Chapter 1- Introduction Flashcards
Anatomy
the structures of the body and their relationship to one another- physically attached or location relative to the other.
Gross (macroscopic) anatomy
the study of large body structures that we can see. Examples include the heart and the kidneys.
Regional anatomy
all structures (muscles, bones, blood vessels, nerves) in a particular region of the body (abdomen, leg etc) are examined at the same time.
Systemic anatomy
body structure is studied system by system. When studying the cardiovascular system, you would look at the heart and all of the blood vessels in the body.
Surface anatomy
how internal structures relate to the overlying skin surface (can be used to locate blood vessels to feel pulses and draw blood).
Microscopic anatomy
studies smaller structures that would need to be examined with a microscope. Subdivisions include cytology and histology
Cytology
The study of cells
Histology
The study of tissues
Physiology
how body parts work or function on a normal level
Often considered at the cellular/molecular level
For example, cells might secrete substances that help with the organ’s function. The stomach secretes HCl that helps with digestion
Principle of complementarity of structure and function
What an organ can do depends on its form Hard bones (from calcium) are necessary for their function (support)
Structural organization of the body
Chemical-cellular-tissue-organ-organ system-organism
Necessary life functions (8)
- Maintaining boundaries
- Movement
- Responsiveness/excitability
- Digestion
- Metabolism
- Excretion
- Reproduction
- Growth
Maintaining boundaries- life function
On the cellular level, a boundary between organelles and the extracellular fluid is established using the plasma membrane. On the organismal level, the skin establishes a boundary between the organs of the boundary and the external environment
Movement- life function
Skeletal and muscular systems work together to coordinate actions
Can be conscious (skeletal muscle) or unconscious (smooth and cardiac muscle)
Movement also occurs when substances such as blood and food move inside the body.
Responsiveness/excitability- life function
Sensing environmental changes and respond to them, in addition to awareness of internal environment- pain, etc.
All body cells are excitable to an extent and have an electrical charge
Example- withdrawal reflex in response to painful stimuli
Which body system is most important in responding to stimuli?
Central nervous system. The cells of the nervous system are highly excitable and communicate with each other
Digestion- life function
Food is broken down into simple molecules- absorbed in blood, delivered to tissues
Metabolism- life function
Sum of all chemical reactions. Depends on the digestive and respiratory systems to make nutrients and oxygen available to the blood. The cardiovascular system will transport these throughout the body
Types of chemical reactions in the body (3)
- Catabolic
- Anabolic
- Cellular respiration
Catabolic reactions
Breaking down substances into smaller parts
Anabolic reactions
Creating larger substances
Excretion- life function
Removal of waste produced during digestive and metabolic functions- byproducts we don’t want to or can’t have in the body.
Metabolic reactions can produce chemicals that are removed in urine
Reproduction- cellular level
cells must divide for organisms to survive on individual level- cells must be replaced when they die. Cells in the stomach are frequently damaged and must be replaced.
Reproduction- organismal level
production of offspring. Must occur on the population level to prevent extinction
Growth-life function
Increase in the number of body cells or increase in the size of individual cells
Building must occur faster than destruction (breaking down/getting rid of stuff). Anabolic reactions must exceed catabolic reactions
Survival needs (5)
Necessary in order to carry out life functions on an optimal level
- Nutrients
- Oxygen- cells can only survive for a few minutes without oxygen
- Water
- Endothermy
- Atmospheric pressure- breathing and gas exchange occur at an appropriate atmospheric pressure
Which nutrients are necessary for survival?
Include carbs, fats, proteins, vitamins and minerals
Lipids necessary for structure- cellular membranes
Minerals are important structurally and chemically
Vitamins are important for multiple reactions like cellular respiration
Why is water important in the body?
Provides an environment for chemical reactions, fluid base for secretion and excretion. Plasma in blood is mostly water as are urine and cerebrospinal fluid
Why is endothermy important in the body?
Body temperature needs to be maintained for chemical processes to occur
Which body system is most important in promoting movement?
The muscular system promotes these activities- includes running and finger movement. Occurs when muscles pull on bones.
Metabolism is regulated by
Hormones secreted by the endocrine system
Homeostasis
The ability of the body to maintain stable internal conditions even though the external world changes continuously. Dynamic state of equilibrium within narrow limits- we make changes constantly
The body is considered to be in homeostasis when its needs are met and it’s functioning smoothly. All of the organ systems work together to accomplish this
How is homeostasis controlled?
Regulated by the nervous system (neural impulses) and the endocrine system (hormones).
The brain sends messages to parts of the body and tells organs how to change activity.
The endocrine system releases hormones that tells individual cells to change their activity
Variable
The event or factor being regulated during homeostasis
3 components of the variable
- Receptor
- Control center
- Effector
Receptor
Receives a message about the state of the variable. Body temp uses a thermoreceptor. Sends the message to the control center along the afferent pathway.
Control center
The brain. For body temp it’s the hypothalamus. Interprets the message as the body is too hot, too cold, or just right. Sends a message to an effector organ along the efferent pathway
Effector
Receives the message from the brain, changes its activity to maintain homeostasis. If the brain gets the message the body is too cold, it sends the message to skeletal muscle tissue and you start to shiver. It raises the body temperature. If the body is too hot, the sweat glands are the effector organs and produce sweat that lowers body temp through evaporation. The effector is never the same thing as the receptor.
