Human Physiology PDF - Lecture Notes

Official Open Human Physiology Learn about the body's organ systems, their functions, and how they maintain health Biological function: How basic organ systems of the body work Function is determined by structure.  Official Open...

Official Open Human Physiology Learn about the body's organ systems, their functions, and how they maintain health Biological function: How basic organ systems of the body work Function is determined by structure.  Official Open Lesson Plan Topics covered: 1. Cells, Tissues and Organs 2. Homeostasis 3. Skeletal System 4. Muscular System 5. Nervous System (Structure & Anatomy) 6. Nervous System (Neurophysiology) 7. Endocrine System 8. Cardiovascular System & Blood 9. Respiratory System 10.Digestive System 11.Urinary System 7  Tissues Official Open  Cells that have similar functions are grouped into tissues.  Similar cells are uniformly spaced and bound together as tissue by non- living matrix which the cells secrete.  Matrix varies in composition from one tissue to another. May take the form of a liquid, semi-solid or solid.  Example: Blood tissue has a liquid matrix. Bone cells are bound by a solid matrix.  Four major types of tissues in the human body A) Muscle tissue B) Nervous tissue C) Epithelial tissue D) Connective tissue The 4 tissue types interweave to form the fabric of the body  Official A. Muscle Tissue Open Specialized for contraction to produce movement of the body parts and of the body itself. Muscle contraction requires adequate blood supply to provide oxygen, calcium and nutrients as well as to remove waste products. Three types of specialized contractile cells (also known as fibres) 1) Skeletal muscle 2) Cardiac muscle 3) Smooth muscle  Official Open A C B Ross and Wilson, Anatomy and Physiology in Health and Illness. Tenth edition. Anne Waugh. Allison Grant  Official 1. Skeletal Muscle Open  Described as skeletal because it forms muscles that move the bones (of the skeleton)  Striated (stripes) as seen on microscopic examination.  “Voluntary muscle”- consciously controlled (contraction + relaxation)  Sometimes contract in response to reflexes  Attached to the bones  Arranged in bundles  Skeletal muscle contraction is stimulated by motor nerve impulses originating in the brain or spinal cord and ending at the neuromuscular junction.  Official Open 2. Cardiac Muscle  Found only in the heart wall  It contracts to make the heart beat  Involuntary muscle:- Not under conscious control  However, under a microscope cross-stripes (striations) characteristic of skeletal muscle can be seen.  Cells are interconnected  Contact between adjacent cells is through intercalated discs which is characteristic of heart muscle.  Thus myocardial cells contract as a whole mass  Official 3. Smooth Muscle Open  Non striated  Involuntary muscle  Found in the walls of hollow organs such as - Stomach (digestive tract), blood vessels, organs of gastrointestinal tract, bronchioles (small air passages in the lungs), ducts in the urinary tracts and reproductive systems  Responsible for the constriction of the cavity thus forces fluid/food through the tubes.  Under a microscope, the cells are seen to be spindle shaped with only 1 central nucleus.  Contraction of smooth muscle is slower and more sustained than skeletal muscle.  Official Open B. Nervous Tissue  Groups of organised cells in the nervous system  Nervous tissue is grouped into 2 categories:- (1) Excitable cells – known as neurons. - Initiate, receive, conduct and transmit information. - Conduct nerve impulses (2) Non-excitable cells – known as glial cells. - They support the neurons Your senses and nervous system. (n.d.). Retrieved April 20, 2016, from http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/ourselves/3_keeping_in_touch5.shtml  Official Open C. Epithelial Tissue  Made of cells that form membranes, which cover and line the body surfaces and glands.  Two Types: (1) Covering and lining epithelium - found on all surfaces such as skin, covering all organs and lining blood vessels and heart (2) Gladular epithelium - sweat glands in skin, salivary glands, lining of the respiratory tract, mammary glands and intestinal glands.  