Chapter 4 Organ Systems of the Body

DEFINITIONS AND CONCEPTS Organ—a structure made up of two or more kinds of tissues organized in such a way that they can together perform a more complex function than can any tissue alone Organ system—a group of organs arranged in such a way that they can together perform a more complex function than can any organ alone Knowledge of individual organs and how they are organized into groups makes the understanding of how a particular organ system functions as a whole more meaningful

ORGAN SYSTEMS Integumentary system (Figure 4-2) Structure—organs Skin Hair Nails Sense receptors Sweat glands Oil glands Functions Protection Regulation of body temperature Synthesis of chemicals Sense organ

ORGAN SYSTEMS Skeletal system (Figure 4-3) Structure Functions Bones Joints Functions Support Movement (with joints and muscles) Storage of minerals Blood cell formation

ORGAN SYSTEMS Muscular system (Figure 4-4) Structure Functions Muscles Voluntary, or striated Involuntary, or smooth Cardiac Functions Movement Maintenance of body posture Production of heat

ORGAN SYSTEMS Nervous system (Figure 4-5) Structure Functions Brain Spinal cord Nerves Sense organs Functions Communication Integration Control Recognition of sensory stimuli System functions by production of nerve impulses caused by stimuli of various types Control is fast-acting and of short duration

ORGAN SYSTEMS Endocrine system (Figure 4-6) Structure Pituitary gland Pineal gland Hypothalamus Thyroid gland Parathyroid glands Thymus gland Adrenal glands Pancreas Ovaries (female) Testes (male)

ORGAN SYSTEMS Endocrine system (cont.) Functions Secretion of special substances called hormones directly into the blood Same as nervous system—communication, integration, control Control is slow and of long duration Examples of hormone regulation: Growth Metabolism Reproduction Fluid and electrolyte balance

ORGAN SYSTEMS Cardiovascular (circulatory) system (Figure 4-7) Structure Heart Blood vessels Arteries Veins Capillaries Functions Transportation Regulation of body temperature Immunity (body defense)

ORGAN SYSTEMS Lymphatic system (Figure 4-8) Structure Functions Lymph nodes Lymphatic vessels Tonsils Thymus Spleen Functions Transportation Immunity (body defense)

ORGAN SYSTEMS Respiratory system (Figure 4-9) Structure Functions Nose Pharynx Larynx Trachea Bronchi Lungs Functions Exchange of waste gas (carbon dioxide) for oxygen occurs in the alveoli of the lungs Warm and humidify incoming air Filtration of irritants from inspired air Regulation of acid-base balance

ORGAN SYSTEMS Digestive system (Figure 4-10) Structure Primary organs Mouth Pharynx Esophagus Stomach Small intestine Large intestine Rectum Anal canal Accessory organs Teeth Salivary glands Tongue Liver Gallbladder Pancreas Appendix

ORGAN SYSTEMS Digestive system (cont.) Functions Appendix Mechanical and chemical breakdown (digestion) of food Absorption of nutrients Undigested waste product that is eliminated is called feces Appendix Structural but not a functional part of digestive system Inflammation of appendix is called appendicitis

ORGAN SYSTEMS Urinary system (Figure 4-11) Structure Functions Kidneys Ureters Urinary bladder Urethra Functions “Clearing” or cleaning blood of waste products; waste product excreted from body is called urine Electrolyte balance Water balance Acid-base balance In males, urethra has urinary and reproductive functions

ORGAN SYSTEMS Reproductive system (Figures 4-12 and 4-13) Structure Male Gonads—testes Genital ducts—vas deferens, urethra Accessory gland—prostate Supporting structures—genitalia (penis and scrotum) Female Gonads—ovaries Accessory organs—uterus, uterine (fallopian) tubes, vagina Supporting structures—genitalia (vulva), mammary glands (breasts)

ORGAN SYSTEMS Reproductive system (cont.) Functions Survival of genes Production of sex cells (male: sperm; female: ova) Transfer and fertilization of sex cells Development and birth of offspring Nourishment of offspring Production of sex hormones