system definition
A group organs that are specialised to perform specific function within an organism
What is classification based on
Function
Homeostasis definition
- It is a dynamic state of equilibrium
- To maintain physiological constancy in a changing environment
How many organ systems in the body?
11
How many bones? ribs?
204
24 (12 front and back)
4 types of cells in the skeletal system and their function?
Osteoblasts - Make bone cells (deposition)
Osteoclasts- Secrete enzymes and acid (resorption)
Osteocytes - differentiated osteoblasts
Chondrocytes - cells in the bone that divide and enlarge in response to growth hormone
What does a lack and excess of growth hormone result in kids and adults?
Lack - dwarfism
Excess:
Adults - acromegaly
Childhood - gigantism
Growth hormone treatment doesnt work on adults
How long is the GIT?
4.5 m
Extends from mouth to rectum
what is the main function of kidneys?
To maintain/regulate the water levels in the blood
How are nutrients and oxygen transported in blood?
nutrients - in plasma
oxygen - RBCs
What do melatonin and insulin regulate?
Melatonin - biorhythms (circadian(sleep cycle))
Insulin - glucose levels
** Part of endocrine system - hormones secreted into blood
What is innate and adaptive immunity?
Innate - non-specific immunity (skin as a barrier, macrophages)
Adaptive - specific immunity (t-cell and b-cell response)
What is the largest organ system - its function and components? which immune system is it part of? what determines its colour?
Integumentary system
– Protective barrier, distinguishes/separates organism from its surroundings
– skin, hair, nails, skin glands+their products
– Innate immunity
– Level of Melanin determines colour
Major organ systems - their organs - their function
Tissue definition
A group of specialised cells grouped together to perform a specific function
4 types of tissue - which ones are excitable? give examples of each
EXCITABLE:
- Muscle [skeletal (attaches bones to tendons) , cardiac (in heart), smooth (vasculature, bronchioles, digestive tract, reproductive tract)]
- Nervous (brain, spinal cord, nerves)
NON-EXCITABLE:
- connective (bone, adipocytes, skin dermis)
- Epithelial (stomach lining, alveoli, epidermis, exocrine ducts, kidneys, intestines)
examples of skeletal musc. not attached to bone or tendon?
diaphragm, tongue, anal sphincter
** attached to tissue
Two cell types in nervous tissue? and function
Neurons: Generate+Conduct electrical impulses
Neuroglia: Do not conduct impulses – are support cells
what forms the myelin sheath in CNS and PNS?
CNS - Oligodendrocytes
PNS - Schwann cells
What tissue are glands made of?
epithelial tissue
Features of epithelial tissue
** NO BLOOD VESSELS
- reproduces rapidly
- tightly packed cells thus tight junctions
** underside linked to connective tissue by non-cellular BM
Where are epithelial cells present?
alveoli, blood vessels, skin, mouth, lips, kidneys
Types of epithelial cells + some of their locations
Simple+stratified:
-Squamous : Flat - for diffusion and filtration – also secretes lubricants
(alveoli, capillaries, lining of heart and lymphatic vessels)
-Cuboidal : For secretion and absorption
(In ducts, kidney tubules, secretory products of small glands)
-Columnar : Mainly absorption + also secretes mucous and enzymes
Ciliated:
- bronchi, uterine tubes, uterus
Non-ciliated/Smooth:
- stomach, digestive tract, bladder
Types of stratified epithelial membrane cells
Keratinised:
– Dead cells present in a dry environment
– Ex. skin cells, hair, nails
Non-keratinised:
– Living cells in a moist environment
– In lips, the mouth, stomach, oesophagus
