Exam 4 Study Guide PDF

**[Exam Unit One]** =============================== **[Biological Macromolecules]** **A.** *► Nucleic acids* **- Composed of nucleotide subunits. e.g., DNA, RNA.** **B.** *► Proteins* **- Composed of amino acids subunits.** **e.g., muscle, hair, blood, antibodies, some hormones** **D.** *► Lipi...

**[Exam Unit One]** =============================== **[Biological Macromolecules]** **A.** *► Nucleic acids* **- Composed of nucleotide subunits. e.g., DNA, RNA.** **B.** *► Proteins* **- Composed of amino acids subunits.** **e.g., muscle, hair, blood, antibodies, some hormones** **D.** *► Lipids* **- Composed of fatty acid subunits.** **[Levels of Biological Organization (Complexity)\ ]** Atomsmoleculesorganellescells tissues organs organ systems organism populationbiological communities ecosystems biomes biosphere **[Maintenance of Life]** **[Homeostasis]\ Homeostasis- A dynamic state of equilibrium in which optimal parameters of the body are maintained.\ \ Homeostatic set point or range- The point or range of a parameter at which the body functions best.** **e.g., salinity (0.9%), temperature (37C), fluids, blood sugar, vessel\ diameter, blood gases, insulin, blood pH** ***Note: Homeostatic set points/ranges may be different between\ age groups & individuals. e.g., body temp, sex hormones*** **[Homeostasis Maintenance Mechanisms]** **1.** *► Negative* **Feedback- Movement [back towards]** ***\ *[Overview of Organ Systems]** ***-Body Covering-*** **1.** *► Integumentary* **- ƒ: Thermoregulation, sensory, interface w/ environment, vitamin D synthesis. e.g., skin, hair, nails, sebaceous & sweat glands, nerve endings.** ***-Support & Movement-*** **2.** *► Skeletal* **- ƒ: Organ protection, muscle attachment, blood production, mineral & fat storage. e.g., bones, ligaments, tendons, cartilages** **3.** *►Muscular* **- ƒ: Movement, thermoregulation, posture, venous return circulation e.g.,skeletal muscles, smooth muscles, cardiac\ muscle, ligaments, tendons.** ***-Transport-*** **4.** *► Cardiovascular* **- ƒ: Pump & transport blood, nutrients, hormones & gases, thermoregulation e.g., heart, arteries, veins, capillaries** **5.** *► Lymphatic* **- ƒ: Interstitial fluid return, immunity, transport of fatty molecules. e.g., lymphatic vessels & nodes, thymus, spleen, appendix, tonsils, lymphocyte blood cells** ***-Absorption & Excretion-*** **6.** *► Digestive* **- ƒ: Food breakdown, absorption of nutrients & elimination of wastes, H~2~0 absorption, vitamin prod. e.g., mouth, teeth, esophagus, liver, gall bladder, pancreas, intestines, rectum** **7.** *► Respiratory* **(Pulmonary)- ƒ: Exchange of gases between environ. & blood, release of toxins. e.g., nasal cavity, trachea, pharynx, larynx, lungs** **8.** *► Urinary* **- ƒ: Remove N wastes from blood, H~2~0 & electrolyte balance, blood pH balance, store & transport urine, hormone production e.g., kidneys, ureters, urinary bladder, urethra** ***- Reproduction-*** **9.** *► Reproduction* **- ƒ: Production & transfer of gametes, copulation, embryo/fetus development, hormone production. e.g., genitalia, gonads, uterus, prostate** ***-Integration & Coordination-*** **10.** *► Nervous* **- ƒ: Sensory reception & interpretation, stimulate muscles & glands. e.g., brain, spinal cord, nerves, sense organs** **11.** *► Endocrine* **- ƒ: Controls metabolic activities of organs & glands, homeostasis, production of hormones. e.g., all glands & organs that secrete hormones** **[Endocrine Glands & Organs]** **e.** *► ovaries* **- ƒ: prod. estrogen hormones** **f.** *► Testes* **- ƒ: prod. androgen hormones** i. **[Cell Structure & Function]** **[Cell Theory]** **1. The cell is the basic living unit of organization** **2. All organisms are composed of one or more cells** **3. All cells arise from pre-existing cells.** **[Primary Cell Structure]** **1.** *►Plasma* **(cell) Membrane- The boundary between the internal & the external environ. Formed from a lipid bi-layer w/ integral & peripheral proteins. ƒ: Regulates what enters and leaves the cell.** **2.** *► Cytosol* **- The semi-fluid environment of the cell. ƒ: supplies the basic substances required for the functioning of the cell.** **3.** *► Organelles* **- Membrane/cytoskeleton bound structures in the cytoplasm which carry on or support the functions of the cell.** ***Note: Cytosol + organelles= cytoplasm*** **4.** *►Nucleas* **- Bound by a membrane. ƒ: Contains chromosomes & nucleolus** **[Cytoplasm Organelles & Structures]** **1. Ribosomes- ƒ: protein synthesis** **2. Endoplasmic reticulum- A system of membranous channels, tubes & flattened sacs which form compartments w/in the cytoplasm** **2. Golgi apparatus- ƒ: receive materials (proteins, etc.) from the ER, package &** **transport them to organelles or the plasma membrane.** **3. Mitochondrion- ƒ: Extraction of energy from CHO, ATP formation.** **4. Lysosomes- Membranous sacs.ƒ: Degredation, recycling of materials, removal of bacteria & worn cells.