Sensory Organs
Sensory Receptors
sensory receptors allow the body to respond to stimuli caused by changes in our internal or external environment
Receptors response
general function responds to stimuli by converting them into impulses
different types of receptors respond to different types of stimuli
Receptor Potential
The potential that develops when an adaquate stimulus acts on a receptor a grades response
when a threshold is reached an action potential in the sensory neurons axon is triggered
Distributions of Receptors:
Receptors of special sense of small taste vision hearing and equillibrium one grouped into localized areas or complex organs
General sense organs of somatic sense one microscopic
Classification by Location
Exteroceptors- On or near the body surface
Often called cutaneous
Visceroceptors-- within body organs
Provide information to the stomach
Proprioceptors- skeletons muscle joints, tendons
Information body movement and muscle stretch
Classification by stimulus detected
Mechanoreceptors activated when deformed to generate receptor potential
Chemoreceptors- activated by amount or changing concentration of certain chemicals
Photoreceptors found only iin the eye respond to light stimuli if the intensity is great enough to generate a receptor potential
Osmoreceptors concentrated in the hypotcuams; activated by changees in concentration of electorlytes in extracellular fluids
Classification of receptors
Classification by structure: divides sensory receptors into those with free nerve endings or encapsulated nerve endings
Free Nerve endings
Most widely distribution sensory receptor
Include both exteroceptors and viscerocptors
Primary receptors for heat and cold
Six types of encapsulated nerve endings; all have connective tissue capsules and are mechanoreceptors
Olfactory receptors
Olfactory sense organs consist of epithelial support cells and olfactory sensory neurons
Olfactory pathway: when the level of odor-producing chemical reaches threshold level
Taste buds: sense organs that respond to gustatory (taste) stimuli; associated with papillae
Chemoreceptors: stimulated by chemicals dissolve in the saliva
Gustatory cells: sensory cells in taste buds: gustatory hairs extend from each gustatory cell into the taste pore
Sense of taste depends on the creation of a receptor potential in gustatory cells because of taste- producing chemicals in the saliva
Taste buds are similar structurally: functionally, each taste bud responds most effectively to one of five primary taste sensations; sour, sweet, bitter,unami, and salty(and perhaps others, such as metallic)
Adaptation and sensitivity thresholds differ for each primary taste sensation
Sense of Hearing and Balance: The ear
external ear; two divisions
Auricle, or pinna: the visible portion of the ear
external acoustic meatus: tube leading from the auricle into the temporal bone and ending at the typanic membrane
Middle ear
Tiny epithelium-lined cavity hollowed out of the temporal bone
Contains three auditory o ssicles
Malleus (hammer): Attached to the inner surface of the typanic membrane
Incus (anvil) : attached to malleus and stapes
Stapes (stirrup) : Attached to the incus
Opening into the middle ear cavity
opening from the external acoustic meatus covered with tympanic membrane
Oval window: opening into inner ear stapes fit here
Round window: opening into inner ear ; covered by a membrane
Opening into the auditory (eustachian)tube
Drugs
ALCOHOL
-may be the world's oldest known drug
-A.K.A ethyl alcohol or ethanol
-Big business in today's society
-Alcohol abuse has become a major public health problem.
**Factors that influence how alcohol will affect a person:
-Age
-Gender
-Weight
-Physical Condition
-Amount of Food Eaten
-Other drugs or medicines taken
**Effects on the Body
-alcohol is a central nervous system depressant
-reduced tension
-lower inhibitions
-impaired concentration
-slower reflexes
-impaired reaction time
-reduced coordination
-drowsiness
-altered emotions
-breathing difficulties
-unconsciousness
-coma
-DEATH
**Addiction
-Chronic drinking can lead to dependence and addiction to alcohol
-Withdrawal symptoms include shaking(tremors), sleep problems, and nausea
-More severe withdrawal symptoms include hallucinations and even seizures
**Effects on the Body
-Alcohol use can also worsen high blood pressure and diabetes, two risk factors for heart disease.
TWO MAIN CATEGORIES of DRUGS
-Crack Cocaine
-Amphetamines (methamphetamine, ecstasy)
-Nicotine
-Marijuana
-Barbiturates (Oxycodone, Morphine, Codeine, Valium)
-GHB
Inhalant Use
*Generally fall into three categories:
-Solvents: paint thinner, nail polish, remover, gasoline, and glue
-Gases:whipped cream dispensers, spray paint, hair spray, deodorant spray, nitrous oxide, ether
-Nitrites: room deodorizers
Drug Abuse- "Why Do People Start?"
