A. Smooth Muscle Fibers
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Marisa Hanson Allison Estle Martin Vicario Taylor Strumwasser Unit 1 Outline Anatomy is study of the parts of the body, while physiology is the study of the interaction of the body parts The human organism can be described on different levels of organization From smallest to biggest: subatomic particles, atoms, molecules, macromolecules, organelle, cell, tissue, organ, organ system, and organism There are three major planes used to describe the human body They are called the midsagittal, transverse, and coronal The midsagittal plane separates the body into left and right sides The transverse plane separates the body into superior and inferior sections The coronal plane separates the body into anterior and posterior regions The abdominal region of the body is separated into nine regions Epigastric (upper middle), right and left hypochondriac (upper sides), umbilical (middle), right and left lumbar (middle sides), hypogastric (lower middle), left and right iliac (lower sides) The abdominal region can also be separated into quadrants Then ,the body as whole is separated into regions, as shown below Otic – ear Axillary – armpit Nasal – nose Mammary – breast Oral – mouth Brachial – arm Cephalic – head Antecubital – front of elbow Frontal – forehead Abdominal – abdomen Orbital – eye cavity Antebrachial – forearm Buccal –cheek Carpal – wrist Mental – chin Palmar – palm Acromial – point of shoulder Digital – finger Geneital – reproductive organs Patellar – front of knee Tarsal – instep Digital – toe Pedal – foot Umbilical – navel Inguinal – groin Coxal – hip Crural – leg Vertebral – spinal column Brachial – arm Dorsum – back Cubital – elbow Lumbar – lower back Sacral – between hips Gluteal – buttocks Femoral – thigh Popliteal – back of knee Plantar – sole Organs work together in systems Integumentary – provides layer to protect the body, as well as maintain temperature Skeletal – maintains structure Muscular – allows for movement Nervous – interprets information; sends commands to other parts of the body Endocrine – creates and sends hormones throughout the body to maintain homeostasis Cardiovascular – moves blood throughout the body Lymphatic – body’s defense system; returns escaped body fluid Digestive – breaks down food Respiratory – exchanges gases; maintains proper concentrations of gases in bloodstream Urinary – removes waste from body Reproductive Fill out this blank diagram with the scientific terms for practice. Chapter 5 Tissues Section 1- Types of Tissues Epithelial cells http://www.youtube.com/watch?v=yWzNItZFWi0&feature=related Simple squamous epithelium -layer of thin, flattened cells -cells fit tightly together -substances pass through the membrane easily -broad, flat nuceli -found in the lungs, capillaries, body cavities Simple cuboidal -cube shaped cells -found in the thyroid gland, ovaries, kidneys, pancreas and salivary glands -helps with reabsorption of liquids in kidneys -helps secretion in glands Simple columnar epithelium -single layer of elongated cells -can have cilia (hairs) -found in the digestive tract, stomach and intestines -helps in absorption of fluid and nutrition, and secretion of digestive fluids Pseudostratified columnar epithelium -not stratified (consistent layers of cells) the nuclei are in aligned in two rows -have cilia -goblet cells dispersed in between -found in the respiratory system Stratified squamous epithelium -stratified, consistent layers of cells, aligned nuclei -found in the skin, older cells become keratinized -lines oral cavities, esophagus, vagina, anal canal Stratified cuboidal epithelial -stratified, many layers -cube shaped -offers more protection than the simple cuboidal epithelial -found in the mammary glands, sweat glands, salivary glands and pancreas Stratified columnar epithelium -multiple layers of elongated cells -base layer of cube cells -found in the urethra and pharynx Transitional epithelium -special type of cell to deal with tension, it can expand -found in the bladder -acts as a barrier to keep the contents from diffusing back out of the bladder Glandular epithelium -secretes products into ducts or body fluids -make up endocrine and exocrine glands Connective Tissues -Most abundant tissue by weight -bind, support and protect areas of the body -have an extracellular matrix -well vascularized, except for ligaments, tendons and cartilage Major cell types of connective tissue Fibroblasts -repair connective tissues by secreting proteins into the ECM Macrophages -clean out foreign materials -begin as white blood cells Mast cells -prevent blood clotting -associated with inflammation and allergies, release histamine Connective tissue fibers Collagenous fibers -make up tendons and ligaments -can resist pulling force Dense connective tissue -has an abundance of collagenous fibers -has poor blood supply Loose connective tissue -has sparse collagenous fibers -binds organs to muscles -binds skin to muscle Adipose tissue -fat; protects, cushions and insulates Cartilage Hyaline -founds at the end of bones in joints -soft part of the nose -supporting rings of the respiratory passage -parts of embryo skeleton begin as hyaline cartilage, replaced with bones Elastic -flexible cartilage -provides a framework, found in the ears, parts of the larynx Fibrocartilage -shock-absorber -tough tissue found in between vertebrae, knees, and pelvic girdle Bone -hard material because of calcium salts, densest cartilage -contains red marrow