The human body (1) Flashcards
Week 1
Definition of Anatomy
The study of the structure of body parts and their relationship to one another
Definition of Physiology
Study of the function of body parts; how they work to carry out life-sustaining activities.
What is the principle of complementarity of structure and function?
When what a structure can do depends on its specific structure.
What is the first level of structural organisation?
Chemical level- atoms combine to form molecules
What is the second level of structural organisation?
Cellular level- cells are made up of molecules (e.g. smooth muscle cell)
What is the third level of organisational structure?
Tissue level- tissues consist of similar types of cells (e.g. smooth muscle tissue)
What is the fourth organisational structure?
Organ level- organs are made up of different types of tissues
What is the fifth level of organisational structure?
Organ system level- Organ systems consist of different organs that work together closely.
What is the sixth level of organisational structure?
Organismal level - the human organism is made up of many organ systems.
Name 8 necessary life functions included in the maintenance of life
Maintaining boundaries, Movement, responsiveness, Digestion, Metabolism, Excretion, Reproduction, Growth.
Maintaining boundaries definition and example
-Separation between internal and external environments must exist
-Plasma membranes separate cells
Movement- what and example
-Muscular system allows movement of body parts via skeletal muscles
-smooth muscle: vasoconstriction/digestion.
Responsiveness definition and example
-Ability to sense and respond to stimuli
-Withdrawal reflex prevents injury
Digestion- what and purpose
-Breakdown of ingested foodstuffs
-Followed by absorption of simple molecules into blood.
Metabolism- definition and example
-All chemical reactions that occur in body cells
-Sum of all catabolism (breakdown of molecules) and anabolism (synthesis of molecules)
Excretion- meaning and examples
-Removal of wastes from metabolism
-Urea (from breakdown of proteins)/ faeces (unabsorbed foods)
Reproduction- two examples
1.Cellular level- reproduction involves division of cells for growth or repair.
2.Organisational level- reproduction is the production of offspring
Growth- definition
Increase inn size of a body part or of organism
Humans are m-
Multicellular
What are the 11 organ systems that work together to maintain
Integumentary, Skeletal, Muscular, Nervous, Endocrine, Cardiovascular, Lymphatic (immunity), respiratory, digestive, urinary, male /female reproductive.
What is the integumentary system and its purpose (2)
-Forms the external body covering
-Protects deeper tissues from injury
-Synthesises vitamin D
-Houses cutaneous (pain, pressure)receptors, and sweat sweat and oil glands.
What is the Skeletal system and what is its purpose (2)
-Protects and supports body organs
-provide framework the muscles use to cause movement.
-Bones store minerals
-Blood cells are formed within bones
What is the Muscular system and its purpose?
-Allows manipulation of the environment, locomotion, and facial expression.
-Maintains posture, and produces heat.
What is the Nervous system and its purpose?
-The fast-acting control system of the body
-It responds to internal and external changes by activating appropriate muscles and glands.
What is the Endocrine system and its purpose?
-Glands secrete hormones that regulate processes such as: growth, reproduction, metabolism by body cells.
What is the Cardiovascular system and its purpose
-Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes
-The heart pumps blood
what is the Lymphatic system/ Immunity and its purpose
-Picks up fluid leaked from blood vessels and returns it to blood.
-Disposes of debris in the lymphatic stream= houses white blood cells (lymphocytes) involved in immunity.
-The immune system response mounts the attach against foreign systems.
What is the Respiratory system and its purpose
-Keeps blood constantly supplied with oxygen and removes carbon dioxide.
-The gaseous exchanges occur through the walls of the air sacs of the lungs.
What is the Digestive system and its purpose
-Breaks down food into absorb-able units
-Enter the blood for distribution into the cells
-Indigestible food = faeces
What is the Urinary system and its purpose?
-Eliminates nitrogenous wastes from the body
-Regulates water, electrolyte, acid-base balance of the blood.
Male reproductive system !!!
-Overall function to produce offspring
-Testes produce sperm and male sex hormone, male ducts and glands.
Female reproductive system
-Overall function is production of offspring
-Ovaries produce eggs and female sex hormones.
-Remaining female structures serve as sites for fertilisation and development of fetus
Give an example of interrelationships among body organ systems
- Digestive and cardiovascular system exchanging nutrients
2.Urinary system taking nitrogenous waste and excess ions from the cardiovascular system.
3.Respiratory system exchange CO2 and O2 with cardiovascular system.
5 factors humans need for survival that must be in the right amounts
1.Nutrients
2.Oxygen
3.Water
4.Normal body temp
5.App atmospheric pressure
Nutrients (survival needs) and 2 examples.
*Chemicals for energy and cell building
1.Fats= long-term energy storage
2.Proteins= needed for cell building and cell chemistry
3.Carbohydrates= major source of energy
4.Minerals/Vitamins= involved in chemical reactions as well as structural purposes.
Oxygen (survival needs)
*Essential for release of energy from foods
Water (survival needs)
*Most abundant chemical in body; provides the watery environment needed for chemical reactions
Normal body temperature (survival needs)
*If body temp falls below or goes above 37 degrees, rates of chemical reactions are affected
Appropriate atmospheric pressure (survival needs)
*Specific pressure of air is needed for adequate breathing and gas exchange in lungs.
Definition of Homeostasis
The maintenance of relatively stable internal conditions despite continuous changes in environment
Variables that can affect homeostasis (3)
Blood sugar, body temperature, blood volume, blood pH, Sodium (potassium, calcium) ion concentrations.
What are the three components of Homeostatic control of variables
1.Receptor
2.Control centre
3.Effector
What is a receptor and what it does.
*A sensor that monitors the environment
*Responds to stimuli (things that cause changes in controlled variables)
What does a control centre do?
*A control centre receives input from the receptor to determine an appropriate response
*Determines set point at which variable is maintained
What does an effector do ?
*Receives output from the control centre to provide the means to respond
*Response either reduces stimulus (negative feedback) or enhances stimulus (positive stimulus)
What is negative feedback (with examples)
*Response reduces/shuts off original stimulus (variable changes in opposite direction of initial change)
Examples:
1. Regulation of body temperature
2.Regulation of blood glucose by insulin
3. Hormone regulation (thyroid feedback loop)
5 steps involved with keeping homeostasis
1.Stimulus= produces change in variable
2.Receptor= detects change
3.Input= Information sent along AFFERENT pathway to control centre
4.Output= Information sent along EFFERENT pathway to effector
5.Response of effector feeds back to reduce the effect of stimulus and returns variables to homeostatic level.
Example of homeostatic response (5 steps)
- (Stimulus) Body temperature falls
2.(Receptor) Temperature-sensitive cells in skin
3.(Control centre) Thermoregulatory centre in brain
4(.Effectors) Skeletal muscles cause the body to shiver
5.(Response) Body temperature rises, stimulus ends.
What is positive feedback (with examples)
*When the response to the stimulus enhances or exaggerates the original stimulus.
(Usually controls infrequent events that do not require continuous adjustment)
Examples:
1.During childbirth, body releases oxytocin causing further uterine contractions.
2.Lacactation, baby sucking = more milk produced.
3.Blood clotting, platelets attracting more platelets at a wound site.