Official How are they classified? Open 1. No. of layers Simple: 1 layer Stratified: > 1 layer 2. Shape of the cells Squamous: Flat Cuboidal: Cube-shaped Columnar: Column-like Anatomy and Physiology I, by OpenStax College  Official Simple Epithelial Tissue Open  Single layer of cells attached to a basement membrane  Covering visceral organs; lining of body cavities, tubes and ducts 4 Types of Simple Epithelium (1) Simple Squamous Epithelium:  Single layer flattened cells;  Permeable lining for heart, blood and lymph vessels, and alveoli of the lungs.  Function: allows diffusion and filtration (2) Simple Cuboidal Epithelium  cube shaped;  Forms lining of kidney tubules, salivary ducts  Function: secretion or absorption  Official Open (3) Simple Columnar Epithelium  Single layer. Column shaped  Lining of digestive systems such as stomach, intestines and urethra  Lines gallbladder and excretory ducts of some glands  Function: secrete mucus or absorb mucus depending on where they are in the body, secretion of enzymes. (4) Simple Ciliated Columnar Epithelium  Ciliated column shaped (ciliated means tiny hair like projections sticking out from the cell membrane)  Lining of bronchi, uterine tubes and regions of the uterus  Function:- Cilia works in waves, all moving together in the same direction. Help to remove mucus, foreign matter and debris, keeping passageways and lining clear.  Function: propels reproductive cells by ciliary action  Official Stratified Epithelial Tissue Open  Stratified squamous epithelium e.g: skin  Stratified cuboidal epithelium e.g: sweat glands, salivary glands  Glands are also derived from epithelial membranes.  Examples: exocrine and endocrine glands. 1. Exocrine Glands: (exo=outside)  Secretions are expressed to the outside of the epithelial membranes (and hence to the surface of the body) through ducts.  Examples: tear glands, sweat glands, mucous glands of digestive tract 2. Endocrine Glands: (endon = within) lack ducts, secrete into capillaries within body (hormones secreted by pituitary gland)  Official D. Connective Tissue Open  Found everywhere in the body  Supporting tissues of the body.  Connect active tissues like bones and muscles. There are 8 types:- 1) Areolar – loose connective tissue found all over the body 2) Cartilage – firm, tough tissue. 3) Bone – hardest. 4) Blood – fluid connective tissue. 5) Adipose – fatty tissue. 6) Lymphoid – semi-solid tissue. 7) Yellow elastic – mainly elastic fibres and very few cells. 8) White fibrous – strongly connective. Mainly closely packed bundles of collagen fibres running in the same direction.  Official Connective Tissue Open Types and functions: 1.Connective tissue proper (Fibrous) bind other tissues together, offer mechanical or metabolic support supports epithelia, surrounds blood vessels and nerves Subclassified into loose, dense, elastic(stomach) and reticular(internal framework) connective tissue 16  Official Connective Tissue Open 2.Specialised connective tissues cartilage - solid; found in growing bones bone - mineralised and hardened (calcium); support and protect organs (brain, lungs); interact with muscles for movement; red blood cell production; storage for minerals (calcium, phosphorus) blood - transports O2, hormones, enzymes; defend against disease adipose tissue - fat storage 17  Official Major Organ Systems in Open the Human Body 1. Integumentary 7. Lymphatic / Immune 2. Skeletal 8. Circulatory 3. Muscular 9. Respiratory 4. Nervous 10. Urinary 5. Endocrine 6. Digestive  Official Open Major Organ Systems in the Human Body 1. Integumentary 2. Skeletal 19  Official Open 3. Muscular 4. Nervous 20  5. Endocrine 6. Digestive Official Open 21  7. Circulatory Open Official 8. Lymphatic 22  9. Respiratory Open Official 10. Urinary 23  Official Open LECTURE 2 HOMEOSTASIS  Official Open Outline  Body fluids: intracellular & extracellular  Principles of homeostasis  Components of homeostatic system  Examples of homeostasis  Negative & positive feedback mechanisms  Total Body Water Official Open  Water makes up 60% of the body weight of an adult male and 50% of a female’s body weight.  