Human Body Systems and Physiology

Comprehensive vocabulary flashcards covering the cardiovascular, digestive, nervous, muscular, reproductive, and integumentary systems based on lecture notes.

Atrium

The top chambers of the heart that receive blood.

Ventricle

The bottom chambers of the heart that pump blood.

Deoxygenated blood

Blood coming from the body into the right atrium characterized by low oxygen and high Carbon dioxide.

Oxygenated blood

Blood that has entered the lungs to get oxygen and remove carbon dioxide, now containing lots of oxygen.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood back to the heart.

Capillaries

Blood vessels where oxygen and Carbon dioxide exchange happen.

Red blood cells

Cells whose job is to carry oxygen using hemoglobin.

Hemoglobin

A protein that holds oxygen within red blood cells.

White blood cells

Cells that fight infection.

Platelets

Components that help blood clot.

Plasma

The liquid part of blood that carries nutrients and hormones.

Bolus

A soft ball of food created after chewing.

Epiglottis

A structure that closes the trachea when swallowing so food does not enter the lung.

Peristalsis

The movement of food through the esophagus.

Mechanical digestion

The physical break down of food into smaller pieces, such as churning in the stomach.

Chemical digestion

The process where enzymes break food into tiny molecules using hydrochloric acid or pepsin.

Chyme

The mixture of foods after they are mixed in the stomach.

Microvilli

Structures whose job is to absorb nutrients.

bill

A substance made by the liver and stored in the gallbladder (referenced as bile regarding fats/lipids).

Bile

A substance that helps break down fats / lipids.

Pancreas

An organ that makes digestive enzymes.

Large intestine

The part of the digestive system that absorbs water and salt.

Ghrelin

A hormone that makes you hungry.

Leptin

A hormone that makes you feel full.

Insulin

A hormone that lowers blood sugar.

Glucagon

A hormone that raises blood sugar.

Central nervous system (CNS)

The main control center including the brain and spinal cord that processes information and makes decisions.

Peripheral nervous system (PNS)

The system that carries messages from the body to the CNS and from the CNS to the body.

Neuron

A nerve cell.

Dendrites

The part of a neuron that receives messages.

Axon

The part of a neuron that carries messages away and sends electrical signals.

Myelin sheath

A protective covering that makes signals travel faster.

Synapse

A tiny gap between neurons where signals pass using neurotransmitters.

Sensory neurons

Neurons that send information like pain, touch, or smell to the brain.

Motor neurons

Neurons that send commands from the brain to muscles for actions like walking or writing.

Somatic nervous system

The system that controls voluntary actions such as walking, talking, or throwing a ball.

Autonomic nervous system

The system that controls involuntary actions such as heartbeat, digestion, and breathing.

ATP

The energy molecule muscles need to contract.

Skeletal muscle

Muscle attached to bone that moves the body.

Cardiac muscle

Muscle found only in the heart.

Smooth muscle

Muscle found in organs.

Tendons

Connect Muscle to bone.

Ligament

Connect bone to bone.

Actin

A thin filament involved in muscle contraction.

Myosin

A thick filament involved in muscle contraction.

Sarcomere

The smallest unit of muscle contraction.

Myofibril

A long muscle fiber made of sarcomere.

Gametes

Sex cells (eggs/ova and sperm).

Fallopian tubes

Tubes that carry the egg toward the uterus and where fertilization usually happens.

Cervix

The opening between the uterus and vagina.

Ovulation

The release of an egg from an ovary, usually happening once per cycle.

Zygote

The result of the sperm and egg joining.

Blastocyst

A divided zygote that implants in the uterus lining (endometrium).

Testes (testicles)

Organs that produce sperm and testosterone.

Scrotum

A sac that holds testes outside the body to maintain a cooler temperature for sperm.

Vas referees

The tube that carries sperm.

Prostate + seminal besides

Structures that add fluid to sperm to nourish it and help movement.

FSH (follicle stimulating hormone)

In females, it helps eggs nature; in males, it helps sperm production.

LH (luteinizing hormone)

In females, it triggers ovulation; in males, it stimulates testosterone production.

Estrogen

A female sex hormone that helps egg maturation, thickens uterine lining, and promotes female characteristics.

Progesterone

A hormone that prepares the uterus for pregnancy.

Testosterone

A male sex hormone involved in sperm production, facial hair, and muscle growth.

Epidermis

The outer layer of skin that acts as a waterproof protective barrier containing dead cells and melanocytes.

Melanocytes

Cells that produce melanin to protect from UV radiation and provide skin color.

Dermis

The middle layer of skin where most action happens, containing blood vessels, nerves, hair follicles, and glands.

Hypodermis

The layer of skin responsible for fat storage, insulation, and cushioning.

Sebaceous gland

A gland that produces oil to keep skin soft and prevent drying.

Vasodilation

The widening of blood vessels to allow more heat to leave the body when hot.

Vasoconstriction

The tightening of blood vessels to lose less heat when the body is cold.