Biology Notes PDF

Anatomical terms In physiology, standard terms are used when referring to anatomical parts of humans. anatomical They always refer to a body that is in the upright, standing position = _...

Anatomical terms In physiology, standard terms are used when referring to anatomical parts of humans. anatomical They always refer to a body that is in the upright, standing position = ______________________ position Front of body Ventral or anterior refers to the ___________________ backofbody Dorsal or posterior means toward the _________________ near Superior means toward the _______________________ Feet Inferior means toward the _______________________ Some are relative to other body parts. mearal is closer to the midline of the body. Something that is ___________ lateralaway from the midline. _________, When referring to an appendage like an arm or a leg: Proximal _________________ means closer to the trunk of the body. distGr __________________means away from the trunk. Organ Systems Organ systems work together in the body. Some organs are involved in the function of more than one organ system. For example, the pancreas plays a role in the endocrine and digestive systems. Other structures and glands also contribute to the operation of organ systems.  ans org Body Membranes or cavities Body membranes line ____________ internal spaces and the ______________________and tube) ____________ that open to the outside. Four types: mucous 1. ______________________________ 2. ______________________________ serous synovial membrane 3. ______________________________ 4. ______________________________ cutaneous 1. Mucous membranes Line passageways that ______________________ open to thexteriorbody Line the tubes of the __________, digestive _____________, respiratory _______________, Urinary and _______________ reproductive systems. Composed of ________________ epithelium loose Fibrous connective tissue overlying___________________________________________ Contains __________________that goblet cells secrete mucus. 2. Serous membranes closed cavities Line__________________(not open to the environment) and cover the surface of organs ______________________________contained within. Pleurat ____________ line the thoracic cavity and cover the lungs. pericardium ____________ forms the pericardial sac and covers the heart. double layer ofperitoneum ___________, called _________, mesentery lines the abdominal cavity and covers its organs. 3. Synovial membranes loose connective tissue Composed only of ___________________________ freely moveable joints Line _______________________________________ Secrete ______________________for Synovial Fluid lubrication. 4. Cutaneous membrane Skin ______________, covers the outside of the body 4.7 Integumentary System Functions: Protects underlying tissues from Trauma ______________________________________ ______________________________________ Pathogen invasion ______________________________________ Water loss body temperature Helps regulate ________________________________________ sensory receptors Contains ________________________, touch such as _________________ temperature and _______________________ receptors. Stimuli Receives _______________________________ = Makes us aware of our surroundings. Vitamin D Synthesizes ________________________________________  Organs of Integumentary System: Skin ___________________________ Derivatives of the skin  hair __________________________  nails __________________________  sure at glands __________________________  oil glands __________________________  way glands __________________________ all 4tissue types Contains ____________________________________________________________. epidermis Skin has two main regions: the _______________________ dermis and the _____________________ subcutaneous Under the skin there is a ____________________________ hypodermis (__________________). Anatomy of Human Skin The Epidermis stratified squamous Keratinized epithelium Made of: ______________________________________________. dead cells Thin, outermost layer of the skin – ____________________ stem cells that produce new epidermal cells are in the deepest layer. ____________ rapidly dividing _____________________________ dermis No blood vessels – nourishment from ___________ Cells of the epidermis melanocytes ________________________________—produce melanin _________________________ Two forms  pheomelanin Yellow-to-red = ______________________________  eumelanin Black-to-brown = ____________________________ epidermis at the base of the ________________________________ Skin color Produces ______________________ DNa and protects from ______________ from UV light. People have the same number of melanocytes but the amount of melanin produced varies. carotene Other contributors to skin color: _______________________ hemoglobin and _____________________. ia min Epidermal cells produce v____________________________ D when exposed to UV rays. Vitamin D is important in the regulation of ___________ _____________ phosphorus levels calcium and _________________ in the body. The Dermis Thick, inner layer of the skin. Made of: dense irregular connective tissue ______________________________________________________ collagen Contains _____________________ elastic Fibers and ______________________ for strength and elasticity. blood vessels Contains ____________________________, sensory receptors ___________________________, glands and __________.  Sensory receptors are specialized for pressure 1. ______________________________ touch 2. _____________________________  Pain 3. _____________________________ not 4. _____________________________ cold 5. ____________________________ The Subcutaneous Layer Technically not part of the skin. Composed of: _______________________________ adipose areolar loose connective and ______________________ tissues just below the epidermis and dermis Functions: protection ___________________________________ temperature regulation __________________________________ stores energy Fat storage = __________________________, insulate ___________________ Accessory Organs of the Skin Accessory organs of the skin: nai is 1. ___________________________ 2. ___________________________ wain glands 3. ___________________________ 1. Nails Phalanges Nails offer a protective covering of the __________________ (fingers and toes). Nails grow from the _______________________ nail root to cover the nail bed _____________________. cuticle The ___________________________ covers the nail root. _______________________—white Lunula half-moon shape at the base. 2. Hair  hair follicles ___________________________—epidermal structures that surround the hair itself. Hair Follicle  hair Shaft ______________________—the portion of hair protruding from the skin.  