Lecture 3 - Organ systems Flashcards
Urinary system
Water regulation and
nitrogenous waste
disposal system.
FUNCTIONS:
•Filters blood to extract metabolic waste and maintain acid – base and mineral balance
•Regulate production of red blood cells
STRUCTURE:
-Kidneys: Regulate total body water volume.Regulate ion concentrations in extracellular fluids.Excrete metabolic wastes, drugs, toxins
-Ureters: kidney bladder
-Urinary bladder: temporary storage of urine
-Urethra: bladder toilet (hopefully)
Reproductive system
Function:
To produce offspring…..
-form specialised cells (gametes)
-gametes must come together
-Genetic information combined – up to the woman
-Gestation and parturition – up to the woman
-The reproductive system
however lies dormant until puberty. Then kicks in a dictates a lot of our actions.
Respiratory system
Consists of air passageways: trachea, bronchi, bronchioles and lungs
FUNCTIONS:
•Exchange of O2 and CO2 with blood
•Regulation of acid – base balance
-Keeps you supplied with oxygen and gets rid of waste carbon dioxide
Digestive system
Organs:
Alimentary canal:
mouth, pharynx, eosophagus, stomach, small intestine, large instestine, then the anus.
Accessory digestive organs:
teeth, tongue, gall-bladder, and the digestive glands, salivary gland, liver and pancreas.
FUNCTIONS:
•The breaking down of ingested food into ‘useable’ nutrient molecules that can enter the cardiovascular or
lymphatic systems. Then it gets rid of indigestible remains (poo)
Skeletal system
-Consists of the bones and cartilage associated with joints
-Made mainly from connective tissue
FUNCTIONS:
•Protects and supports internal organs - forms internal scaffold
•Provides support and framework for muscles to act upon
•Contains bone marrow for blood cells to develop in
•Stores minerals e.g. calcium
Cardiovascular system
•Consists of blood ( carries blood), heart ( pumps blood) and blood vessels
Tissue types:
Muscle tissue (cardiac and smooth),
Connective tissue,
Epithelia (endothelium)
FUNCTIONS:
•Carries gases, waste, nutrients, hormones…
-Transports immune system cells (connective tissue
Endocrine system
•Includes endocrine organs e.g. adrenal gland
- Glands secrete hormones
FUNCTIONS:
•Influences metabolic activity through
hormone signaling.
-Essential for regulation of cellular Homeostasis (growth, metabolism,
reproduction)
Nervous system
•Includes the brain, spinal cord, nerves and sense organs e.g. eyes, ears e.t.c.
-The master controlling and communicating system of body
•Divided into:
CNS – Brain and Spinal Cord
Peripheral Nervous System –nerves, ganglia- link rest of body to CNS
FUNCTIONS:
•Detects changes in internal and external environment, encoding them into electrical impulses and transmitting them along the nerves
•Processes electrical impulses and making decisions – voluntary or involuntary
•Activating effectors = appropriate response – muscular movement or glandular secretions
-Regulates muscles and glands via
electrochemical impulses delivered by neurons
Lymphatic system
• Consists of lymphatic fluid ( lymph ), lymphatic vessels, lymph nodes, spleen, lymph nodules and thymus
FUNCTIONS:
• Transporting various substances
Takes lipids from GT tract to blood
Transports proteins and fluids back to bloodstream
• Development of lymphocytes ( cells responsible for fighting disease )
Integumentary system
WHAT IS IT: Skin and the associated skin components e.g. hair, sweat glands, sebaceous glands and nails The water-proof, stretchable, washable and air-conditioned coat that automatically repairs itself. Forms external body covering
FUNCTION:
• Protects the body from external environment – trauma, bacteria, viruses, UV rays skin = chemical, biological and physical barrrier. Protects deep tissues from injury and synthesis Vitamin D
• Protects underlying tissue against fluid loss
• Excretes metabolic waste via sweat
• Helps make vitamin D by UV light
• Detects pain, touch, dehydration and changes in temperature ( 80% heat lost through skin )
Stratum corneum – dead, flattened cells with keratin
Skin glands: lubricate skin
• Sebaceous glands – secrete sebum to soften skin and hair. Located in dermis. Open into hair follicles, some open directly onto skin.
