What are glial cells in the CNS often referred to as?
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The supporting 'cast'.
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What are glial cells in the CNS often referred to as?
The supporting 'cast'.
What are the four basic types of body tissues?
How much more numerous are glial cells compared to neurons in the CNS?
10 times more numerous.
What are the four basic types of body tissues?
What are the four basic types of body tissues?
What are the four basic types of body tissues?
Epithelia, Nervous, Muscle, Connective tissues
What do tissues contain?
Multiple copies of cells grouped together that cooperate in a similar specialized function.
How are tissues classified?
On two basic parameters: morphology (epithelial and connective tissues) and function (muscles and nerves).
What is one of the key characteristics to look out for in different tissue types?
Cell shape.
What do epithelial cells sit on?
An amorphous basement membrane.
What should be noted about intracellular organelles and cell surface structures in different tissue types?
Prominent intracellular organelles and cell surface structures.
What type of epithelium is responsible for the lining of the intestine?
Simple columnar epithelium.
What are the four basic types of body tissues?
What does the basement membrane contain that links to the surface of epithelial cells?
Proteins.
What is important about the binding and association of cells in different tissue types?
The presence of junctions.
What is an example of specialized simple columnar epithelium?
Cilia.
What are the two parameters used to classify tissues?
Morphology and function.
What type of proteins in the basement membrane provide strength?
Filamentous proteins.
What are tissues?
Aggregates of specialized cells designed for specific functions.
What should be observed about the arrangement and location of cells in different tissue types?
The specific arrangement and location of cells.
What is the function of microvilli in epithelial cells?
Absorption and sensing.
Which tissues are classified based on morphology?
Epithelial and connective tissues.
What are the two main groups of single-celled organisms?
Prokaryotes and Eukaryotes.
What extracellular aspect is important to consider in different tissue types?
Extracellular components.
What is the function of pancreatic acinar cells?
They contain abundant secretory granules that release enzymes for digestion in the small intestine.
Give an example of a simple multicellular organism.
Alga Volvox.
What are the shapes and structures of epithelial tissues?
Epithelial tissues can vary in shape and structure, ranging from flat to column-shaped and can be single or multilayered.
What is the function of cilia in epithelial cells?
Movement, lateral transport, and sensing.
Which tissues are classified based on function?
Muscles and nerves.
What do blood cells express genes for?
They express genes for haemoglobin production.
Give an example of a complex multicellular organism.
Higher animals/plants.
What are some characteristics of epithelial tissues?
Epithelial tissues show surface modifications/adaptations.
What happens to blood cells after they express genes for haemoglobin production?
They lose all their genes and intracellular organelles.
What are the advantages of cell specialization and tissue formation?
Division of labour, coordinated function for tissues, large organisms possible, support and motility, and exploitation of resources not available to single cells.
What do muscle cells express genes for?
They express genes for filamentous contractile proteins (actin and myosin in the cytosol).
What is responsible for the regulation of gene expression?
Transcription.
What are the resident immune cells and phagocytes of the brain?
Microglial cells.
How are epithelial tissues bound to each other?
Epithelial tissues are bound to each other by specialized junctions and adhesion molecules.
What is the defining characteristic of neurons?
The cell process.
What type of cells are astrocytes classified as?
Macroglia cells.
What is the primary function of microglial cells in the CNS?
Phagocytosis and antigen presentation.
What is the function of tight junctions in epithelial cells?
Tight junctions act as sealing barriers, preventing the entry of macromolecules from the intestine to the bloodstream.
What sort of cells do lymphoid cells differentiate into?
Lymphocytes B and T.
What are the primary functions of epithelial tissues?
Secretion, absorption, transport, barrier/protection, and strength/support.
What is myelination?
The process of forming a fatty sheath around the axons of neurons.
What type of contraction is characteristic of skeletal muscle?
Striated, coordinated contraction.
What is the basement membrane in epithelial tissues?
The basement membrane is a specialized layer of extracellular matrix material on which epithelial tissues sit.
