BioSci 107: Human Body Organization

• BioSci 107 explores cells and tissues in the human body, covering the organization of the human body.

Course Objectives

• Identify the eleven systems of the human body, understand their components, and grasp their functions.
• Recognize and name the four basic tissue types.

Structural Organization of the Human Body

• Six levels of structural organization are crucial for understanding anatomy (form) and physiology (function).
• The levels are: chemical, cellular, tissue, organ, system, and organismal.
• Chemical level involves atoms (C, H, O, N, P) forming molecules like DNA.
• Cellular level is exemplified by smooth muscle cells.
• Tissue level includes smooth muscle tissue, epithelial tissues, and connective tissues.
• Organ level involves organs like the stomach comprised of smooth muscle and epithelial tissues.
• System level integrates organs such as the digestive system.
• Organismal level represents the complete organism

Tissues

• Tissues are specific cells and surrounding material working to perform a particular function.
• There are only four basic tissue types: epithelial, muscle, connective, and nervous.
• Organs consist of two or more different tissues joined to provide a function and have a recognizable shape.

Eleven Body Systems

• The human body is organized into eleven systems composed of related organs with a common function.
• The eleven systems: integumentary, muscular, skeletal, nervous, endocrine, lymphatic and immune, cardiovascular, respiratory, digestive, urinary, and reproductive.
• Some organs, like the pancreas, belong to more than one system (digestive and endocrine).

Integumentary System

• The integumentary system includes the skin, hair, nails, and exocrine glands.
• The epidermis covers the surface, protects deeper tissues, and produces vitamin D.
• The dermis feeds the epidermis, provides strength, and contains glands.
• Hair follicles provide sensation from innervation and protection.
• Sebaceous glands lubricate hair shafts and the epidermis.
• Sweat glands regulate temperature through evaporative cooling.
• Nails stiffen and protect digits.
• Sensory receptors detect touch, pressure, temperature, and pain.
• The hypodermis stores fat and attaches skin to deeper layers.

Muscular System

• The Muscular system is also called the skeletal muscles.
• Functions to provide skeletal movement, control entrances/exits, produce heat (via shivering), support the skeleton and protect soft tissues.
• There are Axial muscles that provide support and positioning of the axial skeleton.
• There are Appendicular muscles that support and move the limbs.
• Tendons translate contractile forces into tasks like flexion and extension and are fibrous connections between muscles to bone.
• Aponeuroses are sheet-like and connect muscle to muscle or muscle to bone.

Skeletal System

• Functions to support, protect tissues, store minerals and form blood cells.
• Cartilage provides bone interfaces
• There are hyaline (ribs joints) and fibro- (discs) types of cartilage.
• The axial skeleton (skull, vertebrae, sacrum, coccyx, sternum, supporting cartilages and ligaments) protects the brain, spinal cord, sense organs, and soft tissues of the thorax.
• The axial skeleton support body weight over the lower limbs
• The appendicular skeleton provides internal support and positioned the external limbs; supports and enables muscles to move the axial skeleton.
• Red bone marrow produces red blood cells, in flat bones like pelvis, sternum, skull and ribs.
• Yellow bone marrow stores fat cells that can increase with aging, and will turn yellow to red after major bleeding.

Nervous System

• The nervous system directs immediate responses to stimuli usually by coordinating other organ systems.
• The central nervous system (CNS) acts as a control center for short-term control over other systems and consists of the brain and spinal cord.
• The brain involves complex integrative activities and controls voluntary and involuntary activities.
• The spinal cord relays information to and from the brain and performs less complex integrative activities via reflex arcs.
• Specialized senses (sight, hearing, smell, taste and equilibrium) provide sensory input to the brain, optic nerve belongs to CNS.
• The peripheral nervous system (PNS) links the CNS with other systems and sense organs.

Endocrine System

• The endocrine system directs long-term changes in other organ systems.
• The pineal gland controls day/night rhythms with melatonin.
• The hypothalamus and pituitary gland control many other endocrine glands, regulate growth, and manage fluid balance.
• The thyroid gland controls metabolic rate through thyroxine.
• The parathyroid gland regulates calcium levels.
• The thymus aids in the maturation of lymphocytes.
• The adrenal glands manage water/mineral balance (aldosterone), tissue metabolism (cortisol), and cardiovascular/respiratory functions (adrenaline).
• The kidneys assist endocrine function, and can produce blood cells and regulate electrolyte/mineral balance
• Gonads affects sexual characteristics and reproduction.
• The endocrine system can be affected by excess growth hormone (GH) leading to “gigantism” too much GH from childhood or “acromegaly” too much GH as an adult.

