A2 - Body Tissues Flashcards
What is Tissues?
A tissue is a group of similar cells working together to carry out a specific function.
“Tissue is a group of cells that have similar structure and that function together as a unit. A nonliving material, called the intercellular matrix, fills the spaces between the cells. There are four main tissue types in the body: epithelial, connective, muscle, and nervous. Each is designed for specific functions.”
What is epithelial tissues and its function?
Epithelial tissues (to cover, lining and protection)
There are two types of epithelial tissue, which are:
- Simple epithelial tissue
- Compound epithelial tissue (cover, protect)
“Epithelial tissues are widespread throughout the body. They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.”
What is Squamous?
Squamous is a single layer of smooth flat cells
Function: It allows diffusion and filtration of substances through it.
Location in the body: Lining structures e.g., the alveoli, the heart, the blood vessels etc.
“ Squamous cells are thin, flat cells that look like fish scales, and are found in the tissue that forms the surface of the skin, the lining of the hollow organs of the body, and the lining of the respiratory and digestive tracts.”
What is Columnar?
Columnar is a single layer of cells sitting on a basement membrane. Column shaped cells.
Function: Secrete substances. Absorb substances and excrete substances.
Location in the body: This is found in the small intestine and stomach.
“The columnar epithelium is composed of epithelial cells that are column-shaped. The cell comprising the columnar epithelium is taller than it is wide. Its height is approximately four times its width. The nucleus in each cell is elongated and often found near the base.”
What is Cuboidal?
Cuboidal is a cube shaped cells
Function: Secretion and absorption.
Location in the body: Ovaries, kidney tubules, salivary gland etc.
“Simple cuboidal epithelium consist of a single layer of cells that are approximately as tall as they are wide. This type of epithelium lines collecting ducts and tubes and is involved in absorbing or secreting material into the ducts or tubes.”
What is Ciliated?
Ciliated is a long, rectangular shape. Contain goblet cells that secrete mucus. Have cilia.
Function: Moves particles along and trap particles.
Location in the body: Trachea, bronchioles, fallopian tubes etc.
“Ciliated epithelium performs the function of moving particles or fluid over the epithelial surface in such structures as the trachea, bronchial tubes, and nasal cavities. It often occurs in the vicinity of mucus-secreting goblet cells. Ciliated epithelium is a thin tissue that has hair-like structures on it. These hairs, called cilia, move back and forth to help move particles out of our body. We find ciliated epithelial tissue in our respiratory tract and in the fallopian tubes of women.”
How does the presence of squamous epithelial tissues in the alveoli of the lungs help them to do their job?
Single, thin layers of cells of smooth flat cells. The lungs (alveoli) allow gas exchange to take place by diffusion. Having a thin single layer of flat cells makes diffusion of oxygen and carbon dioxide, quick and easy to travel throughout the lungs. Also, squamous tissues provide a very large surface area.
Explain, how the presence of ciliated epithelial tissue in the lining of the trachea is important to its function?
It has a long, rectangular shape. It contains goblet cells that secrete mucus. And it has cilia. It moves particles along and traps particles. Having a long, rectangular shapes to move particles along allows it to trap particles such as, trachea (this is part of your airway system), bronchioles, fallopian tubes and others.
A. Special features of ciliated tissues - Ciliated cells have a cilia and produce mucus from their goblet cells.
B. Function – One of the functions of the trachea is to protect the lungs from dust and dirt particles.
C. Linking both points (how does a. help/support b.?) – The ciliated cells line the trachea and trap the dust and dirt and they mix it with the mucus. We can then cough up the mucus and release the dust etc. no particles get into the lungs.
What is simple epithelial tissue?
“Simple epithelium has only one cell layer where every cell is in direct contact with the underlying basement membrane. Generally, this type of epithelium is found inside the body probably due to the fragile nature and forms the lining of the body cavities, blood and lymph vessels, heart and respiratory system.”
This is also divided into four types, which are squamous, cuboidal, columnar and ciliated. It has single layer of cells, and it sits on a basement membrane.
What is compound epithelial tissue (Cover and Protect)?
“Compound epithelium tissue is shaped of numerous layers of epithelial cells of dissimilar shapes representing newly shaped and mature cells. This tissue forms the covering of all body surfaces and they are the major tissue in glands. The superficial layer grows outward from below.”
This also divided into two types, which are keratinised (skin, hair nails) and non-keratinised (lining of the mouth and vagina). It has multicellular layers, and it may have a basement membrane.
How does the presence of squamous epithelial tissues in the alveoli of the lungs help them to do their job?