and yellow marrow -contains osteoblasts, and osteocytes Blood -thinnest connective tissue -made of red and white blood cells, plasma and platelets -red blood cells transport gases -white blood cells fight infection -platelets help with clotting -enters connective tissue and helps with majoring activities Epithelial Membranes - Cover the body, hence epithelial membranes. Has three subgroups: Serous, mucous, cutaneous. Serous Membranes - Help with lubricating organs not exposed to outside. Form inner linings of the thorax and abdomen. Mucous Membranes - Contain goblet cells. Line up areas open to the outside of the body, like digestive tract. Skin: Epidermis: Outer layer of skin. All top cells are dead, keratinized. Made of stratified columnar tissue. Thickest on palms and feet. Layers from top to bottom: stratum corneum, lucidum, granulosum, spinosum, basale. Bottom layer of cell are alive; get keratinized as they go up to become the epidermis. Melanocytes make melanin, dark spots on epidermis. Dermis: Made up of connective tissue of collagen and elastic fibers; smooth muscle; nervous; blood. Fingerprints. Binds epidermis to underlying subcutaneous layer and other things. Subcutaneous Layer: Has adipose tissue, insulates. Has major blood vessels that supply the skin. Not actually part of skin. Glands of Skin: Sudoriferous glands are widespread sweat glands of the skin. Eccrine glands respond to body temperature, sweating on hot days, for example. Apocrine glands make you smell. Burns of Skin: First degree burn just burns epidermis. Second degree burn burns most of epidermis and may reach part of dermis—plasma might leak out, blisters. Third degree burns completely destroy the epidermis and reach deep into the dermis. Blood vessels may rupture, and the damage is irreparable. Need an autograft or homograft, skin from you or someone else, respectively. Videos: http://www.youtube.com/watch?v=c_IGuPYLsFI http://www.youtube.com/watch?v=yWzNItZFWi0&feature=related http://science.nationalgeographic.com/science/health-and-human-body/human-body/skin-article.html Chapter 7: Skeletal System Bone Classification Long bones- Forearms and thigh bones Short bones- Wrists and ankles Flat bones- Skull and ribs Irregular bones-Vertebrae Epiphysis: the expanded portion at the end of a bone that articulates with another bone Diaphysis: The shaft of the bone between the epiphysis Compact bone: Found in the wall of the diaphysis, continuous extracellular matrix with no gaps Spongy Bone: Consists of networks of trabeculae, branching bony plates, that creates a network of irregular cavities Periosteum: outside layer of the bone that helps form and repair bone tissue Endosteum: A thin membrane containing bone forming cells, found inside the diaphysis and filled with marrow Osteocytes: Transport nutrients and waste to and from nearby cells by the means of extracellular processes passing through canaliculi Osteon: a cylinder shaped unit formed by layers of extracellular matrix clustered around the central canal. Red Marrow: Found in spongy bone, forms red blood cells, white blood cells and platlets Yellow marrow: medullary cavity is diaphysis: it stores fat. Osteoblasts- They create bone cells. Osteoclasts- They break down the calcified matrix. Epiphyseal Plate- A band of cartilage between the two ossification centers. http://www.youtube.com/watch?v=4qTiw8lyYbs&feature=related Fractures How they Heal 1. Blood escapes from ruptured blood vessels and form a hematoma. 2. Spongy bone forms in regions close to developing blood vessels, and fibrocartilage forms in more distant regions. 3. A bonny callus replaces fibrocartilage. 4. Osteoclasts removes excess bony tissue, restoring new bone structure much like the original. Osteoporosis- Loss of bone mass which usually develops in older women. There are 206 bones in the body. 22 bones in the skull 6 in the middle ear 1 hyoid ( the only bone not attached to any other bone.) 26 vertebrae 25 in the thoracic cage 4 in the pectoral girdle 60 in the lower limbs 2 in the pelvic girdle 60 in the upper limbs Important Cranium bones -Frontal -Parietal -Occipital -temporal Vertebrae -Cervical -Thoracic -Lumbar -Sacrum True ribs (1-7) Connected directly to the sternum. False ribs (8-10) Connected to the 7th rib. Floating ribs (11-12) Not connected to the sternum. http://www.youtube.com/watch?v=1WpD7i4RxnY Chapter 9: Muscular System I. Structure of a Skeletal Muscle A. Introduction 1. A skeletal muscle is an organ of the muscular system. 2. A skeletal muscle is composed of skeletal muscle tissue, nervous tissue, blood, and connective tissues. http://www.youtube.com/watch?v=MGtq0eJshI8 B. Connective Tissue Coverings 1. Fascia is dense connective tissue that separates individual skeletal muscles. 2. A tendon is a cordlike structure that consists of dense connective tissue. 3. Tendons connect a muscle to a bone. 4. An aponeurosis is a sheetlike structure composed of dense connective tissue. 5. Epimysium is a layer of connective tissue that closely surrounds a skeletal muscle. 6. Perimysium is connective tissue that separates muscles into fascicles. 7. A fascicle is a section of a muscle. 8. Endomysium is connective tissue that surrounds individual muscle cells. 9. Deep fascia is fascia that surrounds or penetrates muscles. 