Melanin The color of hair comes from ______________; as melanocytes _________________________ age, they produce less pigment and hair turns gray. Arrector  arrector pilimuscles ___________________________________—attached to the hair Pili Muscle follicle.  Can contract, which creates goosebumps “_______________________________.”  3. Glands oil glands (_____________________)  ___________________ sebaceous sebum produce _______________, which softens the hair and skin. It also retards bacterial growth. Acne ______________________—inflammation of the sebaceous glands. sweat glands  ________________________________ sudoriferous (___________________________________). dermis In the _____________________; their ducts open onto the Skin surface __________________________. body temperature Help to regulate __________________________________. Thin Skin 4.8 Homeostasis  a relatively constant internal environment _________________________________________________________________________________.   There are various conditions in the body that are maintained within a relatively narrow range of normal values. For example: blood glucose ____________________________ ____________________________ PH body temperatura ___________________________ ____________________________ Sodium ion concentration If conditions vary too much, _________________________________. ↑ Il ness results The Internal Environment The internal environment has two parts: blood and interstitial fluid. blood 1. __________________ Or = delivers _________________ nutrients to the and __________________ Tissues CO2 _________________________________ and carries away __________________________ and ___________________. waste interstitial fluid 2. ______________________________ body cesss = surrounds_____________________; substances are exchanged through it. Body systems work together to keep these substances within the range of normalcy. The Body Systems and Homeostasis nervous The ________________________ endocrine and __________________________ systems coordinate the other organ systems. nervous System The ____________________________ faster is ________________________, but the effects of the endocrine __________________________________ last longer system ______________________________. endocrine The ______________________________ hormones secretes ____________________________— chemical messengers that travel in __________________. ____________________________________________ blood Homeostasis by the Organ Systems of the Human Body There are 2 Feedback Mechanisms Positive 1. ___________________________________________ feedback Negative 2. ___________________________________________ feedback 1. Negative feedback mechanisms The primary mechanism used in the body.  Homeostatic mechanisms have three components: receptor _________________________ that detects a change in the internal or external environment control Center _________________________ (such as the brain __________________________) that integrates the information coming from all receptors and selects an appropriate response effector ________________________ (such as a muscle __________________ gland or ______________) that carries out the response 2. Positive Feedback the same direction as origina Stimulus Brings about a change in _____________________________________________________________________ For example, childbirth: the fetus’s head pushes against the cervix, which stimulates signals that are sent to the brain. oxytocin The brain then secretes the hormone ______________, which causes stronger contractions. momoxy toin to be released. This causes ________________________ birth _______________________ stops the positive feedback. o Feuer Can be harmful in some situations (for example, ________________________). Chapter 14 Nervous System – Neurons 14.1 Overview of the Nervous System Overall Function—receives and processes sensory information from both external and the internal environments to coordinate the body’s activities Has two major divisions: Central nervous system consists of the brain and ______________________________ spinal cord. peripheral nervous system ______________________________ consists of nerves _____________________, which lie outside the CNS. The nervous system has three functions: sensory Stimois by sensory receptors respond to _____________ __________________—________________ chs pus to the _________. generating nerve signals that travel via the ______ integration crs sums up the input it receives from all _________________________—the __________ memories over the body, stores ____________, and Motor responses. creates ____________ motor ________________________—generates motor output, which travels from the ________ cns ________ prs via the ________ to muscles, glands, and organs. Cells of the Nervous System Two major cell types neurons 1. ______________________ (nerve cells) Three categories: – ____________ sensory chs receptor _______ sensory (afferent) neurons: __________________ Chs – ____________ (efferent) neurons: _________ motor effector ________________ – ____________ inter neurons sensory and (association) neurons: between _____________ MoxO _______________________________ neurological 2. __________________________________(glial cells) Outnumber neurons 10 to 1 Several types, each with a specific function Neuroglia in the CNS: _________________________, microglia astrocytes ______________________ oligodendrocytes , _____________________________________. Neuroglia in the PNS: _________________________ Schwann Cells What does each type of neuroglial cell do? In the CNS: bacteria and ___________. Microglia—phagocytic cells that remove _______________ debris Metabolic Astrocytes—provide ______________ and ________________ structural support directly to the neurons. myelinsheaths Cns Oligodendrocytes—form ______________________in ____________ In the PNS: Schwann Cells _______________________________—form