Animal Tissues Flashcards
What is a cell?
The basic unit of life.
What is tissue?
A group of similar cells performing a similar function.
What are organs?
A number of similar tissues.
What is a system?
A number of different organs.
What is an organism?
A number of systems that work together.
What is cell differentiation?
Cells that take on different functions.
How many groups are mammalian tissues classified into? Name them.
Four.
- Epithelial
- Connective
- Muscle
- Nerve
Name the four simple epithelium.
- Squamous
- Cuboidal
- Ciliated columnar
- Columnar
What are stem cells?
Undifferentiated cells. (cells without functions)
Where is squamous tissue found?
-Found in the walls of alveoli and blood vessels. (endothelium)
What is the function of squamous tissue?
- Creates a large surface area for CO2 + O2 to pass through easier.
- Easy movement.
- Reduces friction between blood and walls of blood.
What is the structure of squamous tissue?
-A single layer of thin flat cells which interlock tightly.
Where is cuboidal tissue found?
-Lines glands and walls of tubes in the kidney.
What is the function of cuboidal tissue?
- Secretion.
- Absorption of water back into the blood.
- Absorption in the kidneys.
What is the structure of cuboidal tissue?
- Appear cube shaped.
- Round nucleus in the centre of the cell.
- Tightly packed.
Where is ciliated columnar tissue found?
- Found in air passages such as the nose, trachea, bronchi.
- Also found in the fallopian tubes.
What is the function of ciliated columnar tissue?
- Cilia move in waves to move the mucus with the dust upwards away from the
lungs. Goblet cells secrete mucus to trap dust. - In fallopian tubes cilia + mucus propel the ovum to the uterus.
What is the structure of ciliated columnar tissue?
- Have cilia on free surface.
- Columnar in shape.
- Goblet cells may be present.
Where is columnar tissue?
-Lines the digestive system from the stomach to the anus.
What is the function of columnar tissue?
-In small intestines they aid in the movement or absorption of water, food, salts +
vitamins.
-Goblet cells secrete protective mucus in the digestive system.
What is the structure of columnar tissue.
- Elongated, large cells with an oval shaped nucleus near the base.
- Goblet cells may be present.
Where is compound epithelium found?
-Forms the epidermis of the skin and lines of the oesophagus.
What is the structure of compound epithelium?
-Innermost layer has cells that divide actively to replace dead cells.
-Uppermost layer of cells are dead and flattened and are continually rubbed off by
friction.
What is the function of compound epithelial tissues?
- Protective function:
- against mechanical injuries.
- desiccation. (drying out)
- entry of bacteria.
Name the six different types of connective tissues.
- Areolar
- Yellow elastic
- White fibrous
- Blood
- Bone
- Cartilage
Where is areolar tissue found?
- Found as a continuous layer.
- Fills spaces between organs and muscles.
What is the structure of areolar tissue?
-Made up of a jelly-like matrix
-With large fibroblasts which synthesize 2 types of fibres:
1. collagen (white + non elastic) fibres
2. yellow elastic fibres
Contain:
-mast cells
-adipocytes (fat cells)
-macrophages
What is the function of areolar tissues?
- Connects layers of skin.
- Supports + protects organs + muscles.
- Collagen fibres provide strength + yellow fibres allow stretching.
- Mast cells secrete matrix, adipocytes store fat, macrophages provide protection against infection.
Where is white fibrous tissue found?
-In the tendons to join muscle.
What is the structure of white fibrous tissue?
- Consists of a dense network of white collagen fibres which make it strong.
- The matrix is jelly-like.
What is the function of the white fibrous tissue?
-They are very strong so that muscles can pull on the bones to cause movement.
Where is yellow elastic tissue found?
-In the ligaments to join bones to bone at the joints.
What is the structure of yellow elastic tissue?
- Consists of a dense network of yellow elastic fibres.
- the matrix is jelly-like.
Where is blood found? (only connective tissue which is fluid)
-Found in a closed blood system consisting of heart, blood vessels and capillaries.
What is the structure of blood?
- Red blood cells/Erythrocytes, don’t have a nucleus, made in red bone marrow, short lifespan, pigment called haemaglobin which carries CO2 + O2, biconcave discs; allows a larger surface area to volume ratio.
- White blood cells/Leucocytes, produced in red bone marrow and in the lymph nodes, have one or more nuclei present, can move around like amoeba,
- Platelets/Thrombocytes, produced in bone marrow and are cell fragments with no nucleus.
- Plasma, has a white/yellowish colour, mainly water with many substances dissolved in it e.g. glucose, amino acids + CO2.