Human Physiology By Chelsea Finn. The Nervous System There are 100 billion neurons in the human...
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Transcript of Human Physiology By Chelsea Finn. The Nervous System There are 100 billion neurons in the human...
Human Physiology
By Chelsea Finn
The Nervous System
There are 100 billion neurons in the human brain
The Nervous System Standards
Students know how the nervous system and endocrine systems regulate conditions in the body.
Students know the functions of the nervous system and the role of neurons in transmitting electrochemical impulses.
Students know the role of sensory neurons, interneurons, and motor neurons in sensation, thought, and response
Components of the Nervous System
Includes: Central Nervous System
includes brain and spinal cord brain has three parts:
cerebrum, cerebellum, and medulla oblongata
the cerebrum is conscious, while the other two parts are part of the unconscious brain
Peripheral Nervous System responsible for involuntary
actions such as heart beat and the digestive system
divided into sympathetic and parasympathetic systems
these two systems check on each other to create a balance
Nervous System Functions
Receives and compares input of external conditions and the body’s external state
Acts as a control system for all actions
Responds to stimuli
Parts and Types of Neurons (Nerve Cells)
Parts of Neurons: Dendrite: receive and transmit
information from another nerve cell into cell body
Cell Body: contains nucleus, mitochondria, and other organelles typical to eukaryotic cells
Axon: guides electrochemical messages away from the cell body
Types of Neurons: Sensory Neurons: usually have short
axons and long dendrites, carry messages from receptors to the central nervous system
Interneurons: found only in the central nervous system
Motor Neurons: have a long axon and a short dendrite, transmit messages from the central nervous system to muscles
How Nerves Function
Receives sensory input in various forms from electrochemical impulses
These impulses travel along the the lengths of cells up to 250 miles per hour
Body Regulation through loops: Signals from senses go to the neurons. Depending on the impulse, the nerve
cell will either send the impulse to the brain, or react immediately
For example, if a person steps on a nail, an impulse will go to a nerve and the neuron will automatically pick up the foot, without sending the impulse to the brain.
Another example is if a person starts to feel cold, a neuron will send that impulse to the brain and then the person will choose what to do, because it’s not that important to get warmer
The Circulatory System
Students know how the complementary activity of major body systems provides cells with oxygen and nutrients and removes toxic waste products such as
carbon dioxide
Circulatory System
Includes: Red blood cells that carry
oxygen from the lungs to other parts of the body
Arteries that carry blood away from the heart
Veins that carry blood back to the heart
Capillaries that are the point of exchange of blood and the tissues
two pumps in the heart Specialized organs for the
exchange of acquired materials, such as oxygen from the external environment
Circulatory System Functions
Delivers oxygen, nutrients, and hormones to cells in the body
Removes waste such as carbon dioxide, ammonia, and other metabolic wastes
The Heart
Heart has two pumps: One to pump deoxygenated
blood to the lungs The other to pump
oxygenated blood to all other organs and tissues
Contracts in a rhythm to pump blood
Skeletal System
The body has 206 bones
Functions of the Skeletal System
Forms and shapes our bodies with 206 bones
Supports, protects, and allows bodily movement
Produces blood for the body Stores minerals such as
calcium and phosphorus Protects vital organs inside
body
Parts of the Skeleton
Axial Skeleton Consists of bones that
protect organs of the head, neck, and trunk
Forms the axis of the body Contains the skull, sternum,
ribs, and spine
Appendicular Skeleton Attaches limbs to axial
skeleton Contains upper extremities
(arms), lower extremities (legs), the shoulder girdle, and the pelvic girdle
Types of BoneShort Bones: Short and cube-shaped Found in ankles and wristsLong Bones: Longer than they are wide Work as levers Ex. Femur, HumerousFlat Bones: Broad Surfaces for:
Protection of Organs Attachment of Muscles
Ex. Ribs, Bones in the SkullIrregular Bones: Bones that don’t fall into other
categories Ex. Bones in the Vertebra
Bone CompositionMany bones contain both spongy
bone and compact bone.Compact bone: Dense and hard Forms the protective outer layer of
all bones
Spongy Bone: Inside the compact bone Has many tiny holes like a sponge
or sponge cake (porous) Is in most bones
The bone cells are imbedded in inorganic salts like calcium and phosphorus for strength
Collagen fibers give the bone flexibility
Muscular System
Students know the cellular and molecular basis of muscle contraction, including the roles of actin,
myosin, Ca+2, and ATP.
