AIMS – starter slide 5 Give back homework brain questions. Starter. Explain with diagrams and photographs, the sliding filament model of muscular contraction. Muscles, nerves and hormones “pulling together”. Collect in muscle questions Recap Plant Hormones. Homework – Question 2 d) and e) 2011 paper and question 6, 2010 paper. Find your ecology booklets to check through and bring on Thursday

True or false? Restriction enzymes stick sugar-phosphate backbones together. A genetic probe is needed to allow DNA polymerase to make a complementary strand of DNA in a PCR machine. Separation of DNA fragments by electrophoresis occurs from the +ve to the –ve electrode. Electrophoresis can separate fragments of DNA only one base different in length. The cycle of temperatures in the PCR is 95, 55 and 72°C. The PCR mixture includes DNA polymerase which has been taken from a thermophobic bacterium.

AIMS – pantomime and lunch from 1:00 – 1:45 today! Please collect statements of entry from faculty desks. Promonitor 5 Check homework and give out revision timetables. Structure and mechanism of contraction in skeletal muscle. Energy for muscle contraction. Homework – Exam question parts a) b) c) and d) only. Mock on Thursday 12 th January after F211 on the 11 th. (F212 on the 18 th and 215 on the 31st)

Promonitor 5 24 marks – 30 minutes. Write 3 and 5 on lined paper. Page 188, question 3 6 marks Page 189, question 5 10 marks On paper, question 6 c) 8 marks Now let’s check your homework - drawing on booklet page 5, + table page 1.

j) Outline the structural and functional differences between voluntary (skeletal) involuntary (smooth) and cardiac muscle. Skeletal - voluntary Muscle fibre – a single cell. Nuclei Stripes of muscle protein – actin and myosin.

Cardiac and Smooth (__________)Muscle Nucleus Joins between muscle cells Intercalated disc Spindle shaped cell Single nucleus in cell myocyte

Involuntary / Smooth – slow to contract and slow to fatigue. LocationMuscle Arrangement Action Intestinal walls?Peristalsis Iris of eyeCircular and radial bundles ? Arterial walls, cervix and uterus ? Contraction narrows _______. Relaxation dilates _________. Circular and radial bundles Contracting radial muscle dilates pupil/ circular constricts. Circular bundles Why do blood vessels not need longitudinal muscle to act against circular to cause dilation?

Cardiac Muscle – atrial, ventricular and excitatory and conductive. Some cells are myogenic meaning………… especially the SA Node. How do the SAN, AVN, Bundle of His and Purkyne fibres work together to organise the heart beat? Suggest why the wave of excitation only passes down Bundle of Hiss? How do intercalated discs, gap junctions and a latticework of interconnections help the excitation of action potentials pass quickly over the cardiac muscle?

j) Outline the structural and functional differences between voluntary (skeletal) involuntary (smooth) and cardiac muscle. Skeletal - voluntary Muscle fibre – a single cell. Nuclei Stripes of muscle protein – actin and myosin.

Voluntary / Skeletal Voluntary muscle cells form fibres about 100µm wide – containing several nuclei pushed to the outside – why? Antagonistic skeletal muscles move bones at the j_____ by contracting and so p_____ them where they are connected by ______. Define sarcolemma (_________), sarcoplasm (__________) and sarcomere (s______ c_________ u_____ of a _______). Also, sarcoplasmic reticulum (________ ________) and myofibrils (________ ____)

Skeletal / Voluntary Muscle

g) Explain with diagrams and photos the sliding filament model of muscle contraction Muscle Fibre

Myofibrils from a muscle fibre

Muscle Fibre Structure – see page 7 in booklet and 236 in book.

Part of a single myofibril – complete page 7 of booklet. Actin Myosin

1, 2, 3, 4, 5? Now check page 8

Describe what is happening and then complete page 10

Starter – Peer mark your questions (Pdf MS F215 Jan 2011) AIMS – Page 10 matching pairs. Detail of myofibril structure pages 11 and 12 Tell each other story of contraction using pipe cleaners and pages 13 and 14. Check order on page 23. Energy for muscle contraction. Pulling Together – nerves, hormones and muscles.