Total body water can be divided into 2 fluid compartments Intra-cellular compartment Extra-cellular compartment Intra-cellular Fluid fluid within cells. water existing in all body cells. accounts for two-thirds of the body’s water content. contains relatively large amounts of potassium, phosphate and proteins.  Total Body Water Official Open Extra-cellular Fluid fluid outside the cells. further divided into interstitial fluid, plasma, lymph, cerebrospinal fluid and milk. provides a constant environment for cells. transports substances to and from cells. conducts nutrients, cells and waste products throughout the tissues of the body.  Official Homeostasis Open Mechanism by which the internal environment is kept constant and near stable so that cellular metabolic functions can proceed at maximum efficiency. Composition of the internal environment is tightly controlled. Maintained by muscles or glands that are regulated by sensory information from the internal environment. Necessary for life  Official Open Homeostasis  Control of physical and chemical factors - Optimal conditions for survival - Gives us independence from the environment, thus not adversely affected by changes in the external environment (e.g. heat) 1. Physical factors  temperature (36.90C)  pH, salt & water  volume & pressure 2. Chemical factors  O2 and CO2  Levels of nutrients & waste products  Levels of hormones & other regulatory compounds  Official Principles of Homeostasis Open 1. Set point (reference point) – optimal level. An efficient system can quickly restore this point. 2. Detector - detectors or receptors detect any changes, internal or external 3. Control Centre – part of the brain where signals are sent and the data is analysed 4. Effector – bring about the appropriate response to restore the optimum. Open Components of a Homeostatic Official System 1 2 3 Detector or Control Input Effector receptor centre - Set point response Feedback Changed condition  Official Maintaining Constant Body Temperature Open Thermoregulation 1. Receptors / detectors  to monitor external and internal conditions skin, brain, internal organs 2. Control center  a part of the brain where the data is analyzed and signals are sent 3. Effectors  mediate the appropriate response blood vessels carry blood to skin; sweat gland; muscles generate heat during shivering 32  Official Homeostatic Mechanisms Open (A) Negative-feedback system  Body responds to reverse the change Sweating E.g. Heat Dilation of receptors Hypothalamus Rise in in body/ surface body blood skin vessels temp Increased heat loss Decrease in feedback body temp 33  Official Open How negative feedback mechanism helps to maintain homeostasis? If a factor within the internal environment deviates too far from a normal set point, the system responsible for monitoring that factor will initiate a counter change that returns it to its normal state. Ross and Wilson. Anatomy and Physiology in Health and Illness. Tenth Edition.  Official Open Challenge: What happens when the body temperature falls? Shivering E.g. Fall Heat Constriction receptors Hypothalamus in body in body/ of surface temp blood skin vessels Heat production, Reduced heat loss Increase in feedback body temp 35  Official Homeostasis: Blood Glucose Levels Open Glucose is Detector? converted to 36 Control Centre? Glycogen & Effector? stored in liver Insulin: hormone that (+) liver to convert glucose to glycogen, thus reducing blood glucose  Homeostasis of Blood Glucose Level Official Open Insulin-secreting cells of the pancreas activated; release insulin into the blood Uptake of glucose from blood is en- hanced in most body cells Blood glucose levels decline to set point; Elevated Liver takes up stimulus for blood sugar glucose and stores insulin release levels it as glycogen diminishes Stimulus: Imb rising blood ala nce glucose levels Stimulus: (e.g., after Homeostasis: Normal blood glucose declining blood eating four levels (90 mg/100ml) glucose levels jelly doughnuts) (e.g., after Imb skipping a meal) ala nce Low blood sugar levels Rising blood glucose levels Glucagon-releasing return blood sugar cells of pancreas to homeostatic set activated; point; stimulus for release glucagon glucagon release into blood; target diminishes is the liver Liver breaks down glycogen stores and releases glucose to 37 the blood Seeley, Anatomy and Physiology, Chapter 10. 