• Sweat glands – secrete salt and water as swear – cool body. Embedded in dermis or hypodermis. Open into hair follicles, some open directly onto skin.
Two types: Merocrine and Aporcrine ( see bio lab sheet )
Hair: Control body temp
Nails: Protect skin
Sensory receptors: Relay info regarding touch, temp, pain to brain
Lymphatic system
-Soaks up escaped fluid, acts as a waste reservoir.
-Houses lymphocytes involved in immunity.
FUNCTIONS:
•Transporting various substances
Takes lipids from GT tract to blood
Transports proteins and fluids back to bloodstream
•Development of lymphocytes ( cells responsible for fighting disease )
Muscular system
-Consists of skeletal muscle, cardiac muscle and smooth muscle
FUNCTIONS:
•Enables body to move by acting of opposing muscular contraction and relaxation
•Maintains posture
•Plays a role in thermoregulation - generate heat
- Stabilise joints
What does organ level allow
Complex functions become possible, fast task and reactions
E.g. stomach - how tissue types are relating
Internal lining - epithelial tissue ( simple columnar ) = secrete digestive juices ( enzymes ) = breaks things down
Stomach wall - mainly muscle ( smooth - involuntary ) - contracts and relaxes to churn - mechanical digestion - change shape of stomach
Stomach wall - connective tissue - supports muscle structure - hold everything together, binds epithelium to muscle
Nervous tissue - nerve fibres, signal muscle cells to change contraction rate, or stimulate more digestive juices secretion - tell epithelial cells when they need to secrete digestive juices or when muscle tissues
What is an organ system
series of organs all working together to accomplish common function
What is an organ
Discrete structure composed of at least two tissue types, that performs a specific function of the body.
Four tissue types come together
What are the 11 organ systems
Integumentrary system - external body covering
Respiratory system - gaseous exchange
Reproductive system - making and nurturing babies
Urinary system - waste disposal + water regulation
Lymphatic system - returns excess fluid to cardiovascular system, immunity
Endocrine system - regulation of homeostasis
Nervous system - fast acting control system
Skeletal system - supports and protects
Muscular system - movement and heat production
Digestive system - extracts nutrients
Cardiovascular system - network of blood vessels carrying blood around body. Heart pumps it. Moves things around body
What is meant by interdependence
Complex multicellular organisms - connected to each other/ interactions between them - talk to each other
What does each cell of our body require and why
Each cell of our body requires: oxygen, nutrients, waste removal, to be able to respond to external changes
How do organ systems work and why
TOGETHER/ IN UNISON - perform functions needed in life……
- so that all cells are feed and cleaned up
- all cells are protected from dehydration and attack
- all cells can move from danger or towards food/water
- our genetic material is transferred to a new generation
They dont work independently - because we are multicellular - not all cells have ability to independently respond
What are the functions of life
- Maintaining boundaries
- Movement
- Responsiveness
- Digestion
- Metabolism
- Excretion
- Reproduction
- Growth
Maintaining boundaries
- Keeping inside separate from out - selectively take in/out
- Single celled organisms have their plasma membrane
- Our cells all have plasma membranes. Selective permeability allows these to have separate functions form other cells.