What are the main functions of the nervous system?
The nervous system collects, processes/integrates, and sends information.
How many neurons are there in the central nervous system?
100 billion neurons.
What is the role of osteoclasts in bone dynamics?
Osteoclasts are large macrophage-like cells that digest bone.
Where are protoplasmic astrocytes found?
In gray matter.
What type of epithelium is involved in secretion and where is it found?
Columnar epithelium found in the small intestine, colon, stomach lining, and gastric gland.
What types of cells or organisms do microglial cells target for phagocytosis?
Dying neurons, glial cells, or microorganisms.
How are epithelial tissues usually classified?
Based on shape or number of cell layers.
What role do desmosomes play in epithelial cells?
Desmosomes strengthen cell links by linking intermediate filaments.
What are the resident immune cells in the brain?
Microglial cells.
Is skeletal muscle under voluntary or involuntary control?
Skeletal muscle is under direct voluntary control, but can also be involuntary (reflexes/control).
What are the two types of cells in nervous tissue?
Nerve cells and glial (supporting) cells.
What role does epithelial tissue play in secretion?
Epithelial tissue facilitates the release of substances such as enzymes, hormones, and mucus.
What does it mean that epithelial tissues are avascular?
Being avascular means that epithelial tissues do not have blood vessels and obtain nutrients and oxygen from the capillaries of the connective tissue on which they rest.
What is the composition of the myelin sheath?
It is a fatty sheath.
How many more glial support cells are there compared to neurons in the central nervous system?
10 times more glial support cells.
What is the function of osteoblasts in bone formation?
Osteoblasts lay down the framework for bone formation and become trapped as osteocytes.
Where are fibrous astrocytes found?
In white matter.
Which type of epithelium is responsible for absorption and where is it located?
Columnar epithelium located in the intestines and proximal convoluted tubules in the kidney.
What is the characteristic shape of squamous epithelium?
Flat and sheet-like (width of cell greater than height).
How do gap junctions function in epithelial cells?
Gap junctions connect the cytosols of adjacent cells, allowing the passage of very small molecules.
What is a unique cellular characteristic of skeletal muscle?
Skeletal muscle cells are multinucleated.
How does epithelial tissue contribute to absorption?
Epithelial tissue absorbs nutrients and other substances from the external environment or internal cavities.
What is the central nervous system (CNS) composed of?
The brain and spinal cord.
Is the myelin sheath continuous or discontinuous?
Discontinuous with periodic gaps.
What are the three types of eukaryotic cilia?
Primary cilia, motile cilia, and nodal cilia.
How does epithelial tissue contribute to transportation?
By transporting materials across (pinocytosis or endocytosis) or along the epithelium, with transport along the surface driven by motile cilia.
What processes are involved in bone dynamics?
Bone dynamics involve synthesis and remodeling during bone formation, growth, and repair.
What is the function of the axon end bulb?
The axon end bulb is the site of chemical neurotransmitter release.
Describe the appearance of cuboidal epithelium.
Cube-like in appearance (equal height, width, and depth).
What is the purpose of adherens junctions in epithelial cells?
Adherens junctions are spots of connection that link movement proteins (actin) and prevent separation between cells.
What does the peripheral nervous system (PNS) innervate?
The body and head.
What is the function of epithelial tissue in transport?
Epithelial tissue helps in the movement of substances across its surface, either into or out of the body or between different body compartments.
What is the structure of simple squamous epithelial tissue?
Simple squamous epithelial tissue consists of a single layer of flat cells.
What are the periodic gaps in the myelin sheath called?
Nodes of Ranvier.
Where are primary cilia found and what is their function?
Primary cilia are found in most animal cells (epithelial, connective tissues, muscle, and nervous tissues) and function in sensory organs.
How are epithelia named?
Based on their locations.
What type of epithelium provides mechanical support and where is it found?
Stratified squamous epithelium found in the skin.
What is the shape of columnar epithelium?
Column-like (height exceeds the width).
