Histology Flashcards
Tissue
It is a collection of similar cells which act together to perform a particular function
E.g muscle tissue for movement, epithelial tissue for protection
4 types of tissues
- Connective tissue
- Muscle tissue
- Epithelial tissues
- Nervous tissue
Connective - support
Muscle - Move
Epithelial- protect
Nervous - neurons
Epithelial tissue
Function: protection/ protective coverings (skin/ mucus membrane)
- acts as protection against bacteria and a buffer against mechanical injury
- cells are closely packed together
- secretion and absorption
- lines the body’s surface both inside & out
- consists of cells held together by matrix
Connective tissue
Supportive, protective, binding
Fats, ligaments, tendons, bones, cartilage and lymph and blood are all connective tissue structure
Muscle tissue
Contracts and relaxes and moves parts of the body.
- cells here form skeletal, smooth, and cardiac muscle tissue
- voluntary muscles are made up of striated muscle tissue
- involuntary muscles are smooth muscle tissue
- the heart has its own special muscle tissue
Nerve tissue
Makes up the nervous system.
- Carries messages from the brain and coordinates all body functions
- made of neurons (brain, spinal cord, and nerves)
- the neuron receives and conducts electrochemical impulses from one part of the body to another. It’s function is to control and coordinate activities of the body.
Organs
Are groups of tissues designed to perform specific functions.
(Brain, heart, eyes, kidney, liver)
Systems
These are groups of organs which co-operate for a common purpose.
The human body consists of 11 major systems
Name the 11 body systems
Integumentary system (the skin)
Respiratory system
Digestive system
Urinary system
Reproductive system
Skeletal system
Muscular system
Nervous system
Cardiovascular system
Lymphatic system
Endocrine system
What are the basic building blocks for our bodies tissues?
Protein
Proteins are made up of:
Amino acids and enzymes
Thickness of skin varies according to:
Body part, age and race
Skins most amazing ability;
Ability to heal itself through hyper production of cells and blood clotting
What are the functions of the skin? (6) PHASES
- Protection
- Sensation
- Heat regulation
- Excretion
- Secretion
- Absorption
The skin is a protective barrier to:
Outside elements and microorganisms
It has many defence mechanisms to protect the body from injury or invasion.
Acid mantle:
Is the protective barrier made up of sebum, lipids, sweat and water that form a hydrolipidic film to protect the skin from drying out and from exposure to external factors.
Sebum:
Is oil on the epidermis that gives protection
Damage to the skin barrier is the cause of many skin problems including:
Sensitivities, aging and dehydration
Skin can repair itself when injured, protecting the body from infections and damage from injury through:
Hint: these cells are activated to rejuvenate and repair the skin
Fibroblast cells
The barrier function is the skins mechanism that protects us from:
Irritation and (TEWL) Trans epidermal water loss
What does the skin produce as another form of protection from the sun?
Melanin
Melanin
Is the pigment in the eyes, hair and skin that gives us some protection from UV rays
The body maintains a constant temperate of 37• to prevent:
Evaporation of fluids
An increase or decrease in the outside temperature results in:
Vasodilation or Vasoconstriction
Vasodilation
We cool ourselves by evaporation through the sweat glands. Blood vessel dilation also assists in cooling the body.
Vasoconstriction
We protect ourselves from cold by constriction of the blood vessels and decreasing blood flow to extremities therefore the major organs are receiving majority of the blood supply.
Hair follicles can also help regulate:
And protects us from:
Hair follicles can help regulate body temperature and protect us from heat loss.
Which muscle contracts and causes goosebumps to warm the skin?
Arrector Pili muscle
Vasodilation
Protects the body from heat
- increase in diameter of blood vessels
- skin is pink and warm
- caused by relaxation of smooth muscle
- blood in the skin moves more freely
- surface heat is lost and body temperature is reduced through perspiration
Vasoconstriction
- protects the body from cold
- contraction of the smooth muscle
- passage of blood slows, skin pales, a bluish cast may be noticed (loss of oxygen)
- the arrector pili muscle can cause the hairs to rise closing the surface skin, keeping body heat inside
Absorption
Absorption of ingredients, water, and oxygen is necessary for our skins health.
The skin absorbs:____ and discharges:___
The skin absorbs oxygen and discharges carbon dioxide