The Human Body The human body is composed of many systems. We have covered 8 in this course. Circulatory - Immune Respiratory - Digestive Musculoskeletal - Nervous Urinary - Endocrine
THE NERVOUS SYSTEM.0 The nervous system is made up of the brain, spinal cord, and peripheral nerves. It senses the environment and coordinates an appropriate response. The core of the nervous system is the brain and the spinal cord. This is called the central nervous system. The central nervous system is protected from injury by bones and by cerebrospinal fluid. The peripheral nervous system consists of the nerves that carry the signals between the central nervous system and the body. It also relays instructions from the brain to other parts of the body to control many of the body s functions and responses. Reflexes are actions that do not require the involvement of the brain: they occur without conscious thought. The spinal cord acts as a short cut for reflexes.
The Nervous System
Parts of The Nervous system Central Nervous System Brain Spinal Cord
Parts of The Nervous System Peripheral Nervous System Somatic nerves (somatic nervous system) Voluntary Autonomic Nerves (autonomic nervous system) Involuntary Sensory Motor Sympathetic Parasympathetic
Types of Neurons Sensory neurons carry impulses from sensory receptors (eye, ear, nose, skin, tongue) to the brain Motor neurons carry impulses from the brain or spinal cord to muscles for movement or to glands for hormone secretion Interneurons link the sensory and motor neurons in the brain and spinal cord
How Does Communication Occur? Nerve cells are called neurons Neurons use electrical signals called impulses to communicate with other cells Nerve Connective tissue and bundles of neurons
Some Nervous System Disorders Multiple sclerosis (degeneration of myelin sheath in the CNS) Parkinson s disease Alzheimer s disease
Musculoskeletal system Muscular system Skeletal System
THE MUSCULOSKELETAL SYSTEM 3.8 The musculoskeletal system includes all of the bones in a body and the muscles that make them move. It supports the body and protects delicate organs.
Function of the Skeletal System - Protection - protect vital organs in the body (eg. skull protects brain, spine protects spinal cord, ribs protect heart and lungs - Blood-cell production - bone marrow in large bones produce blood cells and releases them into the blood stream.
Function of the Skeletal System Mineral storage Continued bones made up of calcium and phosphorus giving bones strength and rigidity. Support for your muscles Movement
Components of the Skeletal System The skeleton is composed of 3 types of connective tissue. Bone Ligaments Cartilage
Bone The human skeleton is composed of 206 bones Hard and dense tissue Bone is composed of bone cells within a matrix of minerals (calcium, phosphorus) and collagen fibers If your diet is not high in minerals, your body will absorb Ca and P from your bones causing them to weaken
Structure of Bone - Canals inside the bones contain nerves and blood vessels - Only a small percentage of the bone tissue is actually living
Ligaments (connect bone to bone) - are strong tough elastic bands of connective tissue that can stretch - Hold bones and movable joints together - surround the joint to give support and limit the joint's movement.
Cartilage hard but slippery tissue that covers the ends of bones where they meet to form a joint. made up of cells and collagen fibres and is wear-resistant helps reduce the friction of movement by allowing bones to glide over one another Absorbs the energy from the shock of physical movement Found in: Ears, nose, esophagus, joints, disks between vertebrae
Muscles Bones need muscles to move them There are about 600 muscles in the human body Made up of bundles of long cells called muscle fibres that contain specialized proteins
Muscle
Tendons (connect muscle to bone) another type of tough connective tissue on each side of a joint attach to muscles that control movement of the joint.
Cardiac Muscle Makes heart beat involuntary Smooth Muscle Types of Muscles involuntary Found in lining of organs (eg. stomach, esophagus, uterus, walls of blood vessels) Skeletal Muscle Attached to bone voluntary
Antagonistic Muscles One contracts while the other relaxes Work together to move bones Ex. Bicep and tricep
Problems with the Musculoskeletal See page 101 in text System Example: Osteoporosis is the loss of bone tissue, making bones brittle and weak.
THE RESPIRATORY SYSTEM Review the following diagram to locate the components of the human respiratory system: nasal cavity mouth trachea Bronchi alveoli lungs diaphragm
Cow Lungs
THE RESPIRATORY SYSTEM Air travels through the trachea to the lungs. The trachea contains many epithelial cells that have hairlike projections called cilia. Cilia help filter out and remove foreign materials (such as dust) that might otherwise enter the bronchial tubes and lungs. The main purpose of the respiratory system is to exchange gases. Breathing brings air into and out of the lungs, so that gas exchange can occur. Oxygen enters the bloodstream in the lungs by diffusion, and carbon dioxide leaves in the same way. This gas exchange specifically takes place in the alveoli, which are surrounded by capillary networks containing blood. When the blood arrives at the cells, the oxygen diffuses from the blood into the cells. At the same time, carbon dioxide diffuses from the cell into the blood.