What role do microtubules play in the axon end bulb?
Microtubules are involved in vesicle transport within the axon end bulb.
How does epithelial tissue provide barrier and protection?
Epithelial tissue acts as a barrier to protect underlying tissues from mechanical injury, pathogens, and chemical damage.
What is the role of Schwann cells in myelination?
One Schwann cell builds one internode of the myelin sheath.
What types of receptors are found on primary cilia?
Odorant receptors on olfactory neurons and photoreceptors on retinal cells.
How are cells in the nervous system adapted?
They are adapted for local and distant cellular communication.
What is the structure of simple cuboidal epithelial tissue?
Simple cuboidal epithelial tissue consists of a single layer of cube-shaped cells.
What type of epithelial tissue lines the vascular and body cavities?
Simple squamous epithelial, such as endothelium and mesothelium.
What is the role of epithelial tissue in receptor function?
To transduce external stimuli, such as in taste buds (tongue) and olfactory epithelium.
What is the originator cell called that can differentiate and proliferate to make tissues?
Stem Cell
What is the function of mitochondria in the axon end bulb?
Mitochondria provide energy supply in the axon end bulb.
What does 'simple' refer to in epithelial tissue classification?
A single layer of cells.
Who first identified stem cells in the hematopoietic system?
Ernest McCulloch and James Till in 1961.
What is the significance of the selective barrier function of epithelial tissue?
The selective barrier function of epithelial tissue regulates the exchange of substances, ensuring that only specific molecules pass through.
What is the main function of motile cilia?
Motile cilia are responsible for cell movement, such as the movement of fluid and particles across the epithelial.
What is the structure of simple columnar epithelial tissue?
Simple columnar epithelial tissue consists of a single layer of tall, column-like cells.
What is the function of mesothelium?
It lines and encloses the constituents of body cavities such as pericardial, abdominal, and pleural cavities.
What are the distinct morphological domains of epithelium?
The free surface or apical domain, the lateral domain, and the basement membrane.
Where are pluripotent stem cells found?
In the early embryo
What does the term 'avascular' mean in the context of epithelial tissues?
It means that epithelial tissues do not have blood vessels.
What type of muscle is smooth muscle?
Non-striated and involuntary.
What does 'stratified' refer to in epithelial tissue classification?
Multiple layers of cells.
What are synaptic vesicles and where are they located?
Synaptic vesicles are located in the axon end bulb and are involved in storing neurotransmitters.
What is the primary function of erythrocytes?
Transport of O2 and CO2.
What does each cell contain that was present in the first cell of the embryo?
The genome.
In what way does epithelial tissue offer strength and support?
Epithelial tissue provides structural support to the body and helps maintain the shape and integrity of organs.
What structure in motile cilia produces the force needed for motility?
The axoneme, which possesses microtubule-associated proteins.
What is the structure of pseudostratified columnar epithelial tissue?
Pseudostratified columnar epithelial tissue appears to have multiple layers due to varying cell heights, but it is actually a single layer.
What does endothelium line?
The blood and lymphatic vessels.
What is the capability of pluripotent cells?
To differentiate into any different type of cells
What are the four main functions of epithelial tissues?
What is the shape of smooth muscle cells?
Spindle-shaped.
What is pseudostratified epithelium?
Epithelium made up of closely packed cells that appear to be stratified but are not.
What is the synaptic cleft?
The synaptic cleft is the space between the presynaptic membrane and the postsynaptic membrane where neurotransmitters are released.
What is the role of granulocytes and macrophages?
They are phagocytic cells.
How many genes are humans thought to have?
Approximately 25,000 to 30,000 genes.
What is the structure of stratified squamous epithelial tissue?
Stratified squamous epithelial tissue consists of multiple layers of flat cells.
Where are nodal cilia found and what is their characteristic movement?
Nodal cilia are found within the embryo during gastrulation and possess distinct clockwise rotational movement.
What type of division do stem cells undergo to continue the stem cell line?
