Detects movement-touch pressure and vibration
Detects temperature-general sensation adapts quickly
Detects light in the retina
- chemicals through nose and mouth and whole body--through the mouth with
- taste buds, and through the nose to olfactory center
Detects pain but sensory does not adapt, activated by touch, pressure, and chemicals
Bands of fibrous connective tissue that connects muscle to bone
chemical the brain knows when detecting pain
stops prostaglandin but pain still exists
- Responsible for seeing
- 1/3 anterior, 2/3 posterior
blood vessels around the eye and provides nutrients and Oxygen
contains photoreceptors made up of rods that detects light and cones that detects colors/light
focuses light onto retina by contracting and relaxing
muscle ring around lens controls the shape of the lens, contracts lens when looking near and relaxes when looking far
- protects the front of the eye, where
- light enters and bends(refracts) light rays onto lens
actual hole of iris where light enters
colored/pigment part of eye that contains muscle fibers that contracts pupil in bright light and relaxes in dim light
photoreptors that detects light
photoreceptors that detect color
connects eye to brain carries electrical impulses from photoreceptor cells in rods/cones from retina to visual cortex in brain
point in the retina where optic nerve leaves eye and contains no receptors
3 Types of Cone
Blue, green, red
certain colors cannot be distinguished and lack or reduced # of one or more type of cones
Color Blindness cont'd
- No red cones means red looks black
- No green cones can't see red, orange, yellow
- No blue cones is uncommon
involuntary oscillations of the eye due to drinking alcohol
being able to focus on something close/far. change lens to change bending of light onto retina.
loss of accommodation due to age
normal-object at this distance appears correct and clear
Visual Acuity Test
The test with Snellen Eye Chart 20 feet away
Myopia-able to see objects that are close with clearness, cannot see far away to well and concave shape of lens
nearsighted-concave shape of lens
able to see distance clearly, convex lens, causes image to focus behind retina
Farsightedness, concave lens
images blurred, irregular curvature of cornea/lens causes light rays to focus unevenly
Middle part to ear/Auditory Ossicles made up of 3 tiny bones
- 2) incus
external auditory canal
- tympanic membrane
- outer ear
- thin layer of tissue
part of middle ear, aka hammer, auditory ossicles
part of middle ear, after malleus, aka anvil, ear/auditory ossicles
located after incus, middle ear, aka stirrup
vestibular apparatus, cochlea, filled with fluid/sensitive hair cells, gives info to brain about movement, head position, semicircular canals
- part of inner ear after ossicles
- detects rotational movement and balance(motion)
- semicircular canals
- auditory nerve
- part of middle ear
- air filled tube leading to pharnyx
- keeps pressure on both sides of eardrum the same
Receptors of the Ear
- part of middle ear
- air filled tube leading to pharnyx
- keeps pressure on both sides of eardrum the same
How does Hearing work?
- Filled with Fluid/ sensitve hair cells
- Cells sense motion/vibration from sound waves and vibrate eardrum,
- ossicles pick up vibrations, hairs vibrate/send impulses to brain
Conductive Hearing Loss
Sounds not conducted through eardrum across ossicles to vestibular system(inner) of ear. Can be fixed with hearing aid.
Sensorineural Hearing loss
- to hair cells or neurons of inner ear. gradual loss of hair cells with
- age. damage by certain infections/drugs. fixed with cochlear implant
Dizziness with Balance (motion sickness)
- mismatch between sensory input from vestibular apparatus and eyes
- motion sickness
- sensed by the vestibular system and hence the motion is felt, but no motion or little motion is detected by the visual system.
How does Smell work?
olfactory(approx. 1,000) receptors in nose sent to olfactory bulb in brain and sent to limbic system
Part of brain (prefontal cortex) deals with emotions, memory, behavoir and olfaction
chemoreceptors in mouth, made up of buds
- responsible for taste
- located on papilla on tongue
- each bump contains 100-200 buds
- each bud has approx. 40 cells
- 5 primary tastes
- layered with taste buds, different regions detect diff. taste-sweet at tip, salty at sides,
- sour middle, bitter middle back, umami(savory) at very back
5 Primary Taste
When sensory receptors stop responding due to continuous stimulation.