- Unlike single celled organisms, we have extracellular fluid (blood plasma, interstitial matrix in between cells of body - binding them together to make structures) - has water in it, don’t want to lose it = mantain external boundary - keep everyting in and keep it hydrated = not leaking fluid = have skin
- We have to be prevented from drying out, attempts at infection, heat and sunlight. This role is taken on by the Integumentary system = the skin
Movement
- Propelling ourselves from one place to another
- Find food
- Get away from danger
- Fine motor skills – fingers - response to nervous system
Muscular system ( contract and move bones around ) & Skeletal system ( structure )
- internal movements
blood is pumped - cardiovascular system
food is pushed - digestive system
urine is squeezed - Urinary system - bladder
Responsiveness
- Sense and respond to changes in the environment, fast - Nervous system - sending info to brain from nerves - changes in environment
- All cells are able to respond to stimuli, however rapid responses are controlled by the nervous system, as signals are sent as electrical impulses
Digestion
- Digestion - breaking down the large food molecules into smaller ones that can be used by the body – Digestive system - take in nutrients
- Absorbed into the blood and transported around the body – cardiovascular system
- If no cardiovascular system, nutrients sitting in connective tissue around guts - pointless
Metabolism
- All chemical reactions that happen inside your individulal cells
- Anabolism - making new molecules
- Catabolism - break down of existing molecules ( large to small )
- These reactions require nutrients, building blocks, oxygen…..
- Cell respiration – using nutrients and oxygen to trap usable energy
- Digestive system – provides molecules
- Respiratory system – provides oxygen
- Cardiovascular system – transports oxygen and nutrients to cells
- Lymphatic system – returns and drains excess fluid/waste back into blood supply
- Endocrine system – metabolism is regulated by hormones - signalling system internally
Excretion
- Getting rid of waste from the body ( biproducts of digestion and metabolism )
- Digestive system – rid of indigestible food as faeces - fibres - long chain carbs we cant break down, need it to maintain healthy bowel movements
- Urinary system– removes nitrogen containing byproducts of metabolism (ie Urea)
- Cardiovascular system – transports carbon dioxide back to lungs - expel it
- Respiratory system – releases carbon dioxide
Reproduction
-Cellular level – mitosis - 1 cell to 2 cells
-Growth and repair
-Strictly controlled by metabolism ( local supply of energy and nutrients ) and hence all organ systems involved in that
-Organism level reproduction – babies - pass genetic material onto next generation and is conerved- major task of the….
Reproductive system
- But this is tightly controlled by the….
Endocrine system -hormones dictate how acting
Growth
Genetic material grows once passed on
For growth to occur you need all organ systems at some point or another
What is the structure of the skin
-2 layers….
epidermis – epithelial cells
dermis – dense irregular connective tissue
-About 1.7m2 and about 7% total body weight.
-The dermis is vascularised. The epidermis receives nutrients that diffuse through tissue fluid.
-Anchored to other structures (mainly muscle) by the subcutaneous tissue, the hypodermis. Mainly adipose with some areolar tissue.
How does skin act as a biological barrier
Immune cells survey the epidermis (dendritic cells) and dermis (macrophages) to prevent pathogen invasion.
How does skin act as a chemical barrier
Skin secretions
1) acid mantle – retards bacterial growth due to low pH
2) dermicidin in sweat and bactericides in sebum kill bacteria off
3) Epithelial cells secrete defensins
melanin
Chemical pigment shield – prevents UV damage of cells
How does skin act as a physical barrier
- Skin continuity
- Cell hardness due to keratin
- Prevents water loss or gain
Functions of skin
- Temperature regulation
- Cutaneous sensation
- Metabolic functions (ie VitD production)
- Acts as a blood reservoir
- Excretion – we excrete Urea, uric acid in sweat, along with water and salts.
Structure of hair
Dead, keratinised cells
Function of hair
Warmth, sense insects, head hair – protection from trauma and the sun. Eyelashes shield our eyes and nose hairs prevent us inhaling things.
Structure of nails
Dead, keratinised cells
Function of nails
- Protection – damage to fingers tips or toe tips.
- Used as tools
Bones
80 bones make skeleton
Cartilage
i.e. nose, in ribs at joins
What are the 3 types of muscle tissue
- Skeletal muscle
- Cardiac muscle
- Smooth muscle