myelin sheaths in PNS. ______________________ Types of Neurons Three types of neurons, based on function: sensory 1. _______________________________________ neurons Sensory receptor to the —carries nerve signals from a ____________________ __________________________. environment detect changes Sensory receptors— ____________________ in the environment _____________________________________ interneurons 2. _______________________________________ in CNS - found only ________________________________ Receive input from sensory neurons ______________________and other interneurons. neurons Sum up signals received from other _________________, then communicate motor neurons with ___________________________. motor neurons 3. _______________________________________ neurons a. carries nerve impulses ____________ CNS from the _______ to an ______________________________ effector away muscle fixer a. _______________________________  orgaand b. _______________________________ c. ________________________________  which carries out the response to the environmental change. Structure of Neurons  The shape of a typical neuron is specialized for communicating with other cells  All neurons have 3 parts: dendrites 1. ___________________________ = many short, branching projections, receive signals from sensory receptors or other neurons. axon 2. _________________ = a single long extension cell body 3. __________________= enlarged central region, contains the nucleus, other organelles The Structure of Sensory Neurons, Interneurons, and Motor Neurons  Myelin sheath a Xons Covers some ____________________. In the PNS: Formed by Schwann cellwhich _______________________ contain the lipid substance myelin _________________________ in their plasia membranes ________________________________. They wrap around an _______ 100 times. &Xonas many as _______ Several hundred or more cells may be required because a single axon can be several feet long. Each cell myelinates only part of an axon, leaving gaps. node of ranvier ___________________________—space (gaps) between myelin sheaths. long _____________________ axons usually have a myelin sheath, shortaxons usually don’t. __________  ____________________of gray nomyelinated graymatter the CNS is __________ because it contains _______________axons white because it contains ____________________ white mattco _____________ _____________________is myelinated axons  nerve regeneration within the __________. The myelin sheath is important in _______________________________ pus If an axon is severed, the myelin sheath remains and serves as a passageway for new fiber growth. Provides electrical insulation that increases the rate of conduction of a nerve impulse Helps repair the axon  nodes of ranvier ________________________________= Schwann cells Gaps between adjacent _________________________  Saltatory conduction _________________________= messages travel faster as they jump from one node of Ranvier to the next    nodes of Oligodendrocytesform the myelin sheath In the CNS, _______________ _____________________= ranvier myelin sheath Saltatory conduction _________________________= Gaps between adjacent messages travel I faster as they jump from one node of Ranvier to the next 3. What is the name of the structure at the red arrow? 4. Which is the sending portion of the neuron?   nerves ______________________ Consist of parallel __________, axons dendrites __________________, or both _________________________ from many neurons Covered with ___________________________________ touch connective tissue  Categories:  ______________________ sensory  ______________________ motor  _______________ mixed (sensory and motor together) depending on the type of neurons they contain Structure of Neurons: Disease  Multiple sclerosis (MS) myelin A disease in which the _______ sheaths ________________in the Spinal cord ____________________ and ____________ brain are progressively destroyed Results from the destruction of the myelin sheath that surrounds avons in the crys ___________________________________ scieroses The resulting scars, _____________________, interfere with the nerve imprises transmission of ______________________________  Can result in - Paralysis - loss of sensation, including loss of vision The Physiology of a Neuron Nerve impulse ________________________—______________ electrochemical changes that convey information within the nervous system. Watch the video on the PowerPoint at this point.  Resting potential potential energy The _________________ of a neuron at rest. polarized Exists because the plasma membrane is _______________: positive there is a more ________________ charge outside the cell, negatives more ______________ charge inside. It is measured in milivolts ________ (mV). Neurons must maintain their resting potential to be able to send nerve impulses. To do this, they have a protein carrier called Nak ____________ Pump ______________that pumps Na + _____________ out in and K+ ____________ the neuron. sell membrane These are special proteins in the ________________ that actively ____________________ transport sodium and potassium ions across the membrane against their ______________________ concentration esradient These pumps use cellular energy to eject sodium ions from Within __________________ the cell and to bring potassium ions in +0 ____________________ the cell  Action potential nerve impulsesalso called action potentials. _____________are Occur in ___________________ axons A ______________________________ Stimulus is a change that activates the neuron. For example: a stimulus for pain neurons in the skin would be the prick of a sharp pin. threshold ______________________________—the minimum voltage that must be reached in order for an action potential to occur. Equal to ______________mV. 55- nerve A ________________, action Potentialis an electrochemical signal involving sodium and impulse or _______________, ion Channels potassium ions (Na and K+) that cross the cell membrane through ________________________ + Each ion channel is designed to allow only certain ions to pass through it Permanently open orregulated Ion channels may be ________________________ by a gave ______________________which is a protein that changes shape and opens or closes a channel. The transport does __________________ n of require energy as the ions follow a gradient of concentration.  