PHARM 204 Glossary PDF

Basic Terminology Microscopic anatomy: Study of structures that require magnification to see. Cytology: Study of cells. Histology: Study of tissues. Gross anatomy: Study of structures seen without magnification. Morphology: Study of surface structures. Systemic anatomy:...

Basic Terminology Microscopic anatomy: Study of structures that require magnification to see. Cytology: Study of cells. Histology: Study of tissues. Gross anatomy: Study of structures seen without magnification. Morphology: Study of surface structures. Systemic anatomy: Study of organs within a given system. Developmental anatomy: Examines structural changes over time Embryology: Study of early developmental stages. Comparative anatomy: Considers similarities and differences in anatomy between animals. Clinical anatomy: Studies anatomical changes occurring during illness Surgical anatomy: Studies anatomical landmarks for surgery. Radiographic anatomy: Uses x-rays/ultrasound to study anatomy. Cross-sectional anatomy: CT/MRI/spiral scans to study cross sections of the body. Cellular level: Smallest living unit in the body, contains organelles for survival. Tissue level: Consists of many cells. Organ: Consists of a combination of tissues. Interstitium: Recent organ discovery describing space in between cells. Potentially a vector for cancer to metastasize. System: Combination of organs with a common function. Superior/inferior: Up/down to relative point. The head is superior to the legs. The diaphragm is inferior to the heart. Anterior/posterior: Front/back of relative point. The kidneys are posterior to the stomach. The stomach is anterior to the kidneys. Superficial/deep: Describes the depth. First degree burns appear superficial, while third degree burns have burned very deep into the tissue. Medial:.Middle. Your nose is medial to the rest of your face. Lateral: Away from the middle. The limbs are lateral to the body. Proximal/distal: Describes proximity regarding a relative point. The heart is proximal to the lungs and distal to the brain. Sagittal: Separates the body into left and right sections. Midsagittal: Separates the body into half equally. Transverse: Separates the body into proximal/distal sections, being cut at the waist. Coronal: Slices through the shoulders. Cell Anatomy Cytoplasm: Describes everything inside a cell. Cytosol: Intracellular fluid that generates a chemical gradient due to a higher concentration of K ions and lower concentration of Na ions. Net negative charge with lots of protein, amino acids and lipids. Contains all other organelles. Plasma membrane: Membrane spanning the entire surface of the cell. Acts as a physical barrier, regulating material exchange and providing communication adhesion and supports. Reacts to environmental changes if needed. Phospholipids: Has a hydrophilic head with hydrophobic tails. Forms the bilayer and is a major component of the membrane. Can also serve as a lipid reservoir. Peripheral proteins: Proteins on either the inner or outer layer that do not span the entire membrane. Integral proteins: Channels/carriers that are embedded in the membrane and span its entire width. Glycolipids/Glycoproteins: Involved in signaling. Not found in the inner bilayer. Glycocalyx: Formed from glycolipids and glycoproteins in the outer layer. Sterols: Molecules embedded in the inner bilayer that provide stability and regulate the membrane’s response to temperature.  Microvilli: Increases the surface area of the membrane. Can help to absorb nutrients and to circulate extracellular fluid. Diffusion: Passive movement of gases, small ions and lipid-soluble materials driven by the concentration gradient. Osmosis: Diffusion only in regards to water. Follows an osmotic gradient based on solute concentration. Aquaporins: Facilitate the movement of water for osmosis. Can be located in the lipid bilayer. Hypoosmotic: Solution has significantly less solute than compared solution. A cell placed in very salty water will have its cytosol be hypoosmotic compared to the water. Hyperosmotic: Solution has significantly more solute than compared solution. A cell placed in distilled water will have its cytosol be hyperosmotic compared to the water. Facilitated diffusion: Diffusion that requires a carrier/channel to operate. Can be bidirectional as movement of solute occurs in both directions, but will always follow the gradient. GLUT4 transporter: Facilitated diffusion of glucose into cells, mediated by insulin. Active transport: Requires energy (usually ATP) to have a carrier protein transport a solute against its gradient. Only occurs in one direction. Na/K ATPase: Common ATPase that pumps in 2 K and excretes 3 Na for every molecule of ATP. Endocytosis: Active transport (requiring ATP and Ca) of various small molecules into the cell. Does not cross the plasma membrane, and involves fusion of cell membranes. Pinocytosis: Brings small molecules and fluid into the cell. Stimuli affect rate of movement but the mechanism is not fully understood. Phagocytosis: Brings solid particles into the cell, including bacteria and other foreign matter. Steps shown below: ○ The plasma membrane wraps around the object and then detaches, engulfing said object and forming a phagosome. ○ Phagosomes fuse with lysosomes to form phagolysosomes.  ○ Contents are then processed by digestive enzymes. Exocytosis: Removes substances from the cell. Essentially the reverse of endocytosis. Lysosomes: Membrane-enclosed organelles that typically contain catalytic enzymes. Transcription: The process by which DNA is transcribed into mRNA. ○ Initially, RNA polymerase binds to DNA in the promoter region of the gene that is transcribed. ○ The DNA molecule is split. ○ RNA synthesis begins; this is called elongation. ○ Free ribonucleotides then pair up with DNA and are joined by RNA polymerase. ○ Post-transcriptional processing splices the pre-mRNA strand to remove introns. ○ Finally, the mRNA strand is transported out of the nuclear membrane into the cytosol. Translation: The process by which amino acid sequences are created using mRNA. ○ Transcribed mRNA binds to the small ribosomal subunit. ○ Initiation factors then line up the mRNA and tRNA for the initiation codon. ○ The large ribosomal subunit binds, dissociating the initiation factors. ○ Peptidyl transferase in the large ribosomal subunit catalyzes the formation of peptide bonds.  ○ Bonding continues until the termination sequence is reached, resulting in the release of the peptide. ○ mRNA will be broken down in the cytoplasm thereafter. ○ Note: If a leader sequence is reached, the protein will instead bind to either the ER or an organelle’s membrane. The free ribosomes involved will become fixed but translation will then continue as is. Rough endoplasmic reticulum: Organelle responsible for protein synthesis for secretion or integration into membranes. Ribosomes distinguish it from its smooth variant giving it a characteristic bumpy look. Smooth endoplasmic reticulum: Primarily responsible for detoxification and metabolism. Synthesizes sterols, lipids and hormones. Nucleus: Site of DNA storage, rRNA synthesis and transcription. Mitochondria: The house of power for the cell. Double-layered membrane and also has the property of autophagy. Autophagy: Mitochondria can grow, divide, or get consumed. Is essentially a cell within a cell, especially owing to its difference in membrane potential. Mitochondrial DNA is inherited separately as well. Golgi apparatus: Responsible for packaging and performing post-translational modifications on protein. Cytoskeleton: Supports the cell structure and contributes to overall movement. Microfilaments: Made up of actin protein and anchors cytoskeleton to integral proteins. Stabilizes membrane structures like protein and microvilli, additionally anchoring the cell membrane to the cytoplasm. Works together with myosin to produce movement of the cell. Intermediate filaments: Provides strength and integrity to the cell. Stabilizes organelle positions, and can contribute to some cytosol transport. Neurofilaments: Subset of intermediate filaments that specifically support nerve axons. Thick filaments: Responsible for muscle contraction, and is made up of myosin protein. Most abundant in muscle cells and has major interactions with actin. Microtubules: Composed of tubulin protein and constitutes the majority of the cytoskeleton. Change in shape causes a change in overall cell shape, and forms the main component of the cytoskeleton. Forms centrioles for reproduction as well as cilia and flagella. Paracrine: Describes a secretory cell being locally close to a target cell. Can have amine, peptide, or eicosanoid messengers. Synaptic transduction: A synapse is transferred from a neuron to the cell. Can have amino acid, amine, or peptide messengers. Endocrine: Secretory cell utilizes the bloodstream to deliver a hormone to the target receptor. Travels long distances. Messengers can be amines, steroids or peptides. Ionotropic receptors: Ion channels acting as receptors. Can change from open to closed conformation, affecting a cell’s electrical properties. Tyrosine-kinase linked receptors: Autodimerization and phosphorylation as a conformational change occurs when a ligand binds. Autodimerization: A protein dimerizing (merging) with itself or an identical instance. G-protein linked receptors: Receptors bound to a G-protein of some sort. Has three main subunits of alpha, beta and gamma. When a ligand is bound, the G-protein is activated releasing GDP and GTP, with GTP then binding to the alpha subunit. The resulting cascade then differs: Gs pathway: Stimulates the production of cAMP. ○ Upon activation of the receptor, the alpha subunit will bind to Adenylate cyclase and facilitate the conversion of ATP to cAMP. ○ cAMP activates protein kinase A (PKA). ○ PKA will then phosphorylate target proteins to activate the proper response. Gi pathway: Inhibits production of cAMP. Similar to the Gs pathway but instead inhibits conversion of ATP to cAMP.  Protein kinase A: Kinase that phosphorylates proteins. Can change activity of enzymes, transporters, ion channels, etc. Gq pathway: Instead uses second messengers IP3 and DAG to activate protein kinases. ○ When ligand binds and activates the G-protein, the alpha subunit activates PLC (phospholipase C). ○ PLC produces IP3 and DAG from PIP2. ○ DAG moves to activate PKC (protein kinase C), causing phosphorylation of protein and a response in the cell. ○ IP3 will bind to calcium channels on the ER and allow calcium efflux. ○ Calcium will complex with calmodulin and cause further response, and/or activate protein kinases for phosphorylation leading to a response. cGMP: Cyclic guanosine monophosphate. Produced from GTP by guanylate cyclase. Activates protein kinase G, and acts on other effectors. Tissue Anatomy Epithelial tissue: Tissue that covers exposed surfaces, lining internal passageways for protection, sensation and permeability control. Can also produce glandular secretions individually or as a unit. Other key characteristics are listed below. Cellularity: Epithelial cells tend to be bound tightly. Polarity: The apical surface is defined as being exposed, while the basal surface remains attached to tissue. Each surface is also specialized for a specific function. Attachment: The basal surface will be attached to a basement membrane. Avascularity: Epithelial tissue has no blood vessels within, but must instead absorb nutrients from surfaces. Sheets: Typically thin, with a sheet of cells one or more layers thick. Regeneration: Stem cells replace lost or damaged epithelial cells. Basement membrane: Attaches to the basal surface of most epithelial cells. Basal lamina: Secreted by epithelial cells and directly attaches to the basal surface. Consists of glycoproteins, proteoglycans, and microfilaments. Restricts movement of large molecules from connective tissue into the epithelium. Reticular lamina: Secreted by connective tissue. Consists of coarse protein fibres that anchor the basement membrane to the connective tissue. Simple epithelium: A single layer of cells that are fragile. Generally found in unexposed areas, with uniform polarity and shape, allowing for ease of diffusion. Will always be attached to a basement membrane and can regenerate. Stratified epithelium: Two or more cell layers, with each layer varying in height and shape. Stronger than simple epithelium, and acts as protection for exposed areas utilizing its regenerative capabilities. Squamous: Appears like a cracked egg. Cuboidal: Cells appear like stacks of cubes arranged next to each other. Columnar: Cells appear as long columns aligned in rows Simple squamous: Found in pericardial and peritoneal body cavities. Reduces friction, controls vessel permeability and performs absorption/secretion. Stratified squamous: Found on the skin, oral cavity, throat, rectum, anus, esophagus and vagina. Provides physical protection against abrasion, pathogens, and chemical attack, with the bottom having excess stem cells for regeneration. Toughened parts are keratinized. Simple cuboidal: Found on