Nucleus Double membrane, contains DNA (some RNA), site of transcription Cytoplasm Location of organelles, contains freely soluble proteins; site of translation Endoplasmic Reticulum Attached to nuclear membrane Rough ER Embeded with ribosomes Smooth ER Not embedded with ribosomes Ribosomes Site of protein synthesis Golgi Apparatus Site of posttranslational modifications, protein sorting, protein packaging Mitochondria Site of cellular respiration, ATP production Interphase Growth phase of the cell and includes DNA replication Mitosis Divison of the nuclear material (DNA) Cytokinesis Divison of the cytoplasm Adenosine triphosphate (ATP) Generated by cellular respiration Cellular Respiration Comprised of glocolysis, the citric acid cycle, and the electron transport chain Energy used to synthesize ATP Transfer of electrons released from bonds being broken in organic molecules Glycolysis Location Occurs in the cytoplasm Citric acid cycle and electron transport chain location OCcurs in the mitochondria ATP is generated by two mechanisms Subtrate level and oxidative phosphorylation Substrate Level phosphorylation Glycolysis and pyruvate oxidation and the citric acid cycle Oxidative phosphorylation Use of protein gradient to form ATP, uses electron transport and chemiosmosis, most ATP is generated by this Glycolysis Breaks down glucose into two pyruvate, pyruvate is converted into acetyl CoA which is fed into citric acid cycle Citric Acid Cycle Provides energy for OxiPhospho, completes the breakdown of glucose FADH and NADH Electron Carriers that shuffle electrons gathered frmo glycolysis and citric acid cycle to electron transport chain Electron Tranposrt Chain Pumps H+ to outside of inner mitochondria membrane then diffuses it back (chemiosmosis) in order to power ATP synthase that synthesizes ATP from ADP. O2 is final electron acceptor to form water Electron transport chain location Located in the inner membrane of the mitochondria Nucleic acids Include DNA and RNA, nucleic acids are formed from nucleotide bases (ACGT) DNA Composed of nucleotides, each consisting of a sugar phosphate group and a nitrogen-containing base Base Pairing in DNA The DNA strand is held together by hydrogen-bonding RNA differs from DNA RNA is single-stranded, RNA contains a ribose sugar instead of deoxyribose, RNA contains uracil instead of thymine DNA replication Precedes cell division, once helix uncoils each nuceotide strand acts to serve as template, A with T and G with C s DNA to RNA Transcription DNA is transcribed into RNA, uracil replaces thymine. Occurs in Nucleus mRNA Translation Used as template for making a protein, occurs in the cytoplasm mRNA read in triplet bases "one strand of DNA serves as a template for transcription, mRNA becomes attached to ribosomes where tRNA read the codon to determine which amino acid should be added. mRNA read in 5' to 3' direction" Genes Basic unit of heredity is a sequence of DNA nucleotides on a chromosome Chromosomes Consists of a molecule of DNA and its associated proteins, In nondividing cell most chromosomes appear as chromatin Chromsomes Humans have 46 of these, sex cells have 23. DNA is wrapped around proteins called histones, chromsomes consists of two sister chromatids. Two sister chromatids are attached at center at centromere Chromosomes location Chromsomes are located in the nucleus Autosomes Include all chromsomes except the sex chromsomes, 22 pairs in humans Sex chromosomes depend on whether organism is male or female. females have XX males have XY Diploid Cells or organisms having paired chromsomes are diploid and shown as 2n. humans have diploid number of 2n = 46 Haploid Only one set of chromsomes shown as n, sex cells are haploid or n Mitosis Phases prophase metaphase anaphase and telophase Prophase Chromsomes condense, centrosomes move , mitotic spindle forms Metaphase Chromosomes line up in the center of cell (equatorial plane) Anaphase Sister chromatids separate forming daughter chromosomes Telophase The nucleus reforms, chromsomes begin to uncoil, and the mintotic spindle disappears Meiosis Reduces the chromsomal number by half and introduces genetic variation Meiosis I Homologous chromsomes seperate Meiosis II Sister chromatids seperate Meiosis is much different from mitosis 3 reasons: During prophase duplicated chromosomes pair up and crossing over occurs, Chromsomes line up as pairs of homologs not as individual chromosomes, Duplicated chromsomes move towards opposite poles but sister chromatids stay attached Neurons "Main functional cells of the nervous system, capable of generating electric signals ""action potentials""" Glia Glial cells are more numerous than neurons, tend to serve a more supportive role Neuron Doctrine Each neuron is its own entity, isolated from its neighboring neurons by small amounts Reticular Theory Neurons are not distinct units, but are fushed together Two major problems impeded the progress of neuroscience Small size of neurons solved by compound microscope. Ability to view nervous tissue fixed by fixation and stains. Input zone (dendrites) Extensions of the soma that receive incoming information Integration zone (cell body/soma) The main part of the neuron, housing the nucleus and much of hte cellular organelles Conduction zone (axon) Long extension that carries information away from the soma towards axon terminals Output zone (axon terminals/boutons) Housing transmitter(s), the chemical signals or message between neurons and target tissues Signaling within neuron Electrical nature and travels largely in one direction. Signaling usually travels from dendrites to the axon hillock (where the axon originates from the cell body or soma) Neuron communication Synapse is composed of presynaptic membrane to a synaptic cleft to postsynaptic membrane. Neurons have 3 basic shapes Neurons have same basic parts, but they dont all look exactly like Multipolar neurons Numerous dendrites and a single axon and are the most common Bipolar neurons Single dendrite at one and a single axon at the other end, common in sensory