all or nothing Action potentials are ___________________________________________ Once threshold is reached, the action potential happens completely; it doesn’t vary in size. does not Increasing the strength of a stimulus _______________change the size of an action potential. Instead, to convey a stronger signal________________________ it causes More action potentials to eur _____________________________________________________ 1. Generation of an Action Potential: Na+ Gated Channels Open = Depolarization gates open and When an action potential begins, _________________ Nat rushes ______________ the cell. ions Adding positively charged ____________ causes the inside of less negative compared to the axon to become ________________________ the outside. The charge (polarity) inside the axon changes from Negative positive ________________________ to _____________________ Inside the axon Outside the axon Inside the axon Outside the axon  2. K+ Gated Channels open depolarization Called _________________________________ Nat Immediately after depolarization, _______________ close and + _____________________channels open. outside K+ flows ____________________the cell. Inside the axon negative The inside of the cell becomes _______________again. Outside the axon refractory  _______________________period of time immediately after an action potential during which the axon is unable to conduct another action potential __________________________________________________________________________ one way direction This ensures the ________________________of the signal from the cerlbody length of the a yon ____________down the ____________________. We have a problem: The potential difference is correct, but there is a greater sodium ion concentration INSIDE the axon and a greater potassium ion concentration OUTSIDE the axon This is opposite of what is required to generate an action potential How do the ions make it to the “correct” side of the axon plasma membrane? na K Pump The ________________________________ completes the action potential. K _________________-- are returned to the inside of the cell Na _________________ - are returned to the outside of the cell  Resting potential is restored!  adjacent parts In unmyelinated axons, action potentials stimulate _______________________of the axon membrane to produce an action potential. Slow (1M/S) Conduction can be _______________________because each section of the axon must be stimulated. myelinated Fibers In _____________________, nodes of ranvier action potentials only occur at ______________________________ Saltatory Conduction This is called ____________________________and much faster (100m/s) is _____________________________________. Regardless of myelination, action potentials are _____________________________ Self propagating each action potential generates another along the entire length of the axon. 6. Which is the correct order of events when a neuron is stimulated? A. potassium gates open  potassium ions rush out of the cell  sodium gates open sodium ions enter the cell B. sodium gates open sodium ions enter the cell potassium gates open  potassium ions rush out of the cell C. potassium gates open  potassium ions rush into the cell  sodium gates open sodium ions rush out of the cell D. sodium gates open sodium ions rush out of the cell  potassium gates open  potassium ions rush into the cell  Chapter 14. Central and Peripheral Nervous System I. Organization of the Nervous System Skeletal Eyes Muscle - Skinne · 2 "Iheart  Two major divisions of the nervous system Central nervous system (CNS)  Consists of the ___________ brain Spinal cord and _________________ Peripheral nervous system (PNS) ___________________ sensory  __________________ Somatic sensory  _________________ sensory visceral __________________ Motor  _____________________ Somatic motor  _____________________ motor visceral  Stress  Visceral Motor ~ Autonomic nervous system: regulates involuntary activities sympathetic  ____________________ nervous system: in charge during emergency ___________________________________ “Fight or Flight” Parasympathetic  __________________________ nervous system: adjusts bodily functions during -Peaceful Restructives _________________ “Rest and Digest” II. The Central Nervous System A. Protection of the CNS 1. Bones of the skull and vertebral column 2. Meninges - cover brain spinal Three connective tissue membranes that form the Corel meninges _____________________  duramet er ___________________—outermost layer  aracunoia ___________________—middle layer  pin mater ___________________—innermost layer I 3. Cerebrospinal Fluid meninges Fills space between _________________, ventricles ________________________, and the central canal Central Canal of Spinal cord of the ____________________ Functions Shock absorption  _________________  __________________ Support  nourishment __________________  Waste removal __________________ ↳y goes to blood  ChS Meningitis (inflammation of the meninges - Caused by bacteria and viruses; can lead to encephalitis (inflammation of the brain ( Alzheimers = Lack of waste disposal normally, hydrocephalus occurs when Cerebrospinal fluid does not drain into the Cu System When meningitis is suspected, a lumbar puncture fendi to follow  4. Blood Brain Barrier - Structure:  Formed by Eight junctions ___________________between cells in the walls of capillaries ________________ supplying the ___________________________ CNS - Functions:  Protects the CNS by selectingthe substances ___________________________ that can enter the cerebrospinal find the ______________ ________________from blood  Negative effect  Can inhibit many potentially life-saving, infection-fighting, or tumor- suppressing drugs from reaching brain tissue if they are not lipid soluble B. Brain  Cerebrum 1. ________________________ thalamus 2. _______________________ hypothalamus 3. _______________________ 4. Cerebellum _______________________ brain Stem 5. _______________________. 