** **5. Peroxisome- Membranous sacs. ƒ: Catalyze reactions & remove hydrogen** **peroxide.** **6. Cytoskeleton- ƒ: Internal framework of microfilaments and microtubules to which organelles & chromosomes are anchored** **[Cell Surface Features]** **1. Cilium(a)- Extension of the cell membrane. ƒ: Propulsion & movement of substances** **2. Flagellum(a)- Complex structure on cell surface ƒ: Propulsion** **[Membrane Transport]** **I. [Passive Systems]- No cellular energy req. w/ movement [down] a concentration gradient (from higher to lower).** **II. [Active Systems-] Require cellular energy (ATP) to move [against] a concentration gradient (low to high).** **[Diffusion]- Movement of a** *►***Solute from an area of *greater* solute concentration to an area of *lesser* solute concentration across/through a membrane.** **1.** *►Simple diffusion* **- Movement of a solute directly through a the lipid bi-layer (membrane).** **2.** *► Facilitated diffusion***- Movement of a solute through membrane-imbedded proteins via a change in the molecular structure of the\ protein e.g., insulin promotes facilitated of glucose\ ** **[Osmosis-] Movement of** *► water* **molecules from a area of *greater* water molecule concentration to an area of *lesser* water molecule concentration across/through a membrane.\ ** ***Permeable Membrane** ► **Allows all molecules to pass or diffuse through*** ***Semi-Permeable Membrane** ►**A membrane (as a cell membrane) that allows some molecule to pass through but not others*** **[Diffusion Terminology]** *►Isotonic* **- Solute concentration equal on both sides of membrane.** *►Hypotonic* **- Solute concentration lower in environment.** *►Hypertonic* **- Solute concentration higher in environment.** ***\*Understand diffusion problems*** **[Exam Unit Two ]** ================================ **[Basic Concepts of Cellular Reproduction]** **1. ► DNA - Deoxyribonucleic acid. A double-helix structure composed of nucleic acids which acts as the instructions or template for the manufacture of proteins.** **2. ► Chromosome - A DNA molecule and the proteins associated with it.** **3. ► Genes - A specific region of a DNA strand (or chromosome) that influences a certain inheritable trait(s).** **[Functions of Mitosis\ ]1. ►Replacement of cells** **2. ►growth in multi-cellular organisms** **3. ►asexual reproduction** **Interphase** **- Phase BEFORE Mitosis begins Chromosome & organelle replication 46-\>92** **1. ► Prophase - Sister chromatids condense, spindle fibers form, nuclear membrane breaks up, centrioles move to poles** **2. ► Metaphase - Sister chromatids align at center (metaphase plate), spindle fibers attach to sister chromatids** **3. ► Anaphase - Sister chromatids separate and move to opposite poles, now called daughter chromosomes** **4. ► Telophase - Chromosomes arrive at poles, nuclear membrane reassembles, cytokinesis begins...Cleavage furrow=telophase** Phases of the cell cycle: interphase and mitotic phase **► stem cells - Undifferentiated cells that maintain ability to divide.** **[Mitosis & Cancer ]** **[Characteristics of Cancerous Cells]\ 1. ► Abnormal anatomy and physiology\ 2. ► Accelerated mitotic rate** **3. ► Migration into other tissues (local or remote)** **a. ►Benign - Lump-like mass of cells [compressing] surrounding tissues. Freq. encapsulated, slow growing & has not yet invaded other tissues.** **b. ► Malignant(cancerous) - Mass of cells that [invade] surrounding tissues. - Not encapsulated & freq. fast growing** **c. ► Metastasis - Malignant cells travel to other tissues via blood or lymph & secondary malignant tumors.** **Enzymes- Proteins that speed up (catalyze) chemical reactions:** **a) by lowering the *E~A~* required** **b) without becoming part of the reaction** **2. ► Active sites - Region of the enzyme that bonds w/ the substrate.** **[Overview of Є Production]** **Cells obtain Є from organic molecules via breaking & reforming electron bonds.** **e.g., Є is released when bonds in glucose are broken. [Some] of this Є is stored in ATP (AdenosineTri-Phosphate)** **[Overview of Aerobic Cellular Respiration]** **Step 1- Glycolysis: Breakdown of glucose into pyruvic acid. Electrons released & 2 ATP (Adenosine TriPhosphate) formed. No O~2~ req.** **Loc: Cytoplasm** **Step 2-Citric Acid (Krebs) cycle: Pyruvic acid broken down into CO~2~. Electrons released & 2 ATP formed. Loc: Mitochondrion O~2~ req.** **Step 3- Electron transport chain: Synthesis of ATP (34) Loc: Mitochondrion O~2~ req.** *∴ 38 ATP molecules produced for each glucose molecule but 2 ATP are used in the process ∴ 36 ATP net* **[Anaerobic Respiration]** **If O~2~ is not available only glycolysis can occur; results in production of lactic acid.