1. Chapter 33 Anatomy & Physiology IV
Digestive, Musculoskeletal/Connective Tissue,
Integumentary Systems

2. Digestive System: General
Functions: break down and absorb nutrients, needed to sustain life
Nutrients: need to ingest proteins fats, carbohydrates, minerals, vitamins, and water
Can our body make all the vitamins needed to be healthy?
Structures in order: mouth, pharynx, esophagus, stomach, small intestine (duodenum, jejunum, ileum), colon, rectum (p. 688)

3. Digestive System: Mouth
Teeth: mechanically break food into smaller pieces
Salivary glands: produce saliva
contains mucus to lubricate
amylase: enzyme to breakdown starch
Bolus = food mass

4. Digestive System: Esophagus
Esophagus: propels bolus of food to stomach through waves of muscular contractions
Peristalsis: waves of muscular contractions that propel food through the GI tract
Esophageal sphincter: muscular junction between the stomach and the esophagus that prevents food from moving back into esophagus

5. Digestive System: Stomach
Mechanically and chemically breaks food down
Pepsinogen: inactive until exposed to acidic environment, converts to pepsin an enzyme that breaks down proteins
Chyme: acidic paste mixture of food after it is churned and broken down by the stomach
Pyloric sphincter: prevents movement of chyme backward from duodenum to stomach

6. Digestive System: Intestines, Pancreas, and Liver
Liver, gall bladder, pancreas – accessory organs of the GI system
The small intestine is made up of the duodenum, jejunum, and ileum
Liver: makes bile and stores it in the gall bladder
Gall bladder: releases bile (bile salts) into the duodenum; helps break down fats

7. Pancreas: releases many enzymes into the duodenum to further break down fats, proteins, and carbohydrates; releases sodium bicarbonate to neutralize acid
Once food leaves the duodenum the breakdown process of digestion is complete.
Jejunum and ileum: main function is to absorb nutrients from digested food
Villi: foldings of the inside of the small intestine
Microvilli: foldings of the villi
Increase the absorptive ability of the small intesines by increasing the surface area

8. Lacteals: absorb fats and transport to liver (page 691)
Large intestine: called the colon
Functions of colon:
Absorb water
Package waste for removal

9. Musculoskeletal/Connective Tissue: General
Function: to move and support the body
Consists of muscles, tendons, ligaments, bones, and the extracellular matrix
Skeleton: provides support and protection
Muscles: makes movement possible
Ligaments: connects bone to bone
Tendons: connects muscle to bone

10. Musculoskeletal/Connective Tissue: Bones
Axial skeleton: skull, spine, ribs, sternum
Appendicular skeleton: shoulder girdle, pelvic girdle, arms and legs
Two types of bone:
spongy: inner portion; more porous
compact: outer portion; thick & rigid, provides strength
Periosteum: membrane covering all bone; full of blood vessels and nerves

11. Osteoblast: cells that make bone; secrete matrix made of collagen and calcium compound
Osteocyte: mature bone cell
Ossification: the process of cartilage cells being replaced by bone cells
Haversian canals: canals through compact bone that allow blood vessels and nerves to pass through

13. Bone marrow is found in the center of long bones
Bone marrow: yellow stores fat; red makes blood cells (red, white, and platelets)
Epiphyseal plate: growth plate
Most bones form through the process of cartilage first forming the structure, then bone cells move in and lay down bone.

15. Musculoskeletal/Connective Tissue: Ligaments and Joints
Joints: where two bone meet
Ligaments: tough, fibrous bands/sheets of collagen that hold bones together

16. Cartilage: cushion at end of bones
Synovium: membrane surrounding a joint which provides lubrication

17. Types of Joints: Classified based on the movement they allow
hinge: moves in one plane ex: knee or elbow
pivot: rotational movement ex: neck
ball and socket: movement in all planes
ex: shoulder, hip
saddle joint: movement in all planes
ex: thumb

18. Musculoskeletal/Connective Tissue: Muscles and Tendons
Three types of muscle:
skeletal: striations, voluntary, multinucleated
smooth: no striations, involuntary, one nucleus per cell
cardiac: mild striations, involuntary, one to two nuclei per cell

19. Muscles attach to bones through tendons
origin: tendon attached to bone that does not move
insertion: tendon attached to moveable bone
*extremely strong
Muscles work in opposing pairs
flexion vs. extension

20. Musculoskeletal/Connective Tissue: Muscle Physiology
Muscles contract through the actions of actin and myosin after receiving an impulse from the motor nerve (page 700)
Neuromuscular junction: the place where the nerves and muscle communicate
Synapse: small gap
Neurotransmitter: acetlycholine; acts to move impulse across synapse
Sarcomere: smallest functional unit of a muscle; contracts (shortens)

21. Integumentary System Consists of skin, nails, and hair
Largest organ of the body
Two layers:
epidermis – top layer; epithelial cells
dermis – lower layer; contains glands, hair follicles, blood vessels, and sensory nerves
Components: keratin (protein) and melanin (pigment)