a&p 1 unit #3

otto leowi

hypothesized and demonstrated experimentally that neurons communicate by releasing chemicals

ionotropic receptors

receptors found as components of a ligand-gated ion channels

metabotropic receptors

found within plasma membrane associated with a separate ion channel: directly connected to metabolic processes that are initiated when neurotransmitter

EPSP (excitatory post-synaptic potential) or IPSP (inhibitory post-synaptic potential) 

binding of neurotransmitter to receptor leads to what 

acetylcholine, dopamine, serotonin, histamine

what are the major neurotransmitters

acetylcholine 

small molecule NT widely used by the nervous system

cholinergic synapses, and can be found within brain and spinal cord and within autonomic nervous system

what type of synapses bind to Ach and where can they be found

dopamine (catecholamine)

used extensively by CNS, helps to coordinate movement and is involved in emotion and motivation

serotonin

this neurotransmitter functions include mood, regulation, emotions, attention, feeding behaviors, and daily rhythms

histamine

neurotransmitter involved in regulation of arousal and attention

glutamate, glycine, and GABA

what are the three amino acid neurotransmitters

glutamate 

most important excitatory NT in CNS; binds to it ionotropic recptors and opens calcium and sodium ion channels; generate EPSPs in postsynaptic neuron 

glycine and GABA

both major inhibitory NT; include IPSPs on postynaptic neurons by opening chloride ion channels; hyperpolarize axolemma

biogenic amines

class of NT used for many functions such as regulation of homeostasis and cognition; mostly excitatory

norepinephrine and epinephrine 

what are included in the biogenic amines

norepinephrine

found mainly in ANS; in CNS it regulates sleep/wake cycle, attention, and feeding behaviors

epinephrine

used in ANS; has similar functions as norepinephrine; but is more widely used as a hormone by the endocrine system

brain 

soft, whitish-gray organ, anatomically continuous with spinal cord and directly or indirectly controls most of body’s functions 

ventricles

what are the internal cavities of the brain called

cerebrospinal fluid

what are the ventricles filled with

cerebrum, diencephalon, cerebellum, brainstem

what are the four division of the brain 

cerebrum

enlarged superior portion of brain

cerebrum 

responsible for higher mental function such as learning, memory, personality, cognition, language and conscience; performs major roles in sensation and movement as well

diencephalon

deep underneath cerebral hemispheres; central core of brain

diencephalon

responsible for processing, integrating, and relaying information to different parts of brain, homeostatic functions, regulation of movement, and biological rhythms

cerebellum

posterior and inferior portion of brain

cerebellum 

heavily involved in planning and coordination of movement, especially complex activities

brainstem

connects to brain an spinal cord

brainstem

involved in basic involuntary homeostatic functions, control of certain reflexes, monitoring movement, integrating and relaying information to other parts of nervous system

sulci 

shallow grooves on surface 

gyri

elevated ridges found between sulci; together increase surface area of brain

longitudinal fissure 

long deep groove that separates left and right cerebral hemispheres

frontal lobes

most anterior lobes

central sulcus

what is the posterior border of the frontal lobe

frontal lobe 

responsible for planning and excecuting movement and complex mental functions, such as behavior, conscience, and personality 

parietal lobes

responsible for processing and integrating sensory information

temporal lobes 

involved in hearing, language, memory, and emotions 

occipital lobes

process all information related to vision

parieto-occipital sulcus

the occipital lobe is separated from parietal lobe by what

insulas 

deep underneath lateral fissures; neurons in these lobes are currently thought to be involved in functions related to taste and viscera 

gray matter

found in both brain and spinal cord; consists of neuron cell bodies, dendrites, and unmyelinated axons

neocortex

most of the cerebral cortex, a huge surface area

interneurons

all neurons in the cortex are what 

primary motor cortex, primary sensory cortices, and association which integrate different kinds of stimuli

neocortex is divided into three areas, what are they?

commissural fibers, projection fibers, association fibers

cerebral white matter can be classified as one of three types, what are the three types

commissural fibers 

connect right and left hemispheres

corpus callosum

what is the largest and commissural fiber and lies in the middle of brain at base of longitudinal fissure

projecion fibers

connect cerebral cortex of one hemisphere with other areas of same hemisphere, other parts of brain, and spinal cord

association fibers 

restricted to a single hemisphere; connect gray matter of cortical gyri with one another 

basal nuclei

found deep within each cerebral hemisphere; cluster of neuron cell bodies involved in movement

diencephalon

at physical center of brain

thalamus 

hypothalamus 

epithalamus (pineal gland) 

third ventricle 

what are the four structures that make up the diencephalon

thalamus

main entry route of sensory data into cerebral cortex

smell

nearly all stimuli except for what is destined for the cerebral cortex must pass through the thalamus