Negative feedback mechanisms
the variable changes in a direction opposite of the initial change. Prevents severe changes in the body. Examples include thermoregulation and hormones. A hormonal negative feedback system includes the control of glucose by insulin. When blood sugar rises, the receptors sense this change and the pancreas (control center) secretes insulin into the blood. The body cells absorb more glucose and blood sugar falls, so the stimulus for insulin secretion ends.
Positive feedback mechanisms
the initial response enhances the original stimulus to produce a greater response. The variable deviates further from the original range. These mechanisms typically control events that do not need continuous readjustments, and set off a series of linked events- the results of each reaction feed into the next.
Examples- labor and blood clotting- when a blood vessel has been damaged, platelets stick to the injured site and release chemicals that attract more platelets. Ends when a clot is formed. If clotting was a negative feedback loop, the brain would say the clotting response was “too much” and you would just keep bleeding- need the feedback to be positive in this situation
What causes disease?
Homeostatic imbalances. Aging causes the body’s control systems to become less efficient. When negative feedback mechanisms are overwhelmed, destructive positive feedback mechanisms take over (heart failure)
Negative feedback mechanisms overridden by positive feedback mechanisms example
Autoimmune diseases are examples- the immune system launches a reaction against things in the body that shouldn’t be there. For autoimmune diseases, the white blood cells lack the ability to differentiate between cells and attack the body’s cells
Anatomical position
the body is in a standing position with feet slightly apart. The palms face forward and thumbs point away from the body. Used as a reference for anatomical terms.
There are 2 fundamental divisions of your body
- Axial
2. Appendicular
Axial division
makes up the main axis of our body (head, neck, trunk)
Appendicular division
consists of the appendages (limbs) attached to the axial part
Sagittal plane
divides the body into left and right
Medial/midsagittal plane
divides the body exactly in half
Frontal/coronal plane
divides body into anterior and posterior parts
Transverse plane (cross section)
divides the body into superior and inferior parts
Parasagittal planes
All other planes than medial/midsagittal
Superior (cranial)
Toward the head
Inferior (caudal)
Away from the head
Anterior (ventral)
toward the front of the body, in front of
Posterior (dorsal)
toward the back of the body, behind
Medial
toward or at the midline of the body, on the inner side of
Lateral
away from the midline of the body, on the outer side of
Intermediate
between a more lateral and more medial structure- the collarbone is intermediate between the breastbone and the shoulder
Proximal
closer to the point of origin or point of attachment of a limb to the body
Distal
farther from the point of origin
Superficial (external)
toward or at the body surface- the skin is superficial to the skeletal muscles
Deep (internal)
away from the body surface- the lungs are deep to the skin
Dorsal body cavity
protects the organs of the nervous system. Two subdivisions
Subdivisions of the dorsal body cavity (2)
- Cranial cavity
2. Vertebral spinal cavity
Cranial cavity
in the skull, surrounds the brain
Vertebral/spinal cavity
in the vertebral column, surrounds the spinal cord
Ventral body cavity
more anterior body cavity, contains the visceral organs (viscera). Two subdivisions
2 subdivisions of the ventral body cavity
- Thoracic cavity
2. Abdominopelvic cavity
Thoracic cavity
surrounded by ribs and the muscles of the chest. Divided into the lateral pleural cavity and the medial mediastinum
What separates the thoracic cavity from the abdominopelvic cavity?
The diaphragm
Lateral pleural cavities
Each contain a lung
Medial mediastinum
contains the pericardial cavity which encloses the heart, also contains the esophagus, trachea, and other thoracic organs.
Abdominopelvic cavity
inferior cavity, the two parts are not separated by a muscle or membrane. Contains the abdominal and pelvic cavities
Abdominal cavity
contains the stomach, intestines, spleen, liver, and other organs
Pelvic cavity
lies in the pelvis, contains the urinary bladder, some reproductive organs, and the rectum
Serous membrane
Serous membrane- double layered membrane covering internal organs (visceral serosa) and the walls of the cavities (parietal serosa)
Separated by serous fluid that allows the membranes to rub against each other. Named according to location
Pleura
Serosa associated with the lungs
Pericardium
Serosa associated with the heart
Peritoneum
abdominopelvic cavity
Visceral serosa
Covers internal organs
Parietal serosa
Covers the walls of the body cavity
Parietal pericardium
attached to the pericardial cavity (surrounds the heart).
Serous fluid
the layer of lubricating fluid that separates the serous membranes. It’s secreted by both membranes. Allows organs to easily slide across each other and cavity walls, very important for moving organs like the heart and stomach.
Serous cavity
the very small space between membranes, filled with serous fluid.
The 4 abdominopelvic quadrants
One approach to dividing the abdomen. RUQ, LUQ, RLQ, LLQ. The lower quadrants contain the intestines, rectum, reproductive organs
9 abdominopelvic regions
One approach to dividing the abdomen.
- Right hypochondriac region
- Epigastric region
- Left hypochondriac region
- Right lumbar region
- Umbilical region
- Left lumbar region
- Right iliac (inguinal) region
- Hypogastric (pubic) region
- Left iliac (inguinal) region
Organs in left hypochondriac region
Diaphragm, part of stomach, part of liver
Organs in epigastric region
Diaphragm, part of stomach, part of liver
Organs in right hypochondriac region
Liver, diaphragm, pancreas, gallbladder
Synovial cavities
joint cavities enclosed in fibrous capsules that surround the movable joints of the body like the knees. The membranes lining these cavities secrete lubricating fluid.
