Bio final 2025

Circulatory system

Delivers oxygen and nutrients to cells, and it takes waste from cells to be removed. It fights infections and regulates temperature.

Heart

Hallow muscular organ; pumps blood throughout body. It has 2 chambers (atria and 2 ventricles) that push bood to the lungs and rest of the body.

arteries

Blood vessels that carry oxygenated blood away from the heart.

Viens

blood vessels that carry oxygen poor blood back to the heart.

Capillaries

tiny blood vessels where gas exchanges happen and oxygen and nutrients move into cells, and carbon dioxide and waste move out.

RBC

carry oxygen using a protein (hemoglobin) and removes carbon dioxide

WBC

Helps fight infections by attracting bacteria and viruses.

Plasma

liquid part of blood carrying waste, hormones, and nutrients

platelets

helps with blood clotting to stop bleeding when you get a cut

respitory system

exchange of gases between the body and the enviornment. It brings oxygen into the body and removes carbon dioxide from the body. Essential for cellular respiration which produces energy (ATP)

nasal cavity

warms, moistens, and filters air entering the body. It also contains small receptors.

windpipe; trachea/epiglottis

a tube supported by cartilage rings that carries air to the lungs. Epiglottis are flaps of tissues that close over the trachea during swallowing to prevent food from entering the airway

bronchus

trachea splits into two bronchi (one for each lung). Carries air into the lungs. Each _____ branches into smaller tubes.

bronchiole

smaller branches of bronchi within the lungs. Distributes air to the alveoli.

lungs

two large organs where gas exchange occurs. They contain millions of alveoli and are protected bt the ribcage and pluera

alveoli

they are air sacs at the end of the bronchioles. Surrounded by capillaries, they are the site of oxygen and CO2 exchange through diffusion

diaphragm

dome-shaped muscle at the bottom of the chest cavity, contracts to pull air into the lungs and relaxes to push air out so it can control breathing

digestive system

to break down food into smaller molecules so the body can absorb nutrients, and use them for enough growth, energy, and repair. it also removes undigested waster for the body

mouth

begins mechanical digestion by chowing food and chemical digestion with saliva (contains enzymes that break down carbohydrates)

eseophagus

muscular tube that moves food from the mouth to the stomach using movement called perstalis

stomach

uses stomach acid and enzymes to further break down food into a semi-liquid starts protein synthesis

small intestines

most digestion and nutrient absorption hapens; enzymes from the pancreas and bile from the liver help here

large intestines

absorbs water and salts from undigested food and turns waste into feces

rectum

stores feces until they are ready to be eliminated through the anus

pancreas

produces digestive enzymes and releases them into the small intestine, helps regulate blood sugar by producing insulin

gal bladder

stores and releases bile (made by the liver) into the small intestine to help digest fats

liver

produces bile, breaks down toxins, and processes nutrients absorbed from the small intestine

salivary glands

produces saliva, which moistens food and contains enzymes to begin the digestion of starches

urinary system

removes waste from the blood and maintains the body’s fluid and electrolyte balance by producing and excreting urine. also filters blood to remove toxins and extra water

kidneys

bean shaped organs that filters waste and excess water from the blood to make urine. they also regulate blood pressure and produces hormones

ureter

two thin tubers that carry urine from each kidney to the urinary bladder

urinary bladder

a muscular sac that stores urine until it is ready to be excreted. it can stretch to hold about 400-600 mL of urine,

urethra

a small tube that carries urine from the bladder to the outside of the body during urination

urine

liquid waste made by the kidneys. It contains water, salts, and substances the body doesn’t need

muscular systems

allows movement of the body, maintains posture, and producees heat. Moves bones and body parts, also helps breathing, digestion, and heartbeat

smooth

involuntary muscles found in organs. they help more substances inside the body. ex. stomach, intestines, bladder

cardiac

involuntary muscle found only in the heart; it keeps the heart pumping. ex. heart

skeletal

voluntary muscles attached to the bones: they move the body. ex. biceps, triceps, quads

involuntary muscles

muscles you can’t control. work automatically. ex. heart, stomach muscles

voluntary muscles

muscles you can control; used for movement. ex. arms, leg, muscles

muscle fiber

long calls that make up muscles; they contract when stimulated nerves

nervous systems

controls and coordinates all body activities by transmitting signals between different body parts and the brain, controls both involuntary and voluntary actions

neurons

nerve cells that send and recieve messages throughout the body, they are the basic unit of the nervous systems

dendrites

branch-like parts of a neuron that recieve messages from other cells and bring them into the neuron

axons

long fibers that carry messages away from the neuron’s cell body to other nuerons, muscles, or glands

response to a stimulus

when the body sense something (stimulus), the brain processes it and sends a message through the neurons to response (like pulling your hand away from something hot)

central nervous system - also includes brain parts

includese the brain and spinal cord. controls tmost functions of the body and mind.

peripheral nervous system

all the nerves outside the brain and spinal cord. it connects the central nervous system to the rest of the body.