** **[HISTOLOGY]** **[Animal Tissue Groups]** **1. Epithelial** **2. Connective** **3. Muscle** **4. Nervous** **[Epithelial Tissues]** **[Function:]** **1. Water retention e.g., epidermis** **2. Absorption e.g., intestines, lungs, kidney tubules** **3. Secretion e.g., goblet cells, ducts** **4. Protection from abrasion & environment e.g., epidermis** **5. Sensation** **[Connective Tissues]** **[Function]** **1. Attachment- e.g., tendons and ligaments** **2. Support- e.g., mesentaries** **3. Cushioning- e.g., post-ocular fat** **4. Energy Storage- e.g., fat** **5. Thermoregulation- e.g., insulation & thermogenesis from fat** **6. Transport - e.g., blood** **7. Immunity- e.g., blood** **[Characteristics/Components]** **All connective tissues contain:** 1. **Cells-** ***Note: There are many types of CT cells e.g., osetoblasts, macrophages, RBC's, etc.*** **[Muscle Tissue]** =============================== **[Function]** **Produce motion- e.g., movement of limbs, heart beat, peristalsis, thermoregulation** **[Nervous Tissue]** **[Function]** **Production, conduction, perception & integration of internal & external stimuli.** **INTEGUMENTARY SYSTEM** **1. ► Epidermis - [Characters ]** **2. ► Dermis - [Characters ]** **A. Irregular dense conn. tissue** **- collagen & elastic fibers** **- gel-like ground substance** **C. Nerve cells- Both motor & sensory** **D. Blood vessels** **E. Glands- e.g., sweat & sebaceous** **F. Hair follicles** **3. ► Hypodermis(subcutaneous) - [Characters ]** **A. Loose connective tissue** **- Collagen & elastic fibers** **B. Adipose tissue** **C. Blood vessels** **D. Nerves** **[Exam Unit Three]** ================================= [Bone Cell Diversity] 1\. *►* Osteoprogenitors - Stem cells that give rise to osteoblasts & osteocytes 2\. *►* Osteoblasts - ƒ: Bone deposition, immature bone cells building bones 3\. *►* Osteocyte - In lacunae. ƒ: bone maintenance via waste removal, transport nutrients, maintains bone 4\. *►* Osteoclasts - ƒ: Bone & fiber reabsorption, break bone down [Bone Formation] Bone formation begins at ≅ 6 wks. 1\. *►* intermembranous - Originate in sheet-like layers of connective tissue. e.g., flat & sesamoid bones. 2\. *►* Endochondral - From ossification of hyaline cartilage bone models e.g., long, irregular, short bones. 3\. *►* Appositional - Increases diameter of long bones. **MUSCLES** [Function of Muscles] 1\. *►* Movement - A. Skeletal - Movement of skeleton B. Smooth - Movement within hollow organs e.g., intestines, stomach, vessels, bronchioles. C. Cardiac- Circulation 2\. *►* Thermoregulation - e.g. muscle contraction (shivering) 3\. *►* Protection from trauma - e.g., major nerves & vessels 4\. *►* Nutrient reserves - Provide proteins for amino acids & energy. [Muscle Hierarchy] Whole muscle into fascicle(bundles of musc. fibers) into fiber into myofibrils (contractile units) into myofilaments (Cylinders within cylinders) 4\. *►*Epimysium -Irregular CT on surface of muscle. 5\. *►* Perimysium -CT that separates fascicles. 6\. *►*Endomysium -CT that separates fibers (cells) w/in fascicle. [Sarcomere Components] *Thick Filament:* A. *►*Myosin -Thick filamentous contractile proteins w/ cross bridges *Thin Filament:* B1. *►* Actin - Protein backbone of thin filament B2. *►* Tropomyosin - Blocks cross-bridge binding sites on actin. B3. *►* Troponin - Controls position of tropomyosin. [Types of Muscles] 1\. *►* Skeletal Muscles - [Charac.] -attached to bone (usually) -voluntary -rapid contraction & fatigue 2\. *►* Smooth Muscles -[Charac.] -in organs & vessels & dermis -involuntary -slow contraction & fatigue 3\. *►* Cardiac muscles - [Charac.] -in heart -involuntary -rapid contraction & no fatigue Characteristics of Smooth Muscle 1\. Single nucleus\ 2. Thinner actin & myosin\ 3. Fibers more random in distr., no striations\ 4. ACh & norepinephrine as neurotransmitters \ 5. Troponin absent\ 6. May be stimulated by hormones (oxytocin & uterine contractions) \ 7. Stretching may cause contractions (urinary bladder, intestines) Characteristics of Cardiac Muscle 1\. 3D network of branched cells \ 2. Single nucleus \ 3. Actin & myosin have symmetrical dist. striations\ 4. Intercalated disks- increase inter-cellular surface area. Transfer of ions between cells. Rapid, unified contraction \ 5. No refractory (resistance) period than skeletal. No tetanus Characteristics of Skeletal Muscle \- attached to bone (usually)\ -voluntary\ -rapid contraction & fatigue\ - visible striations \ - mult. peripheral nuclei \ - elongated cell \ - made up of CT layers epimysium, perimysium, endomysium [ ] **[Exam Unit Four ]** ================================= **NERVOUS SYSTEM** **[ƒ of the Nervous System]** **1.** *► Sensory* **- Receive stimuli from environ. via sensory receptors in PNS e.g., temp, sound.Stimuli converted to nervous impulse & trans. to CNS for processing (integration).** **2.** *►Intergration* **- CNS processes all sensory signals & creates sensations, memory, thoughts or action.** **3.** *► Motor Function* **- CNS sends impulse to stimulate movement in effectors outside of nervous system e.g., muscles, glands** **[Nervous System Components]** 1. *► Neurons* **ƒ: Produce & transmit & interpret nervous impulses.