Lymphatic System

• Lymphatic system defends against infection and disease, and returns fluid to the bloodstream
• Lymphatic vessels carry water, proteins and lymphocytes, and originate from peripheral sites.
• Lymphatic fluids are fats and fatty acids from the gut, and fluids from the tissue.
• B and T cells carry out immune responses.
• Lymph nodes can consist of monitor composition of lymph, engulf pathogens, and stimulate immune response.
• The spleen monitors circulating blood cells, engulf pathogens, recycles red blood cells, and produce immune responses.
• The thymus controls developments and maintenance of the T cell lymphocytes.

Cardiovascular System

• Cardiovascular system transports cells, dissolves materials nutrients, wastes, and gases.
• Functions of the heart is for propels blood and maintains blood pressure.
• Vessels transport; arteries brings blood from the heart to capillaries.
• Capillaries diffusion takes place between blood and interstitial fluids.
• Veins transport blood from capillaries to the heart.
• Blood transports oxygen and carbon dioxide and transports nutrients and hormones, and removes waste, regulate temperature, defend against illness and maintain an acid base balance.

Respiratory System

• Functions to deliver air to sites where gas exchange occurs between blood and the air, and produces sound.
• Nasal cavity and paranasal sinuses filters and warms air and detects smells.
• The pharynx conducts air to the larynx.
• The larynx protects the opening to the trachea, and vocal cords for vocalisation.
• Trachea conducts air, and is kept open with and cartilage.
• Bronchi conducts air between the trachea and lungs.
• Lungs facilitates the air movement and the exchange of oxygen and carbon dioxide in alveoli and controls the acid base.
• Diaphragm for the muscle of the air movement.

Digestive System

• Processes food and absorbs nutrients
• Consists of the oral cavity that breaks food work and assists the tongue.
• Salivary glands is for buffers, lubricant and their enzymes begins digestion.
• The pharynx move food.
• The oesophagus delivers the food to the stomach.
• Stomach secretes acid enzymes hormones to facilitate chemical digestion.
• The small intestine digests enzymes and regulates hormones, and absorbs nutrients.
• The liver secretes bile and nutrients are regulated in the blood.
• The gallbladder concentrates the bile.
• The pancreas aids for digestive enzymes buffers and is the location for endocrine cells.
• The large intestine and anus facilitates water removal and provides waste storage removal

Urinary System

• Eliminates excess water, salts and wastes.
• Kidneys forms and concentrates urine, and helps to regulate regulates pH and ions, Blood volume & blood pressure, and has an Endocrine function*.
• Ureters conducts urine to bladder.
• Bladder Stores the urine prior to elimination.
• Urethra Conducts urine to exterior.

Reproductive System - Male

• Testes produce sperm and produces hormones.
• Epididymis aids in sperm maturation
• Ductus deferens transports sperm from epididymis
• Seminal glands produce seminal fluid
• Prostate is for seminal fluid
• Urethra transporst sperm to the exterior.
• Penis and scrotum is for Reproduction and thermal control testes

Reproductive System - Female

• Ovaries produce oocytes and hormones.
• Delivery oocyte occurs in the uterine tubes.
• Embryonic development in the uterus
• Vagina and external genitalia- Lubrication, Sperm reception and birth canal.
• Mammary aids in nutrition for the newborns and is a sweat gland and is for integumentary system.

Tissue types

• Tissues are cells in the body that function as isolated units.
• Tissues is group of similar cells (usually of a common embryonic origin) that functions together to carry out specialized activities.
• Histology, is the microscopic study of the tissues of the body.
• The four basic tissues include are: Epithelial, Connective, Muscle, and Nervous.
• Epithelial tissue covers body surfaces, lines hollow organs, tubes, cavities, ducts and forms glands and its major functions are protection, filtration, secretion, absorption and discretion.
• Connective tissues are cells in a matrix of fibers and ground substance protects supports, binds organs together, stores energy and transports blood.
• Muscle tissues are contractile cells (muscle fibers) that provide movement.
• Nervous are the location for conducting nerve cells and supportive neuroglia that aids in detection of changes and generate nerve impulses.