1. Cerebrum thinking The _______________, Conscious _______________________ part of the brain Largest The _________________of the brain. Accounts for ______________ of total brain weight 83 % two hemispheres Divided into ________________by Longitudinal Fissure the ________________________  Each hemisphere receives sensory information from directs movements of > HM -  the __________________ OPPOS it t side of the body  Gyri (sing., gyrus)—thick folds separated by shallow grooves called sulci (sing., sulcus). ↳ Suki = Sink - Each hemisphere has: - a thin outer layer called Cerebral Cortex ________________________________ Outer layer of _______________________ gray matter ________ grey neuroglial matter contains ________________ neuron cell bodies cells, ________________and Short _______, non myelinated ___________ axons _______________. Function: Responsible for sensation, voluntary movement, thought processes, and consciousness. White matter - _________________________layer beneath white matter contains ___________________ ________ myelinated axons - Corbus callosum ____________________________- band of white matter between the two cerebral hemispheres   Cerebrum - Functions: sensory integration The last center to receive ____________ input and carry out __________________ before commanding voluntary motor responses _______________________________________ Other part of brain Communicates with and coordinates the activities of ____________________________ each cerebral hemisphere is divided into lobes: _______________ lobe—the most anterior. _______________ lobe—posterior to the _______ lobe. _______________ lobe—posterior to the _________ lobe. _______________ lobe—inferior to the __________ and _________________ lobes. - What goes on within the cerebral cortex each of the lobes? 3 There are three kinds of functional areas: Cerebral cortex convoluted structure thin , highly Outer layer of Cerebral hemisphere Y matter grey func Sensation, Voluntarymonement thou process& consciousness A. Sensory areas  Various sensory receptors send information to the ___________ where each sense is processed in a different region:  Skin senses - ________ Parietal Parietal  Taste - ______________ Frontal/temporal  Olfaction – ___________  Hearing - _____________ Temporal  Vision - ___________ occipital  Vestibular cortex – _____________________and __________ _____________________________________ Visceral Sensory area – receives info from the _____________ Primary somatosensory area—just behind the centralsulcus parietal lobe. _______________in the ___________ Skin Sensory information from the ___________ Skeletal and ________ Muscles ________________________arrives here. acute Large areas are dedicated to those body areas with ______ & Einsation _______________________________________ The __________ Fall hands and ____________ occupy the largest portion. B. Motor Areas primary motor area ______________________—in central sulcus the frontal lobe just before the ___________________________ , _______________ Voluntary sheletal _________________ signals to _______ muscles begin here. Muscles that control ____________ Facial movement __________ (swallowing, salivation, expression) take up an especially large portion. Lack of oxygen during birth can damage motor areas, Cerebral palsy resulting in __________________________—weakness of the arms and legs. Premotor area— instrument, typing sports , primary motor anterior to the _______________________area. Musemory In front of the primary motor area Learned motor skillsthat are patterned or repetitive coordinates ________________________________________ C. Association areas Sensory area, ___________ Communicate with the ____________ motor areas, and other parts of the brain to ____________ analyzz a ston sensory in put and ______________________________ Assignsmeaning o _____________________to sensory information prefrontal Cortek _____________________________________ o enables us to reason, think, plan for the long term, think about abstract thoughts personality Summary of the Sensory, Association, and Motor Areas of the Cerebral Cortex Diencephalon Includes the thalamus 2. ____________________________________ hypothalamus 3. ___________________________________ third Ventricle Encircles the _______________________________ thalamus 2. ________________—two masses of gray matter. no sensory input makes , cortexur/o “Gateway to the _________ Cerebra itto Cerebral * a stop here cortex ____________________” = Receives all sensory X input except the _______________________ Sense of Smell Sends it on to the appropriate areas of the cerebrum _________________ Also directs _______________, motor activity ______________________, cortical arousal - and derttalase _________________________ of surroundings memory Sensory in put d thalamus ↓ ·cht Cerebrum Except for smell temporal ↓ goes to the Olfactory lobe hypothalamus 3. ___________________ Maintains homeostasis by regulating blood pressure  __________________  __________________ heart rate  _________________ breathing rate  ____________________ digestion-hunger/ __________________________________ fullness  __________________ body temperature  __________________ Water b almee - norvous Coordinates the __________________ endocrin and ______________systems by influencing the _____________ Pituitary gland Limbic - Regulates emotions as part of the _____________________________ system 4. Cerebellum motor cortex Integrates information from the ____________________and sensory pathways _______________________   voluntary movement produce smooth, well-timed ________________________ ______________—compares comparison actual position of a body part to where it ought to be ______________—calculates prediction future positions of a body part during a movement eye movements Coordinates __________________________with body movements _____________________ balance equilibrium ________________, Controls _____________, posture and ____________________ 5. The brain stem includes: midbrain A. __________________ , cerebrum Relay station between the _______________ and the Spinal cord _______________or _____________. Cerebellum Processes information about ______________ Sights and sounds _______________________ !  