Includes: Stomach, Liver, Gall bladder, Large intestine, Small intestine
Functions:
Processes food for use by the body
Removes wastes from undigested food
Urinary System
Includes: Kidneys, Urinary bladder
Functions:
Controls water balance in the body
Removes wastes from blood and excretes them
Male Reproductive System
Includes: Epididymis, Testes
Functions:
Produces sex hormones and gametes
Delivers gametes to female
Female Reproductive System
Includes: Mammary glands, Ovaries, Uterus
Functions:
Produces sex hormones and gametes
Supports embryo/fetus until birth
Produces milk for infant
Homeostasis
Homeostasis is a condition of equilibrium, or balance, in the body’s internal environment
Homeostasis is maintained by regulatory processes
Sensor/Receptor: a body structure that monitors change in a controlled condition
Control Center: sets the range of values the controlled condition should be within
Effector: a body structure that receives output from the control center and produces a response.
Two general regulatory processes:
Negative feedback
Positive feedback
Negative Feedback
Reverses a change in a controlled condition
Example: Body temperature regulation
Stimulus: Body temperature exceeds 37°C
Sensor: Nerve cells in skin and brain
Control Center: Temperature regulatory center in brain
Effector: Sweat glands throughout body
Example of Negative Feedback
The body maintains a relatively constant internal temperature to optimize chemical processes.
Neural impulses from heat-sensitive thermoreceptors in the body signal the hypothalamus.
The hypothalamus, located in the brain, compares the body temperature to a set point value.
When body temperature drops, the hypothalamus initiates several physiological responses to increase heat production and conserve heat.
Narrowing of surface blood vessels (vasoconstriction) decreases the flow of heat to the skin.
Shivering commences, increasing production of heat by the muscles.
Adrenal glands secrete stimulatory hormones such as norepinephrine and epinephrine to increase metabolic rates and hence heat production.
Positive Feedback
Strengthens or reinforces a change in controlled conditions
Example: Labor
Head of baby pushes against cervix
Nerve impulses from cervix transmitted to brain
Brain stimulates pituitary gland to secrete oxytocin
Oxytocin carried in bloodstream to uterus
Oxytocin stimulates uterine contractions and pushes baby towards cervix
Example of Positive Feedback
Milk Production
Infant suckling triggers sensors in the areola, which send a nerve impulse to the brain.
The brain releases the hormone oxytocin from the hypothalamus and anterior pituitary.
Oxytocin triggers myoepithelial cells in alveoli of the mammary glands to squeeze milk into the lactiferous ducts.
The more the baby suckles, the more milk is released and the more milk the body will produce.
Homeostatic Imbalances
When homeostasis is disrupted disease, disorder, and even death may result.
Many factors can contribute, including:
The environment
The individual’s behavior
Genetic Make-Up
Nutrition, exercise, many life-style choices
Basic Anatomical Terminology
Body positions
Regional names
Directional terms
Planes and sections
Body cavities
To communicate accurately about the human body, anatomists use specific terms.
Health professionals need to speak this language in order to accurately communicate about your patients.
Body Positions
Anatomical position is a standardized method of observing or imaging the body that allows precise and consistent anatomical reference
Person stands erect, facing the observer, the upper extremities are places at the sides, the palms of the hands are turned forward, and the feet are flat on the floor
Regional Names
Regional names are names given to specific regions of the body for reference.
*Example: brachial means “arm”
Directional Terms
Right: the patient's right
Left: the patient's left
Used to describe the location of various parts of the body relative to one another.
Anterior (ventral): nearer to or at the front of the body
Posterior (dorsal): nearer to or at the back of the body
Lateral and Medial
Lateral: farther from the midline
Medial: nearer the midline
Intermediate: between two structures
Examples:
The ulna is medial to the radius.
The lungs are lateral to the heart.
The transverse colon is intermediate to the ascending and descending colon.
Superior and Inferior
Superior: towards the head or upper part of the structure
Inferior: towards the feet or lower part of the structure
Examples:
The heart is superior to the liver
The stomach is inferior to the lungs
Proximal and Distal
Proximal: nearer to the attachment of a limb to a trunk
Distal: farther from the attachment of a limb to a trunk
*only used for structure on the same limb
Examples:
The humerus are proximal to the radius
The phalanges are distal to the carpals
Superficial and Deep
Superficial: toward or on the surface of the body
Deep: away from the surface of the body
Examples:
The ribs are superficial to the lungs.
The ribs are deep to the skin of the chest and back.
Planes & Sections
Planes are imaginary flat surfaces that are used to divide the body
Sagittal plane
Frontal (coronal) plane
Transverse plane
Sagittal Plane
Sagittal Plane: vertical plane that divides the body in left and right.
Mid-sagittal: the imaginary lines goes thru the middle.
Para-sagittal: the line cuts the body in unequal parts.
Frontal Plane
Frontal Plane: divides body in anterior and posterior.
Transverse Plane
Transverse Plane: divides body into superior/inferior.
Other words: cross-sectional or horizontal
Oblique Plane
Oblique Plane: passes through the body at an oblique angle
Body Cavities
Body cavities are spaces within the body that help protect, separate, and support internal organs
Dorsal body cavity
Cranial cavity
Vertebral cavity
Ventral body cavity
Thoracic cavity:
Superior mediastinum
Pleural cavity
Pericardial cavity within the mediastinum
Abdomino-pelvic cavity
Dorsal Body Cavity
The dorsal body cavity can be broken down into:
Cranial cavity: contains the brain
Vertebral canal: contains the vertebral column and spinal cord
Ventral Body Cavity
The Ventral body cavity can be broken down into:
Thoracic cavity
Abdominopelvic cavity
The Abdominopelvic Cavity
The Abdominopelvic cavity can be broken down into:
Abdominal cavity: contains stomach, spleen, gallbladder, and most of the large intestine.
Pelvic cavity: contains the urinary bladder, portions of the large intestine and internal reproductive structures
The Thoracic Cavity
The Thoracic cavity can be broken down into:
Pleural cavity: fluid filled space around each lung (right and left pleural cavities)
Pericardial cavity: fluid filled space around the heart
Mediastinum: central portion of the cavity, between the lungs. Contains all the thoracic organs except the lungs
Membranes
Membrane: a thin, pliable tissue that covers, lines, partitions or connects structures.
Serous membrane: slippery, double-layered membrane associated with body cavities that does not open directly to the exterior.
Thoracic Cavity Serous Membranes
The pericardium and pleura membranes cover the heart and lungs, respectively
Abdominal Cavity Serous Membrane
The peritoneum, covers many of the abdominal organs
The visceral peritoneum covers the organs
The parietal peritoneum lines the abdominal wall
Abdominopelvic Regions & Quadrants
The abdominal cavity can be divided into 9 regions to easily describe the location of organs
Summary
The function of the 11 systems of the human.
The levels of organization in the human body.
About homeostasis and the importance of homeostatic feedback systems and how imbalances are related to disorders.
About the negative and positive feedback systems.
How to describe the human body using the anatomical position and specific anatomical terminology.