Detail separate answer between epithelial tissue, connective tissue,muscular tissue and nervous tissue
Epithelial Tissue Epithelial tissues are thin tissues that cover all the exposed surfaces of the body. They form the external skin, the inner lining of the mouth, digestive tract, secretory glands, the lining of hollow parts of every organ such as the heart, lungs, eyes, ears, the urogenital tract, as well as the ventricular system of the brain and central canals of the spinal cord.
The cells making up epithelia are often closely bound to one another through specialized structures called tight junctions. They are also free from blood vessels and nerves and are supported by a connective tissue called the basement membrane. They have polarity with a distinct basal domain facing the basement membrane and the other apical surface facing the lumen of an organ or the external environment Functions of Epithelial Tissue Epithelial tissue has a number of functions, which include protection against abrasion, radiation damage, chemical stress and invasion by pathogens. A single organ can have different types of epithelial tissue based on the substances to which different surfaces are exposed. Protective tissue tends to be thicker, made of multiple layers of cells and often has inclusions such as keratin to provide mechanical strength and resistance. The skin of most mammals contains layers of thick keratinized dead epithelial cells protecting them against water loss and other stresses. Similarly, the esophagus is also exposed to a wide range of different textures, pH levels and chemical compositions from food and drink. Therefore, it also contains protective epithelium. Due to its involvement in the digestive process, however, it remains non-keratinized, and secretes mucus to smoothen the passage of food.
Types of Epithelial Tissue There are different types of epithelial tissue depending on their function in a particular location. The simplest classification of these tissues is based on the number of cell layers.
- Simple epithelia
- Stratified epithelia
When the epithelium is composed of a single layer of cells, it is called simple epithelial tissue and those containing two or more layers of cells are called stratified epithelial tissues. One particular type is called pseudostratified because a single layer of cells having varying heights gives the appearance of being stratified.
Epithelia can also be classified based on the shape of the cells, giving rise to three types:
- Squamous epithelial tissue:consists of extremely thin cells that resemble the scales of a fish
- Cuboidal epithelial tissue: contains cells that appear square in cross-section but are marginally longer than they are wide
- Columnar epithelial tissue:consists of elongated cell involved in absorption of materials
- CONNECTIVE TISSUE
As the name implies, connective tissue serves a "connecting" function. It supports and binds other tissues in the body. Unlike epithelial tissue which has cells that are closely packed together, connective tissue typically has cellsscattered throughout an extracellular matrix of fibrous proteins and glycoproteins attached to a basement membrane.
Connective tissue is the most abundant and widely distributed of the primary tissues.
Connective tissue has three main components: cells, fibers, and ground substance. Together the ground substance and fibers make up the extracellular matrix.
Connective tissue is classified into two subtypes: soft and specialized connective tissue.
Major functions of connective tissue include: 1) binding and supporting, 2) protecting, 3) insulating, 4) storing reserve fuel, and 5) transporting substances within the body.
Connective tissues can have various levels of vascularity. Cartilage is avascular, while dense connective tissue is poorly vascularized. Others, such as bone, are richly supplied with blood vessels
MUSCLE TISSUE Muscle tissue is made of "excitable" cells that are capable of contraction. Of all of the different tissue types (muscle, epithelial, connective, and nervous), muscle tissue is the most abundant in most animals.
MUSCLE TISSUE TYPES Muscle tissue contains numerous microfilaments composed of the contractile proteins actin and myosin. These proteins are responsible for movement in muscles.
MUSCLE TISSUE Muscle tissue is made of "excitable" cells that are capable of contraction. Of all of the different tissue types (muscle, epithelial, connective, and nervous), muscle tissue is the most abundant in most animals.
MUSCLE TISSUE TYPES Muscle tissue contains numerous microfilaments composed of the contractile proteins actin and myosin. These proteins are responsible for movement in muscles.
