1. Chapter 17 & 18 Musculature & Digestive Systems

2. The Musculature System

3. Includes 3 types of Muscle: Includes 3 types of Muscle: Striated, Smooth & Cardiac Striated, Smooth & Cardiac Function of the Muscles: Function of the Muscles: Provide means of Movement Provide means of Movement Keeps blood pumping Keeps blood pumping Moves food thru Digestive System Moves food thru Digestive System Skeletal Muscle usually in Antagonistic Pairs Skeletal Muscle usually in Antagonistic Pairs Flexor (bicep) Flexor (bicep) Extensor (tricep) Extensor (tricep) The Musculature System

4. Skeletal Skeletal Striated Striated Voluntary Voluntary Organ Organ Smooth Smooth Involuntary Involuntary Heart Heart Cardiac Cardiac Involuntary Involuntary 3 Types of Muscle Tissue Skeletal, Smooth and Cardiac

5. How Muscles Work Muscles can only contract & get shorter Muscles can only contract & get shorter They cannot push things, they only pull. They cannot push things, they only pull. They are attached to two different bones and cause them to bend at the joint They are attached to two different bones and cause them to bend at the joint Origin – place the muscle attaches or begins (proximal) Origin – place the muscle attaches or begins (proximal) Insertion – place on the other side of joint muscle attaches (distal side) Insertion – place on the other side of joint muscle attaches (distal side) They work in Antagonistic Pairs They work in Antagonistic Pairs Flexors – cause the joint to bend – bicep Flexors – cause the joint to bend – bicep Extensor – causes the joint to extend ( straighten out) - tricep Extensor – causes the joint to extend ( straighten out) - tricep Muscles are attached to bones w/ tendons Muscles are attached to bones w/ tendons Origin Insertion

6. Smooth & Cardiac Muscle Smooth Muscle – usually are not voluntarily controlled. Found in the walls of hollow organs of the digestive tract & blood vessels. Smooth Muscle – usually are not voluntarily controlled. Found in the walls of hollow organs of the digestive tract & blood vessels. They assist in the movement of food thru the digestive system (peristalsis) and movement of blood thru the circulatory system. They assist in the movement of food thru the digestive system (peristalsis) and movement of blood thru the circulatory system. Cardiac Muscle – found only in the heart. Similar to both Striated & Smooth Muscle tissue. Involuntarily controlled by brain. Cardiac Muscle – found only in the heart. Similar to both Striated & Smooth Muscle tissue. Involuntarily controlled by brain.

7. Skeletal Muscle Structure Skeletal muscles are made up of bundles of muscle fibers which in turn are made of myofibrals (multi-nucleated muscle cells). Skeletal muscles are made up of bundles of muscle fibers which in turn are made of myofibrals (multi-nucleated muscle cells). Each myofibral is made of Each myofibral is made of thin filaments called Actin and thick filaments called Myosin. thin filaments called Actin and thick filaments called Myosin. Muscle  Bundle  Fibers  Myofibrils  Filaments  Actin & Myosin Muscle  Bundle  Fibers  Myofibrils  Filaments  Actin & Myosin Each fiber is divided into functional units called sarcomeres Each fiber is divided into functional units called sarcomeres tendon Muscle Bundle Fiber Myofibril Filaments Sarcomere

8. Skeletal Muscle Sarcomere Sarcomere is divided into various zones. Sarcomere is divided into various zones. Each Sarcomere is separated by Z discs Each Sarcomere is separated by Z discs Light colored bands are I bands Light colored bands are I bands Dark colored bands are A bands Dark colored bands are A bands Middle of the dark A band is H zone Middle of the dark A band is H zone Middle of H zone is the M line Middle of H zone is the M line MyosinActin Muscle contraction begins after a nerve stimulates the muscle fiber. Muscle contraction begins after a nerve stimulates the muscle fiber.

9. Skeletal Muscle Contraction MyosinActin Muscle contraction begins after a nerve stimulates the muscle fiber. Muscle contraction begins after a nerve stimulates the muscle fiber. Impulse causes Actin filaments to slide over (like a ratchet) the Myosin filaments. Impulse causes Actin filaments to slide over (like a ratchet) the Myosin filaments. This shortens the length of the sarcomere. This shortens the length of the sarcomere. Once contracted, the H zone closes up. Once contracted, the H zone closes up. This shortening isn’t much until you add up the thousands of sarcomeres in each muscle bundle. This shortening isn’t much until you add up the thousands of sarcomeres in each muscle bundle.

