BIOS252 Exam 1 Review July 2024 PDF

Live Bios252 Exam 1 Review Week 1 Concepts: Identification, general location, function, and comparative characteristics of skeletal, smooth, and cardiac muscle tissue Skeletal muscle: long, thin, cylindrical in shape, multinucleated, attached to bone and skin, voluntary movement,...

Live Bios252 Exam 1 Review Week 1 Concepts: Identification, general location, function, and comparative characteristics of skeletal, smooth, and cardiac muscle tissue Skeletal muscle: long, thin, cylindrical in shape, multinucleated, attached to bone and skin, voluntary movement, striated. Cardiac muscle: short, fat, branched, uninucleated, found in the heart, attached to intercalated discs, involuntary, striated. Smooth muscle: found in hollow organs, uninucleated, involuntary, lack striations. Functions of muscle: Excitability, conductivity, extensibility, elasticity, contractility Muscle Tissue(cells) Functions location Control (neural) (movement) Skeletal Gross All muscles used in Voluntary Fine our body to move (Except respiratory (attached to bones and ocular muscles) and other muscles) Cardiac Heartbeat Heart Involuntary (ANS) Smooth Peristalsis All hallow organs in Involuntary the body except the heart Detailed gross and microscopic anatomy of skeletal muscle Sarcomere, sarcolemma, and sarcoplasmic reticulum Components of the sarcomere (z-disc, m-line, a band, I band, zone of overlap, thick filament, thin filament, zone of overlap, sarcomere) Types of proteins: contractile, structural, and Regulatory  Organization of a skeletal muscle (microfilaments, myofibril, muscle fiber, muscle fascicle, and skeletal muscle) Connective tissues of skeletal muscle (Epimysium, perimysium, endomysium) Physiology of skeletal muscle contraction and relaxation Steps to the sliding filament theory and important structures along with their functions including Actin. Myosin, Troponin, Tropomyosin, Calcium, ATP Steps involved in relaxation of a skeletal muscle. Sliding filament theory: Myosin Actin Troponin Tropomyosin Ca2+ ATP Action potential (neural control) Action Potential Main events Muscle cell Nerve cell (neuron) Polarized No Ionic exchange Relaxed No signals sent (resting) Depolarized Na+ moves in Contracted signals sent Repolarized K+ moves out Relaxed No signals sent (resting) Direction of skeletal muscle movement is from point of insertion to point of origin of the muscle. For Myosin to engage Actin to slide it to contract the muscle we need: 1. ATP is attached to myosin when it is not engaging actin. To engage actin ATP needs to release energy by removing phosphate to become ADP. ATP->ADP+ P + energy. When myosin is attached to actin you have ADP attached to its head. When it disengages actin, you have ATP attached to it. 2. Ca+ attached to Troponin to bend it so that Tropomyosin can be removed from active site of actin to make it possible for myosin to engage actin. Role of Ca2+ in neuromuscular junction and sliding filament Theory: 1. Extracellular role: Once Ca2+ is released from SR via T-tubule to extracellular environment, it will go inside the neuron (neuromuscular junction), it will attach to synaptic vesicle that contains neurotransmitter called ACH, then that ACH is released in synaptic cleft (space between neuron and muscle cell. 2. Intracellular: Ca2+ that is released inside muscle cell will attach to troponin complex to bend it so that Tropomyosin can be removed from active site of actin to make it possible for myosin to engage actin. Cell to Cell communication Chemical means: one cell releases a chemical (neurotransmitter, hormone, other chemicals) and the other cell will receive it by having a receptor at their membrane. This chemical has a message (1st messenger) For Example, ACH released from neuron and delivered a message to Muscle cell by targeting Na+/K+ channel to open so that through Na+ influx Depolarization (contraction) happens in muscle cell. ACH will open Na+/K+ channel -> depolarization ->contraction Acetylcholinesterase (enzyme) will break ACH and remove it from N+/K+ channel so that channel can close  Why switch from aerobic to anaerobic (fermentation) to produce ATP in skeletal muscles? As Skeletal muscle contract, their size will increase (bulging), they compress blood vessels which will block blood flow and interfere with delivery of Oxygen and glucose to muscle cells. Since we already have glucose stored in our muscles, we can use them, but due to lack of oxygen, we switch to anerobic (using glucose without oxygen). Skeletal muscle metabolism Aerobic respiration, anaerobic glycolysis, and creatine kinase (phosphate) conversion Principles and types of whole muscle contraction Isotonic (concentric and eccentric) and isometric Isometric Contractions: Tension increases to the muscle’s capacity, but the muscle neither shortens nor lengthens Occurs if the load is greater than the tension the muscle is able to develop. Isotonic Contractions: In isotonic contractions, the muscle changes in length (decreasing the angle of the joint) and moves the load. The two types of isotonic contractions are concentric and eccentric Concentric contractions – the muscle shortens and does work Eccentric contractions – the muscle contracts as it lengthens Nomenclature, Location, general attachments, and actions of the major skeletal muscles Use the terms list for your list of muscles you need to be able to identify the location and the list that you need to identify their location and action. Name arrangement of fascicles (unipennate, bipennate, etc.) Muscles NAME MEANING EXAMPLE DIRECTION: Orientation of muscle fascicles relative to the body’s midline Rectus Parallel to Midline Rectus Abdominis Transverse Perpendicular to Transversus abdominis midline Oblique Diagonal to midline External oblique SIZE: Relative size of the muscle Maximus Largest Gluteus maximus Minimus Smallest Gluteus minimus Longus Long Adductor longus Brevis Short Adductor brevis Latissimus Widest Latissimus doris Longissimus Longest Longissimus capitis Magnus Large Adductor magnus Major Larger Pectoralis major Minor Smaller Pectoralis minor Vastus Huge Vastus lateralis SHAPE: Relative shape of muscle Deltoid Triangular Deltoid Trapezius Trapezoid Trapezius Serratus Saw-toothed Serratus anterior Rhomboid Diamond-shaped Rhomboid major Orbicularis Circular Orbicularis oculi Pectinate Comb-like Pectineus Piriformis Pear shaped Piriformis Platys Flat Platysma Quadratus Square, four-sided Quadratus efmoris Gracilis Slender Gracilis  ACTION: Principal action of the muscle Flexor Decreases joint Flexor carpi radialis angle Extensor Increases joint Extensor carpi ulnaris angle Abductor Moves bone away Abductor pollicis longus from midline Adductor Moves bone closer Adductor longus to midline Levator Raises or elevates Levator scapulae body part Depressor Lowers or Depressor labii inferioris depresses body part Supinator Turns palm Supinator anteriorly Pronator Turns palm Pronator teres posteriorly Sphincter Decreases size of External anal sphincter an opening Tensor Makes body part Tensor fasciae latae rigid Rotator Rotates bone Rotatore around longitudinal axis NUMBER OF ORIGINS: Number of tendons of origin Biceps Two origins Biceps brachii Triceps Three origins Triceps brachii Quadriceps Four origins Quadriceps femoris LOCATION: Structure near which muscle is found Example: Temporalis, muscle near temporal bone ORIGIN AND INSERTION: Sites where muscle originates and inserts Example: sternocleidomastoid, originating on sternum and clavicle and inserting on mastoid process of temporal bone Smooth muscle Histology description of smooth muscle Know the steps to create a smooth muscle contraction. Understanding of point of origin and point of insertion in muscles. Neuromuscular junction Neurotransmitters involved. How action potential leads to muscle contraction and relaxation How neurons control muscle cells Muscle movements, terms and definitions involved. Antagonist muscles Agonist muscles Fixator muscles Prime mover muscles Fixator muscles Synergist muscles Week 2 Concepts: General functions and organization of the nervous system Take in information, process it, and send out a response. Excitability, conductivity, secretion Functional organization of the nervous system o Sensory (afferent) o Interneurons (integration) o Motor (efferent) General anatomy of the nervous system CNS: brain and spinal cord PNS: somatic and autonomic (spinal nerves and Cranial nerves) Protective roles of cranial bones and vertebral column, meninges, and cerebrospinal fluid (CSF) Layers of protection from superficial to deep: o Bones: cranial bones and vertebral column o Meninges: dura mater, arachnoid mater, pia mater o CSF – cerebral spinal fluid Meninges: Neurons Parts of a neuron and their function: dendrites, cell body (soma), axon hillock, axon, nodes of Ranvier, myelin sheath, telodendria, synaptic end bulb, synapse. Neuroglial (glial) cells 4 neuroglia of the CNS and their function o Astrocytes – create the blood brain barrier.  