Biology 2221 Content Outline

I. CELL ULTRASTRUCTURE (Organelles) and Functions

    A. Homework Assignment: Know the structures and general functions of the following organelles.

        1. Flagella and Cilia

         3. Golgi apparatus

        4. Ribosomes

        5. Lysosomes

        6. Microvilli

        7. Peroxisomes

        8. Vacuoles / vesicles

        9. Know the processes of intracellular digestion and autolysis

        10.  Endoplasmic Reticulum (rough and smooth)

    B. Cell Membrane Structure/Function Relationships

        1. Structure-A macromolecular complex (mosaic) of phospholipid, protein and carbohydrate.

            a. Phospholipid bilayer basic composition

            b. With dissolved proteins and attached carbohydrates

        2. Function-Control the composition of cytoplasm by regulating materials that enter or leave cell.

            a. Membrane structures form "portals" for material passage and impose restrictions by physical or chemical compatibilities     or incompatibilities.

                1. "Water-Filled" pores

                2. Ion Channels or "gates"

                3. "Carrier" protein molecules

                4. Phospholipid solubility

            b. Mechanisms for moving materials across membrane classified by energy requirement.

                1. Kinetic energy dependent mechanisms.

                    a. Simple Diffusion

                    b. Facilitated Diffusion

                    c. Osmosis

                2. Cellular energy (ATP) dependent mechanisms

                    a. Active transport via carrier proteins

                    b. Bulk Transport

                        1. Endocytosis

                            a. Phagocytosis

                            b. Pinocytosis

                        2. Exocytosis-Golgi and secretions

    C. Mitochondrial Structure/Function Relationships

        1. Double membrane structure

            a. Inner cristae surrounded by outer membrane.

            b. Electron transport molecules in Respiratory Assemblies

        2. Functions to transfer chemical energy of C-H bond electrons into high energy phosphate bonds of ATP

            a. Electron Transport (Cytochrome) System uses electron carrier molecules (cytochromes) and coupled Redox reactions to transfer energy from hydrogen electrons to ATP.

            b. Krebs Citric Acid Cycle increases the electron (H's) yield from nutrient molecules to increase the ATP yield.

            c. Anaerobic Glycolysis is the initial anaerobic breakdown of the carbohydrate glycogen, a polymer of glucose molecules prior to passage into the Krebs cycle when adequate oxygen is available. Also, allows continued limited ATP production under limited oxygen situations.

II. TISSUE TYPES (Specialized cells and matrices)

    A. Epithelial-Cover surfaces or line cavities

        1. Cells prevalent with little matrix

        2. Classified by cell shape and arrangement

    B. Connective-Support and connect organs

        1. Matrix prevalent and secreted by cells

        2. Classified by matrix protein composition and/or arrangement

    C. Excitable Cells-respond to stimulation by electrical and mechanical activity.

        1. Nerve (Neurons and Neuroglia)

        2. Muscle (Skeletal, Cardiac, Smooth)

III. NEUROPHYSIOLOGY/NEUROANATOMY

    A. Cell Types of the Nervous System

        1. Neuroglia-shape, support, and myelination

        2. Neurons-Conductile elements of the N.S.

            a. Cell Body-contains nucleus

            b. Neurites-classed by direction of conduction

    B. Action Potential vs. Resting Potential

        1. All living cells have resting potentials dependent upon ion distributions across membrane (Sodium outside, potassium inside).

        2. Only excitable cells generate action potentials by changing ion distribution across surface membrane.

            a. Phases of the Action Potential (AP)

                1. Depolarization-Sodium diffuses in

                2. Repolarization-Potassium diffuses out

                3. Hyperpolarization-Potassium "over-shoot"

                4. Return to Resting State-Active transport of sodium and potassium by sodium "pump"

            b. Self-Propagation of Action Potential

            c. Myelination and Saltatory Conduction

                1. White matter-myelinated with high velocity and efficiency of conduction

                2. Gray Matter-nonmyelinated for slower, less efficient and more diffuse conduction of AP's

    C. Synapses and Neural Pathways

        1. Synaptic anatomy and "one-way"conduction.

        2. Neurotransmitters (EPSP vs. IPSP)

            a. Acetylcholine/cholinesterase

                1. Nicotinic receptors (excitatory)

                2. Muscarinic receptors (inhibitory)

            b. Norepinephrine (excitatory)

            c. GABA (inhibitory)