** **2.** *► Neuroglia* **ƒ- Supportive cells around neuron, nourish, insulate & structural support neurons** **3.** *► Synapses* **- Gaps between adjoining neurons.** **4.** *► Neurotransmitters* **- Chemicals that carry stimulus across synapse.** **5.** *► Central nervous system (CNS)* **-Brain & spinal cord.** **6.** *► Peripheral Nervous system (PNS)* **- Cranial & spinal nerves.** **[Nervous System Divisions]** **1. CNS-** **2. PNS-** **A. Sensory Division-** **B. Motor Division-** **B1. Somatic** *(SNS)***- Conscious motor activities e.g., skeletal muscle contractions.** a. **Sympathetic Div. - Moves body away from homeostatic set point.** b. **Parasympathetic Div.- Moves body back towards HSP.** **Neural Anatomy** **[Neuron Anatomy]** **1.** *►Cell body* **- Region w/ nucleus** **2.** *► Processes* **- Extensions of membrane** **A.** *►Dendrites* **- ƒ: Deliver impulse to cell body.** **B.** *► Axons* **- ƒ: Carry impulse away from cell body.** **B1.** *► Axon terminal* **- End of axon.** **B2.** *► Synaptic Knob* **- Knob at terminal.** **3.** *► Myelin sheath* **- Insulative layers of membrane of neuroglial cells called Schwann cells in PNS.** **5.** *► Nodes **(**pr: Ron-vee-ay)***- Gaps between adjoining Schwann cells.** **Note: Groups of myelinated axons appear white∴ white matter in brain. Groups of unmyelinated axons appear gray e.g., gray matter in the CNS.** *Path. Note: Multiple sclerosis (MS), an auto-immune disorder stimulated by a virus that inflames & destroys the myelin sheath in the CNS reducing or stopping nervous impulses as hard scars are formed on the axon.* **[*Structural* Classification of Neurons]** **1.** *► Anaxonic* **- Dendrites & axons indistinguishable. Limited to brain & sense organs.** **2.** *► Bipolar* **- Two processs (axon & dendrite) one at each ends e.g., eyes, nose & ears.** **3.** *► Unipolar* **- One process that divides. One end enters CNS or cluster in ganglia in the PNS.** **4.** *► Multi-polar* **- Multiple processes. One axon, others dendrites. Most common in CNS.** **[*Functional* Classification of Neurons]** **1.** *► Sensory* **(afferent)- Carry impulse from PNS to CNS. Mostly unipolar some bipolar.** **2.** *► Motor* **(efferent)- Carry impulse from CNS to Effectors (muscles) in PNS. Multipolar.** **3.** *► Interneuron* **(association)- Links between other neurons. Multipolar in CNS.\ ** *Pathology Note: Amyotrophic Lateral Sclerosis (ALS/Lou Gehrig's Disease) is a progressive degenerative disease that affects motor neurons in the CNS/PNS. As motor neurons die, control of skeletal muscles is lost. Cause unknown & no cure.* **[Neuroglia Cells]** **[ƒ of Neuroglia]** **1. Insulate axons & nerves e.g., Schwann cells** **2. Structural support for neurons e.g., astrocytes** **3. Specialization of neurons** 4. **Secrete growth factors** **5. Direct nutrients to neurons** **6. Remove excess neurotransmitters\ ** **[Classification of CNS Neuroglia]** **1.** *► Astrocytes* **- ƒ: tissue structure, ion reg., glucose metabolism, growth factor, direct nutrients to neurons, reinforce blood-brain barrier.** *Note: A new study (2015) has shown that astroctyes work w/ neurons for\ learning & memory.* ***Note: Brain capillaries have overlapping tight membrane junctions w/o clefts ∴ no free movement of chemicals into brain tissue ∴ the blood/brain barrier.*** **2.** *► Oligodendrites* **- ƒ: form myelin in CNS that can join adjacent neurons providing structural framework, secrete nerve growth factor for neuron repair.** **3.** *► Microglial* **- ƒ: Motile, phagocytize bacteria & debris** **4.** *► Ependyma* **- ƒ: Line cavities of CNS, regulate composition of CSF & ciliated cells help circulate CSF.** **5.** *► Rosehip* **- Multiple dendrites, inhibition of other\ neurons. Only found in humans!** *Path. Note: Most brain tumors & cancers composed of neuroglia.* **90 days between scans. Death at 150 days.** **[Regeneration of *PNS* Axons]** **Damage to cell body kills cell.** **Damage to axon is repairable.** **Note: Axons cannot regenerate segments \> 3mm.** *Path. Note: If a large PNS axon is cut, it must be reconnected ASAP before distal end decomposes.* *If not, a tangled & very painful mass of axons may develop called a [neuroma]. Neuromas are a problem w/amputations.* **Note: CNS axons cannot be repaired since the myelin producing oligodendrites will not reproduce & astrocytes produce scar tissue at injury site.** **[Neurophysiology]** **[Movement Across/Through the Neural Membrane]** 1. *►Leak channels (non-gated)* **- Selectively permeable channels that are always open.** **2.** *► chemically (gated) channels* **- Open when bound to specific chemicals e.g., Ach.** **[Cell Membrane Potentials]** **1.** *►Trans-Membrane Potential* **(TMP)- The amount of electrical [charge] difference between the 2 sides of the membrane when the neuron is at rest (not excited).