glands, ducts, portions of kidney tubules and thyroid glands. Provides limited protection and is mainly used for secretion and absorption. Stratified cuboidal: Rare. Lines some ducts such as the sweat gland duct. Provides protection, secretion and absorption. Simple columnar: Lines the stomach, intestines, gallbladder, uterine tubes and collecting ducts. Provides protection, secretion, and absorption via microvilli on apical surface. Pseudostratified ciliated columnar: Located on the respiratory tract, specifically the nasal cavity, trachea and bronchi. Provides protection and secretion, with surface cilia. Pseudostratified: Only has a single layer of cells but appears stratified due to varying heights. Transitional (pseudostratified) epithelium: Located in the bladder, renal pelvis and ureters. Permits expansion and recoil after stretching. Relaxed image on the left and stretched image on the right. Glandular epithelium: Epithelium that primarily focuses on secretion. Exocrine glands: Glands that secrete onto an epithelial surfaces by way of a duct. Serous glands: Exocrine glands that release lots of water that contain enzymes. Mucous glands: Secretes mucin glycoproteins, which combined with water creates mucous. ○ Mucous cells: Individual cellular unit. Mixed glands: Glands that are both serous and mucous, such as the submandibular salivary gland. Goblet cells: Individual cellular units of glands (unspecified in this course). Secretory sheet: Simplest multicellular exocrine gland. Consists of clusters of gland cells. Secretory sheets in the stomach secrete mucins to protect the stomach lining. Simple exocrine glands: Exocrine glands with ducts that do not branch more than once.  Simple tubular: The simplest gland that looks like a ube. Found in intestinal glands. Simple coiled tubular: Coils slightly. Found as eccrine sweat glands. Simple branched tubular: Contains a single branch. Found in gastric glands and mucous glands of the esophagus, tongue and duodenum. Simple acinar alveolar: Only exist when developing simple branched alveolar glands.  Simple branched alveolar: Branches once. Found as sebaceous glands (those that secrete oil). Compound tubular: Looks like a tree branch. Found as mucous glands in the oral cavity, bulbourethral glands in the male reproductive system, and in the seminiferous tubules. Compound acinar alveolar: Extensively branched acinar. Found in mammary glands.  Compound tubuloalveolar: Combination of acinar and tubular with extensive branching. Found in salivary glands, glands of respiratory passages and the pancreas. Endocrine: Secretions are released by exocytosis directly into interstitial fluid without ducts. Eccrine: Method of secretion for glandular epithelia involving exocytosis through secretory vesicles. Applies to saliva from serous cells and mucins from goblet cells. Apocrine: Secretions are released during the shedding of the apical cell, of which is packed with secretory vesicles. Regrows the cell to restart the process. Holocrine: The entire cell is lysed to release secretions. Requires complete regeneration to resecrete. Neuronal Anatomy Sensory neuron: A neuron that carries information from the PNS to the CNS. Somatic sensory neuron: Transmits info from the environment. Visceral sensory neurons: Transmits info from internal organs. Motor neurons: A neuron that carries motor commands from the CNS to an effector. Gray matter: Nervous tissue dominated by neuronal soma and dendrites. White matter: Nervous tissue with myelinated axons. Dendrites: Neuronal processes that are specialized to respond to specific stimuli. Soma/perikaryon: Cell body of a neuron. Myelin: Membranous wrapping of a neuron’s axon. Produced by certain neuroglia, and increases the speed of action potential propagation. Axon: Long slender cytoplasmic process that conducts nerve impulses. The larger the diameter, the faster the impulse. Hillock: Nerve impulses reach threshold here and initiate propagation. Terminals: Ends of the neuron that usually affect another neuron or organ. Neuroglia: A supporting cell that interacts with neurons. Helps to regular extracellular environment, participates in pathogen defense and repairs nervous tissue. Astrocytes: CNS exclusive. Largest and the most numerous type as part of the blood brain barrier. Oligodendrocytes: CNS exclusive. Form the myelin sheath, as well as internodes and myelin sheath gaps. Can myelinate multiple neurons at once. Microglia: CNS exclusive. Phagocytic cells that are involved in immune response. Ependymal cells: CNS exclusive. Involved in CSF production, it makes up the cellular lining called the ependyma. Satellite cells: PNS exclusive. Surrounds neuron cell bodies in ganglia, regulating oxygen/CO2 levels, nutrients, and neurotransmitter levels.  Schwann cells/neurolemmocytes: PNS exclusive. Surrounds all axons in the PNS, though can only myelinate one neuron at a time due to requiring the entire cell to surround the neuronal axon. Action potential: Electrical impulse that travels through neurons. Requires a voltage threshold to be met before propagation occurs. Ion channels: Protein channel that allows the flow of ions to occur. Ligand-gated: Ion channels that require binding of a ligand to activate. Found at dendrites and soma. ○ Phosphorylation/G-protein gated: Ligand is the phosphorylation or dephosphorylation of a channel. Same distribution as ligand-gated channels Voltage-gated: Requires a change in membrane potential to activate. Found at the axon hillock and at the terminal. Mechanically-gated: Mechanical stimuli activate the channel. Found on the receptor ends of some sensory afferent neurons. Passive: Always open. Found throughout a neuron. ANS Neuroanatomy ANS: Autonomic nervous system that functions outside of the conscious awareness. Responsible for routine adjustments to body systems. Part of the efferent component of the PNS. Requires pre- and postganglionic neurons from the CNS to the effector. Sympathetic: Activates in fight/flight situations. Cell bodies of preganglionic neurons are located in the grey matter of thoracic/lumbar segments.  ○ Adrenal medulla pathway: Only pathway to be directly innervated by preganglionic neurons. Releases epi and norepi into blood. Parasympathetic division: Activates in rest/digest situations. Cell bodies of preganglionic neurons are in the brain stem or grey matter of sacral segments. All postganglionic fibres release ACh. Acetylcholine: Common neurotransmitter of the ANS. Preganglionically, it has an excitatory effect but postganglionically it is usually inhibitory with some exceptions. Norepinephrine/noradrenaline: Neurotransmitter released from postganglionic ganglia of the sympathetic ANS. Adrenergic receptors: See above. I hope you studied pharmacology… Spinal cord: Main relay centre from peripheral neurons to the CNS. Dorsal horns: Located closer to the back of the body, and receives afferent input. Consists of grey matter.  