        3. Synaptic Properties

            a. Summation (Spatial vs. Temporal)

            b. Fatigue

            c. Facilitation

            d. Resistance and reaction times

    D. Reflex Arcs and the functional unit of the human nervous system.

        1. General Properties of All Reflex Arcs with spinal cord anatomy.

            a. Sensory pathway with receptors showing adequate stimulus specializations.

            b. Integrative center within the CNS.

            c. Motor pathway with specialized effectors

        2. Somatic Reflex Arc (Spinal reflexes)

        3. Autonomic Reflex Arcs-Two neurons in motor pathway involving ganglia and "Dual" Innervation of visceral organs.

            a. Sympathetic Arc-Shares thoracic and lumbar spinal nerves and ganglia linked to form sympathetic trunks parallel to spinal cord.

                1. Generally excitatory.

                2. Norepinephrine is the final neurotransmitter at the neuroeffector junction.

            b. Parasympathetic Arc-Shares cranial and sacral spinal nerves and ganglia not linked.

                1. Generally inhibitory.

                2. Acetylcholine is the common neurotransmitter.

        4. Neurohumoral Reflex Arcs

            a. Sensory arm is neural.

            b. Motor arm is hormonal (See ADH and Oxytocin hormonal regulation).

    E. Anatomical Organization of Nervous System

        1. CNS-brain and spinal cord

        2. PNS-cranial and spinal nerves

    F. Brain Anatomy

        1. Prosencephalon

            a. Telencephalon-Cerebrum (hemispheres, cortex and corpus callosum)

                1. Gyri, sulci, and fissures

                2. Lobes of the hemispheres with nomenclature and general functions.

                3. Central Sulcus-Frontal vs. Parietal lobes.

                4. Precentral Gyrus-Voluntary motor area.

                5. Postcentral gyrus-Somatic sensory area.

            b. Diencephalon

                1. Thalami and ventricle III.

                2. Epithalamus and Pineal Gland.

                3. Hypothalamus and Pituitary Gland.

        2. Mesencephalon with cerebral aqueduct

        3. Rhombencephalon

            a. Metencephalon

                1. Fourth Ventricle

                2. Cerebellum and muscle coordination

                3. Pons and transmission tracts

            b. Myelencephalon (Medulla oblongata)

                1. Respiratory centers

                2. Vasomotor centers

    G. White Matter Tracts of the Cord and Corresponding Brain Integration Areas.(Reversed and inverted orientation).

        1. Ascending Sensory Tracts (Postcentral gyrus).

            a. General Properties of All Sensory Mechanisms (Somatic and Special)

                1. Type of stimulus-receptor type and adequate stimulus specialization.

                2. Location of stimulus-receptor location, afferent pathway and integration area of brain

                3. Intensity of stimulus-frequency of action potentials reaching brain (number of and/or degree of receptor stimulation)

            b. Dorsal Column-Refined, discrete sensations.

            c. Lateral Spinothalamic-Crude, poorly localized sensations.

        2. Descending Motor Tract (Precentral gyrus).

            a. Pyramidal-Voluntary motor tract

            b. Corticospinal-Pyramidal tract inferior to decussation area of medulla.

    H. Meningeal Membranes and Cerebrospinal Fluid

        1. Meningeal membranes and spaces

        2. Ventricles and CSF formation/circulation

IV. SPECIAL SENSES

    A. General Properties

        1. Cephalized

        2. Integrated in special brain regions other than pre-and postcentral gryri.

    B. Vision

        1. Properties of vision and the adequate stimulus (light)

            a. Vision requires converting light energy into action potentials for interpretation in occipital cortex of brain.

            b. Light-Waveform of energy with wavelength determining color and peak height determining brightness.

            c. Properties of the visual scene.

                1. Form/Shapes-Collection and focusing reflected light onto photoreceptors.

                2. Color-Different photoreceptors sensitive to light of different wavelengths.

                3. Depth-Binocular vision, learned sizes with size comparisons, moving parallax.

        2. Structure/Function Relationships of Eye.

            a. Tissue layers of the eye.

