move bone (extensor and flexor)
- These muscles are agnostic and work against each other
****Bicep + Tricep, Quadceps + Hamstrings****
What do extensor muscles do?
A muscle that contracts the extension of a joint
What do flexor muscles do?
A muscle that reverses the movement of a joint
What are synovial joints?
- Bones that articulate
- Separated by cavity-filed synovial fluid enabling free movement
- All have the same basic structure
Examples = Hip, Knee and Ankle
What is the synovial joint structure?
- Bones held in position and controlled by ligaments
- Restricting the amount of movement
- Tendons attach muscles to bones
- Enabling muscles to power joint movement
- Cartilage protects bones within joints and provides support
- Reducing wear and tear of joints
- The synovial membrane secretes synovialal fluid
- Which acts as a lubricant to reduce friction between bonds
What is the ball-and-socket joint?
- A round head fits into a cup-shaped socket
- Allowing for Omni-directional movement
**Like the hip**
What is the Gliding joint?
- Two flat surfaces slide over one another
**Vertebrae where there are articulating surfaces****
What is the hinge joint?
- Convex surface fits into a concave surface
- Allowing for movement in two directions
**The elbow****
What is the pivot joint?
- Part of the bone fits into a ring-shaped structure
- Allowing rotation
**The joint at the top of the spine**
What are muscles made up of?
- Made up of bundles of muscle fibres
- Each fibre is a muscle cell (several cm in length)
- Each cell is multinucleate (multiple nuclei)
- Needed for shear size of muscle cell
- From several cells fusing together
What is each muscle fibre made up of?
- Numerous myofibrils
- Made up of contractile(elastic) units called sarcomeres
What are the different parts of the muscle from largest to smallest?
- Tendons
- Which contain connective tissue which contains
- Bundle of muscle fibres which are surrounded by cell surface membrane
- Which contains muscle fibres which have
- Lots of myofibrils
- Which are sections of sarcomeres put together
What are sarcomeres made up of?
- Made up of thin filaments made up of protein
- Actin (I band) + Myosin ( A band, thicker)
- Contracts happen when the two slide over each other in a coordinated way
- This gives the sarcomeres the stripped appearance
What other molecules are associated with actin?
- Troponin part of the thin filament
- Tropomyosin unblocks to allow the myosin heads to bind
- Involved in the sliding filament theory
What are the steps that come before sliding filament theory?
- Nerve impulse arrives at a neuromuscular junction
- Sarcoplasmic reticulum releases Ca2+
- Has membrane-bound sacs around myofibrils
- Ca2+ diffuse through the sarcoplasm
- Initiates sliding filament theory
What are the steps in sliding filament theory?
- Ca2+ attaches to tropin molecules causing movement
- Tropomyosin on actin filament shifts into position
- Exposing myosin-binding sites
- Myosin heads bind with binding sites forming cross bridges
- ADP and P are released from the myosin head
- Myosin changes shape causing movement of filaments with attached actin moving over the myosin
- ATP binds to the myosin head
- Myosin head detaches from actin
- ATPase on the myosin head hydrolyses ATP into ADP and P1
- Changing shape of myosin and returning to the upright position
What happens when muscles relax?
- No more never impulse stimulation
- Ca2+ pumped out of muscle sarcoplasm with ATP
- Troponin and tropomyosin move back blocking myosin binding sites
What happens when there is a lack of ATP?
- Cross bridges remain attached
- Ca2+ cant be pumped out of sarcoplasm
- Meaning myosin binding sites are unblocked
- Causing Rigor Mortis
What is aerobic respiration?
- A large amount of energy is released which is used for phosphorylation for ATP production
- Splitting of glucose into CO2 and H2
- H2 combines with O2 in atmosphere to create H20
- Metabolic Pathway (series of chemical reactions)
What is the overall equation for aerobic respiration?
What are the four stages of aerobic respiration?
- 1-3 are a series of reactions where the products are used in 4 to make ATP
- Each reaction uses its own specific intracellular enzyme
- The enzyme with the slowest rate is limiting
- Determining the overall rate of respiration
- Glycolysis (Cytoplasm)
- Link reaction (Mitochondria)
- Krebs cycle (Mitochondria)
- Oxidative phosphorylation (Mitochondria)
What other can biological molecules be broken down?
**Other Complex Organic Molecules****
- Fatty Acids
- Amino Acids
- Lipids
What is glycolysis?
- Splitting of one molecule of glucose into two smaller molecules of pyruvate (3 Carbon Molecules)
- Happens in the cell cytoplasm
- Anaerobic process (doesn’t require oxygen)