Ventral horns: Located close to the front of the body, and sends out efferent output. Consists of grey matter. Spinal nerves: Formed by merging dorsal and ventral roots together. Since the spinal cord is segmented, one pair of spinal nerves exists per segment. Spinal pairs are organized into groups depending on positions within the spine (see above). PNS Neuroanatomy PNS: Network of peripheral neurons outside of the spinal cord and brain. Afferent PNS: Receives sensory signals that are integrated into the CNS. Efferent PNS: Gives CNS motor commands to effectors. Sensory receptors: Receptors that detect a specific form of energy in the external environment. Modalities: Types of stimuli that a sensory receptor can detect. ○ Mechanical: Includes pressure, touch, stretch, acceleration and sound waves. Received by mechanoreceptors. ○ Light: Photons of light. Received by photoreceptors. ○ Chemical: Including taste (in saliva) and smell (in mucous). Chemicals in extracellular fluid also indicate pain. Received by chemoreceptors. ○ Temperature: Hot and cold. Received by thermoreceptors. Somatosensory receptors: Primarily sense pain. Can be polymodal or specific, including chemical, thermal, and mechanical receptors. Law of specific nerve energies: A given sensory receptor is specific for each modality. Adequate stimuli: A stimulus that is of the same modality of the receptor, within their receptive field and above threshold. Somatic sensation: Includes sensation from skin, muscles, tendons, and joints. Includes tactile and temperature sensation, proprioception, and nociception. Direct configuration: Specialized ending of an afferent neuron is directly affected and thus can send a signal immediately to trigger an action potential. Typically occurs as a result of pain. Indirect configuration: The stimulus acts on a specialized cell, which then releases a transmitter onto an afferent neuron. Can occur as a result of light stimuli. Sensory unit: One afferent neuron and all of its sensory receptors, which belong to the same configuration. Receptive field: Area of a receptive surface that when stimulated, results in a change in activity of an afferent. Typically perceived as one point. Tactile acuity: The ability of a receptive field to discern small structural details in objects that touch the skin. The smaller the receptive field, the better the tactile acuity. Transduction: Change of environmental stimuli into electrical signals by opening/closing channels. Slowly adapting: Continual activity after a sharp increase in receptor potential. Will continue to fire until the stimulus is deactivated. Rapidly adapting: Initial activity at the very start and end of the stimulus. No activity in between. Frequency coding: A higher sustained stimulus equals a higher frequency of action potentials. Population coding: A higher stimulus activates more receptors. Receptors may be on the same afferent, or from multiple afferents. From the same afferent: Multiple receptor potentials summate to increase depolarization, essentially making the same signal stronger. From multiple afferents: Increased number of active afferents increases number of signals. Somatosensory pathway: First-order → Spinal cord/brain stem → Second order → Thalamus → Third-order → Cortex. Modality coding: Each modality has a specialized pathway that will project to a certain cortex. Location coding: Pathways project to specific regions of their target, which is arranged by body part and size of receptive field. Nociceptors: Receptors that detect the unique modality of pain. Specifically, they respond to severe mechanical stimuli, temperatures, or specific chemicals. Transient receptor potential (TRP) channels: Nonselective cation channels that respond to temperature. ○ TRPV1: Activated by heat, acids and capsaicin. ○ TRPA1: Activated by mechanical, cold, and chemical stimulation.  ○ TRPM8: Responds to menthol (cold). Acid sensing ion channels (ASIC): Sensitive to pH changes. Located on nerve endings. Skin mechanoreceptors: Refer to above table. Skin thermoreceptors/nociceptors: Refer to above table. Fibre types: Refer to above table, with the main focus being on Aβ, Aδ and C fibres. First pain: Activates through Aδ fibres, causing a release of glutamate at synapses with 2nd order neurons in the dorsal horn. Faster than second pain. Described to be sharp, pricking pain as a result of intense mechanical stimuli or heat. Small receptive fields. Second pain: A slower pain pathway from C fibre activation, releasing glutamate and substance P at 2nd order neurons in the dorsal horn. Applies to more dull, aching, burning pain and is triggered by polymodal nociceptors with large receptive fields. Nociceptive pain: Detects an unpleasant, potentially damaging stimulus for protective purposes. Inflammatory pain: Following an injury, inflammation occurs to protect the damaged area and promote further healing. Involves release of pro-inflammatory factors. Pathological pain: Pain due to nerve injury, chronic inflammation or otherwise. Undesirable. Hyperalgesia: Exaggerated response to stimuli. Allodynia: Sensation of pain to normally innocuous stimuli. Ventrolateral spinothalamic pathway: See above. Primarily used for nociception/temperature. Referred pain: Pain on a visceral organ is felt as pain on the surface of the body. Convergence-projection theory: Synapses of primary afferents from viscera synapse onto the same 2nd order afferents used by nociceptors in the skin, causing referred pain. Neuropathic pain: Caused by damage/dysfunction to nerves causing highly sensitive nociceptors, and causes a burning sensation that can be spontaneous or as a result of light touch. Exacerbated by sympathetic outflow and can eventually result in hyperpathia. Interoceptors: Monitor many visceral functions, including deep pressure and pain. Exteroceptors: Monitor the outside environment, like touch, temperature, etc. Proprioceptors: Monitor position and movement of skeletal muscles. CNS Neuroanatomy Brain: Primary central nervous system organ. Contains 20 billion neurons and accounts for 95% of nervous tissue. A basic diagram is shown above. Lateral Ventricles (1 and 2): Located in parietal lobes of cerebral hemispheres, separated by the septum pellucidum. Communicates with Ventricle 3 through interventricular foramen. Largest of the ventricles. Ventricle 3: Located in the diencephalon, and communicates with Ventricle 4 through cerebral aqueduct. Ventricle 4: Between pons and cerebellum, linking to the central canal directly. Has numerous foramina on roof to communicate with subarachnoid space. Smallest of the ventricles. Dura mater: Outermost layer of the cranial meninges. Splits into 2 layers, with the space between them containing dural sinuses. Periosteal cranial dura: Outermost layer of the dura mater. Closely associated in the cranial bones and can be felt on the anterior fontanelle of a baby. Meningeal cranial dura: Innermost layer of the dura mater. Falx cerebri: Spatial layer that extends into the longitudinal fissure. Attached to crista galli and tentorium cerebelli. Contains superior sagittal sinus and inferior sagittal sinus.  