2010  Official Homeostatic Mechanisms Open (B) Positive feedback system Occur less frequently in the body A change in the body to increase the magnitude of the change E.g. Blood clotting at the site of the injured vessel triggers the deposition of additional clot so that further loss of blood is halted During childbirth, stretching of the cervix triggers the release of the hormone oxytocin which causes more powerful contractions of the uterus to expel the foetus 38  Official Open How are signals transmitted to maintain homeostasis? The nervous and endocrine systems work together to maintain homeostasis. Nervous system: responds rapidly to short-term changes by sending electrical impulses. Endocrine system: brings about longer-term adaptations by sending out chemical messengers (hormones) into the bloodstream.  Official Open Summary 1. Ability to maintain optimum internal environment makes us less dependent on the external environment. 2. The internal environment of the body is mainly controlled by body fluids. 3. Homeostasis takes place by both positive & negative feedback mechanisms. 40  Official Open What you need to know: Understand what is homeostasis Explain the principles of homeostasis Explain how homeostasis regulates blood sugar and body temperature. 41  Official Open LECTURE 3 Skeletal System 42  Official Open LECTURE OUTLINE Components and Functions Bone Classification Compact and Spongy Bone Bone Formation and Growth Bone Remodeling Joints Clinical Connection: Osteoporosis Total hip & knee replacements 43  Official Open Components of the Skeletal System 1. Bones 2. Cartilage 3. Joints 44  Official Functions of the Skeletal System Open 1. Support - Skeleton forms a rigid framework to which are attached to softer tissue and organs of the body. 2. Protection - Skull, vertebral column, rib cage, pelvic girdle enclose and protect vital organs. 3. Movement - Bones act as levers when attached. Muscles contract causing movement about joints. 4. Hematopoiesis - During fetal development and infancy, skull undergoes changes in shape (molding) during childbirth. Red bone marrow of an adult produces white and red blood cells and platelets. 5. Mineral storage 45 - Matrix of bone is compose primarily of calcium and phosphorus. These minerals can be withdrawn in small amounts if needed elsewhere in the body.  Official Open Functions of the Skeletal System Bone  Support soft tissues & maintains body shape  Protection of internal organs  Brain (skull)  Heart, lungs (ribs)  Site of attachment for skeletal muscle  Storage of calcium in bone matrix  Blood cell formation in marrow 46  Official Open Functions of the Skeletal System Cartilage  Site for bone growth  Bone lengthening  Acts as ‘cushion’ between bones for joint movement  Firm yet flexible support  Nose, ear lobes  Main composition of the foetal skeleton. Tendons  Attach bones to muscles Ligaments  47  Flat bone Official Irregular bone Open TYPES OF BONES Long bone Bones are shaped to Short bones suit their function Sesamoid bone Source: Anatomy and Physiology by OpenStax College 48  Official TYPES OF BONES Open Bones are shaped to suit their function  Official 1. Long bones Open - Function as levers 2. Short bones - Found in confined spaces, transfer forces of movement 3. Flat bones - Provide surface for muscle attachement - Protection of organs 4. Irregular bones - Muscle attachment or movement 5. Sesamoid bones  Official Open 1. Long Bone  Diaphysis  Contains yellow bone marrow  Epiphysis  Contains red bone marrow  Articular Cartilage  Cartilage that covers part of epiphysis that articulates (joins) to another bone  Periosteum  Covers bone surface. Protects and nourishes bone tissue (through blood vessels). 51 Image source: Wikimedia. http://upload.wikimedia.org/wikipedia/commons/9/94/Illu_long_bone. jpg Public domain.  