There are three major types of muscle tissue:
- Cardiac Muscle
Cardiac muscle is so named because it is found in the heart. Cells are joined to one another by intercalated discs, which allow the synchronization of the heart beat. Cardiac muscle is branched, striated muscle. The heart wall consists of three layers: epicardium, myocardium, and endocardium. Myocardium is the middle muscular layer of the heart. Myocardial muscle fibers carry electrical impulses through the heart, which power cardiac conduction. - Skeletal Muscle
Skeletal muscle, which is attached to bones by tendons, is controlled by the peripheral nervous system and associated with the body's voluntary movements. Skeletal muscle is striated muscle. Unlike cardiac muscle, the cells are not branched. Skeletal muscle cells are covered by connective tissue, which protects and supports muscle fiber bundles. Blood vessels and nerves run through the connective tissue supplying muscle cells with oxygen and nerve impulses that allow for muscle contraction. Skeletal muscle is organized into several muscle groups that work in a coordinated fashion to perform body movements. Some of these groupings include head and neck muscles (facial expressions, chewing, and neck movement), trunk muscles (move the chest, back, abdomen, and vertebral column), upper extremity muscles (move the shoulders, arms, hands, and fingers), and lower extremity muscles (move the legs, ankles, feet, and toes).
- Visceral (Smooth) Muscle
Visceral muscle is found in various parts of the body including blood vessels, the bladder, digestive tract, as well as in many other hollow organs. Like cardiac muscle, most visceral muscle is regulated by the autonomic nervous system and is under involuntary control. Visceral muscle is also called smooth muscle because it doesn't have cross striations. Visceral muscle contracts slower than skeletal muscle, but the contraction can be sustained over a longer period of time. Organs of the cardiovascular system, respiratory system, digestive system, and reproductive system are lined with smooth muscle. This muscle can be described as rhythmic or tonic. Rhythmic or phasic smooth muscle contracts periodically and spends most of the time in a relaxed state. Tonic smooth muscle remains contracted for the majority of the time and only relaxes periodically. - Nervous Tissue
Nervous tissue is one of four major classes of tissues. It is specialized tissue found in the central nervous system and the peripheral nervous system. It consists of neurons and supporting cells called neuroglia.
The nervous system is responsible for the control of the body and the communication among its parts. Nervous tissue contains two categories of cells—neurons and neuroglia.
Types of Nervous Tissue The nervous system consists of nervous tissue, which is composed of two principal types of cells called neuron and neuroglia
Neuroglia
There are six types of neuroglia—four in the central nervous system and two in the PNS. These glial cells are involved in many specialized functions apart from support of the neurons. Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes. In the PNS, satellite cells and Schwann cells are the two kinds of neuroglia.
Astrocytes Astrocytes are shaped like a star and are the most abundant glial cell in the CNS. They have many radiating processes which help in clinging to the neurons and capillaries. They support and brace the neurons and anchor them to the nutrient supply lines. They also help in the guiding the migration of young neurons. Astrocytes control the chemical environment around the neurons.
Microglial Cells Microglial cells are small and ovoid un shape with thorny processes. They are found in the CNS. When invading microorganism or dead neurons are present, the microglial cells can transform into a phagocytic macrophage and help in cleaning the neuronal debris.
Ependymal Cells Ependymal cells are ciliated and line the central cavities of the brain and spinal cord where they form a fairly permeable barrier between the cerebrospinal fluid that fills these cavities and the tissue cells of the CNS.
Oligodendrocytes Oligodendrocytes line up along the nerves and produce an insulating cover called myelin sheath. They are found in the CNS.
Satellite Cells Satellite cells surround neuron cell bodies in the peripheral nervous system (PNS). They are analogous to the astrocytes in the CNS.
Schwann Cells Schwann cells surround all nerve fibers in the peripheral nervous system and form myelin sheaths around the nerve fibers. They are found in the PNS. Their function is similar to oligodendrocytes.