Tentorium cerebelli: Separates cerebellar hemispheres from the cerebral hemispheres. Extends across cranium at right angles to falx cerebri. Contains the transverse sinus. Falx cerebelli: Extends from tentorium cerebelli and contains the occipital sinus. Separates the cerebellar hemispheres. Diaphragma sellae: Lines sella turcica of sphenoid bone, anchoring the dura mater to said bone. Encases the pituitary gland. Dural venous sinuses: Channels in between dura mater layers that receive some CSF to circulate. Consists of blood and endothelium. Superior sagittal sinus: Dural venous sinus located on the upper border of the falx cerebri. Inferior sagittal sinus: Dural venous sinus located on the lower portion of the falx cerebri. Transverse sinus: Dural venous sinus that courses laterally with the tentorium cerebelli. Subdural space: Space between the arachnoid mater and dura mater. Arachnoid mater: Second layer of the cranial meninges. Consists of weblike material that underlines it (trabeculae). Arachnoid granulations: Projections of the arachnoid mater that contains CSF. Said CSF then flows into venous circulation. Pia mater: Attached to the surface of the brain and is anchored by processes of astrocytes. Follows the natural sulci and gyri, and additionally helps to anchor larger blood vessels of the cerebrum. Choroid plexus: A grouping of blood vessels located in the ventricles of the brain. Contains ependymal cells to form CSF. All capillaries are fenestrated. Cerebrospinal Fluid (CSF): Circulating fluid that prevents contact of neural tissue with bones. Provides support and transport of nutrients/waste. Appears with colourless plasma and low cell/protein content. Blood brain barrier (BBB): Grouping of astrocytes near all blood vessels of the brain. Provides tight junctions, allowing lipid-soluble material and less water-soluble material. Has four major sites of variance. Hypothalamus BBB: Has increased permeability for hormone diffusion. Pineal gland BBB: Very permeable allowing for gland secretions to be released. Choroid plexus BBB: Fenestrated/no tight junctions. Ependymal cells instead form a blood-CSF-barrier. Posterior Pituitary BBB: Permeable for the sake of releasing hormones. Medulla oblongata: Connects brainstem to spinal cord, acts as a relay for the thalamus and brainstem as well. Regulates visceral functions without conscious control. Gracile nucleus + cuneate nucleus: Passes somatic sensory info to thalamus. Solitary nucleus: Processes visceral sensation from spinal and cranial nerves. Olivary nuclei: Relays info from cerebrum, spinal cord, diencephalon and brainstem to cerebellum. Reticular formation: Contains autonomic nuclei acting as reflex centres that receive input from cranial nerves and the rest of the CNS. ○ Cardiovascular centres: Set heart rate and contraction strength. ○ Respiratory rhythmicity centres: Sets pace of breathing. Pons: Bridges the connection between the cerebellum and brainstem, relaying information to the thalamus in addition. Primarily regulates somatic and visceral motor functions. Varying functions shown in the table above. Transverse fibres: Connect nuclei when relaying commands. Cerebellar peduncles: What relaying nuclei are made of. Mesencephalon (midbrain): Processes auditory and visual information, maintaining consciousness and alertness. Also involved with reflexive somatic motor responses to stimuli. Corpora quadrigemina: Two pairs of nuclei found within the mesencephalon. Tectum: Responsible for processing auditory and visual stimuli. Inferior colliculi: Processes auditory stimuli.  Superior colliculi: processes visual stimuli. Red nucleus: Regulates involuntary control of background muscle tone and limb position. Substantia nigra: Regulates activity in basal nuclei. Loss of neurons in this area causes Parkinson’s. Cerebral peduncles: Present ventrolateral here. Serve the same relaying function as in the pons. Diencephalon: Contains the epithalamus, thalamus and hypothalamus. Epithalamus: Contains the pineal gland, producing melatonin. Thalamus: Splits into a right and a left, connected by the interthalamic adhesion. Relays information to the cerebrum, and processes sensory information. ○ Anterior nuclei: Part of the limbic system. ○ Medial nuclei: Relays info to the frontal lobe. ○ Ventral nuclei: Relays information to parietal lobes. ○ Posterior nuclei: Relays information to occipital lobes. Also includes pulvinar nuclei, lateral geniculate nuclei and medial geniculate nuclei. ○ Lateral nuclei: Adjusts activity in cingulate gyrus and parietal lobe. Cingulate gyrus: Part of limbic system for emotions/behaviour.  Hypothalamus: Involved in emotions, thirst, and some habitual activity. Extends from above the optic chiasm to mammillary bodies. Subconsciously controls skeletal muscle and other visceral functions (e.g. heart rate). ○ Infundibulum: Connects to the pituitary gland from the hypothalamus. ○ Tuberal area: Midsagittal section of the hypothalamus. ○ Supraoptic nucleus: Secretes ADH.  ○ Paraventricular nucleus: Secretes oxytocin. ○ Pre-optic area: Regulates body temperature. ○ Suprachiasmatic nucleus: Regulates circadian rhythm. ○ Autonomic centres: Controls heart rate and BP via regulation of the medulla oblongata. Cerebellum: Second largest brain part, has 2 hemispheres. Coordinates somatic motor function and adjusts output of somatic motor centres for smooth function. Folia cerebri: Folds similar to gyri of the cerebellum. Primary fissure: Separates anterior and posterior lobes. Vermis: Narrow band of cortex that separates the hemispheres. Cerebellar cortex: Controls subconscious coordination of movement. Arbor vitae: Connects cerebellar cortex with cerebellar peduncles Cerebellar peduncles: Splits into three types based on location. ○ Superior: Connects cerebellum with midbrain, diencephalon and cerebrum. ○ Middle: Communicates between cerebellum and pons.  ○ Inferior: Connects cerebellum and medulla oblongata. Cerebrum: Largest portion of the brain. Surface consists of gray matter. Responsible for consciousness, intellectual functions, memory storage, and conscious function of skeletal muscle. Has 2 hemispheres separated by a longitudinal fissure. Sulci: “Grooves” in the cerebrum. Gyri: “Ridges” in the cerebrum. Longitudinal fissure: Separates hemisphere. Corpus callosum: Connects left and right hemispheres. Lateral sulcus/fissure: Separates temporal, frontal and parietal lobes. ○ Located deep within the lateral sulcus. Responsible for sensory, motor, emotion, and cognitive functions. Central sulcus: Separates frontal/parietal lobes.  Frontal lobe: Consciously controls skeletal muscles. Temporal lobe: Consciously perceives auditory/olfactory stimuli. As deep as the insula. Parietal lobe: Consciously perceives touch, pressure, vibration, pain, temperature and taste. Occipital lobe: I like my vision too.  Precentral gyrus: Anterior to the central gyrus. Has pyramidal cells that direct voluntary movements through control of motor neurons. Is part of the primary motor cortex. Postcentral gyrus: Posterior to central sulcus. Neurons receive information for touch, pressure, pain, taste, and are associated with the visual, auditory, olfactory and gustatory cortices. Is part of the primary somatosensory cortex. Association areas: Responsible for integrating and understanding sensory or motor information. ○ Somatosensory association area: Allows for the understanding of size, form, and texture. ○ Premotor cortex: Uses memories of learned movement to coordinate motor activities through the motor cortex. ○ Visual association area: Visually recognizes and interprets objects. ○ Auditory association area: Recognizes sound. Steps for movement: Please see this diagram. If you’ve read this far I commend you this is so last minute :( Pyramidal tracts: Direct commands from the motor cortex direct fine, discrete movements in extremities. Extrapyramidal tracts: Other directions for movement that do not originate from the motor cortex. Central white matter: Consists of various bundles, including: Association fibres: Tracts that interconnect areas of the neural cortex within a hemisphere (arcuate fibres and longitudinal fasciculi). Commissural fibres: Tracts that interconnect the two hemispheres (anterior commissure and corpus callosum). Projection fibres: Tracts that link the cerebrum with other regions of the CNS. Internal capsule: Tracts of afferent and efferent fibres. Basal nuclei: Masses of gray matter embedded in white matter inferior to lateral ventricles. Involved with subconscious control/integration of skeletal muscle tone, coordination of movement patterns, and relay of information from the cerebral cortex. Caudate nucleus: Involved in motor control, learning and emotion. Putamen: Regulates voluntary movements and procedural learning. Globus pallidus: Inhibits excessive movement and fine-tunes motor actions. Subthalamic nucleus: Modulates motor control by preventing involuntary movements. Substantia nigra: Produces dopamine, essential for smooth motor control. Carotid arteries: Any arteries that ascend the neck. Internal carotids: Carotids that enter the skull to supply the brain directly with blood. Carotid sinus: Contains baroreceptors and chemoreceptors. Ophthalmic artery: Supplies the eyes. Anterior cerebral artery: Supplies frontal and parietal lobes, with the communicating artery connecting R and L anterior cerebral arteries. Middle cerebral artery: Supplies midbrain and lateral surfaces. Covers frontal, parietal and temporal lobes. External carotids: Supply the neck and outside of the skull. Branches into the: Lingual artery Facial artery Occipital artery Superficial temporal artery Vertebral arteries: Has a left and right. Originate from the vertebrae as per the namesake. Basilar artery: Fusion of both vertebral arteries. Supplies pons (with extra branching), medulla, and midbrain. Posterior cerebral artery + Posterior communicating artery: Connect basilar artery and internal carotid arteries. Also supplies inferior and medial temporal/occipital lobes, with the inclusions of hippocampus, thalamus and primary visual cortex. Circle of Willis (cerebral arterial circle): Ring-like anastomosis between the basilar and carotid arteries. Functions as a safety mechanism in regards to blood supply from carotids and vertebral arteries. Cerebellar arteries: Arteries that supply the cerebellum. Superior cerebellar Anterior inferior cerebellar Posterior inferior cerebellar Cerebral perfusion pressure: Pressure at which blood is delivered to the brain at the capillary level. Calculated by subtracting the ICP from the MAP. ICP: Intracranial pressure. Typically 5-15mmHg; anything over 20 can cause perfusion issues and the loss of cerebral blood flow. MAP: Mean aortic pressure over the cardiac cycle.. Anywhere from 60-150mmHg; should be kept above 65mmHg for optimal systemic perfusion. Regulated via negative feedback by baroreceptors and ANS. ○ If too low: Hypotension and inadequate perfusion. ○ If too high: Hypertension, with stressed heart and vessels. Neurotransmitters (Note: some definitions are repeated here with updated info) Acetylcholine: Produced by converting Acetyl CoA and choline using choline acetyl transferase (CAT) Acetylcholinesterase: Breaks down acetylcholine in the synaptic cleft, producing acetate and choline. Nicotinic receptors: Ionotropic, involved with reward and anti-anxiety pathways. Acetylcholine is the main ligand. Muscarinic receptors: Metabotropic, located at the NMJ and inside the ANS. Acetylcholine is the main ligand. Synaptic transmission: Referring to the above diagram: 1: Acetylcholine is made using CAT. 2: Vesicles act as storage reservoirs for acetylcholine.  (Not shown) An action potential reaches the terminal, opening voltage-gated calcium channels. 3: Vesicle docking is triggered and acetylcholine is secreted. 4: Acetylcholine binds to a postsynaptic receptor. This causes a response in the postsynaptic cell. 5: Acetylcholinesterase breaks down free acetylcholine into choline and acetate. 