systems Unipolar neurons (monopolar neurons) Single process that extends from the cell body and brances in two different directions, where one branch is input and other output Sensory neurons Detecting and transmitting changes inside and outside the body to the brain Interneurons For integration; processing and interpreting sensory information; includes most of the neurons in brain Motor neurons Executing a response or responses to sensory stimuli via effectors (muscles and glands) Glia functions Glia serve various functions, much of it in support of neuronal function Astrocytes Act to regulate extracellular environment, help in forming the BBB Microglia Act as the immune cells of the brain Ependymal cells Lime the ventricles and secrete cerebrospinal fluid Oligodendrocytes Responsible for myelination in the CNS Schwann cells Responsible for myelination in the PNS Satellite cells Surround cell bodies of sensory neurons Myelination of axons Myelinated axons conduct electrical signals much faster, electrical signal can jump between nodes of Ranvier Multiple Sclerosis Autoimmune disease that attacks the myelin of axons, causing them not to properly function Nervous system anatomical divison Divided into central nervous and peripheral nervous system Central nervous system Includes the brain and spinal cord Peripheral nervous system Includes nerves, ganglia, sensory organs, everything outside the CNS basically Somatic Nervous system Part of the Peripheral nervous system. Innvervates skeletal muscle and sensory systems (it is largely under voluntary control) Autonomic nervous system Part of the CNS that innervates cardiac muscle, smooth muscle, and internal viscera (largely under involuntary control) SNS leaving spinal cord Leaves ventral root and directly innervates skeletal muscle ANS leaving spinal cord Leaves ventral root as preganglonic axon then passes through ganglionic neuron that leaves as post ganglionic axon. Doesnt dirrectly innervate tissue ANS split into two functional divisions Sympathetic and parasympathetic nervous system, most organs and or tissues receive innervation from both Sympathetic nervous system "Exit the CNS at the thoracic and lumbar levels. Prepares body for ""fight and flight""" Parasympathetic nervous system "Fibers exit the CNS at the brain steam and sacral levels. Prepares body for ""rest and digest""" Cranial nerves Serve to innervate the head, neck, visceral organs directly. Doesnt go through the spinal cord. Some of the cranial nerves are mixed, several are exclusively sensory or motor only. Spinal nerves Information flow to and from the periphery occurs largely through spinal nerves. Exit the spinal column bilaterally and are named for the part of the spinal cord they are connected to. Mixed nerves carry both motor and sensory. Lumbar puncture Enter needle into lumbar cistern in order to obtain cerbral spinal fluid for testing Spinal cord color Cell bodies of motor dibers are located within gray matter. Dorsal root ganglia Houses the cell bodies of sensory afferent fibers. Nervous System derivation Formes from ectodermal tissue during neurulation. Gastrulation Process by whihc the embryonic germ layers are formed during blastulation (the formation of a sphere with a fluid filled cavity) Endoderm Gives rise to the digestive and respiratory tracts Mesoderm Gives rise to the skeletal system as well as muscles Ectoderm Gives rise to skin and the nervous system Neurulation Neural plate becomes the neural tube (around 22 days post) Forebrain Gives rise to the telencephalon (cerebrum) and dienephalon (thalamus and hypothal) Midbrain Virtually stays the same Hindbrain Gives rise to the metencephalon (pons and cerebellum) and the myelencephalon (medulla) Brain composed of 4 major lobes Lobes are composed of gyri (ridges) and sulci (grooves) Frontal Lobe Motor functions Parietal lobes Sensory functions Occipital lobes Visual functions Temporal Lobe Auditory functions Precental gyrus Integrating motor functions Postcentral gyrus Integrating sensory functions Basal ganglia Consist of caudate nucleus, putamen. Associated with the control of movement Limbic system Includes the cingulate gyrus and amygdala and is associated with emotion and learning. Other structures include hippocampus, olfactory bulb, and hypothalamus Hypothalamus Composed of several nuclei that control various critical funcitons such as hunger thirst and temperature. Also regulates endocrine system using pituitary gland Thalamus Major relay point for almost all incoming sensory information headed towards the cortices Brain stem Composed of the midbrain, pons (motor and sensory), and medulla (respiration and heart rate) Roof (dorsal) of midbrain Known as the tectum; made of the superior and inferior colliculi Cerebellum Helps with coordinated motor control as part of the motor circuit. Located ventral and posterior of the brain stem. Plays a role in certain aspects of cognition including learning. Brain and spinal cord covering Covered by three connective tissue layers called meninges Dura Matter outermost layer- which in areas is attached to bone Arachnoid membrane Middle layer Pia mater innermost layer- which adheres to the brain Gray matter Appearance is due to the presence of numerous cell bodies, largely associated with processing information White Matter Tissue that contains a high number of myelinated axons. largely associated with transmitting information Cerebrospinal fluid Brain has four interconnected spaces known as ventricles that contain CSF. Brain is bathed in cerebrospinal fluid for protection and nutrients Ventricles Four interconnected spaces that contain CSF. Two lateral, one on the midline, one between brainstem and cerebellum. CSF eventually exits the ventricular system and enters blood and subarchnoid space. Blood brain barrier Brain tissue is largely isolated from systemic circulation by BBB. Movement into can occur through diffusion, transport, and ion channels. Brain blood supply Four major arteries, two internal common carotids and two vertebral arteries