BIO BODY SYSTEMS

excretion is…

• removal of metabolic wastes

• removal of excess heat

Main Excretory organs involved are:

• kidneys

•  liver

• lungs

•  skin

cellular waste

• Wastes that are removed include carbon dioxide, water, salt, urea and uric acid. 

• All excreted wastes travel at some time in the blood. 

Major Metabolic wastes

• carbon dioxide, water

  • CO2 and H2O are from cellular respiration

• certain nitrogen compounds 

  • Breakdown of amino acids from proteins produces nitrogen compounds

    • Urea

    • Ammonia

    • Uric acid

• Mineral salts from metabolism

  • Sodium chloride (NaCl)

Potassium sulfate K2SO4

Structures of the Excretory System

1. Skin 

2. Lungs

3. Liver

4. Urinary System

5. Large Intestine

Large Intestine

• The large intestine removes solid, undigested food from the body after it passes through the digestive system.

• Waste is stored in rectum until it is excreted from the body as solid waste. NOTE:  This is NOT waste produced by the cells (cellular waste) as a part of your metabolism!!!!!

Skin

Wastes such as excess water, salt, urea and uric acid are removed from the body in sweat. 

The Liver and Waste

• The liver produces urea and uric acid as a by-product of the breakdown of proteins

• Urea and uric acid are sent to the kidneys to be processed

Formation of Urea in Liver:

• Amino acids are broken down.

1. amino group, NH2→                 changed to ammonia, NH3 → changed to urea (less poisonous)

• Finally: Urea diffuses back into bloodstream and is filtered out by the kidneys.

• Liver’s role

• Detoxification- 

  • changes harmful substances into inactive or less poisonous substances

  • These inactive substances are returned to blood and are filtered by kidneys.

The urinary system

The kidneys filter the blood to form urine, which is excess water, salt, urea and uric acid 

sequence of unirnary system

Kidneys-> ureter-> urinary bladder-> urethra

Kidneys

2 main functions

1. Remove wastes from cellular metabolism

2. Regulate the concentrations of substances found in the body fluids

*****If kidneys cannot perform these functions a person will die.*****

Kidney structure

3 layers of the kidney

• Cortex- outer layer blood is filtered to remove waste and excess substances

• Medulla- middle layer made up of tubes called collecting ducts that carry the filtered substances (filtrate) to the innermost layer of the kidney

• Pelvis- cavity that collects the filtrate and connects the kidney to the ureter which exits the kidney

Nephron

Nephron- waste filtering unit of the kidney found in the cortex and the medulla

• 1.25 million nephrons in each kidney

Filtration in Nephron 

1. Blood enters kidney through renal artery,

2. Small substances (water, salts and minerals) and wastes (urea) diffuse from the capillaries into the nephron of the kidneys.

3. Urea, excess water and excess substances travel to the renal pelvis to form urine.

4. Water and some dissolved substances are reabsorbed into the blood through the capillaries.

5. Clean blood leaves the kidney through the renal vein. 

What are the 5 Functions of the Skeletal System

1. Movement: Skeletal system provides points of attachment for muscles. Your legs and arms move when the muscles pull on the bones.

2. Support: The backbone is the main support center for the upper body. It holds your head up and protects your spinal cord.

3. Protection: The bones of your skull protect your brain. Your ribs protect your lungs and heart from injury.
4. Makes Blood: Red and white blood cells are formed by tissue called marrow, which is in the center of the bone

5. Storage: Bones store minerals, such as calcium and phosphorus, for use by the body

What is the Structure of Bone

In the spaces of many bones there is a soft connective tissue called marrow.

red marrow

• produces most of the body’s blood cells.

yellow marrow

• stores fat that can serve as an energy reserve.

How Do Bones Develop?

• As an infant, most of your skeleton is cartilage.

• Cartilage is a strong flexible tissue.

• Over time the cartilage is replaced by solid bone, usually complete by the time you stop growing.

• Not all cartilage is replaced in adults.  Many joints contain cartilage, protecting the ends of bones (ears and the end of the nose is also cartilage).

What are Joints?

• A joint is a place where two bones come together.

• Joints allow the bones to move in different ways.

• Two types of joints:

  • Immovable

  • Movable

What are Movable Joints?

• Most of the joint are movable joints.

• Allow the body to move in a wide range of movements.

• Bones in movable joints are held together by strong connective tissue called ligaments.

• Four types of movable joints:

  • Hinge

  • Ball-and-socket

  • Pivot

  • Gliding

What is a Ball-and-Socket Joint?

• Round end of bone fitting snuggly within another bone.

  • Ex. Shoulder and Hip

• Allows the greatest range of motion.

  • The ball-and-socket joint allows you to swing your arm freely in a circle.

What is a Pivot Joint?

• Bone resting atop another bone permitting free movement.

  • Ex. Neck, Wrist and Ankles

• Allows one bone to rotate around another.

  • Allows you to turn your head 

What is a Gliding Joint?

• Allows one bone to slide over another.

  • Ex. Knuckles, wrist, ankle

• Allows your to bend and flex as well as make limited side to side motions.

What is a Ligament?

Connects bone to bone

What is a Tendon?

•  Attaches muscles to bones.

What happens when a neuron is stimulated by another neuron?