                1. Sclera

                2. Choroid layer (melanin pigmentation) with ciliary body

                3. Retina (photoreceptor layer) with bipolar and ganglion cell innervation

            b. Refractory Structures of the Eye and Light Focusing

                1. Cornea

                2. Aqueous Humor (anterior and posterior chambers, glaucoma)

                3. Vitreous Humor and eye shape maintenance

                4. Lens

                    a. Visual accommodation and the ciliary body

                    b. Presbyopia and cataracts

                    c. Photoreceptor Chemistry

                        1. Rod Chemistry and Vitamin A involvement (dim light vision)

                        2. Cone Chemistry-Color vision and visual acuity

                    d. Depth Perception

                        1. Binocular Vision

                        2. Other mechanisms for distance judgement

    C. Hearing and Equilibrium

        1. Properties of Sound (Pressure waves)

            a. Frequency-pitch and ìtimbreî

            b. Amplitude-loudness and the decibel scale

        2. Structure/Function Relationships of the Ear (Converting sound waves into action potentials to transmit properties of sound to brain for interpretation)

            a. Outer Ear

                1. Pinna (auricle) and sound wave collection

                2. External auditory meatus and auditory canal with ceruminous glands

        3. Tympanic membrane

            b. Middle Ear

                1. Ossicles for transmission

                2. Pressure equalization and the auditory tube

                3. Oval and round windows

            c. Inner Ear-location of receptor cells for hearing and position/motion detection

                1. Cochlear Anatomy and pressure transmission/transduction

                    a. Basilar Cells (Organ of Corti) and sound transduction (pitch and loudness)

                    b. Hearing deficits

                2. Vestibular Apparatus and fluid inertia in balance/motion

                3. Vestibulocochlear Nerve Divisions

    D. Chemical Senses (Taste and Smell)

        1. Adequate stimulus-dissolved chemicals and receptor specializations

        2. Taste (Gustation)

            a. Taste Buds and Tongue Papillae-Water soluble stimulus chemicals (salt, sweet,sour, and bitter)

            b. Taste localization on tongue

            c. Gustatory and Olfactory interactions

        3. Smell (Olfaction)-Lipid soluble stimulus chemicals

            a. Olfactory epithelium and receptor theories

            b. Trauma and loss of smell sensation

V. MUSCLE.

    A. Muscle Tissue Types and Histology of Muscle Cells (Fibers)

        1. Skeletal-cylindrical in bundles

        2. Cardiac-syncytium

        3. Smooth-spindle-shaped fibers

    B. Muscle Twitch Properties (speed, strength, duration, neuro- vs. myogenic)

    C. Skeletal Muscle Mechanism of Contraction

        1. Muscle Fiber Ultrastructure (Strength-Striation interdependence)

            a. Myofibrils with Sarcoplasmic Reticulum and T-tubules

            b. Myofilaments (Thick-myosin, and Thin-actin)

        2. Contractile vs. Sliding Filament Theories

        3. Excitation-Contraction Coupling and Calcium

    D. Skeletal Muscle Properties

        1. Single Twitch (Electrical excitation with contraction and relaxation times)

        2. All-or-None vs. Graded Responses

        3. Strength of contraction and Motor Unit structure

        4. Treppe and ìwarm-upî

        5. Tetany and smooth contractions

    E. Cardiac Muscle Properties

        1. Plateaued action potential and myogenic origin

        2. Calcium involvement

    F. Smooth Muscle Properties

        1. Action potential and rhythmicity

        2. Striation-strength correlations

        3. Calcium involvement

VI. NEUROENDOCRINOLOGY

    A. Comparison of neural and endocrine regulation

    B. Posterior Pituitary

        1. Hypothalamic Nuclei and Infundibular Connections

        2. Neurohumoral Reflex Arc Regulation

        3. Hormones of the Posterior Pituitary

            a. Oxytocin

                1. Mechanism/Hormones of Lactation

                2. Oxytocin and milk ejection

            b. Antidiuretic Hormone (ADH)

                1. Hypothalamic osmotic receptors

                2. Mechanism of osmoregulation and ADH

    C. Anterior Pituitary and Trophic Hormones

        1. Negative Feedback Regulation and the Hypothalamic-Hypophyseal Portal system

        2. Hormones of the Anterior Pituitary (Releasing Hormones and Target Organs)

            a. Growth Hormone (GH)-skeletal stature and body biomass addition

            b. Thyroid Stimulating Hormone (TSH)-iodine and metabolic regulation

            c. Prolactin and lactation

            d. Adrenocorticotrophic Hormone (ACTH) and the cortical steroids

                1. Mineralocorticoids-aldosterone

                2. Glucocorticoids-cortisol

                3. Sex Hormones-Estrogens and Androgens

            e. Sex Hormones of Gonadal Tissue (covered in 2222)

        3. Abnormalities (Hyper- and Hyposecretion) of anterior pituitary hormones

©