Controls simple reflex responses to these stimuli, -Clap Such as turning your head toward loud sound _____________________________________________ a B. Pons __________________ Means “bridge” Spinal cord __________ Connects the ______________and cemberum cerebrum with the ________________, thalamus and ______________________________ ____________, hypothalamus With the medulla oblongata, regulates _______________________________. breathing rate Reflex centers coordinate _________________in response to _____________ and ____________ stimuli. medulla oblongata C. __________________ Serves as the pathway for I S All ______________________messages sensory going to the higher brain centers All ________________ motor messages leaving the brain Contains ____________________for reflex centers regulating ___________________ heartbeat –force and rate ________________ breathing – rate (how fast) and how deep __________________________ Vaso constriction (blood pressure) – adjust blood vessel diameter Contains reflex centers for: vomiting [ __________________________ get rid of __________________________ things potentially Coughing __________________________ sneezing harmful hiccuping ___________________________ ___________________________ swallowing umocociliary escalator regulates intensity of the immune responsedinflammation #VAGUS * NERVE Medulla Oblongata   Limbic system anatomy Function rather than ___________________ Defined on the basis of ____________ produce ________________ emotions and _________________ memory Integrates emotions with higher mental functions (reasoning, memory). several brain structures with it includes: ________________—creates anmygdala the sensation of fear. ________________________—plays hippocampus a crucial role in learning and memory. The Regions of the Brain Associated With the Limbic System e olfactory tract Higher Mental Functions memory _____________—ability to recall events from the past. learning _______________—retain and use past memories. Types of memory: short term memory—holds a small amount of information for a few seconds __________________ or minutes; stored in the prefrontal area. Longterm ____________ memory—stores limitless amounts of information for hours, days, or years; memorized facts. ___________ Semantic memory—memorized numbers, words. ____________ episodic memory—memorized persons, events. Skill ____________ memory—performing motor activities  Reticular activating system (RAS) executive assistant - An extensive network of neurons that runs medulla through the ____________ and projects to the Cerebral Cortex Hypothalamus thalamus _______________ , ,  Bypasses the ___________________________ Filters ______________________ Sensory input keeps the __________________________ Cerebral Cortex in an alert and attentive state Stimulates _______________________ muscle tone Aids ___________________________________ posture Helps keep balance When one foot is raised _______________________________________  habituation ________________________________ = brain learns to ignore repetitive, inconsequential stimuli Yet remain sensitive to others unnecessary Stimuli Can filter out _____________________________ For example: you can study with the TV on or fall asleep living next controls pain to a busy airport en dorphins topiatest ___________________________________suppress general anesthetics it. natural Severe injury can cause a________________________ Trauma , stroke , or intoxication morphine ↓ acthere Can Coma to midbrain cause C. Spinal Cord Structure neural tissue  Tube of _________ with a ___________ central canal inside  Protected by ________________of stacked Vertebrae the __________ vertebral ________________ column  ____________ White matter matter toward surface; _________ greymatter matter in center Functions  Drain Conducts messages between the ____________ and body ____________________________  Serves as a __________________________ reflex Center  Locomotion- walking: movement of limbs initiated by _________________ Cerebrum Spinal cord ____________________takes over the movement from there The center for thousands of reflex arcs = ____________________________________ automatic response to stimuli in circuit a Drewired Parts of the circuit:  _________________________ receptor  _________________________ Sensory neuron  _________________________ internewon (at least one)  motor _________________________ neuron  __________________________ expector  Spinal reflexes are decisions made by the spinal cord when _______________________ a speedy reaction safer is A Spinal Reflex Arc  The spinal cord also creates reflex arcs for internal organs. when blood pressure For example: _______________________________________________ fall III. The Peripheral Nervous System  Includes Spinal nerves _______________that originate from the spinal cord _______________that cranidinerves originate from the brain  Spinal nerves: All carry both _____________ Sensory Motor and _________fibers  Cranial nerves ________ 12 pairs · roman numeral Referred to by ________________and ___________ names Head Service the structures of the __________ and certain body parts ______________, including the _______ heart (X) and ____________________________ muscles of nelk Some carry only sensory fibers, others carry only motor fibers, and still others carry both types of 7 Facial fibers 8 Vestibulocholear 9 glossopharyngeal  Subdivisions of the PNS: 1/ Spinal Accessory Conscious_______________ Somatic nervous system: governs __________ sensations and 12 hypogloss al Voluntary movement ______________________ activities involuntary internal ________ Unconscious ____________________: Autonomic nervous system: governs ___________, cardiac Smooth muscles and ____________________, organs ___________, and _________________________. glands  Sympathetic _____________________ nervous system: Forf  prepares the body for “__________________ WR  Increases the _______________________ dilates  ______________________ the airways  for a ready supply of _________ and _____________ oxygen  parasympathetic glucose _____________________ nervous system: conserved  adjusts body functions so that energy is ____________ during resting time ________________________________________ rest digest  ________________________________  promotes _______________, food Sister __________________ digestion  The Synapse Axons branch into fine endings called _____________. Synaptic Knobs Each terminal lies very close to either the dendrite or the cell body of another neuron. This region of close proximity is called a _____________. Synaptic Cleft 2 © The Synapse __________________small Synaptic Cleft gap that separates the sending neuron from the receiving neuron. __________________________—transmits neurotransmitters action potentials across a synapse. Loading… Synaptic Stored in ___________________in vesicles the axon terminals. 