AP2 Unit 1 Study Guide PDF

Unit 1 Study Guide Sensory System -Know the function of a sensory receptor. Respond to a stimulus and initiate sensory input to the CNS. Sensory Vision Hearing Touch Smell Taste Receptor Cells Type of Energy Photorece...

Unit 1 Study Guide Sensory System -Know the function of a sensory receptor. Respond to a stimulus and initiate sensory input to the CNS. Sensory Vision Hearing Touch Smell Taste Receptor Cells Type of Energy Photoreception- Mechanoreception- Mechanoreception- Chemoreception- Chemoreception- Reception detection of detection of detection of detection of detection of light, perceived vibration, pressure, perceived chemical stimuli, chemical stimuli, as sight perceived as as touch perceives as perceived as taste hearing smell Sense Organ Eyes Ears Skin Nose Tongue -Know the two main divisions of sensory cell receptors. 1. Specialized ending of a neuron – receptor is afferent neuron - Somatosensory, olfaction 2. A separate cell that influences a neuron. – receptor regulates afferent neuron - Vision, hearing, taste -Know what transduction is. Transduction: sensory receptor cells transduce different signals in the “real world” into action potentials - must be interpreted by the brain -Know what receptor potentials are. Receptor potentials: depolarization or hyperpolarization of the receptor cell -Know what the following are and what was discussed for each. o Receptive fields – area in which the sensory cell is actived ▪ These can vary in size, depending on cell, location in the body, or sensory modality ▪ Tells brain where the stimulus was o Receptor adaptation – decrease in receptor response to a constant stimulus over time ▪ Decreases the perception of stimulus o Lateral inhibition – sensory cells that are most strongly stimulated inhibit those around them ▪ Use inhibitory interneurons ▪ This allows us to perceive well-defined sensations at a single location Sharpens perception (greater acuity) -Know how the brain interprets incoming sensory information. Sensory information is coming to the brain in the form of action potentials -Know the following and what discussed for each. o Stimulus type – incoming sensory information is brought to specific portions of the cortex ▪ The regions active provides the CNS with information about stimulus type o Frequency coding – provides the CNS with information regarding stimulus intensity ▪ Larger stimulus = more frequent action potentials o Population coding – provides stimulus intensity information ▪ A strong stimulus will be sensed by multiple sensory cells ▪ Receptive field size plays a role. -Know what sensory receptors are classified. Categorized by distribution, stimulus origin, and stimulus type -Know the difference between general sense receptors and special sense receptors. General sense receptors: - Somatic sensory receptors: tactile receptors of skin and mucous membranes; proprioceptors of joints, muscles, and tendons (determine position and movement)  -Visceral sensory receptors: found in walls of internal organs, they monitor stretch, chemical environment, temperature, pain Special sense receptors: - Specialized receptors in complex sense organs of the head - 5 special senses: olfaction, gustation, vision, audition, equilibrium -Know the difference, and examples of each, for somatic sensory receptors and visceral sensory receptors. Somatic sensory receptors- tactile receptors of skin and mucous membranes Ex: proprioceptors of joints, muscles, and tendons (determine position and movement) Visceral Sensory Receptor- found in walls of internal organs Function: they monitor stretch, chemical environment, temperature, and pain -Know the differences and be able to describe what was discussed of the following: o Exteroceptors – detect stimuli from external environment o Interoceptors – detect stimuli from within our internal environment o Proprioceptors – detect body and limb movements -Know the different types of receptors in regards to modality of stimulus, and what they detect. Tactile Receptor Chemoreceptor – chemical binding Photoreceptor – temperature change Mechanoreceptors – distortion of cell membrane Nociceptors – painful stimuli Somatic Visceral -Know what tactile receptors are – how they function, where they are located, the different types (encapsulated and unencapsulated). Tactile receptors – abundant mechanoreceptors of skin and mucus membrnaes Endings can be encapsulated or unencapsulated Unencapsulated – tactile disc, free nerve ending, root hair plexus Encapsulated – tactile corpuscle, end bulb, bulbous corpuscle, lamellated corpuscle -Know what was discussed in regards to referred pain and how it occurs. Referred pain – inaccurate localization -signals from viscera perceived as originating from skin, muscles -many somatic and visceral sensory neurons send signals via the same ascending tracts within spinal cord -somatosensory cortex unable to determine true source Phantom pain – sensation associated with removed body part -stimulation of sensory neuron pathway on remaining portion -cell body of sensory neuron still alive -pain sometimes quite severe Olfaction -Know the structures and cells involved with olfaction, know their functions. Olfaction Hairs – Cilia projecting from receptor cell dendrite - house chemoreceptors for a specific odorant Olfactory