** **[Notes:]** A. **A resting neuron has (-) interior & (+) exterior** B. **K^+^ is major internal** C. **Na^+^ is major external ion** **E. As Na~~+~~ moves into the cell, depolarization occurs & an electrical signal is produced.Cells that can produce an electrical signal are called excitable cells.\ 2.** *► Resting potential* **- The TMP of a neuron at rest (not generating an electrical signal). Regulated by leak channels.\ 3.** *► Graded potential* **- A decrease in the TMP w/distance from the stimulus. Regulated by chemically gated channels.** *►Local currents* **- Movement of positive ions parallel to the membrane. Internal ions (Na) move in response to the negative charges along the inner surface of the membrane.***\ ***4.** *►Action potential* **- (a.k.a. Nervous Impulse/Electrical Signal)- Changes in TMP transmitted (propagated) along axon.\ Note: Begins w/ chemically gated Na^+^ channels; propagates via voltage-gated channels.** **Action potentials propagate along the axon via:** **A.** *►Continuous prognation***- Occurs in [un]myelinated axons. A series of local current membrane depolarizations propagate the action potential down the axon membrane.** **Depends upon establishment of local currents.** **B.** *►saltatory propagation* **- Occurs in myelinated axons. Ions cannot flow through myelin so ions cross at nodes.** **[Synapse Transmission]** **Action potentials (nerve impulses/ information/ messages) must be transmitted across the synapse to the next neuron.\ ** **1.** *► chemical synapse* **- Rely upon neurotransmitters** **2.** *► Electrical synapse* **- Rely upon direct transmission of electrical impulse from one neuron to another via physical contact of membranes (no\ neurotransmitters) via gap junctions.** **[CNS Neuron Communication (Neural Circuits)]** **1.** *►convergence* **- Multiple neurons deliver impulse to a common neuron e.g., PNS to CNS neuron, afferent sensory impulses** **2.** *►divergence* **- Single neuron delivers impulse to multiple neurons e.g., CNS to PNS neurons, efferent motor impulses.** **3.** *► serial* **- Neurons arranged in linear fashion.** **[Neurotransmitters Regulation]** **[Action of NT controlled by:]** **1.** *► Enzymes* **- Break down NT e.g., acetylcholinesterase** **2.** *► Recycle* **- NT taken back into synaptic knob** **3.** *► Neuromodulators* **- Alter release of NT or block its action e.g., endorphin** *Note: Endorphins & enkephalins bind to the opiate pain receptors in the brain & block [Substance P] (a NT that transmits pain).* *Opiates work the same way to decrease pain.* *Path. Note: Opiate addicts have withdrawal pains because body has stopped producing own endorphins in presence of opiates∴ no defense against pain during withdrawal.* **[Misc. NT Pathology]** **1.** *►Alzheimer's* **- *decrease in acetylcholine causes memory loss, dementia & death.*** **2.** *►Clinical depressions* **-- *decrease in norepinephrine & or serotonin causes debilitating sadness.e.g. SAD (seasonal affective disorder)*** **3.** *►Parkinson's disease* **-- *decrease in dopamine causes tremors & muscle rigidity.*** **4.** *►Insomnia* **- *decrease in dopamine & or serotonin causes lack of sleep.*** **5.** *►Epilepsy* **- *increase in GABA, dopamine & norepinephrine causes seizures.*** **\ 6.** *► Schizophrenia* **-- *decrease in GABA leads to increase in dopamine*** **[Drug Action on NT]** **1.** *► Antagonist* **- Binds to receptor & [blocks] NT action.** **2.** *►Agonist* **- [Activates] a receptor e.g., nicotine & dopamine** **As drug use increases, receptor response decreases∴increases amounts drug req. e.g., cigarettes** **NERVOUS SYSTEM Part II** **[CNS]** **[CNS Divisions]** **1.** *►Spinal cord* **2.** *► Brain* **-** **A. Cerebrum** **B. Cerebellum** **C. Diencephalon** **D. Brain stem** **All of the above are covered by meninges membranes.** **[The Meninges]** **1.** *►Dura mater***- Vascular CT w/ nerves & forms internal periosteum of the skull bones & covers spinal cord as it passes through vert.** *Path. Note: Trauma to head may cause blood to collect in space below dura mater∴ subdural hematoma.* **2.** *►Arachnoid mater* **- Avascular membrane that reabsorbes cerebralspinal fluid (CSF)** **Note: Blood flows in a space (dural sinus) between the outer & inner layers of the dura mater.** **3.** *► Pia mater* **- Vascular w/ nerves. Nourishes CNS cells via CSF secretion & attaches dura mater to spinal cord.** **Note: Arachnoid & pia mater separated by the subarachnoid space where CSF is reabsorbed.** **[CSF]** **CSF is similar in composition to plasma from which it is derived** **[ƒ CSF]** **1.** *► Cushion CSF* **2.** *►Nourishes CSF* **3.** *►Transport waste to blood* **4.** *► Ion balane* **[CSF Flow]** **Brain ventricles are interconnected cavities continuous with spinal cord central canal.** **Contain capillary bundles (choroid plexuses) that secrete CSF** *Path. Note: Meningitis is a viral or bact. inflammation of the meninges (usually arachnoid & pia mater). Affects vision, hearing, IQ and may result in death. Of those that recover, many of them may lose limbs.