Body systems and reproductions Flashcards
What is homeostasis
the relatively stable state inside the body of an animal
- many animal organ systems are maintained homeostatically
How is homeostasis maintained?
- Through negative feedback relationships
- if the blood glucose or calcium rises, this sends a signal to organs responsible for lowering blood glucose or calcium
- the signal that restore the normal levels are examples of negative feedback
What happens when there is too much blood glucose level and too little blood glucose level
TOO MUCH: leads to fatigue
TOO LITTLE: dizziness and weakness
What are the two types of blood glucose homeostasis?
Insulin and glucagon
What is the difference between insulin and glucagon?
INSULIN: moves glucose from the body into the cells (lowers glucose level)
GLUCAGON: brings glucose out of storage when necessary(raises glucose levels)
How does insulin works?
After a meal, there is a rise in blood glucose, so cells in pancreas secrete insulin into bloodstream. Pancreatic cells secrete the right amount of insulin to counteract the rise in blood glucose. Liver and muscle cells store glucose and then the blood glucose returns to normal levels as excess glucose stored as glycogen and fat
How glucagon works?
When blood glucose level falls between meals, pancreas cells triggered to secrete glucagon into blood. Glucagon signals liver to release stored glucose into blood and then when the levels are high enough, receptors trigger liver cells to stop.
What is thermoregulation?
Homeostasis referring to the maintenance of a steady temperature state withing the animal. Is not present in ectothermic animals (lizard) but is present in endothermic animals (mammals)
Thermoregulation ( hot weather)
sweating (horses and humans - heat loss through evaporative cooling)
panting(most other animals pant to inhale air to cool the lung surface i.e dogs)
Thermoregulation (cold weather)
Hair follicles lifted upright to trap heat (goosebumps)
- muscles contract to cause shivering (more effective than exercise, because animal stay still)
What is the definition of osmoregulation?
homeostasis referring to the maintenance of a steady water balance within the animal (controlled by kidney)
What happens in osmoregulation?
- is the process of maintaining salt and water balance across membranes within the body
- necessary because animals constantly consume and excrete water and electrolytes
What does the respiratory systems do?
- facilitate gas exchange
- provide body cells with oxygen and remove carbon dioxide
- Lungs have very large surface area
for gas exchange between air
inside lungs and blood from
circulatory system
What does the circulatory system do?
- heart has two pumps that move blood through the pulmonary (lungs) and systematic circulations
What is the difference between arteries and veins?
ARTERIES: vessels that take blood away from heart
VEINS: vessels that take blood towards the heart
What is the endocrine system?
Is a collection of glands in an organism that secrete hormones into the circulatory system, hormones cause cellular changes by binding to receptors on target cells
- hormone levels are controlled through negative feedback
- when hormone levels are high, receptors trigger glands to stop producing more
- glands that produce various hormones located throughout the body
What is difference between pituitary gland, thyroid gland, parathyroid gland, adrenal gland and pancreas? (organs that produce hormones in human beings)
PITUARY GLAND: in brain
THYROID GLAND: in neck
PARATHYROID GLAND: on top of thyroid glands
ADRENAL GLAND: on top of kidneys
PANCREAS: in abdomen between stomach and intestines
What does the human muscoloskeletal system do?
provides structure, support and allows movement
What is the difference between the axial and appendicular skeleton?
AXIAL: bones of skull, vertebral column and ribcage
APPENDICULAR: upper and lower limbs and pelvis
What is the definition of fibrous joints?
bones held together with fibrous connective tissue ( no movement possible)
what is the definition of cartilaginous joints?
bones connected by cartilage ( a small amount of movement is possible)
What is the synovial joints?
have a space between adjoining bones (allows bones around it to move, incorporates a fluid to enable that movement or flexibility)
What does the human nervous system do?
transmits signals between different body regions
- coordinates voluntary and involuntary actions
- made of neurons and glia
What is the definition of glia?
non - neuronal cells that support neuronal development and signaling
What is the definition of neuron?
Specialized cell that can send electrical and chemical signals
- contain dendrites (receives electrical signals ) and axons (sends electrical signal)
What is the definition of the spinal cord?
Transmits sensory and motor input and controls motor reflexes
- coodinates different neuronal signals and transmits message to the brain to control both voluntary/non- voluntary movements
What is the definition of the brain?