Asymmetric division
What is vascular endothelium?
The endothelium of the blood vessels, consisting of simple squamous cells.
Are the cell borders of smooth muscle cells clearly seen?
No, cell borders are rarely seen clearly.
What is the role of the basement membrane in epithelial tissues?
It provides mechanical support and strength.
Where is transitional epithelium (urothelium) found?
It lines the lower urinary tract.
What is the function of platelets?
Coagulation.
What forms the thin filament in skeletal muscles?
Actin.
What is the primary function of white fat?
White fat stores energy but is extremely dynamic.
What determines cell function and structure?
Proteins.
What is the role of transcription factors in gene expression?
They regulate gene expression by turning on or turning off a gene
What are the functions of vascular endothelium?
It controls cellular transport, immune responses, hormone synthesis, and metabolites.
What are microvilli and what is their function?
Microvilli are specialized cells involved in phagocytosis and absorption of nutrients.
What is the primary function of lymphocytes?
Immune response.
Do smooth muscle cells have ordered arrays of myosin and actin?
No, they do not have striking ordered arrays of myosin and actin.
What makes up the thick filaments in skeletal muscles?
Myosin.
What are adipokines and what is their role?
Adipokines are signals produced by white fat that regulate nutritional balance and other systems.
Do most body cells express all of the genes in the genome?
No, they express only a subset of these genes.
How do transcription factors determine differentiation patterns?
By acting in different combinations
What is the role of endocardium?
It is responsible for lining the ventricles and atria of the heart.
What is the function of cilia in epithelial tissues?
Cilia are involved in the movement and transport of mucus along the respiratory tract.
What do plasma cells synthesize?
Immunoglobulin.
What physiological process in the gut is smooth muscle responsible for?
Peristalsis.
What are the two regulatory proteins linked with actin?
Tropomyosin and troponin.
What is the difference between Obob mice and normal mice in terms of leptin production?
Obob mice do not produce leptin, while normal mice produce leptin.
What yields hundreds of different cell types in the human body?
Selective expression of proteins and gene silencing.
What are the main functions of white fat?
Energy storage, insulation, and protection.
What is the role of dendrites in a neuron?
Dendrites direct stimulus towards the cell.
What happens during the differentiation of stem cells?
New sets of genes/proteins are expressed to produce cells with distinct functions
How is compact bone arranged?
Compact bone is arranged cylindrically in Haversian systems.
How are epithelial cells interconnected?
They are interconnected by intercellular joints.
Why do hematopoietic stem cells play a crucial role?
Because blood cells have a limited life-span, ranging between a day and a month.
In which systems can smooth muscle be found?
Urinary system, reproductive system, gut, respiratory system, blood vessels.
How do neurons communicate?
By releasing chemical secretion at the end of cell processes.
What happens during an action potential in skeletal muscle contraction?
Calcium ion is released from the sarcoplasmic reticulum into the sarcoplasm (cytosol) and binds troponin.
What are astrocytes and how did they get their name?
Astrocytes are a type of glial cell in the CNS, named for their irregular, rough, and star-like shaped cell bodies.
How does leptin affect feeding behavior?
Leptin sends a signal to the brain that the body has had enough food to eat.
What are some methods of gene regulation mentioned?
Regulating transcription and modification of DNA through DNA methylation.
What triggers the release of neurotransmitters in the presynaptic neuron?
The influx of Ca2+ through voltage-gated Ca2+ channels.
What is the primary function of brown fat?
Heat production.
What are tissue-specific stem cells?
Stem cells found in tissue
What is the primary function of oligodendrocytes in the CNS?
Cell myelination within the CNS.
What are Haversian systems?
Haversian systems, also known as osteons, are cylindrical structures that make up compact bone.
Give examples of cells with a limited life-span.
Red blood cells, epithelial cells lining the digestive tract, spermatozoa.
What is displayed for actin-myosin binding during muscle contraction?
Tropomyosin.
What are the key structural components of a neuron?