6: Byproducts are recycled back into the axon terminal. Alzheimer’s: Progressive degeneration of cholinergic neurons at the base of the forebrain. Caused by amyloid plaques and neurofibrillary tangles, and causes a loss of cholinergic input from the basal forebrain. Symptoms include memory loss, language, motor and perception deficits alongside chronic confusion. Myasthenia gravis: Most commonly caused by autoimmune destruction of nicotinic receptors of the motor endplate. Causes weakness of muscles, and drooping of eyes. Treated using acetylcholinesterase inhibitors. Biogenic amines: Includes catecholamines, serotonin and histamine. Catecholamines: Type of neurotransmitter derived from tyrosine that includes epinephrine, norepinephrine and dopamine. Dopamine: Binds to dopaminergic neurons, and is synthesized from L-DOPA. Loss of activity can cause motor deficits (Parkinson’s) and excess activity is implicated in schizophrenia. As a key component of reward pathways, heightened activity is associated with substance addiction. Noradrenaline: Synthesized by dopamine beta hydroxylase from dopamine. Deficits of adrenergic activity associated with depression. Monoamine oxidase (MAO): Breaks down biogenic amines. COMT: Inactivates biogenic amines through methylation of a group. Serotonin/5-HT: Derived from tryptophan, and binds to 5-HT receptors. Actions terminated by SERT (blocked by SSRI for depression treatment) in addition to MAO. Cell bodies are mainly located in the brainstem with widespread projections. Main roles include sensory/motor function, mood, anxiety, and regulation of pain. Glutamate: Amino acid transmitter that is the main excitatory CNS neurotransmitter. Can bind to some metabotropic receptors that mostly mediate inhibitory responses, but also binds to ionotropic receptors. Plays roles in long-term potentiation, and several mental disorders. Synthesis shown above. AMPA receptors: Ionotropic; Is a sodium channel. Kainate receptors: Ionotropic; Is a sodium channel. Overactivation can result in excitotoxicity. NMDA receptors: Ionotropic; Calcium channel regulated by magnesium. Inhibited by phencyclidine and memantine. Glutamate acts as a co-agonist with glycine. Aspartate: Works in a similar fashion as glutamate. GABA: Main inhibitory neurotransmitter in the brain. Reduces neuronal circuit activity. GABAA: Ionotropic; Chloride channel that also binds to benzos, barbs and good ‘ol liquid courage. GABAB: Metabotropic receptor. GABAC: Ionotropic receptor in the retina. Glycine: Main inhibitory neurotransmitter in the spinal cord and brainstem. Binds to ionotropic chloride channels, and maintains balance of excitatory/inhibitory influences on motor neurons. Enkephalin: Endogenous opioid that binds to opioid receptors. Neurons are located in the brain stem and dorsal horn of the spinal cord, with obvious roles in pain suppression. Weirdly associated with the letter “L” and strange, abnormal creatures. Substance P: Has a role in pain sensation. Nitric oxide: Not stored and is synthesized on command. Modulates neurotransmitter activity and is associated with pain and vasodilation. Please refer to PHARM 203. Endocannabinoids: Synthesized from membrane phospholipids and targets CB1 and CB2 receptors (metabotropic). Active ingredients of cannabis mimic their effects. Cardiology Heart: Pumps blood throughout the body. Beats at about 70bpm and pumps at 11Lpm. About the size of a clenched fist. Left atrium: Pumps blood returning from the pulmonary vein into the left ventricle. Right Atrium: Is filled by the vena cavae and pumps blood into the right ventricle. Left ventricle: Pumps oxygenated blood into systemic circulation through the aorta. Right ventricle: Pumps deoxygenated blood into pulmonary circulation through the pulmonary artery. Pericardium: Surrounds the outer surface of the heart. ○ Fibrous: Outer layer of the pericardium. ○ Serous: Inner layer of the pericardium. Subdivides into: Visceral layer/epicardium: Inner layer attached to the surface of the heart. Parietal layer: Adjacent to the fibrous pericardium. Epicardium: See Serous pericardium. Myocardium: Composed of cardiac tissue, connective tissue, blood vessels and nerves. Responsible for contracting the heart. ○ Cardiac muscle cells: Striated muscle that can involuntarily contract. Has an abundance of mitochondria and myoglobin for aerobic respiration, with extensive circulatory supply. Innervated by the ANS. ○ Intercalated discs: Specialized cell to cell junctions that allow cells to act in unison when contracting. Desmosomes lock cells together during a contraction. ○ Gap junctions: Connect cardiac muscle cells electrically. Allows the contraction signal to be received uniformly. Endocardium: Internal, endothelial surface of the heart that comes into contact with blood. Pulmonary circuit: Flow of blood starting from the right ventricle and ending in the left atrium. The main goal of this circuit is to oxygenate blood for systemic circulation. Has overall high blood pressure. Pulmonary artery: Carries deoxygenated blood away from the heart into the lungs. Pulmonary vein: Carries oxygenated blood back into the heart. Autorhythmicity: Property by which a cell can generate its own electrical rhythm. Pacemaker cells: Cells that spontaneously depolarize to coordinate the heart rhythm. Located on the SA and AV nodes. Conduction fibres: Rapidly conduct action potentials from pacemaker cells at around 4ms/. Found on internodal pathways, the bundle of His, and Purkinje fibres. Sinoatrial (SA) node: The fastest and first pacemaker of the electrical conduction pathway. Set to fire 70-80 action potentials a minute. Can be altered however by the ANS. Internodal pathways: Electrical pathways that exist between the SA to AV node. Has a slight delay causing a slowdown in signal for the AV node. Atrioventricular (AV) node: Receives the SA node signal, though with a 100ms nodal delay. Fires at about 40-60 action potentials/minute. Innervated by the ANS. Bundle of His: Atrioventricular bundle that receives a signal from the AV node. Splits into left and right to innervate both sides of the heart. Firing rate of action potentials is about 20-40 a minute. Punkinje fibres: Transmits the final impulse to all other myocardial cells. Innervates many ventricular cells, and has a firing rate of about 20-40 action potentials a minute. Phases of cardiac ionic activity: See above for visual diagram. Phase 0: Cells initially have increased Na permeability, allowing the cell to depolarize after threshold. Phase 1: Permeability decreases after sharp depolarization. Phase 2: Increased permeability to Ca and decreased K causes a plateau in the potential. This