Single, thin layers of cells of smooth flat cells. The lungs (alveoli) allow gas exchange to take place by diffusion. Having a thin single layer of flat cells makes diffusion of oxygen and carbon dioxide, quick and easy to travel throughout the lungs. Also, squamous tissues provide a very large surface area.
Explain, how the presence of ciliated epithelial tissue in the lining of the trachea is important to its function?
It has a long, rectangular shape. It contains goblet cells that secrete mucus. And it has cilia. It moves particles along and traps particles. Having a long, rectangular shapes to move particles along allows it to trap particles such as, trachea (this is part of your airway system), bronchioles, fallopian tubes and others.
A. Special features of ciliated tissues - Ciliated cells have a cilia and produce mucus from their goblet cells.
B. Function – One of the functions of the trachea is to protect the lungs from dust and dirt particles.
C. Linking both points (how does a. help/support b.?) – The ciliated cells line the trachea and trap the dust and dirt and they mix it with the mucus. We can then cough up the mucus and release the dust etc. no particles get into the lungs.
Identify the type of tissue where ciliated cells are found.
Simple epithelial tissue
Identify two places in the body where Cuboidal epithelium found (2 marks)
- Small intestine
- Stomach
- Ovaries
- Kidneys
State two types of Compound Epithelial Tissue (2 marks)
- Keratinised
2. Non-Keratinised
Explain two functions of blood
Carry Oxygen around the body (In the form of Oxyhaemoglobin, releases O2 when it reaches the tissues etc, collects CO2 and carries it in the plasma, Plasma carries a number of substances e.g I hormones, sugars, amino acids etc, dissolved in it.
Describe the structure of simple cuboidal epithelium (2 marks)
Cube shaped cells. Basement membrane. One layer of cells.
Describe some of the structural features of keratinised epithelium (4 marks)
Multi layered. Top layer dead cells. Keratin replaces cytoplasm. Basement membrane. Lies on connective tissue. Cells move upwards. New tissue every 28 days. Surface layer of cells desquamate.
Identify which type of connective tissue contains the following:
a. Calcium salts
b. Chondrocytes
c. Osteocytes
d. Collagen and elastin
a. Bone
b. Cartilage
c. Bone
d. Bone
Explain the function of two kinds of connective tissue other than blood.
“1. Cartilage – Protect – Covers bone. Smooth, reduces friction
- Bone – strength (due to calcium salts and cylindrical structure), Support, flexibility (due to presence of collagen and Elastin), Structure and shape
- Adipose tissue – Insulation, protection, energy reserve, Nerve transmission
- Areolar – Connects and wraps muscle fibres etc”
Bones:
This is found in the earlobes, nose, voice box (Adam’s apple) and at the end of all your bones. It has two major component:
• It contains calcium salts and it’s hard. They also contain collagen fibres and it gives flexibility.
• Osteocytes
It gives shape and supports.
Cartilage:
Cartilage is smoother than ice. It doesn’t have nerve or blood supply. Protect bones from wear and tears (prevent friction). They allow it to bend.
Adipose (fat) tissues:
This is found under our skin everywhere in the body. Its function is to insulate (keep you warm), protect you and provide energy. This is also found around organs that protect e.g. the heart. It also speeds up nerve transmissions (impulses). It’s semi-fluid
Areolar tissues:
It is the most common tissue in the body. It’s found covering muscles, blood vessels, nerves and organs. It binds them together. It has white and sticky materials that binds muscles together and it’s semi-fluid. Matrix contains elastin (allows it to stretch) and collagen (gives it flexibility).
Blood:
It has matrix with substances within the matrix. The matrix is the plasma (this makes up 55%, it looks like a straw and it has colors) and the rest is the blood cells (this makes up 45%). There are three types of blood cells:
- Red blood cells - A type of blood cell that is made in the bone marrow and found in the blood. Red blood cells contain a protein called haemoglobin, which carries oxygen from the lungs to all parts of the body. Checking the number of red blood cells in the blood is usually part of a complete blood cell (CBC) test.
- White blood cells – they help fight infection (immune response). Granulocytes e.g. phagocyte. Lymphocytes – produce antibodies – specific. They ‘digest’ the microbes (bacteria). White blood cells are part of the body’s immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes (T cells and B cells).
- Platelets - blood clotting. Platelets, or thrombocytes, are small, colourless cell fragments in our blood that form clots and stop or prevent bleeding. Platelets are made in our bone marrow, the sponge-like tissue inside our bones. Bone marrow contains stem cells that develop into red blood cells, white blood cells, and platelets.
Plasma has cells, hormones, nutrients and C02
