Gen bio 2

• The hierarchical organization of body plans is a characteristic of all multicellular organisms.
• The form (anatomy) and biological function (physiology) of both animals and plants are correlated at all levels of organization.
• The body plan of different species reflects their evolution over millions of years through a process of natural selection and adaptation.
• Bodies of complex multicellular organisms like those of plants and animals are based on levels of organization.
• These organisms are made up of fundamental units we call cells, which can be grouped to perform specialized functions.
• Sizes and shape vary across organisms

  organ system. As organs are

  complex in highly developed animals, such as humans, they often have more than one physiological role and thus, may belong to more than one system
• ORGAN SYSTEMS

  Organ systems are biological systems consisting of a group organs that coordinate through a higher level of organization to perform specific functions.
• DIGESTIVE SYSTEM

  MAIN COMPONENTS

  Mouth, salivary gland, esophagus, pharynx, stomach, stomach, liver, intestine, pancreas, anus

  MAIN FUNCTIONS

  Responsible for processing food by ingestion, digestion, absorption, and elimination; maintains a sufficient amount of nutrients for the body.
• CIRCULATORY SYSTEM

  Main components:

  Heart, blood, blood vessels

  Main Function:

  Responsible for transporting nutrients and other materials (such as oxygen, water, hormones, waste materials, salts) between different parts of the body.
• RESPIRATORY SYSTEM

  Main components:

  Nose, nasal cavity, pharynx, larynx, trachea, lungs

  Main function:

  Responsible for gas exchange; maintains the amount of oxygen and removes the carbon dioxide in the blood; regulates the blood pH along with the kidneys.
• EXCRETORY SYSTEM

  Main components:

  Kidney, ureter, urinary bladder, urethra

  Main function:

  Responsible for excreting metabolic wastes and aiding in the regulation of the osmotic balance of blood and other body fluids.
• Locomotion allows for the movement of the body's organs such as the skeleton, heart, blood vessels, digestive tract, etc.
• The endocrine system consists of different glands such as pituitary, pancreas, thyroid, pineal, and adrenal glands, and other organs that secrete hormones include ovary and testis.
• The endocrine system is responsible for regulating and coordinating the body's metabolic activities and other physiological processes.
• The main function of the muscular system is to generate force and movement.
• The muscular system consists of cardiac muscle, skeletal muscle, and smooth muscle as its main components.
• The nervous system consists of the brain, spinal cord, peripheral nerves, and sensory nerves.
• The nervous system acts as the primary regulatory system and is responsible for processing information through the reception of external and internal stimuli, conduction of impulses, integration of the Information, and transmission of commands for the body to execute the response.
• The main function of the nervous system is to process information and control bodily functions.
• SKELETAL SYSTEM

  Components:

  Bones, ligaments, cartilage, and tendons which make up the skeleton

  Function:

  Responsible for supporting and aiding the movement of the body, protecting the internal organs, and maintaining calcium levels.
• INTEGUMENTARY SYSTEM

  Components:Skin, hair, nails, claws, sweat glands

  Function:

  Responsible for protecting the body from mechanical injuries and infections of pathogens, preventing dehydration, and regulating the body's temperature through sweat glands and blood vessels found in the skin.
• IMMUNE & LYMPHATIC SYSTEM

  Components:

  Tonsils, bone marrow, spleen, thymus, lymph, lymph nodes, lymph vessels

  Functions:

  Acts as the primary defense against different pathogens. The lymphatic system is also responsible for the collection of tissue fluid and its transport to the blood and the absorption of lipid molecules from the digestive system.
• REPRODUCTIVE SYSTEM

  Components:

  Female reproductive parts (ovary, fallopian tube, uterus, cervix, vagina) and male reproductive parts (testis, scroturn, vas deferens, prostate gland, urethra, penis

  Function:

  Responsible for producing and storing gametes, fertilization, and fetal development.
• Homeostasis is the maintenance of a constant internal environment within physiological tolerance limits - it is responsible for maintaining equilibrium. A disease will ensue when a factor deviates from its normal homeostatic range.
• NEGATIVE FEEDBACK

  Stimulus->Sensor->Controlled Center->Effector

  Physiological processes are moderated by feedback loops

  Changed conditions are detected by a receptor

  A corrective response is initiated by an effector

  Homeostasis is maintained via negative feedback

  The effect is antagonistic (opposite) to the stimulus

  Feedback loops are involved in a number of homeostatic processes: thermoregulation, blood pH, water balance
• Positive Feedback Loops: When there is a change in the environment, the cells respond by increasing the rate at which they produce something until the desired effect is achieved.
• Positive feedback occurs when a product feeds back to increase its own production, causing conditions to become increasingly extreme.
• Unlike negative feedback that maintains hormone levels, positive feedback is rarely used to maintain homeostatic functions.
• An example of positive feedback is milk production by a mother for her baby.
• As the baby suckles, nerve messages from the nipple cause the pituitary gland to secrete prolactin.
• Prolactin, in turn, stimulates the mammary glands to produce milk.
• The onset of contractions in childbirth is an example of positive feedback.
• When contraction occurs, oxytocin is released into the body stimulating more contractions.
• HORMONES

  Hormones are chemical messengers released from ductless endocrine glands

  They travel within the bloodstream to act on distant target cells

  Hormones can be either proteins (insulin, adrenaline) or lipids (testosterone, estrogen)
• Endocrine Cells produce hormone
• Target Cell with specific receptor
• ENDOCRINE

  Components of the endocrine system include:

  Pineal gland: Melatonin (biological clock)

  Pituitary gland: ADH (osmoregulation)

  Thyroid gland: Thyroxin (metabolic rate)

  Adrenal gland: Adrenaline (fight or flight response)

  Pancreas: Insulin / Glucagon (blood sugar levels)

  Adipose Tissue: Leptin (appetite control)

  Gonads: Testosterone / estrogen (sex characteristics)
• THYROXIN

  Hormone: Thyroxin

  Endocrine Gland: Thyroid gland

  Function:

  Activated by signals from hypothalamus

  Primary role is to increase metabolic rate

  This results in increased in heat

  production (i.e. Thyroxin regulates body temperatures)

  Thyroxin is secreted by the thyroid gland to regulate metabolic rate and help control body temperature

  Skin(receptor)->Hypothalamus(brain)->thyroxin(thyroid gland) ->hear(metabolic rate)
• MELATONIN

  Hormone: Melatonin Endocrine Gland: Pineal gland (in the brain)

  Function:

  Regulates circadian rhythms (i.e. sleep cycle) ,

  Secretion is suppressed by light stimull that are relayed (via retina) to the hypothalamus Hence, melatonin levels are higher at night

  Melatonin is secreted by the pineal gland to control circadian rhythm
• MELATONIN

  Jet lag is physiological condition caused by a change to normal circadian rhythms The pineal gland continues to secrete melatonin according to an old time zone Taking melatonin supplements may re-calibrate an individual's sleep schedulle