Gas Exchange O 2 and CO 2 have only to diffuse through 2 thin walls: capillaries and alveoli O 2 that we breathe in diffuses from the alveoli into the blood stream and CO 2 leaves the blood stream through the alveoli and into the air we breathe out
Involves the diaphragm (a large sheet of muscle underneath the lungs) and the muscles between the ribs. Is an involuntary process that we can override while talking but only temporarily. It is controlled by a part of the human brain that detects the concentration of CO 2 in our blood Breathing
Respiratory System Diseases See text page 94 Example: TB is an infectious disease caused by bacteria that are breathed into the lungs. It has fairly general symptoms like cough and fever, but can be fatal if untreated.
Non-smoker vs smoker LUNGS
THE CIRCULATORY SYSTEM The circulatory system in humans is the organ system that transports oxygen and nutrients throughout the body and carries away wastes. The system is made up of blood, the heart, and blood vessels.
Function of The Circulatory System - Moves oxygen from the lungs to all the body cells - Moves carbon dioxide from the body cells to the lungs - Moves nutrients from the small intestine to the body cells - Moves waste materials from the body cells to the kidneys and skin to be removed
The Blood Blood is a type of connective tissue that circulates through your body, it consists of 4 components: Red Blood Cells (RBC) White Blood Cells (WBC) Platelets Plasma Did you know - It takes about 20 seconds for a RBC to circulate the entire body
Blood: A type of connective tissue is made of 4 elements: Red blood cells. White blood cells. Platelets. Plasma.
Composition of blood
Components of the Blood: Red Blood Cells -make up approx. 45% of blood volume -contain haemoglobin (protein that carries O 2 ) -have no nucleus (example of cell specialization) White Blood Cells -make up less than 1% of blood volume -function is to fight infection -have a nucleus Platelets -are actually just fragments of cells -make up less than 1% of blood volume -function is to clot blood Plasma -liquid that suspends the other 3 components -makes up approx. 55% of blood volume -contains dissolved materials
Types of Blood Vessels (how the blood is carried): 1) Arteries: blood vessels that carry blood away from the heart heart pumps blood with force so arterial blood pressure is higher than venous blood pressure due to higher pressure, artery walls are thicker than those of veins 2) Veins: blood vessels that carry blood toward the heart contents are under low pressure so walls are thinner than those of arteries 3) Capillaries: tiny blood vessels with very thin walls to allow substances to diffuse between the blood and the body fluids and tissues are the blood vessels that link arteries and veins oxygen and nutrients diffuse from the blood into the surrounding tissues carbon dioxide and other wastes diffuse from tissues into the blood
The Heart (a pump): Made of 3 types of tissue: - Cardiac Muscle Tissue - Nerve Tissue - Connective Tissue Consists of four chambers: - 2 Atria (left and right atrium) - 2 Ventricles (left and right ventricles)
Let s explore the flow through the heart.
Follow the path one red blood cell could take around the body.
Circulatory System Diseases and Disorders See pages 85-86 in the text Example: heart attack is a when a coronary artery becomes completely blocked with plaque or with a blood clot.
THE DIGESTIVE SYSTEM The digestive system is the organ system that takes in food, digests it, and excretes the remaining waste. The digestive system is made up of the digestive tract and 3 accessory organs. The parts of the digestive system in humans are shown here. Know the parts!
THE DIGESTIVE TRACT The Tube in which the food travels through as it is digested (mouth, esophagus, stomach, small intestine, large intestine, rectum, anus)
THE ACCESSORY ORGANS (Liver, Gall bladder, Pancreas)
Mouth -Breaks down food mechanically (teeth and tongue) -Also breaks apart food chemically with saliva (enzymes and water) -Saliva is produced in the epithelial tissue that lines the mouth
Esophagus -A tube connecting your mouth to your stomach -Surrounded by smooth muscle tissue which can contract/relax without conscious thought -Nerve tissue controls muscle contractions -Contractions slowly move along food
Stomach -Holds and churns food -Lining of inside of stomach has cells that produce digestive enzymes and acid -Layers of smooth muscle tissue contract to mix stomach contents
Small Intestine -After stomach in digestive tract -6m long, and narrow -Goblet cells secrete mucus -Does most digestion of food, and most absorption of nutrients
Small Intestines
Large Intestine -1.5m long, and wider then small intestine -Absorbs water after digestion -Waste left over goes to rectum, then anus, and out!
Accessory organs Liver Produces bile (which breaks down fat in food) Gallbladder Where bile is stored Pancreas Creates an enzyme called insulin. Insulin helps regulate the concentration of glucose sugar in our blood, and helps glucose enter our cells.