Types of Muscle
Skeletal Muscle: Responsible for moving limbs,
trunk, and face Responsible for voluntary
movement Made up of elongated cells
called muscle fibers Mostly controlled by Central
Nervous System
Cardiac Muscle: Only found in heart Involuntary
Smooth Muscle: Usually not voluntary Spindle-shaped Found in stomach, intestines,
and walls of blood vessels Can contract without nervous
stimulation
Functions of Muscular System
Determines the shape of our bodies and how we move
40 to 50 percent of our mass Allows motion and movement
of our bodies Maintains our posture Produces heat
Muscle Structure
Attached to bones by tendons that are made of connective tissue Skeletal muscles have bundles called fasicles Fasicles are made up of many muscle fibers Muscle fiber contains many myofibrils
Muscle Contraction
1. An action potential, or wave of electrical discharge, reaches the muscle cell via T tubules
2. The action potential causes calcium to leak out and immediately combine with thin myofilamints
3. This exposes the active site on the actin molecules4. The active site on the actin molecules are now free to bind with the
cross-bridges of the mysoin molecules of the thick myofilament5. After this attachment, stored energy is released as the cross-bridges
pivot, using a power stroke o move toward the middle of the contracting unit. All of the contracting units of a cell move together to make the cell contract
6. Calcium ion concentration in the cytoplasm quickly returns to normal due to the active transport of calcium ions into the extracellular fluid and into the sarcoplasmic reticulum.
7. As calcium detaches from the troponin, the actin active sites become blocked, breaking the bridge connections, and the cell relaxes
Integumentary System
Students know the role of the skin in providing nonspecific defenses against infection.
Skin Function and How it Functions
Protects the body: Serves as barrier
against infection on injury
Helps regulate body temperature through sweat
Removes waste products through the air
Serves as protection against UV light from the sun
Produces vitamin DSweat Pore
Parts of the Integumentary System
Epidermis The outer layer Composed of many sheets of flat
epithelial cells Made of mostly dead cells Most cells under go rapid cell division Newer cells push outward and older cells
loose their content and start to produce keratin
Keratin is a tough protein that makes up calluses, hair, and nails
Does not contain blood vessels
Dermis Contains blood vessels, nerve endings,
glands, sense organs, smooth muscles, and hair follicles.
Helps control body temperature by expanding and shrinking blood vessels
Hair and Nails
Hair is produced by cells called hair follicles
Nails grow from rapidly dividing cells in the nail matrix located near the tips of fingers and toes
Hair protects and insulates the body
Nails grow .5 to 1.2 mm per day
Respiratory System
Students know how the complementary activity of major body systems provides cells with oxygen and nutrients and removes toxic waste products such as
carbon dioxide.
Functions of Respiration
Functions Get oxygen into the body and carbon dioxide and waste gases out of the
body helps maintain body temperature and eliminate excess water from the body
Parts of the Respiratory System
Parts Nose- a passage way for air and also a sense Pharynx- (throat) passage way for air and food Larynx- the voice box, lined with mucus membrane Trachea- windpipe, tube composed of cartilage, lined with mucus membrane,
lies in front of esophagus Bronchi- C shaped rings of cartilage, sweeps out dust particles Lungs- main organ of respiration, millions of alveoli and blood capillaries
