Biology 241 – Lecture: TEST #2 TOPIC REVIEW SHEET Ch. 5: Integumentary System Whatever we didn’t cover before Test #1, we will pick up now:
A. Color of skin; fingerprints; “thick” vs. “thin” skin; sequence of five strata in the epidermis B. Distinct Cell populations in Epidermis: Keratinocytes, melanocytes, Merkel’s cells (and discs), Langerhans cells. Know the location/function of each. C. Melanin production: where (which strata are involved?) And how? Ie: steps involved D. Accessory structures: (Not Hair and Nails) Arrector pili muscles: what they do; what type of muscle are they? E. Glands: 1) Specifically, types of glands associated with the skin: Sudoriferous, Sebaceous, Ceruminous; what each secretes, where product ends up?, whether merocrine, apocrine, or holocrine. 2) Glands in general: derived from epithelial tissue, how classified?, methods of secretion
Ch. 6: Osseous Connective Tissue (Bone C.T.)
A. Functions of the Skeletal System (there are 5 about which you should be able to elaborate) Be SURE you know the term Hematopoiesis (aka: Hemopoiesis) = Blood Cell Production B. Bone Anatomy: 1) Bone Shapes; 2) Significant Parts of a Typical Long Bone 3) All associated structures of a Typical Long Bone; including Sharpey’s Fibers; 4) Structure of Flat, Short, Irregular Bones C. Bone Histology: 1) Know 4 cell types: osteoprogenitor cells, osteoblasts, osteocytes, osteoclasts D. Cancellous (aka: trabecular or spongy) bone and Compact bone which are both types of Lamellar Bone E. Know Structural/Functional Unit of Compact Bone: The OSTEON (aka: HAVERSIAN SYSTEM) and all its component sub-structures. F. Review the Diagram of An Osteocyte in its Lacuna G. Know the two Methods of Ossification: Endochondral and Intramembranous with associated facts concerning which Type of bones are formed via which method? H. Two types of Bone/Cartilage Growth: Interstitial and Appositional. Understand how each is unique to its special purpose and where in/on the bone each occurs. I. Factors affecting Bone Growth: 1) Nutrition (including which vitamins are necessary? Why?); 2) Hormones (which ones do what?); 3) Stress (only the “good stress”, of course); 4) Exercise J. Understand REMODELLING (what it is) and that it is the bone’s normal physiological responses to the stresses put on it. (By contrast, Decalcification, demineralizing, etc. are ABNORMAL physiological responses) K. What is the molecular formula for the calcium phosphate mineral known as “hydroxyapatite”? How do the hormones Calcitonin (the “pro-bone hormone”) and PTH (the “anti-bone hormone”) affect it? Why is understanding this inorganic compound key to calcium homeostasis? L. Know the following Types of Bone Fractures: Simple (closed); Compound (open); Comminuted, Greenstick; Spiral; Impacted; Colles’, Pott’s; and know the four major steps in the process of bone fracture repair.
Ch. 7 + 8: Skeletal System: Axial + Appendicular Skeleton
A. Of these two chapters, you will need to know: The TWO DIVISIONS OF THE SKELETON: Axial Skeleton (80 bones) and Appendicular Skeleton (126 bones) and what they are!!! (Excluding the 6 Ossicles, there are 206 bones in the entire skeleton. B. Know the four sub-compartments of the Axial Skeleton (Skull, Hyoid Bone, Rib Cage, and Vertebral Column) and the four sub-compartments of the Appendicular Skeleton (Shoulder Girdle x 2, Upper Extremity x 2, Pelvic Girdle x 2, and Lower Extremity x 2) C. The skull itself (which consists of 22 bones – not including the ossicles) may be further subdivided into two parts: the Neurocranium (bones that house the Brain – there are 8) and the Faciocranium (bones that support the facial structures – there are 14). D. The rest of this chapter is what you have been working so hard on for LAB….and will only be tested in the Lab setting (ie, on the LAB PRACTICAL EXAM!)
Ch. 9: Articulations (Joints) and Movements
A. SEE PRINTOUT entitled Classification of Joints, including its “Additional Glossary” of terms at the end. B. Know the Types of Movement: Gliding, Angular, Rotation, and Special and the various “opposite pairs” of descriptive terms that describe the possibilities under each Type of Movement: Gliding: intercarpal and intertarsal joints are the best examples; Angular: Flexion/Extension/Hyperextension and Lateral Flexion; ABduction/AD-duction; Circumduction; Rotation: when a bone revolves around its own longitudinal axis as in shaking the head “NO”, turning the torso right and left; medial (internal) rotation and lateral (external) rotation; Special: Elevation/Depression; Protraction/Retraction; Inversion/Eversion; Pronation/Supination; Opposition; and Plantarflexion/Dorsiflexion. Mvmt. at the TMJ (both Gliding + Angular (hinge)) is a Combination Mvmt.