Label the Digestive System!
Endocrine System The endocrine system is made up of glands that produce and secrete hormones Hormones are chemical substances produced in the body that regulate the activity of cells or organs. Hormones regulate the body's growth, metabolism (the physical and chemical processes of the body), and sexual development and function. Hormones are released into the bloodstream and may affect one or several organs throughout the body.
Endocrine System The major glands of the endocrine system are: hypothalamus pituitary thyroid parathyroids adrenals pineal body reproductive organs (ovaries and testes). pancreas
Endocrine System Hormones
Function of the Endocrine Glands Pituitary Gland: "master gland" because of its great influence on the other body organs. Its function is complex and important for overall well-being. Hypothalamus: releases hormones that start and stop the release of pituitary hormones. Thymus is a gland needed early in life for normal immune function. Secretes hormones which help develop the immune system. Pineal Gland: produces melatonin, which controls sleep patterns. Testes: only in male, produce the hormone testosterone. Testosterone helps a boy develop and then maintain his sexual traits.
Function of the Endocrine Glands Ovaries: only in females, produce estrogen and progesterone. These hormones are responsible for developing and maintaining female sexual traits, as well as maintaining a pregnancy. Thyroid: secretes hormones that control metabolism. Adrenal Glands: secretes hormones that help the body control blood sugar, increase the burning of protein and fat, and respond to stressors like fever, major illness, and injury, control blood volume and help to regulate blood pressure, produces some sex hormones (for some secondary sex characteristics in both men and women). Parathyroid Glands: make hormones that help control calcium and phosphorous levels in the body (important for bone growth).
Example Hormones Oxytocin from the Pituitary gland. Controls labour and milk production for nursing mothers. Antidiurectic hormone (ADH) from the Pituitary gland. Increases water absorption in the body (kidneys). Adrenaline Produced in the adrenal glands. Adrenaline works with noradrenaline to produce the "fight or flight" response by increasing the supply of oxygen to the brain and muscles, dilating the pupils, and suppressing bodily functions not useful in an emergency situation (such as digestion). Growth Hormone (GH) from the pituitary gland. GH stimulates growth during childhood and also stimulates cell reproduction, which helps adults maintain muscle and bone mass.
Immune System The immune system is our body s protection system. It is designed to defend against bacteria, viruses, and toxins that invade your body. T cells signal the invasion B cells make antibodies (chemical fighters) Macrophages white blood cells that EAT
Bone marrow Bone marrow is the spongy tissue inside of your bones. It produces adult stem cells (also called tissue stem cells) which can develop into any type of blood cell.
Thymus gland Precursor cells from the bone marrow travel to the thymus gland and here they develop into lymphocytes (white blood cells). Theses white blood cells will produce anti-bodies that fight bacteria and viruses.
Spleen Produces lymphocytes, which in turn produce antibodies (a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses) Filters blood by removing antibody-coated bacteria. It also removes old red blood cells. Located in the upper-left part of the abdomen.
Spleen
Lymph nodes Lymph nodes are filled with white blood cells. Lymph nodes are located throughout the body and swell when you re fighting an infection because they are having to work harder. The main job of the lymph nodes is to filter the lymph (clear fluid that comes from tissues) by eliminating antibody-coated bacteria.
Blood vessels The blood vessels transport all of the blood cells around the body, including white blood cells that fight infection.
The Overall Functions of the Urinary System To remove waste products from the blood and maintain the water balance. This system keeps sodium, potassium and water in balance and remove a type of waste known as Urea from the blood.
Urinary System
Urinary System Parts and their Functions There are two beanshaped kidneys in the urinary system. They are located in your back, just below the ribs. The kidneys filter blood and remove liquid wastes such as urea, uric acid, and ammonium, in the form of urine.
There are two ureters in the urinary system. They are narrow tubes that carry urine from the kidneys to the bladder. Muscles in the ureter walls continually contract and relax forcing the urine downward and away from the kidneys.
A triangle-shaped, hollow organ that is located in the lower abdomen, behind the pelvic bone. The bladder s walls relax and expand to store urine, and contract and flatten to empty urine through the urethra.
These two circular muscles are at the bottom of the bladder. Their function is to help keep urine from leaking by closing tightly around the opening of the bladder.
The nerves in the bladder alert a person when it s times to urinate, or empty the bladder. These signals start in the brain, go through the spinal cord and continue to the nerves located in the sacral area of the back before being sent to the pelvic area.
Urine passes into the urethra which is a tube located at the bottom of the bladder that leads to the outside of the body. The brain signals the bladder muscles to tighten, and it squeezes urine out of the bladder.