10. Subcutaneous fascia is fascia just beneath the skin. 11. Subserous fascia is connective tissue layer of the serous membranes covering organs in various body cavities and lining those cavities. C. Skeletal Muscle Fibers 1. A skeletal muscle fiber is a single muscle cell. 2. The sarcolemma is the cell membrane of a muscle cell. 3. The sarcoplasm is the cytoplasm of a muscle cell. 4. The sarcoplasm contains many small nuclei, mitochondria and myofibrils. 5. Myofibrils are threadlike structures and are located in the sarcoplasm. 6. Myofibrils play a fundamental role in the muscle contraction mechanism. 7. Thick myofilaments are composed of myosin. 8. Thin myofilaments are composed of actin. 9. The organization of myofilaments produces the alternating light and dark striation characteristic of skeletal muscles. 10. A sarcomere is a repeating pattern of a myofibril. 11. Myofibrils may be thought of as sarcomeres joined end to end. 12. I bands are composed of thin actin filaments. 13. Z lines are structures that connect that anchor I bands. 14. A bands are composed of thick myosin filaments overlapping thin actin filaments. 15. The H zone is a central region of an A band that only contains thick filaments. 16. The M line is a region of an A band which consists of proteins that help hold the thick filaments in place. 17. Titin connects proteins that connect myosin filaments to Z lines. 18. A sarcomere extends from one Z line to another Z line. 19. Each myosin molecule consists of two twisted protein strands with globular parts called cross-bridges that project outward along their lengths. 20. Thin filaments consist of double strands of actin twisted into a helix. 21. Actin has a binding site to which the cross-bridges of a myosin molecule can attach. 22. Troponin and tropomyosin associate with actin filaments. 23. Sarcoplasmic reticulum is endoplasmic reticulum of a muscle fiber. 24. Transverse tubules are membranous channels that extend into the sarcoplasm as invaginations continuous with the sarcolemma and contain extracellular fluid. 25. Cisternae are enlarged portions of sarcoplasmic reticulum. 26. A triad is formed by one transverse tubule and two cisternae. http://www.youtube.com/watch?v=Vlchs4omFDM II. Skeletal Muscle Contraction A. Neuromuscular Junction 1. Each skeletal muscle is functionally connected to an axon of a motor neuron. 2. A motor neuron passes outward from brain or spinal cord. 3. Normally, a skeletal muscle fiber contracts only upon stimulation by a motor neuron. 4. A neuromuscular junction is the site where an axon and muscle fiber meet. 5. A motor end plate is a specialized portion of the muscle cell membrane that is extensively folded. 6. A motor unit is a motor neuron and the muscle fibers it controls. 7. A synaptic cleft separates the membranes of the neuron and the membrane of the muscle fiber. 8. Synaptic vesicles store neurotransmitters. http://www.youtube.com/watch?v=ZscXOvDgCmQ B. Stimulus for Contraction 1. Acetylcholine is the neurotrasnmitter that motor neurons use to control skeletal muscle. 2. ACh is synthesized in the cytoplasm of the motor neuron and is stored in synaptic vesicles in axons. 3. When a nerve impulse reaches the end of an axon, acetylcholine is released into the synaptic cleft. 4. ACh combines with ACh receptors on the motor end plate, and stimulates the muscle fiber. 5. A muscle impulse is an electrical signal that is like a nerve impulse. 6. A muscle impulse changes the muscle cell membrane in a way that transmits the impulse in all directions along and around the muscle cell. 7. Ultimately the muscle impulse reaches the sarcoplasmic reticulum and cisternae. http://www.youtube.com/watch?v=CepeYFvqmk4 C. Excitation Contraction Coupling 1. The sarcoplasmic reticulum has a high concentration of calcium. 2. In response to a muscle impulse, the membranes become more permeable to calcium, and the calcium diffuses out of the cisternae into the cytosol of the muscle fiber. 3. When a muscle fiber is at rest, the troponin-tropomyosin complexes block the binding sites on the actin molecules. 4. Calcium ions bind to troponin, changing its shape and altering the position of the tropomyosin. 5. The movement of the tropomyosin molecule exposes the binding sites of the actin filaments, allowing linkages to form between myosin cross-bridges and actin. D. The Sliding Filament Model of Muscle Contraction 1. The functional unit of skeletal muscles is the sarcomere. 2. According to the sliding filament model, when sarcomeres shorten, the thick and thin filaments slide past one another. 3. As contraction occurs, the H zones and the I bands get narrower and the Z lines move closer together. E. Cross-bridge Cycling 1. The force that shortens the sarcomeres comes from cross-bridges pulling on the actin filaments. 2. A myosin cross-bridge attaches to actin in order to pull on the actin filament. 3. The cross-bridge can release, straighten, and combine with another binding site further down the actin filament, and pull again. 4. Myosin cross-bridges contain the enzyme ATPase. 5. ATPase catalyzes the breakdown of ATP to ADP. 6. The force for muscle contraction is provided by the breakdown of ATP into ADP. 7. Breaking down of ATP puts the myosin cross-bridge in a “cocked” position. 8. When a muscle is stimulated to contract, a cocked cross-bridge attaches to actin and pulls the actin filament toward the center of the sarcomere, shortening the muscle. 9. When another ATP binds, the cross-bridge is released, and then breaks down the ATP to return to the cocked position. 10. The cross-bridge cycle may repeat over and over as long as ATP is present and nerve impulses cause ACh release at the neuromuscular junction. F. Relaxation 1. In order for a muscle fiber to relax, acetylcholine must be decomposed by an enzyme called acetylcholinesterase. 