After fertilization, the zygote gives rise many cells to form the embryo. Cells and tissues chapter 3 answer key. The general appearance of microglia is similar to oligodendrocytes, although they are smaller and have undulating processes with spine-like projections. This area is free of ribosomes and most other cell organelles, with the exception of cytoskeletal elements and organelles that are being transported down the axon. Connective tissue, as its name implies, binds the cells and organs of the body together.
The dendritic processes and spines of neurons are essentially expansions of cytoplasm containing most of the organelles found in the cell body. This virtual slide box contains 275 microscope slides for the learning histology. View this slideshow to learn more about stem cells.
Often, neurons that look similar have strikingly different properties. These functions will be discussed in later sections. 17, the surface facing the ventricle contains many microvilli and cilia. Moreover, more than one oligodendrocyte contributes to the myelination of a single internode of an axon.
15 to facilitate the conduction of the action potential through saltatory conduction. Morphologically the "dendrite" and the "axon" may, therefore, be indistinguishable. C. Fibrous astrocytes. Characteristics of nuclei, including size, shape, staining intensity, and distribution of chromatin, are used to distinguish cell types in pathological material. Neurofilaments are a type of intermediate filament found in nerve cells. Embryonic Origin of Tissues. Specific types of intercellular junctions have been noted between the processes of protoplasmic astrocytes. 8 Cellular Elements at the Typical Nerve Terminal. 14, astrocytes form a complete lining around the external surface of the CNS (glial limitans) and around blood vessels (perivascular feet). Many of the terms used in this section are defined below. Chapter 3 cells and tissues quizlet. Link to chapter three in the OpenStax Anatomy & Physiology 2e book. Organs are assembled from the four basic types of tissues and have cells with specialized functions.
Lysosomes contain enzymes that digest compounds that originate inside or outside the cells. The nucleus in neurons is spherical and ranges in diameter from 3 to 18 micrometers depending on the size of the neuron. This preview shows page 1 - 5 out of 15 pages. Chapter 20 - The Cardiovascular System: Blood Vessels and Circulation. Graduation/Transcripts. A number of conventions have evolved to classify and name neurons. Link to a video where you can learn about ribosomes. In inhibitory neurons the synaptic vesicle are often flattened as shown in Figure 8. Previous: Next: Chapter 4 - The Tissue Level of Organization >>. Microglial nuclei are elongated or triangular and stain deeply with alkaline dyes. HEALTH SCIENCESPLTW211 - Chapter 2(Azares).docx - CELLS AND TISSUES 3 The basic unit of structure and function in the human body is the cell. Each of a cell’s parts, or | Course Hero. Nucleus of the neuron is large and round and is usually centrally located. When neurons interact with muscle fibers, the region of functional contact is called the neuromuscular junction or motor endplate (Chapter 4). Many of these cell inclusions are responsible for the expression of genetic information controlling the synthesis of cellular proteins involved in energy production, growth, and replacement of materials lost by attrition.
Consequently, the processes of fibrous astrocytes do not form sheets and do not tend to conform to the shape of the surrounding neurons or vascular elements. Chapter 19 - The Cardiovascular System: The Heart. Identify the main tissue types and discuss their roles in the human body. They contain some enzymes that either produce or degrade hydrogen peroxide. Regions of functional contacts between neurons (synapses) have distinct morphological characteristics. As in other cells, the principal component of the nucleus is deoxyribonucleic acid (DNA), the substance of the chromosomes and genes. Chapter 3 cells and tissues answer key lime. During development, they form scaffolding along which nerve cells migrate to achieve their mature structure. Presynaptic density is the region of darkly staining material of the presynaptic membrane where synaptic vesicles are hypothesized to dock prior to fusion with the presynaptic membrane. Anatomy & Physiology 2.
Microfilaments are 7 nm in diameter filaments arranged as a paired helix of two strands of globular actin. Nervous tissue allows the body to receive signals and transmit information as electric impulses from one region of the body to another. These probably mediate ion exchange between cells. Each of these lines of embryonic cells forms the distinct germ layers from which all the tissues and organs of the human body eventually form. The membrane of the neuron functions as a receptive surface over its entire extent; however, specific inputs (termed afferents) from other cells are received primarily on the surface of the cell body and on the surface of the specialized processes known as dendrites. As will be described later, they also serve as vesicles for reverse transport from axon terminals to the soma. They have a variety of membrane-bound shapes and sizes, ranging in size between 250 and 700 nm in diameter.