Neurons Neurons consist of cell body and one or more slender processes. The neuronal cell body consists of a nucleus and rough endoplasmic reticulum or Nissl Bodies. The cell body is the major biosynthetic center of a neuron and contains the usual organelles for the synthesis of proteins and other chemicals. Arm like processes extend from the cell body to all neurons
The cells making up epithelia are often closely bound to one another through specialized structures called tight junctions. They are also free from blood vessels and nerves and are supported by a connective tissue called the basement membrane. They have polarity with a distinct basal domain facing the basement membrane and the other apical surface facing the lumen of an organ or the external environment Functions of Epithelial Tissue
Epithelial tissue has a number of functions, which include protection against abrasion, radiation damage, chemical stress and invasion by pathogens. A single organ can have different types of epithelial tissue based on the substances to which different surfaces are exposed. Protective tissue tends to be thicker, made of multiple layers of cells and often has inclusions such as keratin to provide mechanical strength and resistance. The skin of most mammals contains layers of thick keratinized dead epithelial cells protecting them against water loss and other stresses. Similarly, the esophagus is also exposed to a wide range of different textures, pH levels and chemical compositions from food and drink. Therefore, it also contains protective epithelium. Due to its involvement in the digestive process, however, it remains non-keratinized, and secretes mucus to smoothen the passage of food.
There are different types of epithelial tissue depending on their function in a particular location. The simplest classification of these tissues is based on the number of cell layers.
- Simple epithelia
- Stratified epithelia
When the epithelium is composed of a single layer of cells, it is called simple epithelial tissue and those containing two or more layers of cells are called stratified epithelial tissues. One particular type is called pseudostratified because a single layer of cells having varying heights gives the appearance of being stratified.
Epithelia can also be classified based on the shape of the cells, giving rise to three types:
- Squamous epithelial tissue:consists of extremely thin cells that resemble the scales of a fish
- Cuboidal epithelial tissue: contains cells that appear square in cross-section but are marginally longer than they are wide
- Columnar epithelial tissue:consists of elongated cell involved in absorption of materials
- CONNECTIVE TISSUE
As the name implies, connective tissue serves a "connecting" function. It supports and binds other tissues in the body. Unlike epithelial tissue which has cells that are closely packed together, connective tissue typically has cellsscattered throughout an extracellular matrix of fibrous proteins and glycoproteins attached to a basement membrane.
Connective tissue has three main components: cells, fibers, and ground substance. Together the ground substance and fibers make up the extracellular matrix.
Connective tissue is classified into two subtypes: soft and specialized connective tissue.
Major functions of connective tissue include: 1) binding and supporting, 2) protecting, 3) insulating, 4) storing reserve fuel, and 5) transporting substances within the body.
Connective tissues can have various levels of vascularity. Cartilage is avascular, while dense connective tissue is poorly vascularized. Others, such as bone, are richly supplied with blood vessels
MUSCLE TISSUE
Muscle tissue is made of "excitable" cells that are capable of contraction. Of all of the different tissue types (muscle, epithelial, connective, and nervous), muscle tissue is the most abundant in most animals.
MUSCLE TISSUE TYPESMuscle tissue contains numerous microfilaments composed of the contractile proteins actin and myosin. These proteins are responsible for movement in muscles.
MUSCLE TISSUE
Muscle tissue is made of "excitable" cells that are capable of contraction. Of all of the different tissue types (muscle, epithelial, connective, and nervous), muscle tissue is the most abundant in most animals.
MUSCLE TISSUE TYPESMuscle tissue contains numerous microfilaments composed of the contractile proteins actin and myosin. These proteins are responsible for movement in muscles.