10. Need-to-Know Skeletal Muscles Know these muscles: Masseter, Trapezius, Deltoid, Pectoralis, Latissimus dorsi, intercostals, Rectus abdominis, External obliques, Biceps brachii, Triceps, Gluteus, Rectus femoris, Biceps femoris, gastronemius

11. General info: General info: Basic “tube-within-a-tube” Basic “tube-within-a-tube” Digestion by mechanical & chemical means Digestion by mechanical & chemical means Mechanical Digestion from cutting, grinding, chewing in mouth. From churning by peristalsis in stomach Mechanical Digestion from cutting, grinding, chewing in mouth. From churning by peristalsis in stomach Chemical Digestion beginning in mouth through stomach & small intestines. Chemical Digestion beginning in mouth through stomach & small intestines. Acidic pH in mouth & stomach Acidic pH in mouth & stomach Switches to basic pH in small intestine Switches to basic pH in small intestine Accessory Organs – food doesn’t pass thru them. They supply digestive “juices”. Accessory Organs – food doesn’t pass thru them. They supply digestive “juices”. Salivary glands, Liver, gall bladder & pancreas Salivary glands, Liver, gall bladder & pancreas The Digestive System Mouth  pharynx  esophagus  stomach  duodenum  jejunum  ileum  cecum  ascending colon  transverse colon  descending colon  sigmoid colon  rectum  anus

12. Upper Digestive Tract Mouth & Pharynx Mouth & Pharynx Teeth Teeth Incisors- slice Incisors- slice Canines – tear Canines – tear Premolars – grind Premolars – grind Molars - grind Molars - grind Tooth Structure Tooth Structure Crown, neck & root Crown, neck & root Enamel – hard for protection Enamel – hard for protection Dentine – softer, alive bone-like Dentine – softer, alive bone-like Pulp – soft blood & nerve tissue Pulp – soft blood & nerve tissue Cementum & Periodontal membrane “glue” tooth to the bony socket Cementum & Periodontal membrane “glue” tooth to the bony socket Chewed Food (smaller pieces w/ higher surface area) mixes w/ saliva becomes bolus. Enzyme Amylase begins Carbohydrate chemical digestion. Chewed Food (smaller pieces w/ higher surface area) mixes w/ saliva becomes bolus. Enzyme Amylase begins Carbohydrate chemical digestion. Swallowed food passes thru pharynx, past epiglottis & into esophagus

13. The Esophagus Involuntary contractions and relaxation of smooth muscle surrounding esophagus moves food down esophagus: Peristalsis Involuntary contractions and relaxation of smooth muscle surrounding esophagus moves food down esophagus: Peristalsis Cardiac Sphincter: Ring shaped muscle separating the esophagus from the stomach Cardiac Sphincter: Ring shaped muscle separating the esophagus from the stomach sphincters  sphincters are muscles that squeeze the digestive tube closed and help move material in only one direction.

14. The Stomach Mechnical & Chemical digestion Mechnical & Chemical digestion Stomach secretes HCl – very acidic Stomach secretes HCl – very acidic Mucus secretions protect lining from self-digestion Mucus secretions protect lining from self-digestion Stomach lining w/ folds to increase surface area Stomach lining w/ folds to increase surface area Bolus is mixed w/ acids for several hours – now called chyme. Bolus is mixed w/ acids for several hours – now called chyme. Carbohydrate and protein digestion takes place. Carbohydrate and protein digestion takes place. Enzyme Pepsin used in protein digestion Enzyme Pepsin used in protein digestion Leaves thru Pyloric Sphyncter to the duodenum. Leaves thru Pyloric Sphyncter to the duodenum. Cardiac Sphincter

15. Small Intestine About 20 ft long, 1”-2” in diameter About 20 ft long, 1”-2” in diameter Most chemical digestion takes place here Most chemical digestion takes place here 3 regions – duodenum, jejunum and ileum 3 regions – duodenum, jejunum and ileum Chemical pH 8 – protein, fats & carbohydrates are digested Chemical pH 8 – protein, fats & carbohydrates are digested Increased surface area by millions of villi and microvilli Increased surface area by millions of villi and microvilli Absorption into blood stream by highly vascular integration surrounding digestive tract. Absorption into blood stream by highly vascular integration surrounding digestive tract.

16. Large Intestine (aka Colon) 5-6 feet in length, 3”-4” in diameter 5-6 feet in length, 3”-4” in diameter Main Functions Main Functions Reabsorption of water Reabsorption of water Reabsorption of vitamins Reabsorption of vitamins Waste elinination Waste elinination Very little digestion (most is done in the stomach & small intestine) Very little digestion (most is done in the stomach & small intestine) Divided into Cecum, Ascending, Transverse, Descending, and Sigmoid Colon Divided into Cecum, Ascending, Transverse, Descending, and Sigmoid Colon Undigested food & Wastes stored in the rectum before being eliminated thru the anus. Undigested food & Wastes stored in the rectum before being eliminated thru the anus.

17. Accessory Digestive Organs Salivary Glands – secretes saliva and enzyme amylase. Mixes w/ food forms Bolus. Salivary Glands – secretes saliva and enzyme amylase. Mixes w/ food forms Bolus. Liver- filters blood & secretes Bile used to emulsify & digest Fats Liver- filters blood & secretes Bile used to emulsify & digest Fats Gall Bladder – stores bile until needed Gall Bladder – stores bile until needed Pancreas- 3 functions Pancreas- 3 functions Release & control of insulin in the Islets of Langerhans. Controls sugar blood levels Release & control of insulin in the Islets of Langerhans. Controls sugar blood levels Release digestive enzymes Release digestive enzymes Produce sodium bicarbonate to convert stomach acid to a basic solution in the duodenum Produce sodium bicarbonate to convert stomach acid to a basic solution in the duodenum

18. Chapter 17 Muscle & Digestive Systems & Digestive Systems That’s all folks!!