15& 16 anatomy notes.pdf

Chapter 15 Special Sense - Vision - Taste - Smell - Hearing - Equilibrium The Eye The Lacrimal Apparatus Structure of the Eyeball 1. Fibrous layer 2. Vascular layer 3. Inner layer 1. FIBROUS LAYER - when the cornea is scratched it is very painful, causes us to tear. 2. VASCULAR LAYER Pupil...

Chapter 15 Special Sense - Vision - Taste - Smell - Hearing - Equilibrium The Eye The Lacrimal Apparatus Structure of the Eyeball 1. Fibrous layer 2. Vascular layer 3. Inner layer 1. FIBROUS LAYER - when the cornea is scratched it is very painful, causes us to tear. 2. VASCULAR LAYER Pupil Constriction and Dilation 3. INNER LAYER (RETINA) - Retina originates as an outpocketing of brain - contains: - millions of photoreceptors cells that transduce light energy - neurons - glial cells - delicate two-layered membrane - outer pigmented layer - inner neural layer INNER LAYER RODS and CONES Posterior Wall (Fundus) of the Right Eye as Seen With and Opthalmoscope Clinical- Homeostatic Imbalance - Retina is fragile and delicate. any G-forces in our eyes can cause detachment FLUIDS in the EYE -> further back -> nearer the front getie/ge Y clear liquid Anterior Lens - biconvex, transparent, flexible, and avascular - changes shape to precisely focus light on retina - if it is a flat shape—> image for far distance - if it is a bulge shape—> image for close distance - sympathetically—> lens to flatten - parasympathetic—> lens to bulge Clinical- Homeostatic Imbalance Visible Light Refraction Light is Focused by a Convex Lens - light goes through a biconvex lens - image inverts—> once on the right side becomes on the left - turns image upside down and inverts from left to right - when image arrives at the occipital lobe the wiring of the input changes back to the original configuration Focusing on the Retina * Bi-convex - majority of the refraction is in the cornea—> constant curvature - laser eye surgery, the laser can microscopic change the shape of the cornea to create better vision Focusing Light on the Retina: distant vision Focusing Light on the Retina: Close e - cross eyed: tries to focus on an image to focus on - near close vision, we don’t want tot go over that to focus on close objects Clinical- Homeostatic Imbalance Functional Anatomy of Photoreceptors - visual pigments: made up of proteins And vitamin A Comparing Rode and Cone Vision - found in the fovea Visual Pigment Opsins are proteins Phototransduction - in the dark we have a depolarized photo receptors - in the light we have hyperpolarized photo receptors Information Processing in the Retina: in the Light Hyperpolarizing is a good thing! The bipolar cell is no longer inhibited In the light In the Dark: - constant glutamate released, constant inhibition - photo transmitter is very active releasing inhibitory neurotransmitter - when you open your eyes when you wake up, you have the ability to see right away—> survival mechanism - the lack of inhibition and excitation of the bipolar cell is so rapid it takes far less time to stop the inhibition to cause excitation —> immediate vision upon opening your eyes Light and Dark Adaptation Clinical- Homeostatic Imbalance Visual Pathway to the Brain and Visual Fields, Inferior View Smell: Olfactory Receptors Physiology of Smell Taste: Taste Buds on the Tongue Basic Taste Sensation Physiology of Taste o only taste in the first period The Gustatory Pathway Hearing and Balance and Equilibrium: Structure of the Ear Clinical- Homeostatic Imbalance Internal Ear Hearing Properties of Sound Frequency and Amplitude of Sound Waves Transmission of Sound to Internal Ear - heterogenous, the fibres (connective tissues) are short and stiff Resonance of the Basilar Membrane —> it is able to decipher the sound wave Sound of Transduction Auditory Pathway and Processing Balance and Equilibrium The Maculae Anatomy of a Macula - each is a flat epithelium patch containing hair cells with supporting cells - hair cells have stereocilia and special “true stereocilium” called kinocilium - located next to tallest stereocilia - stereocilia are embedded in otolith membrane, jelly-like mass studded with otoliths (tiny CaCO3 stones) - Otoliths increase membrane’s weight and increase its inertia (resistance to changes in motion) Activating receptors of a macula - hair cells release neurotransmitter continuously - acceleration/deceleration causes a change in amount of neurotransmitter released - leads to change in AP frequency to brain Activating receptors of a macula - bending of hairdos in direction of kinocilia: - depolarized hair cells - increases amount of neurotransmitter release - more impulses travel up vestibular nerve to brain - bending of hairs away form kinocilia: - hyperolarizes receptors - less neurotransmitter released - reduces rate of impulse generation - thus brain is informed of changing position of head Semicircular Canals The Cristae Ampullares Equilibrium Pathway to the Brain Homeostatic Imbalance Chapter 16 Endocrine System Overview Main Classes of Hormones Mechanisms of Hormone Action Water-soluble Hormones: Bind to Plasma Membrane Receptors and Activate Second-Messenger Systems Lipid Soluble Hormones Bind to Intracellular Receptors and Direct Gene Activation Control of Hormone Release 1. HUMORAL STIMULI 2. NEURAL STIMULI 3. HORMONAL STIMULI Target Cell Specificity Half-Life, Onset, and Duration of Hormone Activity Interaction of Hormones at Target Cells The Hypothalamus Pituitary-Hypothalamic Relationships Posterior Pituitary and Hypothalamic Hormones Anterior Pituitary- Hypothalamic Relatioships Anterior Pituitary Hormones Growth-Promoting and Metabolic Actions of Growth Hormone Clinical- Homeostatic Imbalance Anterior Pituitary Hormones Anterior Pituitary Hormones The Thyroid Gland Thyroid Hormone (TH) Thyroid Hormone: Synthesis Thyroid Hormone (TH) Clinical- Homeostatic Imbalance Calcitonin Parathyroid Gland Adrenal Gland Clinical- Homeostatic Imbalance Adrenal Cortex Adrenal Gland Hormones: Summary of Regulation and Effects Pineal Gland Pancreas Clinical- Homeostatic Imbalance Consequences of Insulin Deficit (Diabetes Mellitus) The Gonads and Placenta Hormone Secretion by Other Organs