There are three major types of muscle tissue:
- Cardiac Muscle
Cardiac muscle is so named because it is found in the heart. Cells are joined to one another by intercalated discs, which allow the synchronization of the heart beat. Cardiac muscle is branched, striated muscle. The heart wall consists of three layers: epicardium, myocardium, and endocardium. Myocardium is the middle muscular layer of the heart. Myocardial muscle fibers carry electrical impulses through the heart, which power cardiac conduction. - Skeletal Muscle
Skeletal muscle, which is attached to bones by tendons, is controlled by the peripheral nervous system and associated with the body's voluntary movements. Skeletal muscle is striated muscle. Unlike cardiac muscle, the cells are not branched. Skeletal muscle cells are covered by connective tissue, which protects and supports muscle fiber bundles. Blood vessels and nerves run through the connective tissue supplying muscle cells with oxygen and nerve impulses that allow for muscle contraction. Skeletal muscle is organized into several muscle groups that work in a coordinated fashion to perform body movements. Some of these groupings include head and neck muscles (facial expressions, chewing, and neck movement), trunk muscles (move the chest, back, abdomen, and vertebral column), upper extremity muscles (move the shoulders, arms, hands, and fingers), and lower extremity muscles (move the legs, ankles, feet, and toes).
- Visceral (Smooth) Muscle
Visceral muscle is found in various parts of the body including blood vessels, the bladder, digestive tract, as well as in many other hollow organs. Like cardiac muscle, most visceral muscle is regulated by the autonomic nervous system and is under involuntary control. Visceral muscle is also called smooth muscle because it doesn't have cross striations. Visceral muscle contracts slower than skeletal muscle, but the contraction can be sustained over a longer period of time. Organs of the cardiovascular system, respiratory system, digestive system, and reproductive system are lined with smooth muscle. This muscle can be described as rhythmic or tonic. Rhythmic or phasic smooth muscle contracts periodically and spends most of the time in a relaxed state. Tonic smooth muscle remains contracted for the majority of the time and only relaxes periodically. - Nervous Tissue
Nervous tissue is one of four major classes of tissues. It is specialized tissue found in the central nervous system and the peripheral nervous system. It consists of neurons and supporting cells called neuroglia.
The nervous system is responsible for the control of the body and the communication among its parts. Nervous tissue contains two categories of cells—neurons and neuroglia.
Types of Nervous TissueThe nervous system consists of nervous tissue, which is composed of two principal types of cells called neuron and neuroglia
NeurogliaThere are six types of neuroglia—four in the central nervous system and two in the PNS. These glial cells are involved in many specialized functions apart from support of the neurons. Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes. In the PNS, satellite cells and Schwann cells are the two kinds of neuroglia.
AstrocytesAstrocytes are shaped like a star and are the most abundant glial cell in the CNS. They have many radiating processes which help in clinging to the neurons and capillaries. They support and brace the neurons and anchor them to the nutrient supply lines. They also help in the guiding the migration of young neurons. Astrocytes control the chemical environment around the neurons.
Microglial CellsMicroglial cells are small and ovoid un shape with thorny processes. They are found in the CNS. When invading microorganism or dead neurons are present, the microglial cells can transform into a phagocytic macrophage and help in cleaning the neuronal debris.
Ependymal CellsEpendymal cells are ciliated and line the central cavities of the brain and spinal cord where they form a fairly permeable barrier between the cerebrospinal fluid that fills these cavities and the tissue cells of the CNS.
OligodendrocytesOligodendrocytes line up along the nerves and produce an insulating cover called myelin sheath. They are found in the CNS.
Satellite CellsSatellite cells surround neuron cell bodies in the peripheral nervous system (PNS). They are analogous to the astrocytes in the CNS.
Schwann CellsSchwann cells surround all nerve fibers in the peripheral nervous system and form myelin sheaths around the nerve fibers. They are found in the PNS. Their function is similar to oligodendrocytes.
NeuronsNeurons consist of cell body and one or more slender processes. The neuronal cell body consists of a nucleus and rough endoplasmic reticulum or Nissl Bodies. The cell body is the major biosynthetic center of a neuron and contains the usual organelles for the synthesis of proteins and other chemicals. Arm like processes extend from the cell body to all neurons