* *Path. Note: Hydrocephalus results when CSF production \> reabsorbtion due to infection, clot, tumor* **The Spinal Cord** **[Components of the Spinal Cord]** **1.** *►conus medullaris* **- End of spinal cord at L1-L2.** **2.** *►cauda equina* **- Nerves radiating from inferior lumbar enlargement.** **3.** *►central canal* **- Continuous with brain ventricles.** **4.** *►gray matter* **- Cell bodies, neuroglia, unmyelinated axons.** **5.** *► white matter***- Myelinated axons arranged in tracts** **[Nerve Tracts]** *►Tracts* **- Axons w/ a common origin, terminus & function (motor or sensory) & cross over in cord or brain stem ∴ right brain receives from left body.** **1.** *► ascending* **- Carry sensory (afferent) impulse up to brain\ 2.** *► descending* **- Carry motor (efferent) impulse down to neurons** *Path. Note: Damage to a tract anywhere along its length will affect its function* *1. Descending tract- Loss of motor functions inferior to damaged area.* *2. Ascending tract- Loss of sensation inferior to damaged area.* **[Experimental Repair of Spinal Tracts]** **1.** *►protein blockers***- Block CNS protein that prevents axon regeneration.** **2.** *►PNS neuron transplant* **- PNS neuron + growth factor.** **3.** *► neural stem cells* **- Brain stem cells induced to form patches.** **[Spinal Cord ƒ]** **1. Spinal reflex (arc) transmission** **2. Conduit for impulses to (afferent) & from\ (efferent) brain** **[Reflex Arcs]** *►Reflex arcs***- Pathways for impulses (reflexes) that do not go through brain e.g., heart rate, blood pressure, sneezing, knee jerk.** **[RA Components ]** **1.** *► Receptor* **- Receives stimulus** **2.** *► Sensory neurons* **- PNS neuron that delivers stimulus to interneuron in CNS.** 3. *► Interneurons***(association)- CNS neurons that relay stimuli. Not** **4.** *► Motor neurons* **- Pass stimulus to effectors.** **5.** *►effectors* **- Turn stimulus into action e.g., muscle contraction.** **The Brain** **[ƒ Brain ]** **1. Process sensory info.** **2. Memory** **3. Reasoning** **4. Coordinate muscles** **5. Coordinate visceral activity** **6. Personality e.g., morality, aggression, compassion** **[Brain Divisions & ƒ]** **I. The Cerebrum** **[Cerebrum Components]** 1. *►convolutions gyri + sulci***- increase in surface area for gray matter.** **2. Lobes- External lobes named after overlying bones** **A.** *►Frontal* **B.** *► Parietal* **C.** *► Temporal* **D.** *► Occipital* **E.** *► Limbic* **\ F.** *► Insula* **3.** *► Cerebral cortex* **(gray matter)- Outermost layer of cerebrum that contains cell bodies** **4.** *► white matter* **- Innermost layer of cerebrum that contains myelinated axons ∴ white appearance.** **[Functional Regions of the Cortex]** **1.** *► motor (efferent)* **ƒ- Frontal lobe e.g., muscles & glands** **2.** *► Sensory (afferent)* **ƒ-** **Parietal-** *►skin, temp, touch, pain* **Occipital-** *►vision* **Temporal-** *► hearing* **3.** *► association (interpretive) areas***- Not directly involved w/ sensory or motor ƒ. Found in all lobes.** **ƒ:** **A. Interpret sensory info.** **B. Memory** **C. Emotions** **D. Problem solving** **E. Speech** **F. Conceptualization of consequence** **(not mature in males until 25 yrs.!!!!!)** **General interpretative area plays primary role in complex & analytical thought.\ Allows words to be recognized & understood***.* *Path. Note: A person w/ [dyslexia] sees letters separately or in broken groups. Caused by congenital defects in perception combined w/ learning behavior errors. Not related to I.Q.!* *Concussion:* *A type of traumatic brain injury (TBI) caused by a bump, blow or jolt to the head or body that causes the head and brain to move rapidly back and forth causing the brain to bounce around or twist in the skull damaging the brain cells and creating chemical changes in the brain.* *Note: A lobotomy (modification of the nerve tracts to & from the frontal lobe) is used to modify behavior)* **[Hemisphere Dominance]** **Both hemispheres active in basic functions; however, one may dominate.** **Non-dominant hemisphere controls non-verbal ƒ, orientation of body, understanding visual & auditory patterns (usually the right hemisphere)** **Both hemispheres communicate via corpus callosum.** *Path Note: Premature babies (\>10 weeks) lack a fully formed corpus callosum (as well as other regional connections) & post-partum development of the corpus collusum does not catch up with brains that were full-term. Premature babies have an increased incidence of autism-spectrum disorder & ADHD.* *Path Note: Premature babies (\>10 weeks early) lack a fully formed corpus callosum (as well as other regional connections) & post-partum development\ of the corpus collusum does not catch up with brains that were full-term. Premature babies have an increased incidence of autism-spectrum\ disorder & ADHD.