2. The action of acetycholinesterase prevents a single nerve impulse from continuously stimulating a muscle fiber. 3. When acetylcholine breaks down, the stimulus to the sarcolemma and the membranes within the muscle fiber ceases. 4. The calcium pump moves calcium back into the sarcoplasmic reticulum. 5. When calcium is removed from the cytoplasm, the cross-bridge linkages break and tropomyosin rolls back into its groove, preventing any cross-bridge attachment. 6. ATP is necessary for both muscle contraction and relaxation. 7. The trigger for contraction is the increase in cytosolic calcium in response to stimulation by ACh from a motor neuron. G. Energy Sources for Contraction 1. Creatine phosphate is an energy source available to generate ATP from ADP. 2. Creatine phosphate includes a high energy phosphate bond. 3. As ATP is decomposed to ADP, the energy from creatine phosphate is transferred back to ADP to produce ATP. 4. After creatine phosphate is used, a muscle cell must depend on cellular respiration of glucose to synthesize ATP. 5. Typically a muscle stores glucose in the form of glycogen. H. Oxygen Supply and Cellular Respiration 1. Glycolysis occurs in the cytoplasm and is anaerobic. 2. Glycolysis releases a few ATP molecules. 3. The complete break down of glucose occurs in mitochondria and requires oxygen. 4. The citric acid cycle and electron transport chain produce water, carbon dioxide and a large amount of ATP. 5. Oxygen is carried in the blood stream bound to hemoglobin. 6. Myoglobin is red in color. 7. Myoglobin stores oxygen in muscle tissue. I. Oxygen Debt 1. Lactic acid threshold is the shift in cellular metabolism from breaking down pyruvic acid into carbon dioxide to pyruvic acid breakdown leading to lactic acid formation. 2. Under anaerobic conditions, glycolysis breaks down glucose into pyruvic acid and converts it to lactic acid. 3. Lactic acid is carried by the blood to the liver. 4. Liver cells can convert lactic acid to glucose. 5. Oxygen debt reflects the amount of oxygen liver cells require to use the accumulated lactic acid to produce glucose, plus the amount the muscle cells require to resynthesized ATP and creatine phosphate, and restore their original concentrations. J. Muscle Fatigue 1. Fatigue is the condition in which a muscle fiber cannot contract. 2. Fatigue may result from decreased blood flow, ion imbalances across the sarcolemma, and the psychological loss of the desire to continue to exercise. 3. A cramp is a sustained, painful, involuntary muscle contraction. 4. The strenuous exercise of aerobic training stimulated new capillaries to grow within the muscles, supplying more oxygen and nutrients. K. Heat Production 1. Heat is a by-product of cellular respiration. 2. Blood transports heat throughout the body, which helps to maintain body temperature. III. Muscle Responses A. Introduction 1. One way to observe muscle contraction is to remove a single muscle fiber from a skeletal muscle and connect it to a device that measures contraction. 2. An electrical impulse is usually used to produce muscle contraction. B. Threshold Stimulus 1. Threshold stimulus is the minimal stimulus needed to start a muscle contraction. 2. An impulse in a motor neuron normally releases enough ACh to bring the muscle fibers in its motor unit to threshold. C. Recording a Muscle Contraction 1. A twitch is the response of a single muscle fiber to the ACh released by a single action potential. 2. A myogram is a recording of the events of a muscle twitch. 3. Three periods of a muscle fiber contraction are latent, contraction, and relaxation. 4. During the period of contraction, a muscle fiber is generating force or contracting. 5. The latent period is the period before contraction. 6. The period of relaxation is the period in which a muscle fiber is decreasing tension. 7. The refractory period is the brief moment when a muscle fiber remains unresponsive to stimulation. 8. An all-or-none response is one in which a muscle fiber contracts completely or not at all. 9. The length to which a muscle is stretched before stimulation affects the force it will develop when stimulated. 10. If a muscle is stretched well beyond its normal resting length, the force will decrease. 11. At very short muscle lengths, the sarcomere becomes compressed and shortening is not possible. 12. In the whole muscle, the degree of tension reflects the frequency at which individual fibers are stimulated and how many fibers take part in the overall contraction of the muscle. D. Summation 1. Twitches in a muscle can combine to become sustained. 2. Summation is the combination of the force of individual twitches. 3. Tetanic contractions are contractions that lack relaxation. E. Recruitment of Motor Units 1. The fewer muscle fibers in the motor units, the more precise the movements can be produced in a particular muscle. 2. All muscle fibers in a motor unit are stimulated at the same time. 3. Multiple motor unit summation is recruitment. 4. Recruitment is an increase in the number of activated motor units. 5. As the intensity of stimulation increases, recruitment continues until all possible motor units are activated in a muscle. F. Sustained Contractions 1. During sustained contractions, smaller motor units are recruited earlier. 2. The larger motor units respond later and more forcefully. 3. Muscle movements are smooth because the spinal cord stimulates contraction in different sets of motor units at different times. 