Histology Topic 1: Introduction Flashcards
(23 cards)
What is histology?
Histology is the study of tissues (aggregates of cells)
and cells at the microscopic level
Why do tissues need to be prepared for viewing under a microscope?
Fresh tissue is non-permanent, sections are not thin
enough and lacks colour.
What is the process of preparing tissue for microscope viewing?
>Fixation: Tissue is preserved >Processing: Water is removed and tissues are impregnated with wax—>to remove water, tissue must go through increasing strengths of Alcohol >dehydrated gradually to prevent shrinkage >Section Cutting: Thin section cut from paraffin embedded tissue—>ribbons of wax and tissue—>tissue placed on slide and wax then dissolved with a clearing agent >Staining: Haematoxylin(stains nucleus blue to black colour) and Eosin(stains cytoplasm and intercellular components pink) added to see intracellular content —>to make prominent the sample is dehydrated in absolute alcohol
The highest surface area to volume ratio is found in which type of a cell? A larger or smaller cell?
Smaller cell
What are the benefits of a higher SA to Volume ratio?
- Larger surface area means more space for nutrients and other solutes to diffuse into the cell
- Smaller volume relative to SA increases efficiency at which nutrients diffuse within a cell
- This all equates to increased rate of diffusion
What are the advantages of multicellularity?
- Allows cell to exceed cell size limits (usually caused by diffusion)
- Allows cell to have a longer lifespan
- Allows for the occurrence of specialized tissues with specific functions
- Allows for the production and repair of damaged cells
Explain the hierachial organization of an organism
- Cells organized into tissues: groups of similar cells that work together on a specific task.
- Organs are structures made up of two or more tissues organized to carry out a particular function,
- Groups of organs with related functions make up the different organ systems
What are the four primary types of tissue?
- Epithelial Tissue
- Connective Tissue
- Muscle Tissue
- Nerve Tissue
What is the integumentary system and what is its function?
▪︎ hair, skin and nails
▪︎ Functions:
-encloses many internal structures of the body
- site for many sensory receptors
What is the skeletal system and what is its function?
▪︎bones, cartilage and joints
▪︎Functions:
- supports the body
- enables movement alongside muscular system
What is the muscular system and what is its function?
▪︎skeletal muscles and tendons
▪︎Functions:
-enables movement alongside skeletal system
- maintains body temperature
What is the nervous system and what is its function?
▪︎Brain, Spinal cord and Peripheral nerves
▪︎Functions:
-detects and processes sensory information
-activates bodily responses
What is the endocrine system and what is its function?
▪︎Pituitary gland, Thyroid gland, Pancreas, Adrenal gland, Testes/Ovaries
▪︎Functions:
-secretes hormones
-regulates bodily processes
What is the circulatory system and what is its function?
▪︎Heart and Blood vessel
▪︎Functions:
- transport nutrients and oxygen to tissues
- equalizes body temperature
What is the lymphatic system and what is its function?
▪︎Thymus, Lymph nodes, Spleen, Lymph vessels
▪︎Functions:
- returns fluid to the blood
-defends against pathogens
What is the respiratory system and what is its function?
▪︎Nasal passage, Trachea, Lungs
▪︎Functions:
- to remove carbon dioxide from the body
- to deliver oxygen to the blood
What is the digestive system and what is its function?
▪︎Stomach, Liver, Gall bladder, Small intestine, Large intestine
▪︎Functions:
- pro
cesses food for use by the body
- removes waste from undigested food
What is the urinary system and what is its function?
▪︎Kidneys and Urinary bladder
▪︎Functions:
- controls water balance in the body
-removes waste from blood and excretes them
What is the male reproductive system and what is its function?
▪︎Epididymis and Testes
▪︎Functions:
- produce several hormones and gametes
- deliver gametes to female gametes
What is the female reproductive system and what is its function?
▪︎Mammary glands, Uterus and Ovaries
▪︎Functions:
-produces sex hormones and gametes
- supports embryo/foetus until birth
- produces milk for the infant
What is the function of Tight Junctions and where are they found?
- Seal plasma membranes tightly together
* Digestive tract lining, bladder lining
What is the function of Adhesion junctions/spot desmosomes and where are they found in the body?
- Permit some movement between cells
- Allow tissues to stretch and bend
- Skin
What is the function of Gap junctions and where are they found in the body?
- Protein channels enable movement of materials between cells
- Liver, heart