Official Open 2. Short Bones Cube-like shape Function: Provide stability and support, some limited motion Include the carpals of the wrists and tarsals of the ankles  Official Open 3. Flat Bones A bone that is typically thin, but actually curved Function: Attachment point for muscles, protect internal organs Examples include the sternum, cranial (skull) bones, scapulae  Official Open 4. Irregular Bones  Complex shape, not easily classified by shape  Function: Protect internal organs  Examples include vertebrae, facial bones  Official Open 5. Sesamoid Bones  Sesame-shaped bones (small and round), are found embedded in tendons  Function: Protect tendons from compressive forces  The most common example is the patella https://openstax.org/details/anatomy-and-physiology  Official Open The head of the femur contains both yellow and red marrow. 1. Yellow marrow stores fat. 2. Red marrow is responsible for making blood Source: Anatomy and Physiology by OpenStax College cells. 56  Official Open Long bones contain both SPONGY bone and COMPACT bone 57  Official Open Microscopic Structure of Compact and Spongy Bone 58  Official Compact bone Open 59  Differences between Compact and Official Open Spongy Bone Compact Bone Spongy Bone Composes the external layer of Internal part of most of short, ALL bones and the diaphyses of flat, irregular and epiphyses of long bones long bones Contains yellow marrow Contains red marrow Storage area for adipose (fat) Source of new blood cells tissue Structurally consists of osteons Structurally consists of a network of trabeculae 60  Joints Official Open Secures bones together and acts as shock absorbers All joint types contain cartilage. Immovable Slightly Freely movable movable 61  Official Growth Open  Fetal skeleton begins as cartilage. As the child grows, cartilage begins to ossify. 62  Official Open Bone Growth Growth Plates (epiphyseal plate cartilage): During childhood and adolescence, this tissue continues to divide and grow, resulting in bone extension. Bone growth is under the control of hormones such as: 1. Human Growth Hormone: Stimulates growth plates 2. Sex hormones: Regulate osteoclast activity(breaks down bone) / promote formation of bone tissue 3. Thyroid hormones: Stimulates replacement of cartilage in epiphyseal plate and long bone 4. Calcitonin: Inhibit the activity of osteoclasts, cells that break down bone. - Nutrients 63  Official Bone Cells Open 1. Osteoprogenitor Cells Stem cell Develops into osteoblast 2. Osteoblast Responsible for bone formation Bone forming cells 3. Osteocyte Mature bone cells Maintains health of bone 4. Osteoclast Involved in bone resorption/removal to maintain the optimum shape. This takes place at bone 64  Official Open Bone Cells Fine balance of osteoblast and osteoclast activity maintains normal bone structure and function Image source: http://www.zoology.ubc.ca/~biomania/tutorial/bonets/anc01.htm 65  Official Open Bone Remodeling A continuous process controlled by the action of bone cells, namely: 1. Osteoblasts (formation of new bone) 2. Osteoclasts (resorption/removal of bone) Occurs when bone is subjected to mechanical stress (weight bearing exercise) and calcium ion regulation (hormonal action) 66  Official Open Clinical Connection: 1. Osteoporosis  What is Osteoporosis?  How does it occur? 67  Official Osteoporosis Open  Condition in which bone resorption/removal is faster than bone formation  Bones become weak and prone to fracture 68  Official Open Who typically suffers from osteoporosis? (1) The elderly (2) Postmenopausal women **Bone are constantly being remodeled by osteoclasts and osteoblasts during your life. Hormonal changes (e.g. menopause) affect the interplay between osteoclasts and osteoblasts, leading to net osteoclast activity and net decrease in bone mass & density 69  Official Open Osteoporosis - Prevention 1. Increase dietary calcium + Vitamin D intake Increase in blood calcium level causes release of calcitonin. Calcitonin(hormone)stimulates removal of calcium from the blood and its deposition in bone. Inhibits osteoclast activity (resorption) while promoting osteoblast activity (formation). 