Has many structurally/functionally different regions
- is the most complex functions that involve neurons from multiple brain regions
What are the functions of the brain?
- cerebral cortex
- basal ganglia
- thalamus
- limbic system
-hypothalamus
-cerebellum - brainstem
what is the definition of cerebral cortex?
controls movement, speech, memory and intelligence
what is the definition of basal ganglia?
allows control of voluntary motor movements
what is the definition of thalamus?
regulates sleep and alertness
what is the definition of limbic system?
regulates emotion and long-term memory
what is the definition of hypothalamus?
makes hormones and controls pituitary gland, controls body temperature, hunger, thirst
what is the definition of cerebellum?
regulates coordination of movement and balance
what is the definition of brainstem
regulates basic functions like heart rate and breathing, connects spinal cord to brain
What is the peripheral nervous system?
- contains both the autonomic and sensory-somatic nervous system
what is the difference between the sensory-somatic and autonomic nervous system?
SENSORY-SOMATIC NERVOUS SYSTEM: made of cranial and spinal nerves, helps avoid/ prevent injuries (fight or flight response)
- transmits sensory information and motor commands between skin/muscle and CSN
AUTONOMIC NERVOUS SYSTEM: provides unconscious control over visceral functions ( acts when an organism at rest, breathing or digestion)
What is the immune system?
system of biological structures and processes that protect an organism against foreign invades
- protects against viruses, parasitic organisms, harmful bacteria
- healthy immune system can differentiate between their own body and foreign invaders
What is the definition of first line of defence?
physical and chemica barriers to infection by foreign organism
what is the second line of defence?
internal destruction of pathogens using cellular and molecular responses
- body identifies nature of pathogen and responds with inflammation of area and phagocytosis
What is adaptive immunity
it provides a longer-lasting, slower- acting, more specific response than innate immune system
- targets a particular pathogen and produce antigens to destroy it
- each pathogen is “remembered” by a particular antigen and this antigen is produced again if body is re-infected
what is the difference between pathogen and antigen
PATHOGEN: disease causing (e.g bacteria virus and parasite)
ANTIGEN: part of the foreign invader that induces an immune response in the body
What is the definition of antibody?
used by the immune system to identify and neutralize foreign objects such as bacteria and viruses
- recognizes a unique part of the foreign target called an antigen
What are they types of immune system cells?
- natural killer cells
- B and T cells
- B cells
- Killer T cells
- Helper T cells
What is the definition of natural killer cells?
destroy host cells infected with a pathogen in an organisms body
what is the definition of B and T cells?
Have receptor molecules that identify specific pathogens as targets
What is the definition of B cells?
identify pathogens when antibodies on its surface bind to a specific foreign antigen
What is the definition of Killer T cells
kill body cells that are infected with pathogens
what is the definition of helper T cells
help determine which immune responses the body makes to a particular pathogen
What does the digestive system do?
consists of organs that work together to digest food and absorb nutrients
what is the definition of digestion?
how the body breaks food down into nutrients, preparing for absorption
- occurs primarily in the gastrointestinal tract
What is the GI tract?
A flexible, muscular tube that extends from the mouth to the anus
- follows the path through the body of:
- mouth -> esophagus-> stomach-> small intestine-> large intestine-> rectum-> anus
what is the definition of Lumen?
inner space within the GI tract , is continuous from one end to the other, and nutrients absorbed through it
What is the definition of nutrients?
a substance the body uses for growth, maintenance and repair of tissues
What are six major classes of nutrients?
-water
- minerals
- vitamins
- carbohydrates
- proteins
- lipids
What does water do?
provides environment in which nearly all body activities are conducted. It transports vital materials to the cells and carries waste products away
What is the difference between macronutrient and micronutrient?
MACRONUTRIENT: body needs these in large quantities daily (produces energy for the body)
MICRONUTRIENT: body needs in small quantities daily ( does not produce energy)
what is the definition of energy?
is the capacity to work
What are the three types of nutrients
- carbohydrates
- proteins
-fats
TRUE OR FALSE? Do vitamins provide energy?
False: this is because it facilitates energy release from fats, proteins and carbohydrates
- are organic molecules and only function if intact