3 © At the Synapse © Postsynaptic Neuron Presynaptic Neuron Synapse Plasma membrane of an axon ending of a sending Presynaptic (presynaptic) neuron Neuron Loading… Synaptic Synaptic knob vesicle Postsynaptic Plasma membrane Synaptic cleft Neuron of a receiving Ion channel Receptor for (postsynaptic) neurotransmitter neuron (a) © 2017 Pearson Education, Inc. Figure 7.6a  The Synapse The events at a synapse: think of a chain of dominos 1. Nerve impulse/Action Potential travels along an axon and reach an _________________________. axon terminal 2. ____________ calcium ions enter the terminal and stimulate ________________to Synaptic Vesicles merge with plasma membrane at the axon terminal of the sending membrane. 3. _________________ Neurotransmitters is released into the synaptic cleft and diffuses across to the __________ receiving neuron. There, they bind to receptor proteins within the plasma membrane. 6 © Signal Transmission at the Synapse (Figure 14.6) 7 © The Synapse Excitation and inhibition Depending on the type of neurotransmitter, the response of the receiving neuron can be toward excitation or toward inhibition. ________________ Excitation occurs if the neurotransmitter causes sodium gates to open. ________________ inhibition occurs if a neurotransmitter causes potassium ions to exit the receiving neuron. 8 © The Synapse Synaptic integrationcalso summation) Integration—summing up of multiple incoming excitatory and inhibitory signals. If a neuron receives enough excitatory signals to outweigh the inhibitory ones, its axon will transmit a signal. On the other hand, if a neuron receives more inhibitory than excitatory signals, summing these signals may prohibit the axon from reaching threshold. 9 © Integration of Excitatory and Inhibitory Signals at the Synapse Figure 14.7a (photo): Omikron/Science Source 10 © The Synapse Removal of a neurotransmitter The short existence of neurotransmitters at a synapse prevents continuous stimulation of receiving membranes. Loading… If the neurotransmitter were to linger in the cleft, the receiving cell would be unable to respond to a new signal from a different cell. 11 © The Synapse Removal of a neurotransmitter After neurotransmitter has initiated a response, it is removed from the synaptic cleft. Some synapses have _____________________________ enzymes that inactivate the ______________________________________________ neurotransmitter down acetylcholine. Acetylcholinesterase (ACHE) For Example: the enzyme ____________________breaks Some drugs can block acetylcholinesterase - Aricept the treatment of dementia and patients with Alzheimer’s disease People with Alzheimer's disease have reduced levels of acetylcholine in the brain. 12 © The Synapse Removal of a neurotransmitter In other synapses, the sending membrane reabsorbs the Reuptake neurotransmitter – called __________ The reuptake can be blocked by drugs For Example: SSRIs – Selective Serotonin Reuptake Inhibitors used as an Anti-Depressant © The Synapse Neurotransmitter molecules There are more than 100 neurotransmitters. For Example: acetylcholine, norepinephrine, dopamine, serotonin, glutamate, and GABA. Neuron–muscle, neuron– organ, and neuron–gland synapses use neurotransmitters. 14 © Neurotransmitter molecules In the CNS: _____________________ norepinephrine is important to dreaming, waking, and mood. Serotonin ________________________ is involved in thermoregulation, sleeping, emotions, and perception. __________________________ dopami regulates emotions and complex movements Many drugs act at the synapse; some interfere with neurotransmitters. © Check Your Progress 14.1 Describe the three types of neurons, and list the three main parts of a neuron. Describe how a nerve impulse is propagated. Summarize how a nerve impulse is transmitted from one neuron to the next. 16  Chapter 15 Senses emble I. Introduction  Sensory Receptors ~ specializeda rename -Structures that are specialized to detect changes __________________ external in the ________ or environment _______________________________ Internal Stimuli - called _________________________ - Respond by generating electrochemical __________________________________________ messages StimulOS strong enough, then action - If a _____________is to the brain potentials are conducted __________________  Sensation awareness to stimuli - is _____________________________________ -How ___________is sensation experienced (e.g., as sight or which part of brain sound) depends on __________________________ receives impulses _________________________________________  Perception -______________________________________ conscious awareness of sensation -Understanding the stimulus occurs when ____________________________________________________ Cerebral cortex interprets Sensory input  Sensory adaptation continuously stimulated -Sensory receptors stop responding when ______________________________________________ decrease in awareness - leads to a _______________________________________________of the stimulus send Fewerimpulses - sensory receptors ____________________________________________ to the brain Varies among receptors adaptquickly  Pressure and touch receptors _____________________________________  Receptors in muscles and joints that report on body position ______________________ never adapt Classes of Receptors: __________________________ mechanoreceptors – stimulated by mechanical forces – eg. Hearing, balance, matching ! touch, blood pressure ___________________________________________- thermoreceptors changes in temperature ___________________________________________ Photoreceptors – respond to light ____________________________________________ Chemoreceptors – respond to chemical substances ________________________________– Pain receptors respond to chemicals released by damaged tissues II. General Senses - know these well !  