* **[Memory & Learning]** *► Knowledge* **- Possession of facts** *► Learning* **- Acquisition of knowledge** *►memory* **- Retention of that learned knowledge** *► Intelligence* **- The ability to learn, retain & process knowledge.** **[Types of Memory]** **1.** *► short term***- Short duration, mostly electrical in function. Neurons connected in a circuit & continue to stimulate each other.** **2.** *► long term* **- Long duration, structural in function.New synapses are formed allowing memory.** **[Basal Nuclei (Ganglia)]** **Masses of gray matter below lateral ventricles. ƒ: subconscious control of skeletal muscles & coordinate learned movement patterns e.g., dance, musical instruments; produce the NT dopamine.** *Path. Note: Parkinson's disease is a decline in dopamine due to death of basal nuclei cells. Causes tremors then paralysis. Cause believed to be chemical and traumatic damage to brain e.g., boxing.* **II. The Diencephalon** **Surrounds third ventricle; almost all gray matter.** **[Regions of the Diencephalon]** **1.** *►thalamus* **- ƒ: Receives, filters & directs [all] afferent sensory impulses to correct region of cortex. Routes info. from hypothalamus to cortex.** **2.** *►Hypothalamus* **- ƒ: Homeostasis** **A.** *► mamillary bodies* **- ƒ: Olfactory relay** **B.** *► Hypophysis* **(Pituitary gland)- ƒ: Hormone production.** **i. Emotion (indirectly) (limbic system has\ most influence)** **3. Epithalamus-** **A.** *►Pineal gland* **(body)- ƒ: Produce & secrete melatonin.** **B.** *►choroid plexus***- ƒ: Produce & secrete CSF.** **III. The Brain Stem** **[Regions of the Brain Stem]** **1.** *►Midbrain* **- Myelinated fibers w/ some gray matter.** **ƒ: Connects brain stem with superior brain & relays messages.** **A.** *► Cerebral aqueduct* **- ƒ: Connect ventricles 3 & 4.** **B.** *► corpora quadrigemina* **- ƒ: Relay centers for visual & hearing reflexes** **2.** *► pons* **- ƒ: Fibers relay impulses from medulla to cerebrum & from cerebrum to cerebellum.** **3.** *►medulla oblongata***- ƒ: Fibers relay impulses from cord to cerebrum.** **[Basal nuclei in M.O. Regulate:]** **A. Heart rate** **B. Blood pressure** **C. Respiration** **4.** *►Reticular formation* **- Network of fibers & gray matter (throughout brainstem).** **ƒ: Activates cortex into state of wakefulness. Decrease in activity results in sleep. Also filters impulses to send to cortex (as does thalamus)** *Path. Note: Damage to the reticular formation results in a coma or persistent vegetative state.* *Coma- Not awake or aware* *P.V.S.- Occasionally awake but not aware.* *Path. Note: Intense cerebral activity stimulates the reticular formation causing insomnia.* **[Types of Sleep]** **1.** *► Slow wave* **(non-REM)- decrease in activity of reticular formation & cortex. Causes restful, dreamless sleep w/ decrease in BP, heart & resp.** *Path Note: Sleep walking occurs during non-REM sleep when the frontal cortex partially activates but the rest of the brain remains in non-REM. Strongly influenced by genetics. 4% of adults.* **2.** *► rapid eye movement* **(REM)- Regions of cortex active. Dreams w/ irreg. increase in BP, heart & resp. Long term memory stored.** *Path. Note: REM sleep important. If missed, cannot be made up for the next night. Marijuana & alcohol interfere with REM sleep.* *\>\>\>\>Long term memory is stored during REM!* **IV. The Cerebellum** **[Regions of the Cerebellum]** **1. Cerebellar cortex** **2. White matter** **3. Peduncles- Nerve tracts that communicate w/ other parts of CNS.** **[Autonomicƒ of Cerebellum]** **A.** *►Balance* **B.** *►Coordination of skeletal muscles* **C.** *►Posture* **D.** *► Intergration* [ ] **[The Limbic System]** **A functional group of tracts & nuclei in the cerebrum & diencephalon.** ***Note: This is a functional grouping & not an anatomical structure.*** **[ƒ of Limbic System]** 1. **Establishing emotional states** **Amygdaloid- "fight or flight" response, linking emotions w/ specific memories.** **2. Link conscious functions of cerebrum w. unconscious & autonomic functions of brain stem.** **3. Memory storage & retrieval** **Hippocampus- Learning, storage & retrieval of long-term memories.** **[Peripheral Nervous System]** **[Nerve Fiber Classification]** ***Functional* Classification:** **1.** *► sensory nerves* **(afferent)** **2.** *► motor nerves* **(efferent)** **3.** *►mixed nerves* **- Contain both sensory & motor** ***Structural* Classification:** **1.** *►cranial* **- Originate from brain (12 pairs)** **2.** *►spinal* **- Originate from spine (31 pairs)** **[Structure of Peripheral Nerve]** **[Mixed Nerve Hierarchy Overview]** **Peripheral nerve, into, fascicle, into, fiber / axon** **[Cranial Nerves]** **1. 12 pairs** **\#1 Olfactory-** *Olfaction* **\#2 Optic-** *Vision* **\#3 Oculomotor-** *Move eye, eyelids and iris.* **\#4 Trochlear-** *Superior oblique muscle of eye.* **\#5 Trigeminal-** *Sensory for forehead, face, eyes.* **\#6 Abducens-** *Lateral rectus muscle of eye.