Nerves (CN I) – bundles of olfactory cell axons - project through skull’s cribriform plate and enter olfactory bulb Olfactory Bulbs (pair) – ends of olfactory tracts located under brain’s frontal lobe Olfactory Tracts (pair) – project directly to primary olfactory cortex (in temporal lobe), hypothalamus, amygdala, and other regions -Understand how the receptors are ‘set up’ for olfaction. Hair like structures on the end that hold receptors – where chemical binds  Where you breath in, binds to mucous, and then bind to olfactory receptors that are located on olfactory hairs We have at least 1000 types of olfactory receptor proteins that sit in the olfactory receptor cells -Understand the transfer of the odorant binding to sending the signal to the brain. Enters nasal cavity, binds to nasal receptor, signals to neuron that chemical is present, signal to the brain -Know the pathway of G protein activation and the roles of: -Odorant -Odorant receptor -Adenylate cyclase – when its active, it takes ATP present in the cell to Cyclic AMP -Na+/Ca2+ channel – when open calcium and sodium enter into the cell Odorant binds to odorant receptor, activates G-proteins, G-proteins activate Adenylate cyclase, Adenylate cyclase takes ATP present and changes it to cyclic AMP, cAMP opens Na+/Ca2+ channel, sodium and calcium enters the cells and causes membrane potential and influx, which causes the signal for an AP -Understand the sensitivity of the olfactory receptors One olfactory receptor cell only detects one smell Gustation -Know and understand the structure of a taste bud, the types of cells found within it, and their functions. Papillae – nipple-like structures on dorsal surface Taste Buds – onion shaped organs housing taste receptors Gustatory cells: receptor cells detect tastants (live 7 to 9 days) Supporting cells: sustain gustatory cells Basal cells: neural stem cells that replace gustatory cells -Know the 5 different tastes and the receptors that are used. Salty – Na+ through ion channel Sour – H+ through ion channel (and other effects) Sweet and Umami – chemical binds to membrane receptor Bitter – chemical binds to membrane receptor -Know the steps from chemical binding to action potential initiation. 1. Binds to receptor 2. signal for change in cell 3. releases neuron to signal for ap Vision -Be able to describe how light waves are transferred and sent to our eyes. -The cornea allows light waves to go in. -The lens allows specific amounts of light to come through. The suspensory ligaments pull to adjust the size - The light then hits the retina – where there are the visual details -Know the pathway of light as it goes through the eye. - Hits Cornea - Passes through anterior chamber - Passes through pupil - Passes through posterior chamber - Hits lens - Through posterior cavity - Hit retinal wall -Understand and be able to describe the function of the lacrimal system. Lacrimal System – producing tears Tear – liquid fluid Function: Hydrate the eye and catch things that we don’t want in the eye -Know the function of aqueous humor, it production and resorption. Aqueous humor – water-like substance - help with maintenance/shape of the eye - cleans the lens  Made my ciliary prosses. Moves through the posterior chamber. It fills up and runs over the lens into the anterior chamber. Cleans iris and cornea - have to recycle the fluid through the scleral venous sinus -Know the muscles involved with pupil regulation. Sphincter Pupillae – contracts, bright light Dilator Pupillae – contracts, low light -Know how the pupil diameter is regulated. Adjust if there is too much light and not enough light Too much light: constricted pupil, narrow opening Not enough light: dilate pupil, wide opening -Know what occurs to the eye in regards to nearsighted and farsighted. Be able to correlate the terms myopic and hyperopic. Nearsighted – can see up close but not far, the shape of the eye is more flattened horizontally. The light wave ends early. The focal plane hits before it gets to the retina. Farsighted – can see far away but not up close. More smooshed vertically. The light waves go past the retina. **Focal plane doesn’t line with retinal wall Perfect Vision – hits the retinal wall at the perfect spot Myopic – nearsighted Hyperopic – farsighted LASIK – adjust the shape of the lens, to change how the light waves will reflect off and hit the retinal wall Take the cornea off, like can opener, use laser to adjust the shape of the lens -Be able to describe layers and layout of the retina. Retina – visual process Cell types: - photoreceptor cells - bipolar cells - ganglion cells – neurons that the axons travel to form the optic nerve and send to the brain * Light comes and past these cells to come back to be processed -What occurs at the fovea? How about the optic disk? What is found in these regions? Fovea Centralis – what you are looking directly at – best vision - Shorter wall because of only having cones (shorter) Optic discs- the point where the optic nerve enters/exits the eye - sensory neurons go through the optic nerve and to the occipital cortex -What are the two types of photoreceptors? How are they similar and different? rods – more numerous, responsible for light (on/off), respond better to dim light more rods in front than back cones – less numerous, responsible for