2. Weight-bearing exercise Mechanical stress & gravity help to maintain skeletal strength & bone thickening by stimulating osteoblasts. 70  Official Open Homeostatic Mechanism (Blood Calcium Regulation) Brain Calcitonin released Thyroid receptors Negativ e feedb ack sys Increase in tem calcium uptake into Change bone and detected by decrease in thyroid blood receptors calcium Rise in Blood calcium levels in homeostasis levels blood calcium 71  Official Open Calcitonin “Hormone”  Produce and release by the thyroid gland.  Regulate the blood’s calcium and phosphate levels.  Inhibit the activity of the osteoclasts (cells that break down bone)  By preventing the breakdown of bone, calcitonin reduces the amount of calcium in the blood.  Calcium level drop = Calcitonin level drop 72  Official Open 2. Osteogenesis Imperfecta    73  Official Open What you need to know Functions of Bone, Cartilage, Tendons and Ligaments Definition of Osteoblasts, Osteocytes, and Osteoclasts Difference between Spongy and Compact bone (examples of each) Bone Development and Remodeling Different structural and functional types of joints and examples of each Clinical examples 74  Official Open LECTURE 4 The Muscular System 75  Official Open LECTURE OUTLINE  Functions  Types  Skeletal Muscle  Sarcomere  Contraction  Types of contraction  Exercise  Clinical Connection 76 Open Functions of the Muscular Official System 1. Body movement 2. Maintenance of posture 3. Respiration 4. Production of body heat Eg. shivering when it’s cold 5. Constriction of organs & vessels 6. Heart beat 77  Official Skeletal Muscle Open Also known as voluntary muscle because there is conscious control over it. Attached to bone via tendons and are used to move the skeleton. Contain cells that contract (shorten) in response to stimulation, then passively lengthen and return to their resting state. Contraction of a whole skeletal muscle occurs because of coordinated contraction of its individual fibre. 78 Contraction generates force for movement  Official (A) Skeletal Muscle: Characteristics Open 1. Contractibility shorten; bring about movement of attached structures 2. Excitability stimulation by nerves 3. Extensibility stretched to normal resting length 4. Elasticity recoil to resting length after being stretched 79 Open Official (B) Skeletal Muscle: Organisation 1.Fascicle: Bundle of muscle fibers 2.Muscle fiber: Skeletal and smooth muscle cells 3.Myofibril: Long cylindrical structures arranged in parallel inside each muscle fiber. Myofibrils are made up of two proteins (i) Actin (ii) Myosin Sarcomeres: Segment of a myofibril from one Z-disc to the next. Each myofibril contains thousands of sarcomeres 80  Official Open Skeletal Muscle Fascicle Anatomy Striated appearance is due to the arrangement of the sarcomere  Official Open Muscle Fiber Structures 1. Sarcolemma - plasma membrane of a muscle fiber 2. T-tubules - invaginations of sarcolemma 3. Sarcoplasmic reticulum - specialized smooth endoplasmic reticulum - Crucial for cellular calcium ion storage!  Official Open http://www.lookfordiagnosis.com/mesh_info.php? term=Sarcolemma&lang=1  Official Open Skeletal Muscle Organisation 1. Sarcomeres: Functional unit of a myofibril Segment of myofibril from one Z-disc to the next Each myofibril contains thousands of sarcomeres!  Official Open  Official To understand Open The Sarcomere muscle contraction, you just have to know how a Zsingle Disc: Marks the end of each sarcomere sarcomere works! unit H zone: Thick filaments (myosin) I band: Thin filaments (actin) A band: Contains both thick and thin filaments 86  Official Open Relaxed Sarcomere During contraction, H zone and I bands basically disappear, and the Z discs are pulled closer together Contracted Sarcomere The A bands move closer together but DO NOT change in length 87  Official Open Open Muscle Official Contraction Step by Step 1. Nervous impulse reaches neuromuscular junction 2. The neurotransmitter Acetylcholine (ACh) is released – attaches to receptors in sarcolemma http://www.shelfieldpeonline.co.uk/assets/images/neuromuscular_junction.jpg 89  Official Open 3. Action potential generated – electrical signals that spread over sarcolemma to T tubules to sarcoplasmic reticulum. 