(Biol. 241: Topic Review Sheet – Test 2 Page Two) Ch. 10: Muscle Tissue
A. Overview of Muscle Tissue: 3 Types (Skeletal, Cardiac, Smooth) 5 Functions, 4 Properties (excitability, contractility, extensibility, elasticity); Connective Tissue components (Endo-, Peri-, Epimysium); and Microscopic Anatomy of a Skeletal myofiber (muscle cell) – know all the important organelles, myofilaments, arrangements, etc. (Sarcomere; 1 A-Band (overlapping actin/myosin), 2 I-Bands (actin only), H-zone (myosin only), 2 Z-discs, Actin myofilaments, Myosin myofilaments. What exactly is a Myofibril? Also, what three intracellular conditions exist to keep a myofiber “relaxed”….and how must each of these conditions change to allow for contraction? B. Understand the Sliding Filament Model (Remember: Troponin-tropomyosin complex while in its original position effectively prevents muscular contraction. Recognize “power stroke” and “recovery stroke” as important parts of the physiology of contraction. C. Understand all important components of a NeuroMuscular Junction (NMJ) D. Understand the importance of motor units, and that it is the adjustment of the number of motor units that are active at any one time which is the basis of variability in muscle tension. The process of increasing the number of active motor units is called recruitment (motor unit summation) E. Understand that it takes energy to get a myofiber to relax as well as to contract. What is rigor mortis? F. Energy Sources (for Muscle Contraction) Immediately available ATP (“stored” on myosin heads) converts to ADP and provides only enough energy for about 2-3 seconds of muscle contraction. If muscle activity continues beyond a few seconds, the myofibers MUST generate more ATP. In order to do this, myofibers utilize three methods: 1) from Creatine Phosphate (CP) (aka: phosphocratine); 2) by anaerobic cellular respiration; and 3) by aerobic cellular respiration. (1) CP and ATP constitute the initial Energy sources, for up to about 15 seconds of strenuous muscle contraction. (2) The Glycogen-Lactic acid System (glycolysis of glucose molecules liberated from myofiber glycogen) is an anaerobic pathway that will yield a net gain of 2 ATP’s per glucose molecule; enough ATP for another 30-40 seconds of maximal muscle contraction. (3) The Aerobic system along with glycolysis is now used for prolonged muscular activity – as long as sufficient oxygen and nutrients are available. These nutrients include glycogen, fats, and proteins (aka: glucose, fatty acids, amino acids)And, this is where the “oxygen debt” comes in and must be “paid back” in order to restore CP levels and to convert non-useable lactic acid to useable glucose. G. All-or-None Principle H. Special Considerations for understanding Muscle Contractions: (1) Know the term Myogram = a graph representation of the events of a muscle contraction. (It plots muscle tension along the “Y” axis and Time along the “X” axis.) (2) Skeletal myofibers are capable of producing different kinds of contractions, depending on the stimulus frequency. Various types of contractions are: TWITCH, WAVE-SUMMATION, UNFUSED TETANUS (aka: TREPPE), FUSED TETANUS, ISOTONIC, and ISOMETRIC. (3) Refractory period is the time when a muscle has temporarily lost excitability; Skeletal myofibers have a very short refractory period; Cardiac myofibers have a very long refractory period (4) Wave summation is the increased strength of a contraction resulting from the application of a second stimulus before the myofiber has completely relaxed after a previous stimulus; Spatial summation is when stimuli come to several motor units simultaneously. (5) Muscle Tone: a sustained contraction of only certain portions (fascicles) of a skeletal muscle belly results in “partial tension” (tone) and occurs even in a “relaxed muscle”. Tone is essential for maintaining posture. HYPOTONIA is a condition of less-than-normal tone. HYPERTONIA refers to increased muscle tone and is expressed either as spasticity or rigidity. I. Comparative Histology of Muscle Tissue (1) How does the arrangement of SR and T-tubules in Smooth myofibers and in Cardiac myofibers differ from that in Skeletal myofibers? Please elaborate. (2) What special properties does each of the myofiber types have? How is the “trigger” for smooth muscle contraction different than that for skeletal and cardiac? J. What are the causes of muscle FATIGUE? K. Be familiar with the many criteria used for NAMING muscles: their Size, Shape, Number of Heads, Direction in which fascicles run, Location, Origin/Insertion, Function; with the name being a COMBINATION of these. L. Know the following terms: Prime Mover (aka: Agonist); Antagonist; Synergist; Fixator; Origin (head), Insertion; Tendon; Ligament; Aponeurosis; and Muscle belly.