exchange oxygen and carbon dioxide
Gas Exchange
1. Gas exchange happens in the alveoli
2. The alveoli are the tiny sacs found in the lungs
3. Their walls are extremely thin, enough to allow gas to diffuse through them
4. The alveoli are lined with pulmonary capillaries, which have walls thin enough to permit gas exchange.
5. The inhaled gases diffuse from the alveoli to the blood in the capillaries, while carbon dioxide diffuses in the opposite direction from the capillaries to the alveoli
6. Now, pulmonary blood has oxygen and the lungs are holding carbon dioxide.
7. Then, exhalation occurs and gets rid of the carbon dioxide
Excretory System
Students know the homeostatic role of the kidneys in the removal of
nitrogenous wastes and the role of the liver in blood detoxification and glucose
balance.
Parts of the Excretory System
Kidney- bean-shaped organ, made up of tiny units called nephrons, it filters the blood, re-absorbs the blood, and secrets the waste
Ureter- the waste that has been filtered out is secreted through this tube
Bladder- a hollow organ, walls are made of muscle, where the ureters empty into
Urethra- receives the urine from the urinary bladder and disposes it
Function of the Excretory System
Disposes of waste such as toxins, excess water, other solutes, and normal components of the blood that are present in greater-than-normal concentrations
Regulates blood pressure, metabolism, and blood compisition and volume
How the Excretory System Functions
1. The kidney filters out blood of its small molecules and ions. It reclaims needed amounts of useful materials.
2. The kidney secretes blood through ureters
3. Ureters empty out into the bladder
4. The urethra receives the urine from the bladder and disposes of it
Endocrine System
Students know how feedback loops in the nervous and endocrine systems regulate conditions in the
body.
Parts of the Endocrine System
Hypothalamus and Pituitary Gland- both found in brain, both produce growth hormone or growth horrmone-releasing hormones
Thyroid Gland- found in the neck
Liver- produces insulin like growth factor
Pancreas- produces insulin Adrenal Glands- produce
testosterone and adrenoline Stomach- produce gastrin Ovaries- produce estrogen Testes- produce testosterone
Functions of the Endocrine System
Regulates mood, tissue function, metabolism, sexual function, and reproductive processes
Controls glands that secrete hormones that circulate through the body through the bloodstream to affect cells in specific organs
Regulates growth and development
Helps nervous system in regulating the body through loops
How the Endocrine Functions
Endocrine glands secrete their products into the blood or interstitial fluid without storing the product.
Hormones are carried in the bloodstream to different cells in the body and act as messengers
The cells interpret the messages and act on them
Digestive System
Students know the individual functions and sites of secretion of digestive enzymes (amylases, proteases,
nucleases, lipases), stomach acid, and bile salts.
Functions of the Digestive System
Uses enzymes to Process and break down the chemical compounds in food into molecules that can be absorbed and used by the cells as energy
Builds and replaces cells and tissues that are constantly dying
Parts of the Digestive System
Mouth: Food is partially broken
down here by chewing and salivary enzymes
Esophagus: Food is pushed down this
tube by rhythmic muscles
Stomach: Food is bathed in gastric
acid
Small Intestine: Food is broken down by bile,
pancreatic enzymes, and other digestive enzymes.
Large Intestine: Water and electrolytes are
removed from food
The Digestive Process
1. Food is partly broken down by chewing in the mouth and salivary enzymes that break down the starches in smaller molecules
2. Food goes through the esophagus using rhythmic movements that allow humans to eat or drink up-side down
3. In the stomach, food is churned in gastric acid
4. Food then passes through the duodenum, the jejunum, and the ileum in the small intestine. Bile, pancreatic enzymes, and other digestive enzymes help break down the food.
