Histology Topic 1: Introduction Flashcards
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