thalamus 

this structure regulates cortical activity

hypothalamus (boss of the ANS)

this structure performs several vital functions critical to survival; include regulation of ANS, sleep/wake cycle, thirst and hunger, and body temperature

pituitary gland

the hypothalamus is anatomically and functionally linked to what structure

cerebellum 

makes up posterior and inferior portion of brain; functionally connected with cerebral cortex, basal nuclei, brainstem, and spinal cord to coordinate movement 

vermis

the cerebellum is anatomically divided into cerebellar hemispheres connected by a structure called what

folia

ridges that cover the exterior cerebellar surface on cerebellum

brainstem

vital to our immediate survival as its nuclei controls many basic homeostatic functions such as heart rate and breathing rhythms

superior midbrain, middle pons, and inferior medulla oblongata

what are the three subdivisions of the brainstem

brainstem

controls many reflexes (programmed, automatic responses to stimuli); functions in movement, sensation, and maintaining alertness

spinal cord

serves as a relay station and as an intermediate point between body and brain; processing station for some less complex activities such as spinal reflexes

extends proximally from foramen magnum to region between first and second lumbar vertebrae

spinal cord extends from where to where

narrow posterior median sulcus 

can be seen on entire length of posterior side of cord

wider anterior median sulcus

can be seen on entire length of anterior side of cord

conus medullaris

cone shaped distal end of cord

spinal nerves

components of PNS; carry sensory and motor impulses to and from spinal cord

anterior horn, posterior horn, and lateral horn

spinal gray matter makes up three distinct regions of the spinal cord, what are they?

funiculi

spinal white matter is organized into general regions called what _____________ that lie on each side of spinal cord

ascending tracts

carry various kinds of sensory information 

descending tracts

transmit motor information from specific regions in brain down spinal cord to specific regions in body

cranial meninges, cerebrospinal fluid, and blood brain barrier

what are the three features found within the protective shell of skull provide additional shelter for delicate brain tissue

cranial meninges 

three layers of membranes that surround the brain are called what 

cerebrospinal fluid (CSF)

clear. colorless fluid that bathes brain and fills cavities including spinal cord canal

blood brain barrier

prevents many substances from entering brain and its cells from blood

(superficial to deep): epidural space, dura mater, subdural space, arachnoid mater, subarachnoid space, and pia mater

what are the three cranial meninges and its spaces 

epidural space

between inner surface of cranial bones and outer surface of dura mater; only a potential space as dura is normally tightly bound to bone only allowing for passage of blood vessels

dura mater

outermost menix; thickest, and most durable double layered membrane composed mostly of collagen fibers with few elastic fibers

subdural space 

serous fluid-filled space; found deep to dura mater that houses veins that drain blood from brain 

arachnoid mater

second meningeal layer deep to subdural space; thin weblike membrane with some degree of elasticity

subarachnoid space

found deep to arachnoid mater contains major blood vessels of brain; filled with CSF

pia mater 

deepest meningeal later; only meninx in physical contact with brain tissue

ependymal cells

ventricles are lined with what kind of cells and filled with cerebrospinal fluid

right and left lateral ventricles (first and second ventricles)

found within cerebral hemispheres and resemble ram’s horns when observed in anterior view

third ventricle

narrow cavity found between two lobes of diencephalon

fourth ventricle

between pons and cerebellum; connected to third ventricle by cerebral aqueduct

cushions brain and maintains a constant temperature within cranial cavity

removes wastes and increases buoyancy of brain

what are some functions of cerebrospinal fluid (CSF)

simple squamous epithelial cells of blood capillaries and astrocytes

the blood brain barrier consists mainly of what type of cells

water, oxygen, carbon dioxide, and nonpolar, lipid-based molecules

what are some substances that are able to pass through the blood-brain barrier

most large, polar molecules

what are effectively prevented from crossing the blood-brain barrier

homeostasis 

defined as maintenance of a relativley stable internal environment in face of ever-changing conditions

nervous and endocrine systems

what are the main systems dedicated to maintaining homeostasis

hormones

the endocrine system secretes __________ into blood; regulates functions of other cells.

action potentials 

nervous system sends _______________; excite or inhibit target cells `

nuclei of reticular formation and hypothalamus

what two structures of CNS are concerned directly with maintenance of homeostasis

autonomic nervous system

maintenance of vital functions (heart pumping, blood pressure, and digestion) and regulates function of body’s viscera is largely controlled by what

medulla

where is the vasopressor center located 

increases rate and force of cardiac contractions and causes blood vessels to narrow; causes increases in blood pressure

what occurs when the hypothalamus stimulates the vasorpessor center