4. Sarcoplasmic reticulum releases calcium ions into cytoplasm of muscle cells. 90  Official Open 5. Calcium ions bind to - Troponin - Causes conformational change to move tropomyosin - Myosin binding sites are now exposed 91  Official Open 6: Myosin heads (on thick filament) bind actin filament and pull toward center of sarcomere, generating contraction (Power Stroke) 7: ATP binds to myosin head, stimulating the release of actin 92  Official Open Summary of Molecular Events  ADP- and Pi-bound myosin head binds to open myosin-binding site on actin  Myosin-actin binding induces release of Pi  Pi release induces the power stroke  ADP is released during the power stroke  Myosin dissociates from actin upon binding by ATP  ATP hydrolysis resets myosin head to original conformation  Cycle repeats  Official Clinical Application: Tetanus Infection Open Caused by the gram- positive bacterium Clostridium tetani (found worldwide in soil, animal faeces) Releases a neurotoxin that prevents the inhibition of nervous impulse activity on 94 www.zuova.cz/informace/pic/nrlpab23_clte1.jpg  Official Open This prevents calcium reabsorption by the sarcoplasmic reticulum Results in prolonged contraction of the muscle fibers Symptoms often begin in facial muscles (lockjaw) and then progress down the body Prevention  Tetanus can be prevented by vaccination  Initial vaccination should be followed by booster shots every ten years. 95  Official Energy Sources for Contraction Open ATP = Adenosine Tri-Phosphate  ATP is the energy source for contraction.  Very little ATP is stored in muscle fibres (also known as muscle cells).  Only enough to power muscle contractions for a few seconds.  Hydrolysis of ATP energizes myosin. Myosins are motor proteins that move along actin filaments.  So how do muscles regenerate ATP? 96  Official Open ATP is replenished within muscle fibres by …. 1. Breaks down creatine phosphate (CP) ADP + CP ATP + Creatine + Energy CP donates its high energy phosphate group to ADP, forming ATP + creatine. Reaction catalysed by creatine phosphokinase (CPK). 2. Glycolysis (anaerobic = does not require oxygen) Metabolic pathway that produces 2 ATP molecules by converting glucose molecule into pyruvate, water and NADH. Glucose supplied via blood or from glycogen stores in the muscle tissue. 97  Official Open ATP is replenished within muscle fibres by …. 3. Cellular respiration (Aerobic = requires oxygen) If oxygen is available, pyruvate can be further broken down aerobically to produce as many as 30 additional molecules of ATP. Fats can also be broken down aerobically to produce large quantities of ATP. 98  Official Open Types of Contraction 1. Isotonic:  Myofilaments successful in sliding movements, the muscle shortens, and movement occurs.  Examples: Bending knee or elbow, rotating your arm, smiling 2. Isometric:  Contraction that creates force with no movement  Myosin myofilaments are “skidding their wheels”; tension in muscle keeps increasing. No sliding occurs. 99  Example: Try to move a really heavy object by  Official Open Exercise and Muscles Aerobic (Endurance): Increases blood supply to muscles - increases oxygen storage in muscle, - makes body metabolism more efficient, - improves digestion. However, it does not increase muscle size. Eg. jogging, biking, etc. 100  Official Open Exercise and Muscles Strength (Resistance): Eg. Weight lifting (Anaerobic)  Uses isometric exercises  to make muscles contract with as much force as possible. http://www.qwa.org/products/images/IMG_7030.jpg  Increases muscle bulk and strength, because it  Ageing reduces the sizeincreases individual fibres of muscle fibres as well as within the muscle their endurance and strength 101 (hypertrophy).  Official Open What you need to know General functions of muscle The three types of muscle tissue and how they are different Structure of the (myosin, actin, band names, etc) Sarcomere What happens to the sarcomere during contraction Types of Contraction (Isotonic vs. Isometric) Aerobic vs. Resistance Exercise 102