Comprehensive Biology Review – Q1 & Q2 Topics

Vocabulary flashcards covering key biological terms from homeostasis, organ systems, and genetics discussed in the lecture notes.

Homeostasis

Maintenance of a stable internal environment despite internal or external changes

Negative feedback

Regulatory loop in which the response reduces or opposes the original stimulus

Positive feedback

Regulatory loop in which the response enhances or amplifies the original stimulus

Stimulus

Any change that disturbs an organism’s steady-state conditions

Receptor

Cell or tissue that detects a stimulus

Relay

Transmission of a message via nerves or hormones from receptor to effector

Effector

Muscle or gland that carries out the response to a stimulus

Hypothalamus

Brain region that links nervous and endocrine systems; regulates temperature, appetite, and pituitary activity

Thermoregulation

Homeostatic control of body temperature

Insulin

Pancreatic hormone that lowers blood glucose by promoting cellular uptake

Glucagon

Pancreatic hormone that raises blood glucose by stimulating glycogen breakdown

Pituitary gland

Endocrine ‘master gland’ that secretes hormones controlling other glands

Anterior pituitary

Front lobe of pituitary that releases FSH, LH, TSH, ACTH, GH, and MSH

Posterior pituitary

Back lobe of pituitary that stores and releases ADH and oxytocin

Follicle-stimulating hormone (FSH)

Pituitary hormone that stimulates ovarian follicle growth and sperm production

Luteinizing hormone (LH)

Pituitary hormone triggering ovulation and stimulating testosterone production

Thyroid-stimulating hormone (TSH)

Pituitary hormone that prompts thyroid to secrete T3 and T4

Adrenocorticotropic hormone (ACTH)

Pituitary hormone that stimulates adrenal cortex to release cortisol

Growth hormone (GH)

Pituitary hormone promoting body growth and metabolic regulation

Antidiuretic hormone (ADH)

Posterior pituitary hormone that promotes water reabsorption in kidneys

Oxytocin

Posterior pituitary hormone causing uterine contractions and milk ejection; aids bonding

Thyroxine (T4)

Thyroid hormone that sets basal metabolic rate

Triiodothyronine (T3)

More active thyroid hormone that increases cellular metabolism

Calcitonin

Thyroid hormone that lowers blood calcium by stimulating bone deposition

Parathyroid hormone (PTH)

Hormone that raises blood calcium by stimulating bone resorption

Pineal gland

Endocrine gland in brain that secretes melatonin

Melatonin

Hormone regulating sleep-wake and seasonal cycles

Adrenal cortex

Outer adrenal layer producing cortisol, aldosterone, and other corticosteroids

Cortisol

Glucocorticoid hormone involved in stress response and metabolism

Glucocorticoids

Steroid hormones that increase blood glucose and suppress immunity

Aldosterone

Mineralocorticoid that regulates sodium and water balance

Adrenal medulla

Inner adrenal region secreting epinephrine and norepinephrine

Epinephrine (adrenaline)

Hormone that triggers ‘fight-or-flight’ responses

Norepinephrine (noradrenaline)

Hormone/neurotransmitter that increases heart rate and blood pressure

Testosterone

Androgen produced by testes; influences male traits and libido

Estrogen

Ovarian hormone controlling female secondary sex traits and ovulation

Progesterone

Ovarian hormone preparing uterus for pregnancy

Islets of Langerhans

Endocrine cell clusters in pancreas that secrete insulin and glucagon

Blood glucose

Concentration of sugar circulating in the bloodstream

Respiratory system

Body system that exchanges oxygen and carbon dioxide

Trachea

Windpipe conducting air from larynx to bronchi

Bronchi

Two primary airways branching from trachea into lungs

Bronchioles

Small airway branches within lungs leading to alveoli

Alveoli

Microscopic air sacs where gas exchange occurs

Mucous membrane

Moist epithelial layer that secretes mucus and traps particles

Olfactory epithelium

Sensory tissue in nasal cavity responsible for smell

Pharynx

Muscular throat cavity shared by respiratory and digestive tracts

Larynx

Voice box; routes air and food and houses vocal cords

Nose functions

Warming, moistening, and filtering inspired air

Stomata

Leaf pores that regulate gas exchange and water loss in plants

Photosynthesis

Process by which plants convert light energy to chemical energy

Cardiovascular system

Heart and vessels that transport blood, nutrients, and wastes

Atrium

Upper heart chamber that receives blood

Ventricle

Lower heart chamber that pumps blood out

Tricuspid valve

Valve preventing backflow from right ventricle to right atrium

Pulmonary valve

Valve between right ventricle and pulmonary artery

Bicuspid (mitral) valve

Valve between left atrium and left ventricle

Aortic valve

Valve between left ventricle and aorta

Pulmonary circulation

Blood flow from heart to lungs and back

Systemic circulation

Blood flow from heart to body tissues and back

Coronary circulation

Blood supply to the heart muscle itself

Arteries

Thick-walled vessels carrying blood away from heart

Veins

Vessels returning blood to the heart; have large lumens and valves

Capillaries

Microscopic vessels where exchange with tissues occurs

Leukocyte

White blood cell that defends against pathogens

Erythrocyte

Red blood cell that transports oxygen and carbon dioxide

Thrombocyte

Platelet cell fragment that initiates blood clotting

Plasma

Liquid matrix of blood composed mostly of water

Nervous system

Control system that senses, integrates, and responds using neurons

Central nervous system (CNS)

Brain and spinal cord

Peripheral nervous system (PNS)

All nerves outside CNS

Sensory (afferent) division

PNS nerves carrying impulses to CNS

Motor (efferent) division

PNS nerves carrying impulses from CNS to effectors

Somatic nervous system

Voluntary motor control of skeletal muscles

Autonomic nervous system

Involuntary control of smooth muscle, heart, and glands

Neuron

Nerve cell specialized for electrical signaling

Synapse

Junction where a neuron communicates with another cell

Reflex arc

Direct nerve pathway producing rapid, involuntary response

Skeletal muscle

Voluntary striated muscle attached to bones

Cardiac muscle

Striated involuntary muscle composing the heart

Smooth muscle

Involuntary non-striated muscle in organs and vessels

Sarcomere

Basic contractile unit of striated muscle fiber

Actin

Thin filament protein that slides during muscle contraction

Myosin

Thick filament protein with motors that generate contraction

Exoskeleton

External skeleton of arthropods made of chitin

Endoskeleton

Internal skeleton of bone or cartilage in vertebrates

Osteocyte

Mature bone cell maintaining bone tissue

Osteoblast

Bone-forming cell

Osteoclast

Bone-resorbing cell

Ligament

Connective tissue attaching bone to bone

Tendon

Connective tissue attaching muscle to bone

Hinge joint

Joint allowing movement in one plane (e.g., elbow)

Ball-and-socket joint

Joint allowing rotation and movement in many directions (e.g., shoulder)

Phototropism

Plant growth response toward or away from light

Geotropism

Plant growth response to gravity

Turgor movement

Reversible plant movement caused by changes in internal water pressure

Mechanical digestion

Physical breakdown of food into smaller pieces

Chemical digestion

Enzymatic breakdown of food molecules

Peristalsis

Wave-like contractions of smooth muscle propelling food

Epidermis (skin)

Avascular outer layer of skin composed of stratified squamous cells