- key functional cells
- transmits signals to/from brain, within the brain
- contains dendrites, axons, cell body, axon endings, myelin, nodes of Ranvier
cure for motion sickness
- drugs that inhibit messages from vestibular apparatus
- look to horizon
a neuron specialized to pick up messages and transmit them toward the cell body. many short branching on a neuron.
Cell Body of Neuron
- controls cell's metabolic activity(i.e cytoplasm)
- contains organelles and nucleus
- A long extension from cell body of a neuron that carries an electrochemical
- message away from the cell body toward another neuron or effector
- (muscle or gland).
- The tips release a chemical called a neurotransmitter that can affect the
- activity of the receiving cell/neuron or effector(muscle or gland)
A muscle or a gland that brings about a response to a stimulus. Quadriceps of the patellar reflex. Triceps contract when tapped on tendon.
- The sheath insulates axons, increases the speed at which impulses are conducted along nodes of Ranvier, and assists in the repair of damaged
- neurons. Made by Schwann cells.
A type of glial cell in the peripheral nervous system that forms the myelin sheath by wrapping around the axon many times.
Nonexcitable cells in the nervous system that are specialized to support, protect, and insulate neurons, produce glucose. Also called neuroglial cells or neuroglia. Divide faster than neurons and take waste away.
A protein molecule located in(lipids) the cytoplasm(cell body) and on the plasma membrane(peptides) of cells that is sensitive to chemical messengers. Process happens within brain and reactions sent from brain
- The type of nerve transmission along a myelinated axon in which the nerve impulse jumps from one node of Ranvier to the next.
- Greatly increases the speed of nerve conduction.
- Sensory input(receptors)
- Motor output(effectors)
neuron signals that sense changes (hot flame near finger)conduct nerve impulses from the sensory receptors toward the central nervous system.
neuron signals that control action (finger moves away from flame)carry information away from the central nervous system to an effector, either a muscle or a gland.
Damaged or destroyed myelin where nerve cells do not communicate.An autoimmune disease in which the body's own defense mechanisms attack myelin sheaths in the nervous system.
Symptoms of Multiple Scelrosis
numbness, muscle weakness, less coordination, hearing/vision loss, symptoms are hard to diagnose and cause/cure unknown
- A nerve impulse.
- An electrochemical signal conducted along an axon.
- A wave of depolarization caused by the inward flow of sodium ions followed by repolarization caused by the outward flow of potassium ions.
Generation of Action Potential
- Depolarization caused by influx of Sodium
- Repolarization caused by efflux of Potassium out of cell
- Restoration of original (resting conditions)
Sequential opening and closing of sodium channel gates and potassium channel gates.
Produces Action Potential
Node of Ranvier
- A region of exposed axon between Schwann cells forming a myelin sheath.
- In myelinated nerves, the impulse jumps from one node of Ranvier to the next, greatly increasing the speed of conduction.
- This type of
- transmission is called saltatory conduction.
- A difference in the number of molecules or ions between two adjacent regions.
- Molecules or ions tend to move away from an area where they are more concentrated to an area where they are less concentrated.
- Each type of molecule or ion moves in response to its own concentration gradient.
- Potassium high inside and low outside.
- Facilitated diffusion since charged.
- Because many positive charges outside they want to go inside neuron.
- Travel across membrane with no transformation.
- Protein-lined pore or channel through a plasma membrane through which one type or a few types of ions can pass.
- Important in the generation and propagation
- of nerve impulses.
- Continually open to allow sodium in.
Gated Ion Channels
- sodium-channel gates.
- closed and opened when charged by N+/K+.
- Once closed no more can enter
(sodium / potassium)
- A molecular mechanism in a plasma membrane that uses cellular energy in the form of adenosine triphosphate (ATP) to pump ions against their
- concentration gradients.
- Active transport.
- Resets sodium and potassium content.
- Typically, each pump ejects three sodium ions from the cell while bringing in two potassium ions.
Description of Action Potential from figure 7.6 within 5 miliseconds.
- Begins at resting potential 1.5 seconds level -70(means interior is at negative charge).
- increases at 1.5 and membrane depolarization begins until reaching threshold at -60 and 2 secs continues until excitatory stimulus increases thereby opening the sodium gates.
