Biology: Unit 1

Drew Whalen
Flashcards by Drew Whalen, updated more than 1 year ago
Drew Whalen
Created by Drew Whalen about 6 years ago


Nervous & Endocrine Systems

Resource summary

Question Answer
Nervous System - A high speed communication system which delivers information to and from the brain and spinal cord all over the body
Sensors - Gather information from the external environment - Ex: Sense Organs
Conductors - Carry information from sensors to modulators or from modulators to effectors - Ex: Nerves
Modulators - Interpret sensory information and send information to effectors - Ex: Brain & Spinal Cord
Effectors - Part of the body that responds because of information from a modulator - Ex: Muscles & Glands
Central Nervous System - Receives sensory information and initiates control - Brain & Spinal Cord
Skull - Hard casing that protects the brain
Vertebrae - Protects Spinal cord
Meninges - Three protective membranes surrounding the brain and spinal cord - They are filled with cerebrospinal fluid
Ventricles - Cavities in the brain which are filled with cerebrospinal fluid
Grey Matter - Brownish-grey nerve tissue consisting of mainly cell bodies within the brain and spinal cord
White Matter - The white nerve tissue of the brain and spinal cord, consisting of mostly myelinated neurons
Peripheral Nervous System - The nerves that enter and leave the brain and spinal cord
Autonomic Nervous System - The part of the nervous system that relays information to the internal organs that are not under the conscious control of the individual - Two parts Sympathetic & Parasympathetic
Sympathetic - Speeds up muscle activity and activities in times of stress - Fight or Flight response
Parasympathetic - The network of nerves that counteract the sympathetic nervous system to slow down heart rate and relax muscles
Somatic Nervous System - The part of the nervous system that relays information to and from skin and skeletal muscles that are under conscious control of the individual
Brain - An organ of soft nervous tissue contained in the skull of vertebrates - Functions as the coordinating center of sensation and intellectual and nervous activity
Cerebrum - Largest part of the brain - Responsible for complex behavior and intelligence & interprets sensory inputs and initiates motor response - Divided into 4 lobes: Frontal, Temporal, parietal & occipital lobe
Frontal Lobe - Contains primary motor area, premotor area, Bronca's area (Motor Speech), and pre-frontal area (Association)
Temporal Lobe - Contains auditory association area, primary auditory area and sensory speech (Wenche's area)
Parietal Lobe - Contains primary somatosensory area, somatosensory association area and primary taste area
Occipital Lobe - Contains primary visual area and visual association area
Corpus Callosum - Layer of white matter which connects the two hemispheres of the cerebral cortex -transmits between the two hemispheres really quickly
Cerebellum - The part of the brain that is responsible for muscle coordination - 50% of the brains neurons, 10% of the space
Midbrain - A short segment of the brain stem between the cerebellum and pons - Involved in sight & hearing
Pons - Contains bundles of Axons traveling between the cerebellum and the rest of the CNS - Regulates breathing with the Medulla Oblongata - Has reflex centers involved in head movement
Medulla Oblongata - Involved in: Controlling heart rate, vomiting, adjusting blood pressure, hiccuping, controlling breathing & swallowing
Thalamus - sensory relay center of the brain that governs the flow of information from all other parts of the nervous system
Hypothalamus - The part of the brain that acts as the main control center for the autonomic nervous system, reestablishes homeostasis and controls the endocrine hormone system
Neurons - Can live for up to 100 years - Don not undergo cell division after adolescence (But some can be repaired) - Utilize aerobic cellular respiration (oxygen) to produce ATP for cell processes and Na+/K+ pump
Sensory Neurons - Take information from a receptor (such as pain or light) to he CNS via interneurons
Interneurons - Connect sensory neurons to the CNS and the CNS to the motor neurons
Motor Neurons - Receive information from the CNS via interneurons an carries it to an effector
Dendrites - Sites on nerve cells that receive signals from other neurons