detecting color, higher light waves, light-activated primarily found at the back of the eye @ the fovea centralis, shorter -What photopigment is present in rods? How are they different in the cones? Rods contains rhodopsin – a protein made up of opsin & retinal Different proteins -How does light activate a photopigment? -The retinal molecule starts as a cis-form when dark To the trans-form when the light turns on ** Like a light switch Rhodopsin sits in membrane. Retinal molecule – cis/trans form Enzyme – phosphodiesterase changes cGMP and GMP Transducin Off form: rhodopsin has retinal in cis form, transducin/phosphodiesterase is sitting inactive Active Form: light waves come in and hit retinal molecule to the trans-form Activate transducing, then active phosphodiesterase causes cGMP to GMP, GMP opens a sodium channel, sodium enters photoreceptor cell, and sodium influx causes a neurotransmitter. Photoreceptor cells activated and cause chain to bipolar cell, ganglion cells, axon of ganglion cells exit through optic nerve, some cross at optic chiasm and get carried to the back of the brain to the visual cortex of the brain. Many cells causes for changes and adaptations. Audition (Hearing) -Have a basic understanding of how sound waves travel in regards to air molecules. Auditory (hearing) – transduction of sound waves into action potentials Frequency (Hz) – number of waves/second Loudness (intensity) – differences in the amplitude Disrupting the air molecules around us, and those waves can travel to those around us -Know the structure of the ear and how sound waves travel through the ear. How sound travels: External Ear, External acoustic meatus. To the Middle Ear – Oval Window -Know what, and where the pharyngotympanic tube is located (Eustachian). Describe what the normal function of it is and compare the differences of an adult and child. Auditory Tube/Pharyngotympanic (Eustachian) – runs from pharynx (throat) to tympanic membrane Function: Equalize pressure across the tympanic membrane, from outside and the inside *Closed when mouth is closed, open when mouth is open Ex: airplane – changes in air pressure from external ear to internal ear. Adults – The tube runs down to the pharynx at a slant If there was something that got into the tube it would be washed out Child – Tube runs at a horizontal plane If there is something that is covered with bacteria or a virus, it can get into the tube, get stuck and get an ear infection -What happens when children (or adults) have tubes placed in their ears? If there is a build up a tube is placed to help with drainage. Allow for drainage of fluid that would build up in the tube. Ear tube placed in the membrane. Fluid exits out of the ear Over time the shape of the tympanic membrane changes and the tube will fall out. -Know how sound waves send a signal to the brain. Hit tympanic membrane – vibrates like drum, causes ossicles to vibrate and amplifies (malleus/incus/stapes), stapes hit oval window, fluid starts moving within the cochlea, waves of fluid signal to the brain. -Know the mechanics of the cochlear duct and basilar membrane bending, hair cell bending, etc. Cochlear duct – filled with endolymph, this is where things are going to happen. Fluid movement occurring Basilar membrane – sits under hair cells, flexible, pushes and causes hair cells to bend 1 inner hair cell, 3 outer hair cells – doing the transduction – sitting within membrane Hair – cilia sits within the tectorial membrane -Know why K+ ions go into hair cells when the stereocilia bend? Hair cells are mechanoreceptors When the hair cells bend, they open, when they open it cause K+ to flood Potassium causes depolarization and the release of a neurotransmitter to signal to start an AP -Know the properties of endolymph. Fluid, very high in levels of K+ -How do hair cells use frequency coding? Thickness of the membrane -What is the function of the semicircular canals? Semicircular Canals – detect angular -What is the function of the utricle and saccule? Utricle & Saccule – head movement – up down back forth -What type of information does the brain receive from these receptors? -Know how information/stimulus is detected in the semicircular canals, utricle and saccule and how it is interpreted by the brain. Utricle & Saccule – otolithic membrane, hair cells are sitting within a jello. Otoliths – ear stones, protein, can break free/come loose and travel to other locations. If they get stuck in semicircular canals can signal to the brain and cause a false singal. = vertigo Depending on head movement, the jello mixture causes movement and pulling on hair cells Ex: elevator, driving a car Semicircular Canals – as you move your head it pushes in internal structures and pushing on hair cells that signal to the brain. The moving of the head causes the fluid to move. The moving causes bending of the cupula -Why does the world spin when you have had too much to drink? Sea sickness – when your ears tell your brain you are moving but your eyes don’t see you moving. Endocrine -Know what an endocrine gland is and its general function Endocrine System – communication means used in the body. Secrete hormones into the circulatory system. -Know what a hormone is and its general function. Hormones – chemicals that signal changes in cells that have the receptor for that