causes a longer duration of 250-300ms for the contraction itself. Phase 3: Repolarization occurs and K is let back into the cell while Ca has decreased permeability. Phase 4: The cell is at rest and is prepared for another contraction. Cardioacceleratory centre: Located in the medulla oblongata. Increases heart rate and activates sympathetic neurons. Cardioinhibitory centre: Located in the medulla oblongata. Activates parasympathetic neurons and decreases heart rate. Innervated by the vagus nerve. Outer adventitia: Outermost layer of a blood vessel that anchors it. Media: Middle layer of a blood vessel that is lined with smooth muscle. Can constrict or dilate a vessel. Intima: Endothelium of a vessel. Arteries: Blood vessels that carry blood away from the heart. Compared to veins, they have thicker walls, more smooth muscle, thin elastic membranes in media and intima, and no valves. Additionally, they retain their circular shape when cut and their endothelial lining has pleated folds. Veins: Blood vessels that carry blood towards the heart. Thinner walls, less smooth muscle, no pleated folds and no elastic membranes compared to arteries. Due to this, they will also collapse when cut. However they also contain one-way valves to prevent blood backflow. Elastic arteries: 2.5cm diameter arteries with all elastic membranes. Very resistant and is able to use recoil during diastole to pump blood forward. Aorta, pulmonary trunk, brachiocephalic trunk Muscular arteries: 0.4cm in diameter which can be changed with ANS control. Radial, ulnar, external carotid, brachial, femoral, mesenteric arteries Arterioles: 30 micron diameter arteries with thin adventitia. Has incomplete muscle layers in media but can still control blood flow between arteries and capillaries. Capillaries: 8 micron diameter. Incredibly delicate without any adventitia or media, and is responsible for material exchange. Continuous: Capillaries with complete endothelial lining. Most common type found in the CNS/skin. Fenestrated: Capillaries with incomplete endothelial lining, using pores to increase exchange rate. Found in the kidneys, small intestine and endocrine glands. Sinusoids/discontinuous: Capillaries that have incomplete endothelial lining with large gaps and pores. Found in liver, spleen, and lymph nodes. Systemic circuit: Describes the blood flow all over the body. Has a lower blood pressure than the pulmonary circuit, with thicker walls to facilitate long-distance travel. Aorta: The largest vessel in the body, split into three components. Ascending aorta: First part of the aorta that receives freshly oxygenated blood. Splits off into coronary arteries at its base. Aortic arch: Top portion of the aorta that splits into many vessels, with some of them subdividing further. Below is a list of them in the chest and upper limb: ○ Left common carotid: Supplies the left side of the head and brain. ○ Left subclavian: Supplies the left arm, brain and spinal cord. ○ Brachiocephalic trunk  Right subclavian artery: Supplies right arm, right head, brain and spinal cord. Right vertebral Right thyrocervical Right intestinal thoracic Right axillary ○ Right brachial Right radial Right ulnar Right common carotid Descending aorta: Heads down into the thoracic cavity and GI circulation. Coronary arteries: Supply heart with oxygenated blood from the ascending aorta. Splits into left and right. They have the highest pressure in the systemic circulation, as the blood demand of the heart at maximum exertion increases 9x! Left coronary artery: Larger in diameter and supplies more blood to the left ventricle. Right coronary artery: Has atrial branches to supply right and left atrium. Coronary veins: Drain deoxygenated blood from the heart into the coronary sinus, which then drains into the right atrium. Lymphatic system: System of vessels, nodes, and organs that return excess filtrate to circulation. Open system, moving from capillaries to veins. Veins will drain into the thoracic duct and then into the right atrium. Has valves much like regular veins, with lymph flow through lymphatic veins being similar to blood flow in regular veins. Lymph: Fluid of the lymphatic system that is mostly excess filtrate. Lymph node: Areas where foreign material will undergo an immune reaction. ECG/EKG: Electrocardiogram. Measures electrical activity of the heart externally through surface currents. P wave: Represents atrial depolarization. QRS complex: Signifies ventricular depolarization and atrial repolarization. T wave: Represents ventricular repolarization. PQ segment: Shows AV nodal delay. QT segment/interval: Represents ventricular systole. Prolonged QT can cause irregular heartbeats and tachycardia. TQ segment/interval: Represents ventricular diastole. Cardiac cycle: See above diagram for full details. Ventricular filling: Shown as phase 1 above. Consists of atrial systole filling ventricles, but also a minor amount originating from a previous cycle.  Isovolumetric ventricular systole: Shown as phase 2 above. An initial increase of pressure pushes the AV valves closed, though it is not high enough to open the semilunar valves. Ventricular ejection: Shown as phase 3 above. Semilunar valves open as pressure builds. Pressure shoots up to be higher than in the arteries, forcing blood out of the heart. Blood pressure will then drop rapidly after ejection. Ventricular diastole: Shown as phase 4 above. Blood pressure drops further as the ventricles relax. Reverse blood flow pushes semilunar valves back together, and blood flows into the relaxed atria. AV valves open and fill atria passively, though no blood enters or leaves the ventricle at this point. Tricuspid: AV valve that regulates blood flow on the right side between the atrium and the ventricle. Bicuspid: AV valve that regulates blood flow on the left side between the atrium and the ventricle. Pulmonary valve: Semilunar valve that regulates blood flow from the right ventricle to the pulmonary artery. Aortic valve: Semilunar valve that regulates blood flow from the left ventricle to the aorta. Diastole: Pressure measured at the lowest point, when the blood is leaving the aorta and the aortic valve closes. Systole: Pressure measured at the highest point, when the blood rushes into the aorta. Dicrotic notch: When the aortic valve closes at the end of systole, the backflow causes a slight pressure increase. Lub: Sound of the AV valves closing. Dub: Sound of the semilunar valves closing. Baroreceptors: In the aortic arch and carotid sinuses. Respond to stretching from pressure changes in arteries.