- at 2.5secs wave reaches 0 and sodium ions enter neuron reducing negative charge increasing to +30(positive charge) at 3 secs and potass gates open allowing positive charges to leave at 3.5 secs.
- at 4 secs potassium gone, back to resting state but slightly more sodium cells fewer potass which is corrected by Na+/K+ pump which restores original distribution.
The interval following an action potential during which a neuron(sodium channels) cannot be stimulated to generate another action potential. Sodium channels are closed and cannot be reopened.
The site of communication between a neuron and another cell, such as another neuron or a muscle cell. Electrical travel down axon.
- At the end of axon.
- vessicles inside are neurotransmitters that bind to neurons(dopamine, epinephrin).
- electrical travel down axon
- action potential
Chemicals that facilitate communication between neurons across synapse by direct action of another cell or group of cells.
Imbalance of Neurotransmitters
Lead to disorders
- A neurotransmitter in the central nervous system thought to be involved in regulating emotions and in the brain pathways that control complex movements.
- not enough causes depression, anxiety, parkinsons
- A neurotransmitter in the central nervous system thought to promote a generalized feeling of well-being.
- not enough cause depression/anxiety
- It is the neurotransmitter released at neuromuscular junctions and causes muscle contraction.
- not enough causes Alzheimers
- Aka Adrenaline.
- A hormone secreted by the adrenal medulla, along with norepinephrine, in response to stress.
- They initiate the physiological "fight-or-flight" reaction.
- not enough cause depression
Central Nervous System
- Includes Brain and Spinal Cord
- Controls all voluntary and involuntary responses
- Front of the brain
- Primary, speech, reasoning, logic, mild when sleeping
- Back of brain behind parietal
- Located behind ears.
- Olfaction(chem recepter of nose and mouth)
- At bottom above brain stem
- maintains homeostasis
- and coordinates hormonal control of nervous/endocrine systems (ie neurotransmitters)
- releases hormones
Peripheral Nervous System
- The part of the nervous system outside the brain and spinal cord.
- It keeps the central nervous system in continuous contact with almost every part of the body. It is composed of nerves and ganglia.
- The two branches are the somatic and the autonomic nervous systems.
directs voluntary, skeletal muscle control, part of peripheral nerv. system
- Sympathetic and Parasympathetic responses
- cardiac and smooth muscle involuntary adjust activities of internal organs
- fight or flight
- prepares body for stress
- everything increases internally except digestion
- rest and digest
- governs bodily activities during restful situations
- Rapid responses to prevent injury.
- Sensory Neurons don't pass through brain
- Brain receives sensory input while reflex occurs
- rapid integration to prevent injury and travels a short distance
- A nerve cell specialized to conduct nerve impulses from the sensory receptors toward the central nervous system.
- All Sensory nerves. leading
- towards the brain.
- A neuron specialized to carry information away from the central nervous system to an effector, either a muscle or a gland.
- Trauma to the head
- white matter of the brain effected
- Hard to diagnose
- Sensation that an amputated or missing limb and is moving appropriately with other body parts. symptoms often painful
- Can be treated with the mirror box by tricking brain its seeing two arms and sends signals to existing arm
- unable to socially connect and read facial cues
- defective mirror neurons
- neuron that fires both when animal acts and watches another animal perform same act.
- neuron mirrors behavior of another as if it were performing itself.
- A cerebrovascular accident.
- A condition in which nerve cells die because the blood supply to a region of the brain is shut off by stopping of the heart, usually because of hemorrhage or atherosclerosis.
- The extent and location of the mental or physical impairment caused by a stroke depend on the region of the brain involved.
- access to memories are disrupted
- dna wrapped around histomes
How do we determine which region of the brain is affected in different disorders?
By the actions of the individual like if someone is losing their memory a sign of alzheimers, if someone is dizzy, nauseas, and cannot remember due to a head trauma then it is a concussion.
magnetic resonance imaging determines what region of brain is affected in different brains
- An association neuron.
- Neurons located within the central nervous system
- between sensory and motor neurons that serve to integrate information.
part of body most sensitive to touch (from quiz)
Will have the longest distance between 2 points
Mostly Somatic but sometimes Autonomic (from quiz)
learned reflexes(from quiz)
Autonomic reflex of the pupil
A chemical messenger released by cells of the endocrine system that travels through the circulatory system to affect receptive target cells.
