Neurobiology Exam 1 (Chapters 1-5)

microfilament

2 strands of actin

Franz Gall

Believed bumps on the surface of the skull reflect bumps on the surface of the brain and proposed that propensity for certain personality traits was related to dimensions of the head. Took many samples of people with various personality traits --> phrenology-correlating the structure of the head with personality traits

Nervous System is divided into __________ and ___________.

Central Nervous System (Brain and Spinal cord) Peripheral Nervous System (everything else)

meninges

Dura mater arachnoid mater pia mater covers and protects the brain, encloses and protects vessels that supply brain

Galen

Greek physician. He performed many sheep dissections. Studied the cerebellum and cerebrum. Cerebellum is hard and cerebrum is soft. Thought that cerebrum= receives sensations and cerebellum=commands muscles. Also discovered that the brain is hollow with ventricles filled with fluid.

Carl Wernicke

His patient could speak but could not understand language. Wernicke's area--> posterior part of temporal lobe (aphasia)

peripheral nervous system is divided into the _______ and ________ divisions

afferent (sensory division) and efferent division (motor)

Hippocrates

believed that the brain was not only involved in sensation but was also the seat of intelligence.

Aristotle

believed the mind was located in the heart which contained all emotions and thinking, the brain was used as a radiator used to cool the heart

reticular theory

brain is an exception to cell theory (individual cell is the elementary functional unit of animal tissues). Neurites of different cells are fused together to form a continuous reticulum or network similar to the arteries and veins of the circulatory system.

CSF

cerebrospinal fluid filtrates (subarachnoid space is filled with this)

nucleus

chromatin: DNA and associated proteins nucleoli: stain darker and contain DNA-RNA and enzymes that control RNA synthesis RNA molecules are synthesized by RNA polymerase and are then processed into mRNA to carry the genetic instructions for protein assembly from the nucleus to the cytoplasm

axon (found only in neurons!!!!!!!!!!!!)

conduction of nerve impulse -specialized for the transfer of information over distances -can be <1 mm-1 m long the beginning: axon hillock middle: axon proper (microtubules) end: axon terminal (or synaptic button) ~turned off~ cytoplasm of the axon differs from that of the terminal -microtubules do not extend into the terminal -numerous mitochondria -contains membranous bubbles called SYNAPTIC VESICLES -inside membranous surface has dense covering of proteins -No RER and few ribosomes -NO PROTEIN SYNTHESIS occurs in the axon -proteins are synthesized in the soma and are "shipped down" to the axon called AXOPLASMIC TRANSPORT

white matter

contain fibers that send/receive information to/from the gray matter, modulates distribution of action potentials

enteric nervous system

controls the gastrointestinal system

Marie Flourens

critic of phrenology, experimentally showed that the cerebellum had role in coordination of movement and the cerebrum in sensation and perception via experimental ablation method (destroying parts of the brain to determine their function) Challenged phrenology because 1) shape of the skull is not correlated with shape of the brain 2) experimental ablations showing particular traits are not isolated to the portions of the cerebrum specified by phrenology. Also thought that all regions of the cerebrum participate equally in cerebral functions --> WRONG ------------------------------------- showed that the cerebellum plays a role in the motor coordination and the cerebrum is involved in the sensation and perception with experimental support (birds) ~different parts of brain associated with specific functions~

Franz Nissl

developed Nissl stain. This stains nuclei and clumps (nissl bodies) Useful because 1) distinguishes between neurons and glia 2) study arrangement of neurons

neurons

electrically excitable cells that process and transmit information through electrical and chemical signals

SER (network of interconnected membrane tubes)

fatty acid/steroids/lipid synthesis, Ca 2+ storage, protein folding

sympathetic nervous system

fight or flight

axon hillock

generate nerve impulse (action potential)

Alan Hodgkin-Andrew Huxley

giant squid axon for ionic basis of action potential. Used voltage clamp to "clamp" the membrane potential of an axon at any value. Could deduce the changes in membrane conductance that occur at different membrane potentials by measuring the currents that flowed across the membrane. The rising phase of the action potential was indeed caused by a transient increase in gNa and an influx of Na+, falling phase was associated with an increase in gK and an efflux of K+. Proved existence of sodium gates in axonal membrane. Gates opened by depolarization above threshold and closed when the membrane has positive membrane potential. Deactivated only when membrane potential returns to a negative value..