Page 11 – 14. Animations 1. s/animations/muscles/muscles.html Quiz and basic parts of the myofibrilhttp:// s/animations/muscles/muscles.html 2. sarcomere shorteninghttp://highered.mcgraw-hill.com/sites/ /student_view0/chapter42/animations.html# 3. sliding filamenthttp:// 4. hill.com/sites/ /student_view0/chapter10/animation__myofila ment_contraction.html myosin heads movehttp://highered.mcgraw- hill.com/sites/ /student_view0/chapter10/animation__myofila ment_contraction.html 5. hill.com/sites/ /student_view0/chapter10/animation__breakdown_of_atp_and_cross- bridge_movement_during_muscle_contraction.html Detail! hill.com/sites/ /student_view0/chapter10/animation__breakdown_of_atp_and_cross- bridge_movement_during_muscle_contraction.html 6. good contraction cycle

Page 13 in booklet - h) Outline the role of ATP in muscular contraction

Contraction! 1.When calcium arrives, it attaches to _____ which releases _______, and the myosin heads are ready with ADP and P attached. 2.Myosin head attaches to actin and P is released. 3.Stored energy in head causes it to bend back and sweep actin over the myosin. 4.ADP is released. 5.New ATP breaks cross bridge as it attaches to myosin head. 6.ATP is hydrolysed to ADP and P, releasing stored energy into head. 7.Myosin head returns to upright position. See back page for simple version – put it in order.

MUSCLE CONTRACTION – SOME KEY WORDS Write sentences containing one or more of these words in their correct context. Actin Myosin Tropomyosin Troponin Calcium ATP ATPase Power stroke Hydrolysis

Initiation of contraction See page 15 of booklet. What is missing from this animation? tml neuromuscular junction – not much detailhttp:// tml hill.com/sites/ /student_view0/chapter10/animation_ _action_potentials_and_muscle_contraction.htmlhttp://highered.mcgraw- hill.com/sites/ /student_view0/chapter10/animation_ _action_potentials_and_muscle_contraction.html Starter above + quiz good long onehttp:// Page 15 – check round room and then page 22 question

h) Outline how the supply of ATP is maintained in muscles Energy for muscle contraction See page 16 in booklet Circulating lactic acid stimulates a greater blood supply to muscles – why is this useful? Answer questions 1 – 3 page 237

k) Responses to environmental stimuli in mammals are coordinated by nervous and endocrine systems. What does that mean? Give an example. Page 238 – What do stimuli feed into the systems? Give 2 examples. These survival strategies may be long or short term – give examples of each. How can the brain influence hormonal secretion?

You feel threatened! Page 17 What will happen to : Pupils? Heart rate and blood pressure? Arterioles to digestive system and skin? Arterioles to liver and muscles? Blood glucose level? Metabolic rate? Ventilation depth and rate? Sweat production? Erector pili muscles in skin? Endorphin (pain killers) in brain?

l) Explain how in mammals the “flight or fight” response to environmental stimuli is coordinated by nervous and endocrine systems. Coordination What kind of stimuli might elicit stress? Which part of the brain would “understand” the danger? Which part of the brain will then be stimulated to trigger the ________ NS and the secretion of ________ from the a_______ m________?

When threatened, apart from releasing adrenalin from the adrenal medulla……….the hypothalamus releases…. ACTH (Adreno-corticotropic hormone) Adrenal cortex30 corticosteroids Some help body resist stressors CRF (corticotropin releasing factor) released into pituitary gland

What will be going on inside these dog’s brains and physiology? Try stretch and challenge and card sort. Why do they not run or fight immediately?

Have a great Christmas and feel in control of your revision and work!

You feel threatened! What will happen to : Pupils? Heart rate and blood pressure? Arterioles to digestive system and skin? Arterioles to liver and muscles? Blood glucose level? Metabolic rate? Ventilation depth and rate? Sweat production? Erector pili muscles in skin? Endorphin (pain killers) in brain?