Organisation Of The Human Body Lectures 1.1-1.3 Flashcards
What are the levels of organisation of the body?
- Chemical level- molecules composed of atoms
- Cellular level- cells are basic unit of life
- Tissue level
- Organ level
- System level
- Organism level
What are the 4 main types of cells?
-epithelial cells
-nerve cells
-muscle cells
-connective tissue cells
What are epithelial cells?
-tightly attached together and line hollow organs (e.g. blood vessels or digestive organs)
What are nerves cells specialised for?
-specialised for communication.
Motor neurons send signals from the brain to muscles and glands to control functions.
What are muscle cells specialised for?
specialised for contraction and produce movement. Examples are: skeletal, cardiac and smooth muscle.
What are connective tissue cells?
-diverse group of cells
-all provide structural strength
Function of muscle tissue?
Provides movement
Function of nervous tissue?
Rapid internal communication
Function of epithelial tissue?
Transport, function and protection
Function of connective tissue?
Supports and protects organs
Binds tissues together
Muscle tissue:
All muscles are attached to bones
What does the Gastrointestinal tract include?
⁃ inside is lined with epithelial tissue
⁃ Wall contains smooth muscle
⁃ Nervous tissue controls muscle contraction and gland secretion
⁃ Connective tissue binds all the above tissues together
What is homeostasis?
-maintenance of a stable internal environment
What are body cells contained in?
A watery internal environment where exchanges are made
Intracellular fluid (ICF)
-environment in which the cells live
-two components; plasma and interstitial fluid
-examples= synovial fluid, amniotic fluid etc
What are the factors of the internal environment that are homeostatically regulated?
-concentration of oxygen, carbon dioxide waste products pH, water and electrolytes
-volume and pressure
-temperature
What are the three elements of a homeostasis control system and what are their functions?
-receptor: detects deviations from normal in the internal environment that need to be held within narrow limits
-control centre: integrates info with other relevant info
-effector: makes appropriate adjustments in order to restore factor to its desired value
What is feedback? And what are the types of feedback in a homeostatic control system?
Feedback: refers to responses made after a change has been detected
-Negative: stimulus causes a response—> leads to a decrease of the original stimulus. Involved in maintaining homeostasis
-Positive: stimulus causes a response—-> leads to an enhancement of the original stimulus. Process is enforced until its interrupted
What is feedforward and what is an example?
-used for responses that occur before a change in the stimulus occurs
Example = increased cardiac output
Regulation of blood glucose levels by a negative feedback mechanism:
-main type of homeostatic control
-involves pancreatic hormones
-opposes the initial change as the output shuts off the original stimulus
-negative feedback mechanism= variable changes in the opposite direction to that of the initial change—> returns to its original ideal value or set point.
Regulation of human body temperature by a negative feedback mechanism:
-involves the hypothalamus
-essential for stable cellular metabolism
-varies within the body: core vs outer shell
-varies among individuals and throughout the day
-body temp is at 37 degrees
Positive feedback mechanisms regulating blood clotting:
-response enhances the original stimulus—> output is increased
-changes occur in the same direction as the initial disturbance= disturbance moves further from the original value
-blood clotting mechanisms enhance the original stimulus so that the output is increased—> end point is reached= equilibrium is restored again.
-positive feedback usually controls infrequent events that do not require continuous adjustments.
What can a disruption in homeostasis lead to?
Illness and death
-pathophysiology= abnormal functioning of the body associated with disease