4. Muscle tone is the amount of sustained contractions in a muscle. 5. Muscle tone is important for maintaining posture. G. Types of Contractions 1. An isotonic contraction is a type of contraction that produces movement of a body part. 2. A concentric contraction is an isotonic contraction in which shortening of the muscle occurs. 3. An eccentric contraction is an isotonic contraction in which lengthening of the muscle occurs. 4. An isometric contraction is a contraction in which muscle tension increases but no movements of body parts are produced. 5. An example of an isometric contraction is standing. 6. An example of an isotonic contraction is walking. H. Fast and Slow Twitch Muscle Fibers 1. Type I fibers are slow-twitch fibers. 2. Examples of type I fibers are those in the long muscles of the back. 3. Type I fibers are red in color because they contain a relatively large amount of myoglobin. 4. Type I fibers are resistant to fatigue. 5. Type IIa fibers are fast twitch glycolytic fibers. 6. Type IIa fibers are white in color because they contain relatively small amounts of myoglobin. 7. Type IIb fibers are fast twitch oxidative fibers. 8. All muscles include a combination of fiber types. IV. Smooth Muscles A. Smooth Muscle Fibers 1. Compared to skeletal muscle fibers, smooth muscle fibers are shorter and they have single nuclei. 2. Two major types of smooth muscle are visceral and multiunit. 3. Multiunit smooth muscle is located in the irises and the walls of blood vessels. 4. Visceral smooth muscle is located in the walls of hollow organs except for the heart. 5. Fibers of visceral smooth muscle are connected by gap junctions. 6. Rhythmicity is a pattern of spontaneous repeated contractions. 7. Peristalsis is a wavelike motion produced by smooth muscle contraction. 8. Peristalsis helps force the contents of a tube along its length. B. Smooth Muscle Contraction 1. Compared to skeletal muscle fibers, smooth muscle fibers lack troponin and use calmodulin to bind calcium instead. 2. Two neurotransmitters that affect smooth muscle are acetylcholine and norepinephrine. 3. Hormones affect smooth muscle by stimulating or inhibiting contraction in some cases and lettering the degree of response to neurotransmitters in other cases. 4. Stretching of smooth muscle can trigger contractions. 5. Smooth muscle is slower to contract and relax than skeletal muscle. 6. Unlike skeletal muscle, smooth muscle fibers can change length without changing tautness. V. Cardiac Muscle A. Cardiac muscle appears only in the heart. B. Cardiac muscle is composed of striated cells, forming fibers that are interconnected in branching, three-dimensional networks. C. Cardiac muscle fibers can contract longer than skeletal muscle fibers. D. Intercalated discs are membrane junctions that join cardiac muscle fibers together. E. Intercalated discs allow muscle impulses to travel rapidly from cell to cell. F. A syncytium is a group of muscle fibers that contract as a unit. VI. Skeletal Muscle Actions A. Introduction 1. Skeletal muscles generate a great variety of body movements. 2. The action of each muscle mostly depends upon the kind of joint it is associated with and the way the muscle is attached on either side of that joint. B. Body Movement 1. Bones and muscles interact as levers. 2. The four basic components of a lever system are rigid bar, fulcrum, object that is moved against resistance, and a force. 3. In scissors, the handle and blades form a rigid bar. 4. The fulcrum of scissors is the screw. 5. The resistance of scissors is the material to be cut. 6. The force of scissors is supplied by the person on the handles. 7. In a first-class lever system, the parts are arranged resistance, fulcrum, force. 8. Besides scissors, other examples of first class lever systems are seesaws and hemostats. 9. In a second-class lever system, the parts are arranged fulcrum, resistance, force. 10. An example of a second-class lever system is a wheelbarrow. 11. In a third class lever system, the parts are arranged resistance, force, and fulcrum. 12. An example of a third-class lever system is a pair of tweezers. 13. In the action of bending the upper limb at the elbow, the rigid bar is the forearm bones, the fulcrum is the elbow joint, the resistance is the hand, and the force is applied by muscles on the anterior side of the arm. 14. Bending the arm at the elbow is an example of a third-class lever system. 15. When the upper limb straightens at the elbow, the rigid bar is forearm bones, the pivot is the elbow, the resistance is the hand, and the force is applied by the triceps brachii muscle located on the posterior surface of the arm. 16. Straightening the arm at the elbow is a first class lever system because the parts of the lever are arranged resistance, fulcrum, force. 17. An example of a second-class lever system in the body is a movement produced at the temporomandibular joint (opening of the mouth) C. Origin and Insertion 1. The origin of a muscle is the immovable end of the muscle. 2. The insertion of a muscle is the movable end of a muscle. 3. When a muscle contracts, its insertion is pulled toward its origin. 4. The head of a muscle is the part nearest its origin. 5. The origins of the biceps brachii are the attachment to the coracoid process of the scapula, and the attachment to a tubercle above the glenoid cavity of the scapula. 6. The insertion of the bicep brachii is the radial tuberosity of the radius. 