The purpose of this lab is to evaluate the relationship between motor neurons and their associated muscle’s electrical activity via neuromuscular junctions through: determining the correlation between EMG (electromyogram) activity and muscle force, observing muscle fatigue, as well as calculating the conduction velocity associated with the Achilles tendon reflex arc. An additional purpose of this lab is to demonstrate the effects of arm circumference and relative dominance on muscle fatigue. Hypothesis
creates a reflex action to activating neurons to skip the spinal cord and protect your brain. The nerve cells can be categorized by their connections, structure, and neurotransmitters. The structural classification is depending on shape and size of the cell body, its dendritic tree, axon length, and the nature of the connections it makes. The neurons with one, two, or more than two neurites, are unipolar, bipolar, and multipolar respectively. Most of neurons in vertebrate nervous systems are multipolar
Sclerosis is an insidiously developing, adult-onset, progressive anterior horn cell degeneration with associated degeneration of descending motor pathways. Despite increasing clinical and research interest, its cause remains obscure. Although many theories as to its cause have been proposed, no intervention has yet been shown to modify biologically determined motor system degeneration. There is no clear cut neuropathological diagnosis for Amyotrophic Lateral Sclerosis (ALS). Instead, clinicians must
[1]. They consist of muscle fibers that contain sarcoplasmic reticulum and the t-tubule [1]. Skeletal muscle contractions are driven by the release of acetylcholine (Ach) at neuromuscular junctions (NMJ) between motor neuron terminals and muscle fibers [2-4]. The binding of Ach with the motor end plate changes the permeability of the muscle fiber, resulting in an action potential (AP) [3]. Once an AP is initiated, it is conducted into the muscle cell through the T-tubule, which triggers the release
filament model of contraction using appropriately labeled diagrams of a relaxed and contracted sarcomere. (a.) The region of a myofibril between two successive Z discs is a sarcomere. It averages 2 micrometers long and is the smallest contractile unit of a muscle fiber. It contains an A band flanked by half an I band at each end. Within each myofibril, the sarcomeres align end to end like boxcars in a train. (b) In a relaxed muscle fiber, the thin and thick filaments overlap only at the ends of
nervous systems also consist of neurons which are a nerve cell that carries out the functions of the nervous system by sending and receiving impulses. Another neuron that I have learned about would be motor neurons these neurons are very important because they help muscles to contract and gland secretion, these motor neurons are also known as efferent nerves. The efferent neurons give impulses from the neural cell body to the target muscle or organs. Motor neurons also have a process called the axon
REVIEW SHEET EXERCISE 2 Skeletal Muscle Physiology NAME: Jasmine Young LAB TIME/DATE: 1. Define each of the following terms: • motor unit - A motor unit consists of a motor neuron and all of the muscle fibers it innervates. • twitch - Skeletal Muscle twitch is the mechanical response to a single action potential. It has three phases known as the latent, contraction, and relaxation phase. • threshold - the threshold is the minimal stimulus needed to cause a depolarization of the muscle plasma membrane
responsible for connecting the CNS to organs and the limbs of the human body (Brodal 1-18). Although each structure is unique, they all consist of nerve cells called neurons, which are considered the building blocks of the nervous system and are composed of dendrites and a single axon (Gartner and Hiatt 186-218). The structure of the neuron empowers the nervous system to interpret all incoming information, such as a smell, pain, or taste, and is responsible for sending critical nerve information that
them a striped look. The muscles are considered voluntary, which means that the contractions can be controlled. A skeletal muscle contains bundles of muscle cells. Inside each cell are threadlike myofibrils, which are divided into sarcomeres, the unit of contraction. They are bundled together by connective tissue that extends past it to form tendons. A tendon is a strap of dense connective tissue that attaches a muscle to a bone. Tendons make joints more stable by keeping the adjoining bones appropriately
branched, contain a single nucleus, have band-like striations, and are not under conscious control. They have thicker striations, called intercalated discs, where one muscle fiber joins the next fiber. Smooth muscle Smooth muscle is located in the walls of hollow visceral (internal) organs such as the intestines, stomach, urinary bladder, respiratory passages, and blood vessels. They are classified as visceral, nonstriated, involuntary muscles. The muscle fibers contain a single nucleus, no striations