Anatomy: Body Systems

• Here are study notes on the various body systems

Digestive System

• The liver is the largest organ in the digestive system
• The liver secretes bile and absorbs toxins, chemicals, and alcohol
• The colon (large intestine) consists of the cecum, ascending colon, transverse colon, descending colon, sigmoid, and rectum
• The colon absorbs excess water
• The stomach lining is called Rugae
• The stomach contains Parietal Cells (Hydrochloric Acid)
• The stomach converts Bolus to Chyme
• Amylase includes Salivary Amylase, Pancreatic Amylase and breaks down carbohydrates
• The appendix is an accessory organ that creates bacteria beneficial for digestion
• The rectum, the colon's last part, collects undigested food waste for elimination through the anus

Respiratory System

• Breathing involves inhalation and expiration
• The epiglottis, a muscle, covers the trachea (windpipe)

Nervous System

• The hypothalamus makes enzymes for emotions and body temperature regulation
• Sulci are folds (bottom folds) in the brain
• Gyri are ridges (upper ridges) in the brain
• The cerebellum regulates posture and balance
• The sympathetic nervous system controls heart rate/sweating
• The Medulla Oblongata controls the breathing process
• The occipital lobe, located at the back of the head, controls vision, perception, and consciousness
• The temporal lobe handles hearing, smell, and memory
• Sensory nerves in the dermis area deliver sensory input to the brain

Circulatory System

• Homeostasis involves sodium retention, potentially causing hypertension
• Platelets are responsible for blood clotting
• Leukocytes fight pathogens
• Arteries carry oxygenated blood throughout the body, leading to forceful bleeding upon cutting
• Veins carry deoxygenated blood

Musculoskeletal System

• Tendons connect muscle to bone
• Cramps occur with a sudden loss of electrolytes
• Skeletal muscle is a voluntary muscle, meaning it can be controlled and improved
• The pectoral girdle includes the scapula (shoulder blade) and clavicle (collarbone)
• The sternum, also known as the breastbone, is a long, flat bone that protects the heart

Integumentary System

• Sebaceous glands produce sebum, excluding the palms, flat area of the feet, and lips
• Melanin, produced by melanocytes, creates dark pigment to protect skin from UV rays

Excretory System

• Urine has urea, uric acid, and creatinine
• The urethra expels urine from the urinary bladder

Endocrine System

• The pituitary gland regulates growth, antidiuretic function, thyroid stimulation, luteinizing hormone, and follicle-stimulating hormone
• Oxytocin is a hormone responsible for contractions of the womb in pregnant women
• Testosterone is a secondary hormone for body improvement
• Luteinizing hormone is responsible for ovulation and signals the egg is ready for fertilization

Immune System

• Leukocytes fight pathogens
• Vitamin C boosts WBC (White Blood Cells) production