*feel older
* feel cool
*feel different
*peer pressure
*fit in
* fun
* Media (advertising, TV, movies, music)
*friends/family
*relieve stress/ relax
--Idea that it's easy quit
--"just want to try it"
--Social crutch: feel confident in social situations, something to handle or hold
--Deal with problems: escape, pressure, depression, boredom
--Don't know how to say no.
Lobes of the Brain
Lobes of the Cerebrum
*Fissures (deep grooves) divide the cerebrum lobes
*Surface lobes of the cerebrum
-Frontal
-Parietal
-Occipital
-Temporal
Specialized Areas of the Cerebrum
*Primary somatic sensory area
-Receives impulses fro the body's sensory receptors.
-Located in parietal lobe
*Broca's area
-Involved in our ability to speak
*Primary motor area
-Sends impulses to skeletal muscles
-Located in frontal lobe
Regions of the Brain: Cerebrum
*Cerebral areas involved in special senses
-Gustatory area (taste)
-Visual area
-Auditory area
-Olfactory area
*Interpretation areas of the cerebrum
-speech/language region
-language comprehension region
-general interpretation area
Layers of the Cerebrum
*Gray Matter(cortex): outer layer in the cerebral cortex composed mostly of neuron cell bodies.
*White Matter: fiber tracts deep to the gray matter.
-corpus callosum connects hemispheres
*Basal nuclei: islands of gray matter buried within the white matter.
Regions of the Brain: Diencephalon
*Sits on top the of the brain stem
*enclosed by the cerebral hemispheres
*Made of 3 parts
-Thalamus
-Hypothalamus
-Epithalamus
Diencephalon: Thalamus
*Surrounds the third ventricle
*The relay station for sensory impulses
Transfers impulses to the correct part of the cortex for localization and interpretation.
Diencephalon: Epithalamus
*forms the roof of the third ventricle
*houses the pineal ody (an endocrine gland)
*Includes the choroid plexus- forms cerebrospinal fluid.
Sensory Receptors
sensory receptors allow the body to respond to stimuli caused by changes in our internal or external environment
Receptors response
general function responds to stimuli by converting them into impulses
different types of receptors respond to different types of stimuli
Receptor Potential
The potential that develops when an adaquate stimulus acts on a receptor a grades response
when a threshold is reached an action potential in the sensory neurons axon is triggered
Distributions of Receptors:
Receptors of special sense of small taste vision hearing and equillibrium one grouped into localized areas or complex organs
General sense organs of somatic sense one microscopic
Classification by Location
Exteroceptors- On or near the body surface
Often called cutaneous
Visceroceptors-- within body organs
Provide information to the stomach
Proprioceptors- skeletons muscle joints, tendons
Information body movement and muscle stretch
Classification by stimulus detected
Mechanoreceptors activated when deformed to generate receptor potential
Chemoreceptors- activated by amount or changing concentration of certain chemicals
Photoreceptors found only iin the eye respond to light stimuli if the intensity is great enough to generate a receptor potential
Osmoreceptors concentrated in the hypotcuams; activated by changees in concentration of electorlytes in extracellular fluids
Classification of receptors
Classification by structure: divides sensory receptors into those with free nerve endings or encapsulated nerve endings
Free Nerve endings
Most widely distribution sensory receptor
Include both exteroceptors and viscerocptors
Primary receptors for heat and cold
Six types of encapsulated nerve endings; all have connective tissue capsules and are mechanoreceptors
Olfactory receptors
Olfactory sense organs consist of epithelial support cells and olfactory sensory neurons
Olfactory pathway: when the level of odor-producing chemical reaches threshold level
Taste buds: sense organs that respond to gustatory (taste) stimuli; associated with papillae
Chemoreceptors: stimulated by chemicals dissolve in the saliva
Gustatory cells: sensory cells in taste buds: gustatory hairs extend from each gustatory cell into the taste pore
Sense of taste depends on the creation of a receptor potential in gustatory cells because of taste- producing chemicals in the saliva
Taste buds are similar structurally: functionally, each taste bud responds most effectively to one of five primary taste sensations; sour, sweet, bitter,unami, and salty(and perhaps others, such as metallic)
Adaptation and sensitivity thresholds differ for each primary taste sensation
Sense of Hearing and Balance: The ear
external ear; two divisions
Auricle, or pinna: the visible portion of the ear
external acoustic meatus: tube leading from the auricle into the temporal bone and ending at the typanic membrane
Middle ear
Tiny epithelium-lined cavity hollowed out of the temporal bone
Contains three auditory o ssicles
Malleus (hammer): Attached to the inner surface of the typanic membrane
Incus (anvil) : attached to malleus and stapes
Stapes (stirrup) : Attached to the incus
Opening into the middle ear cavity
opening from the external acoustic meatus covered with tympanic membrane
Oval window: opening into inner ear stapes fit here
Round window: opening into inner ear ; covered by a membrane
Opening into the auditory (eustachian)tube
Drugs
ALCOHOL
-may be the world's oldest known drug
-A.K.A ethyl alcohol or ethanol
-Big business in today's society
-Alcohol abuse has become a major public health problem.