o Oligodendrocytes – form the myelin sheath in the CNS. o Microglial cell – immune function (phagocytosis) o Ependymal cells – create CSF. 2 neuroglia of the PNS and their function o Schwann cells – form the myelin sheath in the PNS. o Satellite cells – support PNS neurons Neurophysiology The steps involved in nerve conduction. Saltatory conduction: Current passes through a myelinated axon only at the nodes of Ranvier Voltage-gated Na+ channels are concentrated at these nodes Action potentials are triggered only at the nodes and jump from one node to the next Much faster than conduction along unmyelinated axons  Conduction difference between myelinated versus demyelinated axons Action potentials versus graded potentials Graded Potentials: Short-lived, local changes in membrane potential Decrease in intensity with distance Their magnitude varies directly with the strength of the stimulus Sufficiently strong graded potentials can initiate action potentials Action Potentials (APs): A brief reversal of membrane potential with a total amplitude of 100 mV Action potentials are only generated by muscle cells and neurons They do not decrease in strength over distance They are the principal means of neural communication An action potential in the axon of a neuron is a nerve impulse Types of summation Types of channels used for conduction: ligand-gated, voltage-gated, mechanically gated. Steps of action potential and how they involved in physiology of neurons including Polarized, Depolarized, Hyperpolarized and Repolarized. Action potential Membrane potential Ionic exchange across the membrane of neurons (axon) Action Potential Main events Muscle cell Nerve cell (neuron) Polarized No Ionic exchange Relaxed No signals sent (resting) Depolarized Na+ moves in Contracted signals sent Repolarized K+ moves out Relaxed No signals sent (resting)  Extracellular side of the membrane versus intracellular side of the membrane Net charge at resting: the difference of charges (millivoltage) between all negatively and positively charges ions. Extracellularly: Na+, K+, Cl-, Proteins (A-), Hco3- Intracellularly: Na+, K+, Cl-, Proteins (A-), Hco3- Count all negative and positive charges on both sides. At rest when there are no ionic exchanges between extracellular and intracellular side of the axon, the net charge extracellularly is Positive. Intracellularly, there will be net charge of negative. At rest (membrane): 1. Na+/K+ channels are closed. No ionic exchange 2. Extracellular side has net charge of positive, dominant ion is Na+ 3. Intracellular side has net charge of negative, dominant ion is K+ Synapses What they are and how presynaptic and post synaptic neurons function. Axo-somatic Axo-dendritic Axo-axonic Due having neurons connecting (synapse) at different levels, we can see different types of synapses such as: Axodendritic (axon of presynaptic neuron connects to dendrites of post synaptic neuron) Axosomatic Axoaxonic Dendrodendritic Excitation versus inhibition Excitation (action potential) Inhibition (No action potential) Chemicals that can promote activities in a cell by targeting specific receptors at membrane level are called 1st messengers. Examples include: - Neurotransmitters - Hormones - Chemicals These are used as cell to cell communication means. One cell will release 1st messenger and other cell will receive it at their receptor levels. Once 1st messenger is received by other cell, a cascade of reaction will initiate intracellular activities such as protein synthesis and opening ion channels. In this process often we see presence of a 2nd messenger to activate enzymes. These 2nd messengers include cAMP and cGMP cAMP ATP->ADP +P ADP->AMP+P AMP+P-ADP ADP+P->ATP