Cell Body - The main part of a neuron - Contains the nucleus and other organelles
Axon - Long cylindrical extension of a neuron's cell body that can range from 1mm to 1m in length - Transmits impulses along its length towards the next neuron
Schwann Cells - Insulating cells around the axons of some nerve cells in the PNS
Myelin Sheath - The fatty layer around the axon - Speeds up nervous transmissions - Unmyelinated neurons: grey matter - Myelinated neurons: white matter
Terminal Branches - The end of the axon that branches off and comes in close contact with the dendrites of neighboring neurons - Contains terminal vesicles
Terminal Vesicles - On the ends o the terminal endings - Contains neurotransmitters which are released during stimulous
Terminal Vesicles - On the ends of the terminal endings - Contains neurotransmitters which are releases during stimulous
Polarization - Also referred to as "At Rest" - When the outside of the neuron is positively charged compared go the inside - Neuron is not being stimulated
Depolarization - Can not occur unless there is enough stimulus - The potassium ion channels close and the sodium ion gates open and Na+ goes in but more K+ goes out and neutralizes the neuron and the continues down the axon and onto other neurons
Repolarization - After the Na+ channels open, K+ channels reopen to cause K+ to move out and the Na+ channels close - The original concentrations are restored by pumping Na+ out and K+ in
Synapsis - The junction between a neuron and another neuron or muscle cell
Neurotransmitter - Chemicals that are secreted by neurons to stimulate motor neurons and central nervous system neurons
Excitory response - Process in which the neurotransmitter reaches the dendrites of a postsynaptic neuron and a wave of depolarization is generated by the resultant opening of sodium gated channels
Inhibitory Response - Process in which the postsynaptic neuron is made more negative on the inside to raise the threshold of stimulus
Acetylcholine - Primary neurotransmitter of both the somatic and the parasympathetic nervous system - Can be excitatory or inhibitory - Excites skeletal muscles but inhibits cardiac muscles
Noradrenaline - Also known as Norepinephine - Primary neurotransmitter of the sympathetic nervous system - Excitatory
Glutamate - An amino acid - Found in the cerebral cortex - 75% of all the excitatory transmission in the brain
Gamma Amino Butyric Acid (GABA) - Most common inhibitory neurotransmitter in the brain
Dopamine - Neurotransmitter that elevates mood and controls skeletal muscles
Serotonin - Formed from Trytophan, an amino acid - Involved in alertness, sleepiness, thermoregulation and mood
Depressants - Slows down the CNS - Relaxes and causes people to feel less pain, also decreases coordination and movement - Ex: Alcohol, heroin, morphine, Valium & anesthetics - Anesthetics can be general or local
Stimulants - Speeds up the CNS - Increases energy and confidence - Ex: Caffeine, cocaine, Ecstasy (MDMD) and nicotine
Hallucinogens - Cause an altered state or reality - Affect memory or pleasure centers as well as perception - Ex: Marijuana & LSD (acid)
Multiple Sclerosis - Autoimmune disorder, no cure - The body's own immune cells attack the myelin and they become inflamed or damaged - Symptoms vary Ex: blurred or double vision, slurred speech, loss of coordination, weakness and seizures
Alzheimer's Disease - Degenerative disorder, no cure & limited treatment - Affects the brain and causes dementia (impairment of intellectual functions: Memory & orientation) - The result of deposits of a protein, amyloid, distrupts nerve cell communication - Acetylcholine levels drop
Parkinson's Disease - Chronic movement disorder caused by gradual decline of the neutrons that produce dopamine, no cure but symptoms can be treated with drugs or surgery - Symptoms include: Slight tremors & stiffness of limbs on one side of the body then tremors spread to both sides and movement becomes slow
Meningitis - A bacterial or viral infection of the meninges - Bacterial meningitis is fatal but there are some vaccines symptoms include: Headache, fever, stiff neck, light sensitivity, vomiting and drowsiness - Tests done via spinal tap