* **\#7 Facial-** *Facial expression & taste buds.* **\#8 Vestibulococulear-** *Equilibrium & hearing.* **\#9 Glossopharyngeal-** *Pharynx, tonsils,* **\#10 Vagus-** *Speech, swallowing.* **\#11 Accessory-** *Transmit to neck muscles,* **\#12 Hypoglossal-** *Move tongue.* **On Occasion Our Trusty Truck Acts Funny, Very Good Vehicle Any How.** **2. All but olfactory originate from brain stem.** 3. **Mostly mixed nerves** **[Spinal Nerves]** **1. 31 pairs named after vertebrae from which they emerge.** **2. All are mixed nerves** **3. Enter / exit cord via roots.** **A. Dorsal roots- Sensory neurons entering cord.** B. **Ventral roots- Motor neurons exiting cord.** **[Nerve Plexuses]** *► plexus* **- Interlacing nerve networks** **ƒ: Distributes a single function between multiple spinal nerves ensuring redundancy.** **1.** *►Cervical* **2.** *► Brachial* **3.** *► Lumbar* **4.** *► Sacral* **[Life-Span Changes]** **1. Brain cells begin to die** *(apoptosis)* **even before birth.** *Path. Note: In [schizophrenia], these cells do not die & these extra neurons produce too much dopamine leading to hallucinations.* **2. Synapses decrease in number** **3. Neurotransmitters decrease** **4. Action potential transmission decrease** *(by 10%)* **5. Decrease sensitivity of foot & ankle nerves results in falling.** **6. Irregular sleep to due changes in reticular system (in brain stem)** **Special Senses** **[Hearing]** **[Ear Components]** **1.** *►External ear* **A.** *► auricle* **(pinnae)- ƒ: Collect sound** **B. External auditory canal (meatus)** *of temporal bone***-\ ƒ: Conduct sound to middle ear.** **B1.** *►hairs* **- ƒ: Filter debris** **B2.** *►ceruminous* **(wax) glands-\ ƒ: Trap debris** **2.** *►middle ear* **A. Tympanic cavity** *of temporal bone* **A1. Tympanic membrane (tympanum)-** **ƒ: Collect, concentrate & transmit sound to inner ear.** *Malleus maintains* *cone shape.* **A2. Auditory ossicles- ƒ: Amplify & conduct sound to inner ear via:** **-***► malleus (hammer)* **-***► incus* *(anvil)* **-***► stapes (stirrup)* **ƒ: Push against oval window to move inner ear fluid to stimulate hearing receptors.** ***Note: Tympanic reflex- In response to loud sounds, the ossicles become immobile reducing conduction of sound to the inner ear to protect the hearing receptors.*** *Path note: Loud sounds travelling rapidly e.g., gunshots, air horns, reach the inner ear before the tympanic reflex can occur resulting in hearing damage.* **B.** *►auditory tube* **(eustachian tube)- ƒ: Allow air pressure equalization on each side of tympanum.** *Path note: Change in elevation results in unequal pressure on the tympanum resulting in hearing impairment unless pressure is equalized by yawning, chewing, etc..* *Path note: Otitis media is inflammation & fluid accumulation in the middle ear. Usually caused as bacteria moves up the eustachian tube from the nasopharynx. Most common in children due to short tube length.* **Tube fallen into and healed in middle ear.** **3.** *► inner ear***(labyrinth)- ƒ: Reception of sound & equilibrium** **[Components]** **A.** *► cochlea* **(in temporal bone)- ƒ: Hearing sensation** **A1.** *►bony* **(osseous) labyrinth- Passageway\ through temporal bone.** **A2.** *► membranous labyrinth***- Membranous passageway w/in bony labyrinth.** **-***►spiral organ* **(Organ of Corti)- w/ hearing receptor hair cells** *(≈16,000)* **that move against a tectorial membrane to stimulate neurons.** *Path note: Prolonged or repeated exposure to sounds above 85-90 dB will result in the destruction of the hair cells resulting in permanent hearing loss ∴ sensorineural deafness.* **[Review: Path of sound waves:]** Auricle (pinnae), into, ext. auditory canal (meatus), into, tympanum, into, ossicles, into, oval window, into, scala vestibule, into, cochlear duct & spiral organ, into, scala tympani, into, round window, into, tympanic cavity *Path note:* ***[Hearing Loss]*** *1. Conductive- Interference w/ conduction to inner ear e.g., wax ext. auditory\ canal (meatus), ossicles* *2. Sensorineural- Interference w/ inner ear transmission e.g., cochlea, auditory\ nerve* *Path note: 95% of deafness cases are a result of wax or foreign object accumulation in the ext. auditory meatus ∴ conductive deafness.* *Path note: Cochlear implants treat sensorineural deafness & hearing aids help with conductive deafness.\ * **B.** *►vestibular complex* **- ƒ: Equilibrium** **B1.** *►labyrinth sacs* *(utricle & saccule)* **ƒ: Static Equilibrium (maintaining stability & posture when still)** **Contain macula & otoliths. Movement causes otoliths to stimulate hairs cells\ of the macula sending impulse to brain.** **\ B2.** *► semicircular canal***- ƒ: Dynamic equilibrium (maintaining\ stability & posture while moving)** **Ampullae house hair cells that respond to movement of endolymph.** **Rapid movement of head or body causes fluid of the SCC to stimulates the hair cells sending impulse to brain.**