7. When the biceps brachii contracts, the elbow bends. D. Interaction of Skeletal Muscles 1. A prime mover is the muscle primarily responsible for producing an action. 2. A synergist is a muscle that assists the prime mover. 3. An antagonist is a muscle that resists the action of a prime mover. VII. Major Skeletal Muscles A. Introduction 1. The name of a muscle may reflect its size, shape, function, number of origins, attachment sites, or direction of its muscle fibers. B. Muscles of Facial Expression 1. As a group, muscles of facial expression connect the bones of the skull to connective tissue in region of the overlying skin. C. Muscles of Mastication 1. Muscles of mastication produce chewing movements. D. Muscles That Move the Head and Vertebral Column E. Muscles That Move the Pectoral Girdle F. Muscles That Move the Arm G. Muscles That Move the Forearm Muscles of the Abdominal Wall 1. The linea aspera is a band of connective tissue that extends from the xiphoid process to the symphysis pubis. J. Muscles of the Pelvic Outlet 1. The pelvic diaphragm forms the floor of the pelvic cavity. 2. The urogenital diaphragm fills the space within the pubic arch. K. Muscles That Move the Thigh 1. For the following muscles, list their origins, insertions, and actions L. Muscles That Move the Leg M. Muscle That Move the Foot VIII. Life-Span Changes A. Signs of aging of the muscular system begin to appear one’s forties. B. At a microscopic level, myoglobin, ATP, and creatine phosphate decline. C. Connective tissue and adipose tissue begin to replace some muscle tissue. D. Exercise can help maintain a healthy muscular system E. According to the National Institute on Aging, exercise should include strength training, aerobics, and stretching. Nervous System Charlie Frishberg, Lauren Worley, Avery Anton, James Grant, Paris Sorci, and random people that joined the table. +Kimball Nervous System Basics • Split into two main portions: the Peripheral Nervous System and the Central Nervous System • PNS split into Somatic, Autonomic, Visceral • Entire Nervous System composed of neural tissues. (Neurons, and neuroglial cells) Anatomy of a Neuron • http://www.youtube.com/watch?v=ob5U8zPbAX4 • Dendrites, Soma, Myelin Sheath, Axon, Nodes of Ranvier, Axon Hillock. Synpatic Cleft Signal Transmission • Acton potential depolarizes the Axon terminal. • The Axon terminal becomes permeable to Calcium. The Calcium enters the terminal and causes the vesicles containing neurotransmitters to fuse with the synaptic membrane. • Neurotransmitters are then released into the synaptic cleft. Classification of Neurons • Structural • Functional • Sensory(afferent)-toward CNS • Interneurons- within brain or spinal cord. Form links between neurons • Motor (efferent)- away from CNS Neuroglia of the PNS Schwann cells: produce myelin found on the peripheral myelinated neurons. Satellite cells: support clusters of neuron cell bodies called ganglia Neuroglia of the CNS Astrocytes: Star-shaped; between neurons and blood vessels; Aid in metabolism; respond to injury in brain tissue; important role in regulating the BLOOD BRAIN BARRIER. Oligodendrocytes: make up the myelinated axons in the CNS Microglia: Help support neuons and phagocytize bacterial cells Ependyma: Ciliated; form the inner lining of the spinal cord; Covers the ventricles; line the choroid plexus. Cell-Membrane potential: http://www.youtube.com/watch?v=jcZLtH-Uv8M Repolarization Sodium potassium pumps pump 2 potassium in and 3 Sodium out. Signals cant fire in refractory period. THE BRAIN The Meninges From top to bottom Dura mater Arachnoid Pia mater CSF is in between the arachnoid and pia mater CSF is made by the choroid plexuses in the 3rd ventricle CSF circulates from choroid plexus to 3rd ventricle around frontal lobe, and look at the book honestly. Functions of the spinal cord They do reflex arcs: which are your reflexes. Duh. There is ascending and descending tracts. Remember that the Insula is another lobe inside the brain. PAGES 405 and 415 in the Anatomy book have charts if you want to know the function of each part of the brain. Senses: Taste, Sight, Hearing, Touch, Smell By: Julia, Stephanie, Anthony, Jake, Kaylee, Scott Taste: Taste Buds: - Taste buds (Gustatory cells) are scattered in the roof of the mouth, the linings of the cheek, and the walls of the pharynx. Taste Receptors: - Taste cells are modified epithelial cells - Taste hairs are tiny microvilli that protrude from the outer ends of the taste cells. (Super sensitive) - Chemoreceptors Taste Sensations: - Sourreceptors are stimulated by acids - Sweetreceptors are stimulated by carbohydrates - SaltReceptors are stimulated by ionized inorganic salts - Bitterreceptors stimulated by organic compounds - Constantly going under sensory adaptation - Taste cells are rapidly dividing continuously because they are epithelial cells so as one gets older taste won’t diminish as is the sense of smell. - Taste cells are replaced every 3 days Sight: Eyelid Composed for four layers, skin muscle connective tissue, and conjunctiva. The conjunctiva is a mucous membrane that lines the inner surfaces of the eyelids and folds back to cover the anterior surface of the eyeball, except for the cornea. Lacrimal Apparatus Lacrimal gland secretes tears, Canaliculi collect tears. Lacrimal sac collects from the canaliculi. Nasolacrimal duct collects from the lacrimal sac and empties tears into the nasal cavity, Extrinsic Muscles Superior rectus, rotates eye upward and toward midline. Inferior rectus, rotates eye