bio 152 module 5

sensation

receiving information about the environment; afferent neurons; requires receptor activation, sensory neuron activation -> action potential

stimulus

change from homeostasis or an event in the environment

integration

information processing

response - output

voluntary or involuntary; usually a muscle or a gland controlled by an efferent neuron

dura mater

strong protective sheath over the entire brain and spinal cord

arachnoid mater

loose sac around the central nervous sytem; filed with cerebrospinal fluid to provide liquid cushion

pia mater

follows the gyri and sulci in the cerebral cortex and fits into the grooves and indentations

cerebrum

conscious thought, perception, decision making

diencephalon

sensory input and homeostasis

brainstem

transports motor and sensory information, controls many autonomic functions

cerebellum

coordinates movement and balance; alcohol abuse degenerates neurons in the cerebellum

visual cortex

occipital lobe

auditory cortex

temporal lobe

somatosensory cortex

parietal lobe

motor cortex

frontal lobe

wernicke's area

spoken and written comprehension

broca's area

spoken and written language production

lateralization

non symmetrical brain function

frontal lobe

decision making and temperament

hippocampus and amygdala

long-term memory formation and emotional responses

thalamus

all sensory information, except smell, passes through the thalamus, before processing by the cortex, including consciousness and sleep

hypothalamus

regulating homeostasis, in charge of the autonomic nervous system and endocrine system through its regulation of the anterior pituitary gland; strong connections with hippocampus and amygdala

midbrain

transmits (but does not process) auditory and visual information; coordinates the two senses

pons

main connection between the cerebellum and the brain stem;receives input from the forebrain output to cerebellum

medulla

cardiovascular and respiratory centers; regulate vomiting, hicupping, swallowing, coughing, sneezing

2 divisions of the autonomic nervous system

sympathetic and parasympathetic

sympathetic nervous system

associated with fight or flight; increase oxygen intake and deliver to skeletal muscles, shut down oxygen so blood will only carry more oxygen; redirect blood flow to skeletal muscle and other relevant tissues; reduce heat by muscle contraction

parasympathetic nervous systwm

rest and digest; sexual arousal, salivation, lacrimation (tears), urination, digestion and defecation

autonomic

stimulus usually non consciously perceived (referred pain); involuntary response; effectors: smooth and cardiac muscle and glands; multiple neurons

somatic

stimulus is usually consciously perceived, involuntary and voluntary responses; effectors: skeletal muscle; single neurons

chemoreceptor

interprets chemical stimuli; such as an object's taste or smell

osmoreceptors

respond to solute concentrations of body fluids

nociceptor

the presences of chemicals from tissue damage, or similar intense stimuli (pain)

mechanoreceptor

physical stimuli, such as pressure and vibration, and the sensation of sound and body position (balance)

thermoreceptors

sensitive to temperatures above or below normal body temperature

reception

activation of sensory receptors by stimuli

perception

conscious awareness of a sensation; requires sensory signal reaches cortex, signal is processed, signal is sent to be made aware of

tastants

sensitive chemicals in food

salty (Na+) and sour (H+)

detected by ions

sweet, bitter, and umami

detected with g-protein coupled receptors

odorants

pass over the olfactory epithelium dissolve into mucus and bind proteins

external ear

auricle, ear canal, tympanic membrane

middle ear

ossicles: malleus, incus, and stapes

cochlea

hearing

vestibule

balance

organs of corti

contain hair cells, names for the hair like stereocilia extending from the cell's apical surfaces

head position sensed by

utricle and saccule

head movement sensed by

semicircular canals

3 layers of eye tissue

fibrous tunic (sclera and cornea), vascular tunic (choroid and ciliary body and iris) or neural tunic (retina)

fovea

highest visual acuity

optic disc

blind spot

photoreceptors inner segment

nucleus and other organelles

photoreceptors outer segment

specialized structures for photoreception

rods

shape and low light

cones

color (red blue and green)

somatosensation

general sense; receptors located all throughout the body

perception of pain

somatic is perceptible; autonomic is only perceptible when especially strong and sometime unexpected (referred pain)