Huntington's Disease (Huntington's Cholera) - A lethal disorder in which the brain progressively deteriorates over a period of 15 years, no cure, symptoms appear after age 35 - Causes progressive decrease in mental and emotional abilities and loss of control of major muscle movements - Symptoms include: Memory loss, dementia, involuntary twitching, chorea (jerky movements) and personality changes
MRI - Magnetic Resonance Imaging - Uses a combination of large magnets, radio frequencies and computers to produce a detailed images of the brain and other structures
EEG - Electroencephalogram - Electrodes are attached to the forehead and scalp and brain waves are recorded - Printout of brain waves help diagnose certain disorders like sleep disorders and locating tumors
CAT Scan - Computerized Tomography Scan - Takes a series of the cross-sectional X-rays to create a computer generated 3D image of a part of the body
PET Scan - Radiation is used to produce a colored 3D images of body function and metabolism
Eye - Two global organs in the head through which people and vertebrate animals see
Iris - The muscle that adjusts the pupil to regulate the amount of light that enters the eye
Pupil - The aperture in the middle of the iris of the eye - The size of the aperture can be adjusted to control the amount of light
Lens - A transparent bi-convex body situated behind the iris of the eye to focus an image on the retina
Retina - The innermost layer of the eye - Contains rods and cones bipolar cells and ganglion cells
Sclera - The thick white outer layer that gives the eye its shape
- Cornea - The clear part of the sclera at the at the front of the eye
Choroid Layer - The middle layer of the eye which absorbs light and prevents internal reflection - This layer forms the iris at the front of the eye
Rods - Photoreceptors in the eye - More sensitive to the light than cones but unable to distinguish colour
Cones - Colour receptors in the eye - (red, gree, blue)
Fovea Centralis - Concentration of cones on the retina located directly behind the center of the lens - Vision is more acute here
Optic Nerve - Conducts information received from rods and cones to the brain for interpretation
Blind Spot - An area on the retina where there are no rods and cones present - Located where blood vessels enter the eye
Cataracts - Cloudy or opaque areas on the lens of the eye that increases in size over time and can lead to blindness if not medically treated
Glaucoma - Build-up of the aqueous humor in the that irreversibly damages the nerve fibers responsible for peripheral vision
Myopia - Near-sightedness, or difficulty in seeing things that are far away - The condition is caused by too strong ciliary muscles or a too-long eyeball
Hyperopia - Far-sightedness, or difficulty in seeing near objects - This condition is caused by weak ciliary muscles or a too short eyeball
Astigmatism - Abnormality in the shape of the cornea or lens that results in uneven focus
Corrective Lenses - Near-sighted: The images focuses in front of the retina, concave lenses - Far-sighted: The images focuses behind the retina, convex lenses - Astigmatism: Unique and may require combinations of convex and/or concave lenses to bring images into focus
Laser Surgery #1 - Photorefractive keratectomy (PRK): non-invasive, simple procedure - May diminish eyesight
Laser Surgery #2 - LASIK surgery: More complex, some surgeries required (corneal) - May diminish eyesight
Corneal Transplant - Corneas come from donors, no need to match blood types - Recovery is long but most patients do well
Outer Ear - Consists of the pinna and the auditory canal
Auditory Canal - Contains hairs and sweat glands, some are modified to secrete wax to trap foreign particles
Middle Ear - Contains: Tympanic membrane, ossicles, round window, oval window, eustachian tube
Tympanic Membrane - The eardrum - A membrane of thin skin and fibrous tissue that vibrates in response to sound waves - Located between the outer ear and the middle ear
Ossicles - The group of three small bones between the eardrum and the oval window of the middle ear - Transmit sound waves from the eardrum to the inner ear - Malleus: Hammer, Incus: anvil, Stapes: Stirrup
Round Window - One of the two small openings at the end of the middle ear
Oval Window - Same as round except located behind the stapes
Eustachian Tube - Bony passage extending from the middle ear to the nasopharynx that plays a role in equalizing air pressure on both sides of the eardrum - Yawning can cause the air to move through the tubes and the ear will "pop"