**Factors that influence how alcohol will affect a person:
-Age
-Gender
-Weight
-Physical Condition
-Amount of Food Eaten
-Other drugs or medicines taken
**Effects on the Body
-alcohol is a central nervous system depressant
- in Low Doses, alcohol can produce:
-reduced tension
-lower inhibitions
-impaired concentration
-slower reflexes
-impaired reaction time
-reduced coordination
- In Medium Doses:
-drowsiness
-altered emotions
- In High Doses:
-breathing difficulties
-unconsciousness
-coma
-DEATH
**Addiction
-Chronic drinking can lead to dependence and addiction to alcohol
-Withdrawal symptoms include shaking(tremors), sleep problems, and nausea
-More severe withdrawal symptoms include hallucinations and even seizures
**Effects on the Body
- Central Nervous System
- Liver
- Kidneys
- Heart
-Alcohol use can also worsen high blood pressure and diabetes, two risk factors for heart disease.
TWO MAIN CATEGORIES of DRUGS
- Stimulants
-Crack Cocaine
-Amphetamines (methamphetamine, ecstasy)
-Nicotine
- Depressants
-Marijuana
-Barbiturates (Oxycodone, Morphine, Codeine, Valium)
-GHB
Inhalant Use
*Generally fall into three categories:
-Solvents: paint thinner, nail polish, remover, gasoline, and glue
-Gases:whipped cream dispensers, spray paint, hair spray, deodorant spray, nitrous oxide, ether
-Nitrites: room deodorizers
Drug Abuse- "Why Do People Start?"
*feel older
* feel cool
*feel different
*peer pressure
*fit in
* fun
* Media (advertising, TV, movies, music)
*friends/family
*relieve stress/ relax
--Idea that it's easy quit
--"just want to try it"
--Social crutch: feel confident in social situations, something to handle or hold
--Deal with problems: escape, pressure, depression, boredom
--Don't know how to say no.
Lobes of the Brain
Lobes of the Cerebrum
*Fissures (deep grooves) divide the cerebrum lobes
*Surface lobes of the cerebrum
-Frontal
-Parietal
-Occipital
-Temporal
Specialized Areas of the Cerebrum
*Primary somatic sensory area
-Receives impulses fro the body's sensory receptors.
-Located in parietal lobe
*Broca's area
-Involved in our ability to speak
*Primary motor area
-Sends impulses to skeletal muscles
-Located in frontal lobe
Regions of the Brain: Cerebrum
*Cerebral areas involved in special senses
-Gustatory area (taste)
-Visual area
-Auditory area
-Olfactory area
*Interpretation areas of the cerebrum
-speech/language region
-language comprehension region
-general interpretation area
Layers of the Cerebrum
*Gray Matter(cortex): outer layer in the cerebral cortex composed mostly of neuron cell bodies.
*White Matter: fiber tracts deep to the gray matter.
-corpus callosum connects hemispheres
*Basal nuclei: islands of gray matter buried within the white matter.
Regions of the Brain: Diencephalon
*Sits on top the of the brain stem
*enclosed by the cerebral hemispheres
*Made of 3 parts
-Thalamus
-Hypothalamus
-Epithalamus
Diencephalon: Thalamus
*Surrounds the third ventricle
*The relay station for sensory impulses
Transfers impulses to the correct part of the cortex for localization and interpretation.
Diencephalon: Epithalamus
*forms the roof of the third ventricle
*houses the pineal ody (an endocrine gland)
*Includes the choroid plexus- forms cerebrospinal fluid.