IB BIO HL: Integration of Body Systems

Cells

the microscopic building blocks of an organism

Multicellular

an organism containing many, different types of cells

Tissues

group of cells working together

Organs

group of tissues working together

Organ systems

group of organs working together

Emergent properties

a characteristic that arises from the interactions between individual components within a system

Nervous system

the network of nerves that send electrical signals/messages around the body

Endocrine system

the network of glands that secrete chemical messages into the bloodstream

Blood plasma

clear, yellowish fluid part of the blood that carries blood cells

Cerebral cortex (cerebrum)

region of the brain, responsible for learning, memory, language, and consciousness

Cerebellum

region of the brain, responsible for balance and muscle coordination

Medulla oblongata

region of the brain stem, responsible for unconscious activities

Hypothalamus

region of the brain, works with the pituitary gland in regulating endocrine system

Pituitary gland

region of the brain, works with the hypothalamus in regulating endocrine system

Central nervous system (CNS)

brain and spinal cord

Brain

the processing center for all body system functions

Spinal cord

pathway for communication between the brain and the rest of the body

Conscious processes

refer to mental activities that an individual is under control of

Unconscious Processes

refer to mental activities that occur without individual’s awareness

Sensory neurons

convey messages from sense receptors to the spinal cord and the cerebral hemispheres of the brain

Interneurons

connect sensory and motor neurons

Motor neurons

convey messages from cerebral hemispheres and the spinal cord to effectors such as muscles

Nerves

bundles of sensory and motor neurons surrounded by a protective sheath

Pain reflex arc

involuntary response to pain that occurs before our brain is able to process it; ONLY reaches spinal cord

Effector

referring to body part (typically muscle) that reacts to electrical signal

Circadian rhythms

the physical, mental, and behavioral patterns that respond primarily to light and dark

Melatonin

hormone secreted by pineal gland that helps establish a cycle of waking up and sleeping

Pineal gland

endocrine gland in middle of brain, regulates body’s circadian rhythm by secreting melatonin

Epinephrine (adrenaline)

neurotransmitter responsible for fight-or-flight response

Adrenal glands

endocrine glands on kidney, produces hormones that regulate metabolism, immune system, blood pressure, stress, etc.

Baroreceptors

stretch-sensitive receptors that monitor blood pressure

Chemoreceptors

detect changes to blood chemistry (mainly pH)

pH

measure of how acidic or basic a substance is

Ventilation

supply of air to the lungs

Cardiovascular control centre

part of the medulla oblongata, receives signals from chemoreceptors to increase/decrease heart rate

Respiratory control centre

part of the medulla oblongata, regulates rate + depth of ventilation and pH of blood

Digestive system

organs that work together in order to digest food

Persitalsis

involuntary relaxation and contraction of muscles to move contents along the digestive system

Autonomic nervous system (ANS)

responsible for the control of bodily functions which are not under conscious control

Enteric nervous system

branch of the autonomic nervous system which controls movement of food along digestive system

Swallowing

voluntary action of digestion process

Egestion

act or process of discharging undigested or water material from a cell or organism

Voluntary control

actions that are under control of organism (ex: swallowing, blinking)

Involuntary control

actions that are not under control of organism (ex: breathing, heart beat)

Tropism

growth in response to stimulus

Phototropism

growth of a plant in response to light

Positive phototropism

growth of a plant part towards light

Quantitative data

numerical or calculated data

Qualitative data

observation / interpreted data

Precision

how close measurements are to each other

Accuracy

how close results are to the correct value

Reliability

measure of how similar results are for the same experiment carried out many time

Phytohormones

plant hormones that regulate growth and development in plants

Auxin

plant hormones that causes elongation of cells in shoots/stems

Auxin efflux carrier

protein pumps that actively transport auxins out of plant cells

Cytokinin

plant hormones that promote cell differentiation and growth

Ethylene

phytohormone gas that stimulates the ripening of fruit

Fruit ripening

process of organ transformation from unripe to the edible ripe stage having attractive blend of color, taste, aroma and texture

Positive feedback

response that tends to magnify or increase process