Inner Ear Contains the vestibule, the semicircular canals and the cochlea
Vestibule - Involved in balance and equilibrium
Semicircula Canal - Three tubes involved in balance and equilibrium
Cochlea - Involved in hearing - Has many parts such as: Vestibular canal, Tympanic canal, Colchlear canal, Basilar membrane, Spiral organ and Tectorial membrane
Vestibular Canal, Tympanic Canal, Cochlear Canal - The three canals in the cochlea - Vestibular canal joins the tympanic canal and leads to the round window
Basilar membrane - One of the two parallel membranes that comprise the organ of Corti in the inner ear - Forms the lower wall of the cochlear canal
Spiral Organ (Organ of Corti) - The sensory part of the cochlea which responds to sounds - Sends information to the auditory nerve
Tectorial Membrane - One of two parallel membranes that comprise the spiral organ in the inner ear - During the transmission of sound waves the basilar membrane vibrates causing the sensory hairs to flex against the tectorial mambrane
Nerve Deafness - Caused by damage to hair cells in the spiral organ - hearing loss uneven, some frequencies more affected than others, cannot be reversed
Conduction Deafness - Usually caused by damage to the outer ear that affects transmission to the inner ear - Not usually a total loss of hearing - Can be helped with a hearing aid
Ear Infections - Caused by fluid build up behind the ear drums, common in children - Fluid builds up because of the shallow angle of the auditory tube
Hearing Aids - A small device that fits in or on the ear worn by a partially deaf person to amplify sound
Eustachian Tube Implants - Also called tympanostomy tube surgery - Used to treat infections - Tiny plastic tubes are placed in a slit in the eardrum relieving the pressure from the built up fluid and allowing it to drain
Endocrine System - Body system that works in parallel with the nervous system to maintain homeostasis by releasing chemical hormones from various glands - Comprised of hormone producing glands and body tissue
Endocrine Glands - Glands that have ductsand secrete substances such as sweat, saliva, tears, milk or digestive enzymes
Hormones -Chemical signals that are sent to many parts of the body -Examples: adrenaline and noradrenaline from the neurons of the adreanal glands
Target Organs -Organs that contain receptors for a particular hormone
Steroid Hormones - Hormones produced from cholesterol - they have 4 carbon ring structure with different side groups and have to be carried in blood by a protein carrier (fat soluble) - Ex: Cortisol, progesterone, testosterone... - Made in the rough ER - Works by binding and entering the cell
Non-Steroid Hormones - Composed of protein, peptides, or amino acids - Water soluble - Ex: Adrenaline, thyroxine, glucagon... - Does not enter cells, bonds to receptors
Hypothalamus - Controls the endocrine system as well as the autonomic nervous system to maintain the body's internal environment - Produces 2 hormones: ADH and Oxytocin
Pituitary Gland - Master gland - 2 Glands: Anterior lobe & Posterior lobe
Anterior Pituitary - Produces: HGH, Prolactin, TSH, Adrenocorticotrophin, FSH & LH
Posterior Pituitary - Stores and releases ADH & Oxytocin produced by the hypothalamus
Thyroid Gland - Butterfly shaped gland between the larynx and the neck - produces Thyroxine and Calcitonin
Parathyroid Gland - Produces Parathyroid hormone (PTH)
Adrenal Gland - Two distinct sections: Adrenal Cortex & Adrenal Medulla
Adrenal Cortex - Produces glucocorticoids (cortisol), mineralcorticoids (aldosterone) and small levels of sex hormones
Adrenal Medulla - Secretes adrenaline and noradrenaline - also involved in the fight or flight response
Pancreas - Produces insulin and glucagon
Pineal Gland - Small cone-shaped structure located deep within the brain - produces melatonin
Thymus Gland Lymphatic tissue located between the lobes of the lungs and the upper chest cavity and usually disappears during puberty - Produces thymosin
ADH: Anti-Diuretic Hormone - Produced in the hypothalamus - Stored and released in the posterior pituitary - Controls water levels
Oxytocin - Produced in the hypothalamus and stored and released in the posterior pituitary - Triggers muscle contractions in childbirth and promotes lactation
HGH: Human Growth Hormone - Somatotrophin - produced in the anterior pituitary - Controls growth
