UNIT 1: let me break down what u are (part 1)

INTRO

• anatomy: the study of the structure and shape of the body and its parts and their relationships to one another

  • large body structures= gross anatomy

• physiology: the study of how the body and its parts work/func

BODY SYSTEMS

• integumentary system (skin)

  • system parts:

    • skin

  • system funcs:

    • synthesis of vitamin d

    • temp regulation

    • germ barrier

    • packaging

      

• skeletal system

  • system parts:

    • bones

    • ligaments

    • appendages/ appendicular bones:

    • axial bones:

    • marrow (without it bone would shatter)

      • yellow: adipose tissue (fat tissue)

      • red: creates blood cells (hematopoiesis)

  • system funcs:

    • storing minerals (calcium, phosphorus for strength)

    • creating blood

    • providing framework for body

    • protecting certain organs

      

• Muscular system

  • system parts:

    • muscles

      • latimus:

      • skeletal muscle

      • smooth muscle

      • cardiac muscle

  • system funcs:

    • to contract/shorten to create movement

  

• Nervous system

  • system parts:

    • nerves

      • cranial nerves

    • brain

    • spinal chord

    • neurons

      • motor (movement)

      • sensory (detection)

        • ex: texture

      • interneurons (decision making)

  • system funcs:

    • sending electrochemical signals

    • detection (input thru sensory neurons)

      • ex: feeling pain

    • reaction

      

• Endocrine system:

  • endo=internal

    • system parts:

      • pituitary gland

      • thyroid gland

      • pancreas

      • mammary glands

    • system funcs:

      • producing hormones (usually not smth the glands need themselves)

      • the blood transports hormones to their location

      • hormones are chemical messengers

        

• Cardiovascular system:

  • system parts:

    • heart

    • blood vessels

    • red = artery = oxygenated

    • blue = veins = deoxygenated

  • system funcs:

    • carry oxygen, nutrients, hormones, & other substances to and fro the tissue cells where exchanges are made

    • heart pumps blood out of its chambers into the blood vessels to be transported to all body tissues

      

• Lymphatic system

  parallel to the cardiovascular system

  • system parts:

    • lymphatic vessels

    • lymph nodes

    • spleen

    • tonsils

  • system funcs:

    • vessels return fluid leaked from the blood back to the blood vessels so that the blood can keep flowing

    • clean the blood and house cells involved w immunity

      

• Respiratory system

  • system parts:

    • pharynx

    • larynx

    • trachea

    • bronchi

    • lungs

  • system funcs:

    • keeps the blood constantly oxygenated

    • removes carbon dioxide

      

• Digestive system

  • system parts:

    • piping running from mouth to butthole

    • esophagus

    • stomach

    • small/large intestines

    • liver

    • salivary glands

    • pancreas

  • system funcs:

    • break down food and deliver the products to the blood for dispersal to the body cells

    • pooping 🥺💩

      

• Reproductive system

  • system parts:

    • dudes:

      • seminal vesicles

      • prostate gland

      • penis

      • vas deferens

      • testis

      • scrotum

    • gals:

      • mammary tissue

      • uterine tube

      • ovary

      • uterus

      • vagina

  • system funcs:

    • creating little devils

      

• Urinary system

  • system parts:

    • kidneys

    • ureters

    • bladder

    • urethra

  • system funcs:

    • removes nitrogen-containing waste (i.e urea & uric acid) from the blood and flushed them from the body in urine

    • constantly monitoring the amt of electrolytes in the body

      

NECESSARY LIFE FUNCS

What does this highly organized human body do?

• every cell of the human body is surrounded by an external membrane that contains its contents and allows needed substances in while preventing unnecessary/harmful substances from entering

• skin prevents the internal organs from drying out, attacked by bacteria, and from the effects of heat/sunlight/chemicals in the environment

• movement: includes all the activities promoted by the muscular system

  • ex: propelling ourselves from point a to point b, moving food thru the GI tract

• responsiveness/irritability: the ability to sense changes (stimuli) in the environment and then react to them.

  • ex: ur reflex to pull your hand away from the stove if it gets too hot

  • most of the responsiveness is handled by the nervous system, but the body cells are irritable to some extent

• digestion: the process of breaking down ingested food into simple molecules that can then be absorbed into the blood

  • then distributed across the cardiovascular system

• metabolism: broad term that refers to all the chem reactions that occur within body cells.

  • regulated chiefly by the hormones secreted by the glans of the endocrine system

  • includes:

    • breaking down complex substances into simpler building blocks

    • making larger structures from smaller ones

    • using nutrients and oxygen to make ATP (adenosine triphosphate) that powers cellular activities

• excretion: the process of removing excreta, or shits, from the body

  • several organ systems get rid of waste, like the urinary system gets rid of nitrogen-containing metabolic wastes in pee

• reproduction: the production of offspring

  • regulated precisely by hormones

    • can occur on the cellular or organismal level

      • cellular reproduction: cell divides, producing two identical daughter cells that may then be used for body growth/repair

    • baby making process

• growth: increase in size, usually accomplished by an increase in # of cells

  • for growth to occur, cell-constructing activities much occur at a faster rate than cell-destroying ones

SURVIVAL NEEDS

• nutrients: contain chemicals used for energy and cell building (taken thru food)

  • carbohydrates: major energy-providing fuel for body cells

  • proteins are essential for building cell structures (as well as fat, but not as much)

  • fats: also cushion the body organs and provide reserve fuel

  • minerals & vitamins: req for chem reactions that go on in cells and for oxygen transport in the blood

• oxygen: req for creating chem reactions that create energy (ATP)

• water: provides fluid base fro body secretions and excretions

• norm body temp:

  • as body temp drops below 98 F (37 C), metabolic reactions become slower until they stop

  • when body temp is too high chem reactions proceed too rapidly and body proteins begin to break down (denature).

• atmospheric pressure: force exerted on the surface of the body by the weight of air

  • at high alt, where air is thin and atmosphere pressure is lower, gas exchange may be too slow to support cellular metabolism

HOMEOSTASIS

• homeostasis: body’s ability to maintain relatively stable internal conditions even tho the outside world is constantly changing

  • dynamic state of equilibrium/ a balance in which internal conditions change and vary but always stay within very narrow limits

  • communication is achieved chiefly thru the nervous and endocrine system (working together)

  • variable: factor being regulated

  • stimuli: environmental changes

  • all homeostatic control mechanisms have three components:

    • receptor: some type of sensor that monitors and responds to changes in the environment It responds to such stimuli by sending info (input) to the second element, control center via afferent pathways

    • control center: determines the level (set point) at which a var is to be maintained, analyzes info it receives and then determines the appropriate response or course of action

    • effector: provides the means for the control centers response (output) to the stimulus. info flows from the control center to the effector along the efferent pathway. the results of the response feeds back to influence the stim, either by depressing it (neg feedback) or enhancing it (pos feedback)

  • neg feedback mechanisms: the net effect of the response is to shut off the orig stim or reduce its intensity

    • ex: thermostat set at 68F—> the heater will turn on when temp drops below set temp—> warmer house—> back to set temp

      • REDUCED the stimulus

  • pos feedback systems: rare, but tend to increase the original stimulus and to push the variable farther from its original value

    • ex: childbirth- hormones increase and increase until the baby is birthed

  • homeostatic imbalance: any disease, since it alters the body’s ability to maintain homeostasis