downward and toward the midline. Medial rectus, rotates eye toward the midline. Lateral rectus, rotates eye away from the midline. Superior oblique, rotates eye downward and away from the midline. Inferior oblique, rotates eye upward and away from the midline. The Outer Tunic Cornea, helps focus light rays. Sclera, white portion of the eye that protects and is an attachment for the extrinsic muscles. Middle Tunic Choroid coat provides blood supply as while absorbs extra light due to it’s pigments. Ciliary body holds the lens and it’s fibers help move the lens for focusing. Iris controls light intensity and is pigmented. Aqueous humor fills the spaces between the cornea and the lens, providing nutrients and maintaining the shape of the front of the eye. Inner Tunic Vision Retina contains visual receptors. It is composed of many layers the macula lutea, fovea centralis, optic disc, and the vitreous humor. Macula lutea is the yellowish spot in the retina. Fovea centralis is the center of the macula lutea; it produces the sharpest vision. Optic disc is the blind spot. Vitreous humor is the thick gel that supports the internal structures of the eye and helps maintain its shape. Passes through CorneaAqueous humorLensVitreous humorRetinal layersPhotoreceptor cells Lenses Convex lenses cause light waves to converge Concave lenses cause light waves to diverge Visual Receptors Rods contain light sensitive pigment called rhodopsin, they are hundred times more sensitive to light than cones. Helps to provide vision in dim light and produces colorless vision. Cones contain light sensitive pigments called erythrolabe, chlorolabe, and cyanolabe. These provide images in bright light that are shape and colored. Sense of Hearing: a. The outer ear includes the auricle, the external acoustic meatus, and the tympanic membrane. It collects sound waves created by vibrating objects. b. Middle ear 1) Auditory ossicles of the middle ear conduct sound waves from the tympanic membrane to the oval window of the inner ear. They also increase the force of these waves. 2) Skeletal muscles attached to the auditory ossicles provide the tympanic reflex, which protects the inner ear from the effects of loud sounds. c. Auditory tubes connect the middle ears to the throat and help maintain equal air pressure on both sides of the tympanic membranes. d. Inner ear 1) The inner ear consists of a complex system of connected tubes and chambers-the osseous and membranous labyrinths. It includes the cochlea, which houses the organ of Corti. 2) The organ of Corti contains the hearing receptors that vibrations in the fluids of the inner ear stimulate. 3) Different frequencies of vibrations stimulate different sets of receptor cells; the human ear can detect sound frequencies from about 20 to 20,000 vibrations per second. e. Auditory nerve pathways 1) The nerve fibers from hearing receptors travel in the cochlear branch of the vestibulocochlear nerves. 2) Auditory impulses travel into the medulla oblongata, midbrain, and thalamus and are interpreted in the temporal lobes of the cerebrum. Sense of Equilibrium a. Static equilibrium maintains the stability of the head and body when they are motionless. The organs of static equilibrium are located in the vestibule. b. Dynamic equilibrium balances the head and body when they are moved or rotated suddenly. The organs of this sense are located in the ampullae of the semicircular canals. c. Other structures that help maintain equilibrium include the eyes and the proprioceptors associated with certain joints. Touch: There are three kinds of touch receptors that sense mechanical forces ha deform or displace tissues. Free nerve endings are the simplest of receptors that lie between epithelial cells. The give us the sensation of itching. Tactile (Meissner’s) corpuscles are small oval masses of connective tissue. Two or more sensory nerve fibers branch into each corpuscle and end within it as tiny knobs. These receptors are responsible for fine touch such as on the lips, fingertips, palms, soles, nipples, and external genital organs. Lamellated (Pacinian) corpuscles are relatively large, ellipsoidal structures composed of connective fibers and cells. They are found in the deeper dermal tissue of the hands, feet, penis, clitoris, urethra, and breasts and also in tendons of muscles and ligaments of joints. These receptors detect vibrations in tissues. Receptor Types Chemoreceptor respond to changes in chemical levels in the environment Nocioreceptors respond to tissue damage Thermoreceptors respond to temperature changes Mechanoreceptors respond to mechanical forces that adjust muscle length, and width Photoreceptors respond to changes in the visible light spectrum Sensations and Perception Sensations are feelings that result from sensory stimulation Perceptions are the feeling caused by the cerebral cortex processing a stimulation Sensory adaptations are adjustments of the sensory receptors to ignore continuous stimulation, like how a cut hurts at first and then only becomes a weak, light pain later. This occurs because signals are triggered to fire at slower rates. Balance and Equilibrium Static equilibrium is when the body maintains the stability of the head when the rest of the body isn't moving. Static equilibrium is controlled by the organs in the vestibule In the vestibule, special organic compounds called otoliths, sense movement by responding to gravity. As they move around, they stimulate special hair cells in the vestibule to send signals to the