A cell body (soma), receptive dendrites, a transmitting axon, and an end terminal called the synapse.
What happens to the feeding behavior of Obob mice?
Obob mice feed voraciously due to the lack of leptin production.
What are the two types of astrocytes and where are they found?
Protoplasmic astrocytes are found in the gray matter, and fibrous astrocytes are found in the white matter.
What determines how a cell looks and functions?
Differentiation programmes that determine levels and patterns of protein expression.
What happens when neurotransmitters bind to receptors on the postsynaptic neuron?
It results in the opening of ligand-gated ion channels.
From what do white fat cells (adipocytes) form?
Fibroblast-like precursors.
How many neurons can one oligodendrocyte myelinate?
Multiple neurons.
What is the function of osteocytes in compact bone?
Osteocytes are bone cells that maintain the bone matrix.
What activates the myosin-actin cross-bridge?
ATP.
What is the function of the synapse in a neuron?
It serves as the end terminal for neuronal signaling.
What is the feeding behavior of normal mice in relation to leptin?
Normal mice feed normally because leptin produced by white fat signals the brain that they have had enough food.
What metabolic support do astrocytes provide to neurons?
Astrocytes provide lactate to neurons, glycogenesis, ionic balance, neural growth factor, and glial scar formation.
Are differentiation programmes stable in adult tissues?
Yes, they are mostly quite stable.
What is the function of voltage-gated Na+ channels in action potential?
They open to allow the influx of Na+, triggering an action potential.
What occupies most of a mature white fat cell?
A single droplet of fat.
What role do oligodendrocytes play in cell survival?
They promote cell survival through trophic support.
What is the Haversian canal?
The Haversian canal is a central channel in the Haversian system that contains blood vessels and nerves.
What are the four types of connective tissues?
Fibrocollagenous tissues, cartilage, bone and teeth, adipose tissues (white and brown fat), and blood.
How does myosin move during muscle contraction?
Myosin moves down and up the actin filament.
What do differentiated cells contain despite their distinct appearance?
A similar set of organelles (nucleus, ER, Golgi, mitochondria, lysosomes, cytoskeletal elements, etc.).
What makes neurons excitable?
They are chemically and electrically excitable.
What are the functions of astrocyte processes?
Astrocyte processes surround and insulate synapses, reuptake glutamate and GABA from synapses, and inactivate glutamate to glutamine and recycle glutamine.
What is the role of the SNARE complex in neurotransmission?
It helps in the docking and fusion of synaptic vesicles with the plasma membrane.
Where are the nucleus and cytoplasm located in a mature white fat cell?
Squeezed into the periphery of the cell.
How do oligodendrocytes protect axons?
They protect the axons and coordinate the distribution of ions along the axon.
What are canaliculi in the context of compact bone?
Canaliculi are small channels that connect osteocytes in compact bone, allowing for nutrient and waste exchange.
What is a major feature of connective tissues?
A mix of different cells and extracellular matrix (ECM).
What is an action potential?
It is the result of neuronal excitation (depolarization) that travels down the axon to the end terminal, leading to the release of neurotransmitter.
What occurs at the axon terminal during neurotransmission?
Action potentials depolarize the axon terminal, leading to the influx of Na+ through voltage-gated Na+ channels.
What is the main difference between oligodendrocytes and Schwann cells?
Oligodendrocytes myelinate multiple neurons in the CNS, while Schwann cells myelinate a single neuron in the PNS.
What are the components of the extracellular matrix (ECM) in connective tissues?
Fibrous proteins (such as collagen), structural carbohydrates and proteins, and mineral deposits.
What is the unidirectional basis for neuronal signaling?
The structural arrangement of a neuron, including the cell body, dendrites, axon, and synapse.
What is the primary function of fibroblasts in fibrocollagenous tissues?
Fibroblasts synthesize fibrous proteins such as collagens, elastins, and extracellular matrix components like proteoglycans.
What type of proteins are found in the extracellular matrix of connective tissues?
Fibrous proteins such as collagen.