hormone. -Know what types of changes can occur from endocrine signaling - Change protein activity - Change gene expression (protein synthesis) -Know the major endocrine glands. - Parathyroid Glands -Adrenal Glands -Adrenal Cortex -Adrenal Medulla -Pituitary Gland -Pineal Gland -Thyroid Gland -Know the different classes of hormones discussed Peptides: - most hormone - Ex: insulin, glucagon Amino Acid Derivatives - epinephrine, norepinephrine Steroid Hormones -from cholesterol - Ex: Aldosterone, testosterone, estrogen -Know how blood glucose levels are maintained o Know the hormones involved. o Insulin – increase blood/glucose /Glucagon – decrease blood glucose (take out of storage and put in blood) o Know the glands and tissues/cells involved. o Know the signaling pathways involved. o Steps: o Glucose moves into the cell via facilated diffusion o Cellular metabolism of glucose to ATP o ATP binds to K+ channels o Know what the Islet of Langerhans is, what cell types are here and what these cells produce.  o Know the function and where you find GLUT2 and GLUT4. o Insulin binds to insulin receptors only, and singals to adipose cell to put more glucose transporters on their surface -Know the two types of diabetes mellitus and how they develop, how they are different and what is affected in the two different types. Type 1: Insulin is not produced 5-10% of cases Autoimmune disorder – immune system kills beta cells Type 2: Insulin is produced but not regulated -Know how Ca2+ is regulated in the blood. o Know the three ways we regulate Ca2+ levels o Know the hormones involved in Ca2+ regulation and what they signal, and how they alter Ca2+ levels. o Know how calcitonin and PTH are regulated and their roles in Ca2+ blood levels. o Causes calcium to come out of storage and go into the blood o Know what osteoclast and osteoblast cells are and their function. -Know how Vitamin D is made and its importance in Ca2+ levels. - Vitamin D is derived from cholesterol – steroid hormone - produced in our skin – UVB rays - absorbed from our digestive system – fish, added to milk - We can’t absorb Ca2+ without Vitamin D - Vitamin D increases Ca2+ levels in blood – increases absorption from the digestive tract -Know what Rickets is and how it develops. - Bone disease due to lack of Vitamin D – not enough Ca2+ absorbed from digestive tract -Know what osteoporosis is and how it develops and what is often used to treat it. - Decreased bone density – associated with age - Bone mass peaks at age 20-30, and declines after - Women are most susceptible due to menopause – estrogen decreases osteoclast numbers Best way to prevent: Make sure you are getting lots of Ca2+ in your diet NOW -Be able to describe what a tropic hormone is. Tropic Hormone – hormone that causes the release of another hormone -Know the ‘layout’ of the pituitary gland. Anterior – hormones are produced in the hypothalamus and travel to the anterior pituitary to tell them to produce and release a hormone Posterior – hypothalamus produces the hormone and just gets carried and released from the posterior -Know the similarities and differences of the anterior and posterior pituitary. Posterior – hormones released into the blood system Anterior – hormones released stimulate the release of OTHER hormones -Know what hormones are secreted by the posterior pituitary and the role of these hormones. Hormones secreted by posterior (directly into the blood) 1. ADH – water reabsorption in the kidney 2. Oxytocin – smooth muscle contractions in reproductive tissue a. Lactation, uterine contractions, sperm transport -Know the hypothalamic and anterior pituitary hormones, their target gland and their functions. -Know the importance and the function of growth hormone. Important for growth, especially bone and muscle growth - stimulates the liver to produce signaling molecules (IGF) – increases growth of bone, muscle, and organs (heart, lungs, etc.) -Know the signaling pathway of thyroid hormone. -Know the importance and function of thyroid hormone. Thyroid hormone – regulates metabolism in the body - Every cell in the body contains thyroid hormone receptors -Know the importance of iodine for thyroid function. Iodine for thyroid function: - Iodine is necessary for thyroid hormone production -Know what a goiter is and how it often develops. Goiter – enlarged thyroid gland, usually due to iodine deficiency -Know the disorders and associated effects of the various thyroid hormone disorders. Too much TH: -hyperthyroidism -high levels of TH, low levels of TSH -Graves Disease: autoimmune disease Too little TH: -hypothyroidism -low levels of TH, high levels of TSH -Hashimoto’s Disease: autoimmune disease - Childhood: leads to severed mental retardation, decreased growth, deafness Table - Hormone - Receptors Process - Light wave in eye - Steps of olfaction - Gustation – know diff between sodium and hydrogen (salty/sour) - Insulin – steps how they go up - glucagon f LAB: Parathyroid Adrenal Cortex – Adrenal Medulla – produces epinephrine to help with/ fight or flight Pituitary gland – growth, metabolism. It has to do with homeostasis. Produce ASTH, growth hormone Pineal gland – release melatonin Thyroid gland – helps with growth, metabolism, energy levels, releases T3 and T4 Posterior – vasopressin oxytocin Anterior pituitary - LH FSH ACTH