• An impulse begins when a neuron is stimulated by another neuron or by the environment.

Name and describe three types of neurons.

1. Sensory Neurons:  carry impulses from sense organs to spinal cord & brain.

2. Motor Neurons:  carry impulses from brain & spinal cord to muscles and glands

3. Interneurons:  connect sensory and motor neurons and carry impulses between them

Describe the role of the myelin sheath.

the myelin sheath surrounds the axon  and insulates it.  It creates gaps, “nodes”, where the axon membrane is exposed.  Impulses can jump from node to node, which increases the speed at which the imp

All-or-None Principle:

the level of stimulus required to activate a neuron is called a threshold.  Any stimulus stronger than the threshold will produce an impulse, and if weaker then it will not produce an impulse.

Discuss the overall function of the central nervous system (CNS)

• The central nervous system relays messages, processes information, and analyzes information.

Describe the functions of the two divisions of the peripheral nervous system.

Sensory Division:  transmits impulses from sense organs to the CNS

Motor Division:  transmits impulses from the CNS to muscles or glands

.  How is the central nervous system protected from injury?

• The skull and vertebrae in the spinal column protect the brain and spinal cord.  

• Both are wrapped in three layers of connective tissue called meninges.  

• Cerebrospinal fluid between spinal cord and meninges and brain and meninges acts as a shock absorber.

What is the role of the hypothalamus?

• is the control center for recognition and analysis of hunger, thirst, fatigue, anger and body temperature

• controls the coordination of the nervous and endocrine systems

Describe the function of the endocrine system.

made up of glands that release their products (HORMONES) into the bloodstream.  These HORMONES deliver messages throughout the body.

Compare endocrine glands and exocrine glands.

• Endocrine Glands:  release hormones directly into bloodstream

  • Ex.  Pancreas releases insulin and glucagon into bloodstream to regulate glucose levels.

    • Insulin – decreases glucose levels

    • Glucagon – increases glucose levels

• Exocrine Glands:  release hormones directly into organs that use them

  • Ex.  Glands that release sweat, tears and digestive juices

What are prostaglandins and why are they called “local hormones”?

• Prostaglandins:  modified fatty acids that are produced by a wide range of cells.  They affect only nearby cells and tissues (“local hormones”)

  • Ex.  Can causes smooth muscles to contract, like uterus, bronchioles, blood vessels

  • Ex.  Causes pain sensation in headaches (aspirin inhibits synthesis of prostaglandins)

What are the advantages of having both a nervous system and an endocrine system?

• TRWO METHODS OF COMMUCATION

• Nervous system can deliver messages cell to cell.

• Endocrine system can deliver messages by sending hormones into the bloodstream (nervous cannot).

  Why is the hypothalamus an important part of both the nervous and the endocrine system?

• influenced by the levels of hormones in the blood and by sensory information collected by other parts of the CNS.  Interactions between the endocrine and nervous systems take place at the hypothalamus.

Three Basic Functions of the Nervous System

sensory

Integrative

motor

Neurons: Nerve cells

• Cell body with many extensions or processes (nerve "fibers") which conduct impulses. There are two types of processes:

• 1. Dendrites - shorter, more numerous. Receive Signals

• 2. Axons - single, long "fiber" which Sends/Conducts signals

Glial Cells/Neuroglia

• supportive tissue of the nervous system (more numerous than neurons). Five types

• 1. Microglial Cells
  2. Oligodendrocytes
  3. Astrocytes
  4. Ependymal Cells
  5. Schwann cells

Sensory neurons

Carries impulses from receptors e.g pain receptors in skin to the CNS( brain or spinal  cord)

Relay neuron

Carries impulses from sensory nerves to motor nerves.

Motor neuron

Carries impulses from CNS to effector e.g. muscle to bring about movement or gland to bring about secretion of hormone e.g ADH

Blood Vessels

• Carry blood to cells

• Lined with smooth muscle tissue 

• Three kinds: 

  1. Arteries

  2. Capillaries

  3. Veins

Arteries

away

• Carry oxygenated blood from the heart to the rest of the body.

Capillaries

• Branch off of the Arteries

• The smallest of the blood vessels

  • some have diameters as small as 1 red blood cell

• Takes blood to cells

Veins

• Takes deoxygenated blood from the capillaries back to the heart

Platelets

blood cells that stick to broken blood vessels to stop bleeding when you are cut

how many chambers are in the heart

4

Two types of Arteries

Arteries start with A takes blood away !!

• Aorta – Largest blood vessel in the heart

• Pulmonary Artery – Carries blood containing carbon dioxide from your heart to your lungs

Three Types of Veins

• Veins start with V brings blood back to me 

  • 1. Inferior Vena Cava – Where the blood enters the heart from the body.

  • 2. Superior Vena Cava – Where the blood enters the heart from the body.

  • 3. Pulmonary Vein – Carries blood-containing oxygen from your lungs to your heart.

the Four Valves of the Heart

• Tricuspid Valve – Lets the blood fill in the right atrium before it enters the right ventricle.

• Bicuspid Valve – Lets the blood fill in the left atrium before it enters the left ventricle

• Right Semi lunar Valve- Lets the right ventricle fill before releasing the blood into the pulmonary artery.

• Left Semi lunar Valve – Lets the blood fill in the left ventricle before sending it to the aorta