cerebellum to let the brain know the positioning of the head. Dynamic equilibrium is the body's ability to balance the head and the body while they are moving. This is controlled by the ampullae in the semicircular canals. The cristae ampullarae function by suspending hair cells in a membrane. When motion occurs, the membrane moves as well, and the hair cells are stimulated and send the signals to the brain. Life Span Changes Diminished senses are the most common sign of aging. Age related hearing loss reflects damage to the hair cells in the organ of Corti, degeneration of the auditory nerve, or titinus Age related visual problems include dry eyes, floaters, light flashes, presbyopia, glaucoma, cataracts, macular degeneration, and retinal detachment. Most of these acn be dealt with by an ophthalmologist, or an eye surgeon. Smell: Olfactory Receptors: Chemoreceptors that chemicals dissolved in nasal secretions stimulate. Olfactory Receptors function together with taste receptors and aid in food selection. Olfactory Nerve Pathways: Nerve impulses travel from the olfactory receptors through the olfactory nerves, olfactory bulbs, and olfactory tracts. They then go to the interpreting centers in the limbic system of the brain. Endocrine System • General • Endocrine System secretes hormones that act on target cells • Local Hormones: Paracrine and Autocrine cells • Paracrine- affect neighboring cells • Autocrine- Affect secretory cells • Hormones regulate metabolic processes and play roles in reproduction, development, and growth • Types of Hormones • Steroid hormones: sex hormones, secretions of adrenal cortex (glucocorticoids, minerlcorticoids, androgens, estrogens, progesterone) • Permeates cell membrane and enters nucleus • Non-steroidal hormones: amines, proteins, glycoproteins, peptide, prostoglandins • Does not permeate cell membrane and acts via second messenger activation (i.e. DAG, cAMP, cGMP) • Hormone Action • Steroid/Thyroid: • Secreted • Enters cytoplasm/nucleus • Combines with receptor • Hormone-receptor complex binds to DNA and promotes/inhibits transcription • mRNA → protein synthesis • Synthesis produces effects • Nonsteroid • Secreted • Combines with receptor site on membrane → activates G protein • Adenylate cyclase activated • ATP → cAMP • cAMP activates protein kinases • These activate proteins • Effect change • Receptor molecule has binding site (for hormone) and activity site (interacts with membrane proteins) • Hormone = 1st messenger • Biochemical in cell = 2nd messenger • Hormone Control Sources (by negative feedback) • 1) hypothalamus controls release of tropic hormones • 2) nervous system stimulates glands • 3) response to changes in internal environment • Pituitary Gland • At the base of the brain, attached to the hypothalamus by the pituitary stalk • Anterior Lobe • • • • • • • • • • • GH, TSH, ACTH, FSH, LH, PRL Posterior Lobe • ADH, OT Hypothalamus • Releasing hormones anterior pituitary • Somatotropes relase GH • Mammatropes release PRL • Thyrotropes release TSH • Corticotropes release ACTH • Gonadotropes release FSH, LH Growth Hormone • Stimulates cell enlargement/division • Stimulates movement of amino acids through cell membranes • Increases protein synthesis • Increases fat use • Decreases carbohydrate use • Peaks during sleep • Stimulated by growth hormone releasing hormone, inhibited by somatostatin Prolactin • Increases milk production • Stimulated by prolactin secreting factor, inhibited by prolactin release inhibiting hormone Thyroid-Stimulating Hormone • Stimulates growth of thyroid gland • Stimulated by TRH & exposure to cold/emotional stress Adrenocorticotropic Hormone • Controls secretion of adrenal cortex • Stimulated by corticotropin-releasing hormone Follicle-Stimulating Hormone • Stimulates follicle growth • Secretion of estrogen • Production of sperm Luteinizing Hormone • Release of sex hormones • Egg release Antidiuretic Hormone • Contracts smooth muscle • Increases blood pressure • Collecting duct cells reabsorb water for less urine Oxytocin • Antidiuretic • Contracts uterus • • • • • • • • • • • • • Ejects milk Thyroid Gland • 2 lobes w/ isthmus, below larynx, anterior to trachea • Removes iodine from blood • Follicular cells produce thyroxine & triidothyronine regulate metabolism (needs iodine for this) • T3 more potent • Extra follicular cells produce calcitonin (lowers blood Ca) Parathyroid Glands: on the posterior of the thyroid gland Parathyroid hormone- increases blood calcium ion concentration Adrenal Glands • Ontop of the kidneys • Adrenal Medulla- connected to nervous system • EPI, NE Adrenal Cortex • Aldosterone( mineral corticoid) • Conserves Na+ excretes K+ • Renin angiotensin in system - gets released when there are changes in blood pressure • Na+ reacts with angiotensin Cortisol ( glucocorticoid) • Inhibits protein synthesis • Release of fatty acids • Increase in blood glucose concentration Pancreas • Glucagon stimulates the breakdown of glycogen glucose • Insulin stimulates uptake of glucose into liver , promotes diffusion of glucose into cell membranes Somatostatin • Into cell membrane (except inhibits glucagon, insulin brain) Pineal Gland • Within brain • Melatonin • Inhibited by light • Sleep cycles Thymus • Posterior to sternum, beneath lungs • Thymosus; production/differentiation of T lymphocytes Overies • Estrogen • Progesterone Placenta • • • Estrogen • Progesterone Testes • Testosterone General stress Syndrome • Sympathetic activity • CRH, ACTH, Cortisol • Glucagon, GH, ADH