The Endocrine System
- The organ system that that maintains homeostais consistancy.
- Any gland that secretes hormones.
- Such as the pituitary gland and thyroid gland, and of organs, such as the kidneys and pancreas.
- Influences growth, metabolism, synthesis of cell structures.
- Maintains tempurature and circulation.
- A hormone (the primary mineralocorticoid) released by the adrenal cortex that stimulates the reabsorption of sodium within kidney nephrons.
Goes to Pancreas where pancreas makes insulin that cells convert to energy
Aka lipid molecule
- Have receptors inside target cells.
- Derived from cholesterol.
- Secreted primarily by the ovaries, testes, and adrenal glands.
- Keeps cells fluid
- Backbone for steroid hormones
Produces estrogen(steroid sex hormone) and progesterone.
- Steroid producing gland.
- Sits above kidneys.
- Steroid producing gland.
- Includes Adrenal Medulla and Cortex.
releases epinephrine and noepinephrine to prepare body for stress
Process which Steroid Hormones enter cells.
- Binds to receptors (inside target cells)
- Hormone receptor complex enters nucleus and binds to DNA.
- Certain genes are activated.
- Proteins inlude enzymes that are synthesized where activity is altered in cell.
- Made up of protein.
- Partially polar so water soluble.
- Binds to recepter on surface.
- interaction causes sequence of changes inside cell but not in the nucleus.
- Levels (i.e amount)controlled by Negative/Positive feedback.
- Increased levels of molecule inhibit further release.
- Sends signal to stop release once its obtained the amount needed.
- A -->B-->C--shutdown
- Increased levels of molecule promotes further release.
- A--->B--->C-->signal keeps making more.
- Ex. During birth pressure on cervix sends signal to hypothalamus which tells pituatary gland to send more oxytocin so uterus contracts until baby is out and once pressure is gone process ends.
- Produces insulin(peptide hormone) to lower blood glucose.
- Glucagon(peptide) increases blood glucose.
- Negative feedback if no Diabetes.
- Part of digestive system next to stomach.
- A condition characterized by excessive urine production, an abnormally high blood glucose level, and the presence of glucose in the urine.
- Positive feedback loop.
- Caused by deficient production of insulin (type 1) or decreased sensitivity to insulin (type 2).
- Produces Peptide hormones ADH and Oxytocin, ACTH that goes to Adrenal gland to release adrenaline, FSH and LH that promote sperm and ova ovaries, and TSH that stimulates thyroid gland
- Below Hypothalamus
ADH- Antidiuretic hormone
Produced by pituitary gland that promotes water absorption (function) by the kidneys.
- The anterior pituitary hormone that controls the synthesis and secretion
- of glucocorticoid hormones from the cortex of the adrenal glands.
FSH-Folicle stimulating hormone
A hormone secreted by the anterior pituitary gland that in females stimulates the development of the follicles in the ovaries, resulting in the development of ova (eggs) and the production of estrogen, and in males stimulates sperm production.
TSH-Thyroid stimulating Hormone
The anterior pituitary hormone that acts on the thyroid gland to stimulate the synthesis and release of thyroid hormones.
- stimulates breastmilk ejection
- stimulates uterine contractions during childbirth
- At the throat.
- releases thyroid stimulating hormone
- produces Thyroid hormone
- decreases blood levelss of calcium and phosphate.
- Regulates metabolism.
- Promotes development and function of nervous, muscular, skeletal, and reproductive systems.
Enlarged Thyroid gland(goiter)
- may happen if diet is deficient in iodine
- treatable with iodine or Thyroid Hormone
Which cells are responsible for nerve growth and regeneration?
A muscle twitch results from the impulse carried by a __________ neuron.
Which of the following is true of the refractory period?
- The neuron cannot be stimulated.
- Immediately after an action potential, the neuron cannot be stimulated again for a brief instant, called the refractory period.
The transmission of a nerve impulse between two neurons across a synapse is __________.
- Dynamic equilibrium is dependent upon.
- Three canals in each ear that are oriented at right angles to one another and contain sensory receptors that precisely monitor any sudden movement of the head.
- They detect body position and movement.
- Regions of the central nervous system that are white owing to the presence of myelinated nerve fibers. White matter is important in neural
- communication over distances.