Prolactin - Produced in the anterior pituitary - Stimulates mammary gland tissue and milk production - (non-steroid)
TSH: Thyroid Stimulating Hormone - produced in anterior pituitary - Controls secretion of thyroxine in the thyroid gland
ACTH: Adrenocorticotrophin - Produced by the anterior pituitary - Regulates production of cortisol and aldosterone in the adrenal cortex
FSH: Follicle Stimulating Hormone - Produced in the anterior pituitary - Stimulates development of gametes (sperm and egg)
LH: Lutenizing Hormone - Produced in the anterior pituitary - Stimulates ovulation in females - Helps stimulate testosterone production in males
Thyroxine - Produced in the thyroid gland - Increases metabolic rate especially in the heart, skeletal muscle,liver and kidney - non-steroid and contains iodine
Calcitonin - Produced in the thyroid gland - Causes calcium levels to drop in blood by reabsorbing it into bones
PTH: Parathyroid Hormone - Produced in the parathyroid gland - Causes bones to release calcium into the blood from bones
Glucocorticoids - Cortisol - Produced in the adrenal cortex - Stimulates carbohydrates synthesis, breaks down fats, and reduces immune system abilities (inflammatory response)
Mineralcorticoids - Aldosterone - Produced in the adrenal cortex - Regulates water balance by increasing sodium reabsorption in the colon which causes the hypothalamus to release ADH
Adrenaline & Noradrenaline - Both produced in the adrenal Medulla - Both act to increase heart rate and blood pressure - Involved in fight or flight response
Insulin - Produced in the pancreas - Causes excess blood sugar to be stored as glycogen in the liver and as fat in adipose tissue
Glucagon - Produced in the pancreas - Has the opposite effect of insulin - Causes glucose to be released from glycogen and fatty acids and amino acids and released into the blood stream
Melatonin - Produced in the pineal gland - Involved in sleep - Has a circadian rhythm, a daily biological cycle or regular pattern - Melatonin levels increase as the day goes on, producing the feeling of sleepiness
Thymosin - Produced in the thymus gland - Stimulates production and materials of lymphocytes into T-cells
Discovery of Insulin - Discovered by Canadian scientists Fredrick Banting and Charles Best - Experimented on dogs and their pancreases
Pituitary Dwarfism - Abnormally short stature caused by insufficient HGH production during childhood - All parts are in proportion and puberty may be delayed or not at all - Can be treated with HGH therapy during childhood
Gigantism - An excess of HGH production prior to puberty - Uncontrolled growth, long bones in the skeleton - Usually caused by a tumor on the pituitary - Can be treated with surgery on the pituitary gland
Acromegaly - Excess HGH production during adult years - Symptoms include excessive thickening of bone tissue - Usually caused by a tumor on the pituitary gland - Treatments: Tumor removal, drugs, etc.
Hyperthyroidism - Grave's Disease - Autoimmune disorder caused by an excess of thyroxine - Anitbodies attach to TSH receptors on thyroid cells causing the thyroid to produce more thyroxine - Causes enlarged thyroid, sweating, moist skin, excess heat production and increases metabolic rate
Hypothyroidism - A deficiency of thyroxine production - Causes low metabolic rate, reduces tolerance to cold temperatures, weight gain but decreased appetite, decreased mental capacity, weakness/ fatigue and so on
Goiter - A swelling of the thyroid gland due to a lack of iodine - Reduced iodine means less thyroxine produced so metabolic rate decreases, and pituitary increases TSH secretions which causes the thyroid to swell - Goiters are not much of health problems thanks to "iodized salt"
Diabetes - A disorder where blood sugar levels are elevated constantly - Can cause circulatory disorders, blindness and/or weight loss - Two types: Diabetes Mellitus & Type 2 Diabetes
Diabetes Mellitus - Juvenile diabetes - Insulin dependent: pancreas doesn't make any insulin - Suggested to be am autoimmune disorder, body's own cells attack the pancreas and destroy the cells which make insulin
Type 2 Diabetes - Adult-onset diabetes - Insulin produced but the body is less sensitive to it or it is not produced enough - 90% of all diabetes are type 2
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