Camillo Golgi

has Golgi staining. It stains a limited number of cells at random in their entirety. Fixed nervous tissue with potassium dichromate and silver nitrate which showed neurons have a central region that contains the cell nucleus and thin tubes (cell body and neurites)

neurofilaments

intermediate filaments. consist of individual long protein molecules each of which is coiled in a springlike configuration

Paul Broca

localization of functions in the cerebrum (localization of specific functions to different parts of brain). Patient who could understand language but not speak--> lesion in the left frontal lobe--> this region of cerebrum was responsible for speech

microglia

main immune cells of the brain, macrophages

Golgi Stain

makes a small percent of neurons become darkly colored in their entirety. Reveals neuronal cell body (where nucleus is) and neurites. Used to work on circuitry of the regions of brain.

dendrite shape

mental retardation, amphetamine treatment

efferent division

motor signals that travel to an effector such as muscles and glands that respond to electrical stimulation. system by which CNS communicates and controls muscles and glands

neuron doctrine

neurites of different neurons are not continuous with each other and communicate by contact, not continuity. Cell theory also applies to neurons. ~the nervous system is made up of discrete individual cells~

the two types of brain cells are ______ and _____

neurons and glia

somatic nervous system

part of the peripheral nervous system associated with skeletal muscle voluntary control of body movements. consists of afferent and efferent nerves

blood brain barrier

protects from within, tight junctions sew cell membranes together. Prevent blood borne toxins . allows water, some gases, and lipid-soluable molecules in by passive diffusion, glucose, AA, nonpolar. Astrocytes are necessary in creating the blood-brain barrier

skull

protects the CNS because it is a hard outer covering

golgi apparatus

protein modification, protein packaging in vesicles 1.protein enters ER while being synthesized by ribosome 2. protein exits ER travels to cis face of golgi apparatus 3. protein enters golgi apparatus and is processed as it moves through cisternae. 4. protein exits golgi apparatus at trans face and moves to plasma membrane 5. protein is secreted from cell

RER (network of interconnected membrane tubes)

protein synthesis, assembly, modifications RER--> Nissl bodies. RER abounds in neurons

mitochondria

providers of energy source in the form of ATP cellular respiration: mitochondria inhale pyruvic acid and O2 which enter the krebs cycle and produce ATP from ADP. when a mitochondrion exhales 17 ATP molecules are released per molecule of pyruvic acid

soma

receive and integrate inputs

dendrites (greek for tree)

receive and integrate inputs -the bushy, branching extensions of a neuron that receive messages and conduct eletrical signals toward the cell body -antennae of the neuron and are covered with thousands of synapses -dendrites of some neurons are covered with dendritic spines that isolate signal specificity

parasympathetic nervous system

rest and digest

neuronal soma have the

same intracellular components (cell body, cytosol, nucleus, SER, RER, ribosomes, golgi, mitochondria, lysosomes, cytoskeleton)

cytoskeleton

scaffolding that gives the neuron its characteristic shape

ventricular system

set of four interconnected cavities (ventricles) in the brain where CSF is produced. 2 lateral ventricles, third ventricle, fourth ventricle

Otto Loewi

showed that synaptic tansmission between nerves and the heart is chemically mediated. [had a dream] ecperimented on frog heart. It slowed both hearts that were vagally innervated

neuron

soma= contains cell nucleus neurites= tubes that radiate from soma axons="wires" that carry OUTPUT of neurons dendrites= come in contact with many axons, antennae of the neuron to receive incoming signals or INPUT

the efferent division is divided into the ______ and _______

somatic NS and autonomic NS

Nissl Stain

stains the nuclei of all cells as well as clumps of material surrounding the nuclei of neurons (clumps=nissl bodies) Useful because it distinguishes between neurons and glia. It allows us to study arrangement of neurons in parts of the brain [specialized regions] nissl bodies can be demonstrated by a method of selective staining using an aniline stain to label extranuclear RNA granules. clumps of RER and polyribosomes in RER

microtubules

straight thick-walled hollow pipes made of tubulin molecules

glia (glue)

support, insulate and nourish neighboring neurons -about 90% of brain cells- maintain homeostasis, form myelin, and provide support and protection for neurons

the autonomic NS is divided into the _________ and ________

sympathetic nervous system and parasympathetic nervous system (and enteric nervous system)

autonomic nervous system

the part of the nervous system responsible for control of the bodily functions not consciously directed such as breathing, the heartbeat, and digestive processes

axon terminals

transmission of information

afferent division

transmits impulses from peripheral organs to the CNS. sensory signals that travel away from the stimulus

Ramon y Cajal

used Golgi stain to work out circuitry of brain. He argued that neurites of different neurons are not continuous with each other and communicate by contact, not continuity (neuron doctrine) Nobel prize 1906

nodes of Ranvier

where myelin sheath has interruptions leaving a short length where the axonal membrane is exposed. Myelin speeds the propagation of nerve impulses down the axon.