5. The food then passes through the large intestine where water and electrolytes are removed from the food.
6. At the end of the process, solid food is stored in the rectum until excreted by the anus
Digestive Enzymes
Amylases- digests starch into small segments of multiple sugars and into individual soluble sugars
Gastric Amylase- degrades starch (little significance) Pancreatic Amylase- degrades most hydrocarbons besides
starch, glycogen, and celluloseNucleases- degrade nucleic acidsLipases- found in the first part of the small intestine, break down
fatty acidsPepsin- the main gastric acid in the stomach, breaks down
proteins in smaller peptide fragments
The Reproductive System
Students know how hormones (including digestive, reproductive, osmoregulatory) provide internal
feedback mechanisms for homeostasis at the cellular level and in whole organisms.
Functions of the Reproductive System
To ensure the survival of the species by
Producing egg and sperm cells
Transporting and sustaining these cells
Nurturing the development of offspring
Producing hormones
Parts of the Reproductive System
Females: Fallopian Tubes- eggs travel through
these Uterus- where baby matures Cervix- bottom end of the uterus Ovaries- where eggs are produced Vagina- repository for sperm
Males: Testes- where sperm is produced Scrotum- sac where testes are held Epididymis- where sperm is stored,
where sperm mature Vas deferens- tubes which carry sperm
from scrota to urethra Prostate Gland- the largest of the
accessory glands which puts its secretions directly into the urethra
Penis- where the urethra goes through
How the Reproductive System Functions
Uses hormones There are 2 types of hormones:
Steroids Protein and Polypeptide hormones
Reproductive System uses estrogen, a steroid, to mature females
Estrogen is responsible for: development of breasts further development of the uterus and
vagina broadening of the pelvis growth of pubic and axillary hair increase in adipose (fat) tissue
Reproductive system uses testosterone to mature males
Testosterone is responsible for: Development of sex organs Deepening of voice Facial Hair Etc.
Immune System
Immune System Standards
Students know the role of the skin in providing nonspecific defenses against infection.
Students know the role of antibodies in the body's response to infection.
Students know how vaccination protects an individual from infectious diseases.
Students know there are important differences between bacteria and viruses with respect to their requirements for growth and replication, the body's primary defenses against bacterial and viral infections, and effective treatments of these infections.
Students know why an individual with a compromised immune system (for example, a person with AIDS) may be unable to fight off and survive infections by microorganisms that are
usually benign.
Students know the roles of phagocytes, B-lymphocytes, and T-lymphocytes in the immune system.
Functions of the Immune System
Detects and eliminates pathogens such as viruses or parasitic worms using an intricate network of tissues, organs, cells, and chemicals
Even though the immune system is highly effective, humans use vaccination processes to further protect humans from infectious diseases
Parts of the Immune System
Bone Marrow- where all immune system cells originate
Thymus- produces mature T cellsLymphatic System- network of vessels
carrying lymph, or tissue-cleansing fluid, from the tissues into the veins of the circulatory system, it absorbs nutrients from the small intestines,
Tonsils- found in throat, act as a filter against disease organisms
Spleen- lies under diaphagm, acts as a filter against foreign organisms that infect the bloodstream, filters out old red blood cells from the bloodstream
Skin- acts as physical barrier of defense
How the Immune System Functions
leukocytes circulate through the body between the organs and nodes by means of the lymphatic vessels
There are 2 types of leukocytes: lymphocytes and phagocytes
Phagocytes chew up invading organisms
Lymphocytes allow the body to remember and recognize previous invaders
The two types of lymphocytes are called B lymphocytes (B cells) and T lymphocytes (T cells).
B cells produce antibodies in response to foreign proteins of bacteria, viruses, and tumor cells.
Bibliography
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookNERV.html
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Circulation.html
http://www.sirinet.net/%7Ejgjohnso/muscle.html http://www.besthealth.com/besthealth/bodyguide/reftext/html/
skin_sys_fin.html http://www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookRESPSYS.html http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/K/
Kidney.html http://kidshealth.org/parent/general/body_basics/endocrine.html http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/ http://mcb.berkeley.edu/courses/mcb135k/outline/repro.html http://www.encyclopedia.com/doc/1E1-immunity.html