touch __________________________  Pressure __________________________  vibration _________________________  temperature __________________________  body + limb position __________________________  __________________________ Pain  __________________________– Some Chemoreception from chemicals released by damaged tissues  Receptors located in Skin -_________________________________ - _________________________________ muscles bones - _________________________________ - _________________________________ joints - _________________________________ internal organs  We are not usually aware of the general senses, but they are still important Provide information about _________________________________________________ body position  General sense receptors involve either free or encapsulated nerve endings dendrites - Free nerve endings are the tips of ______________ of ____________________________________ Sensory neurons - Encapsulated nerve endings are those in which a ________________________________________ Connective tissue capsule and encloses Protects the tips of the dendrites of sensory neurons _________________________________________________________________________________  Different mechanoreceptors occur in the skin:  __________________________: Merkel disks ___ Free nerve endings that end on Merkel cells, detecting ____________________________________________________ Light touch  _________________________________: messiners corpuscles ___________ encapsulatednerve endings, tell us ______________________________________________________ tells us where we are touched to... this allows me Receptors Receptors sensitive to sensitive to pressure fine touch  Pacinion Corpuscles layers of tissue surrounding a nerve ending, sense ___________________________: first pressure or vibration _________________________________________________________  ___________________________: Ruffini endings ______________ encapsulated nerve endings, respond to _____________________________________________________ continuous pressure  Thermoreceptors temperature changes respond to ______________ below surface Free nerve endings located just ____________ Specialized ______________________ One type responds to warmth, another to cold · Range of temperature  Adapt Rapidly active when temperature is changing, but adapt when _________________– temperature is stable get used to it -  Pain receptors _________________________found free nerve endings all in _________of the body Damaged tissue – toxins, mechanical stimuli, electrical stimuli - releases Chemicals that alert freener ve endings _______________________________________________________________________  __________________________ Asprin and ____________________ ibuprofen interfere with the production of released chemicals  Referred pain ________________________________________ Pain felt somewhere besides the injury site of ________________________________________  is felt as pain in the skin also Common with damage to ______________________ internal organs III. Special Senses Specific location A. __________________________ Vision B. __________________________ hearing E C. __________________________ equilibrium D. __________________________ smell E. taste _________________________  Vision A. ___________________________________________ 1. The Structures of the Human Eye  The wall of the eyeball has three layers: Sclera Outermost layer—____________________________ cornea and ______________________________ Middle layer—__________________, choroid _____________, civiarybody iris and ______________ Innermost layer -_____________________________ retina holds lens in place helps  The outer layer is _________ andFibrous - focus eyes tough , ______________ Sclera white of eye  The _________________________  ____________ protectsand snapes ___________________ the eye  Serves as attachment site of muscles _________________________________ Cornea transparent  _________________________at the front of the eye  Allows ___________________________________ enter light to  Vascular The middle layer is __________________________________________ Choroid blood vessels  Contains ___________________________that supply eye tissue with ___________ nutrients and ________________ oxygen  Contains ________________, melanin which absorbs light reflected from the retina  Ciliary body Muscle  Ring of tissue, primarily ___________________, lens that encircles the _________ holds lens in place + changes shape  _______________________________________________ Iris  ________________________of muscular part Ciliarybody the choroid in front of the __________  _____________________________________________ regulates pupil size  Pupil Center of the iris - An opening in the __________________________ - Allows light to enter the eye and reach ___________ the retina dilates - ___________________ in dim light constricts - ______________________ in bright light  Retina photo receptors inner most layer of the eye, it contains ______________________ The _______________ that electric Signals respond to light by generating ___________________________  Types of photoreceptors- modified ____________________ neurons Roches ______________ – for low resolution of night vision – don't detect color _______________________________________ __________________ cone Cones on the average retina – – over 6 million ______ require bright light – ___________________________ color Vision Fovea greatest concentration of cones  Region of the retina with the ___________________________________– small area – 1/1000th of visual field  Objects are focused here for _____________________________________ Sharp Vision  Optic ___________ Nerve o Visual Carries visual information from the eye to the brain  _________ occipital cortex of _______________ lobe- for ________________________ interpretation  blind Spor ____________________________________ retinas Region where the _______ ________ leaves the __________ Optic nerve The retina lacks _______________________________ Photo receptors here An image that strikes the ______________________________ blind spot cannot be seen The two eyes together provide complete vision because the blind spot for the right eye is not the same as the blind spot for the left eye.  photon receptors Eyes = ________________________________  Brain = __________________________________ interprets neural input from retina Forea  catara(ks Glaucoma Leading cause second leading cause or blindness of blindness aqueous pressure damages hazy Vision Optic here  Posterior compartment  Located between the _______Lens and the retina ____________________________  Contains ____________ Vitreous humor ______; a jelly-like never fluid that is __________________replaced  Anterior compartment