Types of Tissue Flashcards
How can you go from an atom to an organism?
Atom->Molecule->Cell->Tissue->Organ->Organ System->Organism
What are the different types of body systems
Cardiovascular (CV)
Respiratory
Endocrine
Nervous
Gastrointestinal (GI)
Urogenital (UG)
Musculoskeletal (MSK)
Integumentary
Lymphatic and Immune
What are the five vital organs for human life and function?
Brain- coordination centre, neurones
Liver- detoxifies blood and keeps pH stable
Kidneys- filtration of blood
Lungs- maintains [oxygen] and breathing
Heart- pumps blood around the entire body
What are the four main types of tissue in the human body?
Epithelial
Nervous
Muscular
Connective
What are some of the features of epithelial tissue?
Highly cellular tissue that forms the covering of all body surfaces
Found in outer layer of skin, lining of body cavities, blood and lymph vessels
Protects exposed and internal surfaces from abrasion, dehydration and destruction by chemical or biological agents
They can proliferate to produce new cells when cells become damaged or worn
Secrete mucus to protect lining (as of goblet cells)
How can epithelial tissue be described based on the cells in the tissue?
Cell shape:
Sqaumous – flattened cells whose width is greater than their height
Cuboidal – cells appear as high as they are wide; spherical nuclei centrally positioned
Columnar – cells whose height is greater than their width; oval nuclei positioned at the base of cells
Number of layers:
Simple – single layer of cells
Stratified – two or more layers of cells
Pseudostratified- when there is only one layer but it looks like two or more layers
Cell surfaces
Basal – nearest to basement membrane
Apical – nearest to lumen (free space)
Lateral – between adjacent cells
What are the functions of epithelial cell?
Protection
Epithelial cells from the skinprotect underlying tissue from mechanical injury, harmful chemicals, invading bacteria and from excessive loss of water
Sensation
Sensory stimulipenetrate specialised epithelial cells. Specialised epithelial tissue containing sensory nerve endings is found in the skin, eyes, ears, nose and on the tongue
Secretion
In glands, epithelial tissue is specialised tosecrete specific chemical substancessuch as enzymes, hormones and lubricating fluids
Absorption
Certain epithelial cells lining the small intestineabsorb nutrients from the digestion of food
Excretion
Epithelial tissues in the kidneyexcrete waste products from the body and reabsorb needed materials from the urine.Sweatis also excreted from the body by epithelial cells in the sweat glands
Diffusion
Simple epitheliumpromotes the diffusion of gases, liquids and nutrients. Because they form such a thin lining, they are ideal for the diffusion of gases (eg. walls of capillaries and lungs)
Cleaning
Ciliated epithelium assists inremoving dust particles and foreign bodieswhich have entered the air passages
Reduces Friction
The smooth, tightly-interlocking, epithelial cells that line the entire circulatory systemreduce friction between the blood and the walls of the blood vessels
How would you describe the epithelial tissue in the Bowman’s capsule – kidney?
Simple squamous epithelium
How would you describe the epithelial tissue in the Ileum – small intestine?
Simple columnar epithelium
How would you describe the epithelial tissue in the Oesophagus – Digestive system?
Stratified cuboidal epithelium
What are some features of connective tissue?
Most abundant tissue within the body
Consists of cells and an extracellular matrix (ground substance and protein fibres)
Essentially connects the epithelial tissue to the rest of the body
Not normally exposed to the outside environment e.g., cartilage, tendons, fascia, blood
What are some examples of the different types of connective tissue?
Tendon: Dense connective tissue
Blood: Fluid connective tissue
Cartilage: Supporting connective tissue
What are the functions of connective tissue?
Protection of organs
Provision of structural framework for the body
Connection of body tissues
Connection of epithelial tissues to muscle
Nutritional support to epithelium
Repair of body tissues
What are some general features of muscle tissue?
Specialised to contract and produce movement
Contains highly organised bundles of cells
What are the three different types of muscle tissue?
Skeletal muscle tissue
Smooth muscle tissue
Cardiac muscle tissue
What is the purpose of each different type of muscle tissue?
Skeletal muscle tissue: produces voluntary movement of the skeleton in the musculoskeletal system
Smooth muscle tissue: aids digestion and discretion in the gastrointestinal and urinary system
Cardiac muscle tissue: propels (pumps) blood throughout the body in the cardiovascular system
What are the key characteristics of the skeletal muscle?
Primarily involved in locomotion
Also involved in maintaining posture
Under voluntary control
Cells are large, cylindrical and elongated
Often known as striated muscle due to the appearance of contractile proteins; have a striped appearance
Average adult male - 42%, average adult female - 36% skeletal muscle (total body weight)
Arranged in regular parallel bundles
What are the key characteristics of the smooth muscle?
Lines structures including the stomach, intestines, and blood vessels
Primary function is to influence movement of material into, out of, and within the body
Involuntary muscle type
Non-striated – different arrangement of muscle cells compared to skeletal muscle
What are the key characteristics of the cardiac muscle?
Cardiac muscle (myocardium), found only in the heart, not subject to voluntary control
Striated similar to skeletal muscle
While skeletal muscles are arranged in regular, parallel bundles, cardiac muscle use unique junctions called intercalated discs to link cells together
Why are intercalated discs important?
Heart cells must beat in unison - intercalated discs allow calcium to regulate united beating
What is the point of the nervous system?
Allows for rapid communication of information from one region of the body to another
What is the nervous system comprised of?
Central nervous system (CNS) – brain and spinal cord
Peripheral nervous system (PNS) – peripheral nerves and ganglia
What is the ganglia in the peripheral nervous system?
Synaptic relay stations- neuronal bodies
What are the different components of the nervous system, and what are their purposes?
Somatic nervous system – controls voluntary movements
Autonomic nervous system – regulates functions of internal organs
Sympathetic – fight or flight
Parasympathetic – regulates functions which don’t require quick response
What cell type forms the nervous system?
Neuron is the structural and functional unit of the nervous system (nerve cells)
What is nervous tissue comprised off?
Nervous tissue is made up of different types of nerve cells, all of which having an axon, the long stem-like part of the cell that sends action potential signals to the next cell
What are some functions of the nervous system?
Sensory input, integration, control of muscles and glands, homeostasis, and mental activity
How can an organ be defined?
A collection of tissues joined in a structural unit to serve a common function
What are the components of an organ?
Main tissue
Parenchyma
“Sporadic” tissues
What is the main tissue?
The main tissue is that which is unique for the specific organ, such as the specialized cells of the stomach
What are some examples of sporadic tissue?
Sporadic tissues include the nerves, blood vessels, and connective tissues
What is a hollow organ?
A hollow organ is a visceral organ that forms a hollow tube or pouch, such as the stomach or intestine, or that includes a cavity, like the heart or urinary bladder
