Chapter 1
elements of a homeostatic control system (S Raceer)
.1. Stimulus - produces change in variable 2. Receptor - Detects changes; (RECEPTOR) - responds to stimuli (changes) by sending information (input) along the afferent pathway to the second component, the control center 3. Input - Information sent along afferent pathway to control center. (CONTROL CENTER) - determines the set point, which is the level (or range of levels) at which a variable is to be maintained. Determines the appropriate response. Information (output) then flows from the control center along the efferent pathway to the third component, the effector. 4. Output - info sent along efferent pathway to effector 5. Response - of effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level.
Two Major Divisions of the body
1.) Axial - Head neck, and trunk 2.)Appendicular - Limbs (legs and arms)
Body Planes 1.) Median (Sagittal) 2.) Frontal (Coronal) 3.) Transverse
1.) Sagittal plane (saj′ĭ-tal; "arrow") - is a vertical plane that divides the body into right and left parts. Types of sagittal planes: -Midsagittal Plane - (median) cut made perfectly down the midline -Parasagittal Plane - cut was off centered 2.) Frontal planes (coronal), like sagittal planes, lie vertically. Frontal planes, however, divide the body into anterior and posterior parts 3.) Transverse, or horizontal, plane runs horizontally from right to left, dividing the body into superior and inferior parts Many different transverse planes exist, at every possible level from head to foot. A transverse section is also called a cross section.
3 Components of Homeostatic control of variables
1.)Receptor - monitors environment, responds to stimuli (sends through AFFERENT pathway) 2.)Control Center - determines set point at which variable is maintained, receives input from receptor, and determines appropriate response (sends through EFFERENT pathway) 3.)Effector - receives output from control center. Provides the means to respond to the stimulus through negative or positive feedback
*body homeostasis
Ability to maintain relatively stable internal conditions even though the outside world changes continuously.
*principle of complementarity of structure and function
Although it is possible to study anatomy and physiology individually, they are really inseparable because function always reflects structure. That is, what a structure can do depends on its specific form.
Regional Terms
Anatomical terms that refer to specific visible landmarks on the surface of the body
Orientation and Directional Term Anterior (ventral) VS Posterior (dorsal)
Anterior - toward or at the front of the body; in front of (the breastbone is anterior to the spine) Posterior - toward or at the back of the body; behind (the heart is posterior to the breastbone)
Orientation and Directional Term Lateral
Away from the midline of the body; on the outer side of (the arms are lateral to the chest)
Two major divisions of body: Axial and Appendicular
Axial - head, neck, and trunk Appendicular - limbs (legs and arms)
Orientation and Directional Term Proximal
Closer to the origin of the body part or the point of attachment of a limb to the body trunk (the elbow is proximal to the wrist)
Dorsal and Ventral Body Cavity's and their subdivisions
Dorsal -Cranial Cavity -Vertebral Cavity Ventral -Abdomin-pelvic Cavity -Abdomical Cavity -Pelvic Cavity -Thoracic Cavity -2 pleural cavities (each surrounds one lung) -Mediastinum - surrounds other thoracic organs and contains pericardial cavity which contains the heart
Subdivision of Developmental Anatomy
Embryology (em″bre-ol′o-je), a subdivision of developmental anatomy, concerns developmental changes that occur before birth.
Orientation and Directional Term Distal
Farther from the origin of a body part or the point of attachment of a limb to the body trunk. (the knee is distal to the thigh)
What type of cut would separate the brain into anterior and posterior parts.
Frontal
Which subdivision of anatomy studies tissues of the heart?
Histology is a subdivision of microscopic anatomy that studies the tissues of the body, including cardiac muscle tissue of the heart.
*relationship between homeostatic imbalance and disease
Homeostasis is so important that most disease can be regarded as a result of its disturbance, a condition called homeostatic imbalance. As we age, our body's control systems become less efficient
Ventral Body Cavity (2 Subdivisions)
Houses internal organs collectively called the viscera (vis′er-ah; viscus = an organ in a body cavity), or visceral organs. 1.) The superior subdivision, is the thoracic cavity - surrounded by the ribs and muscles of the chest. The thoracic cavity is further subdivided into: -Lateral pleural cavities (ploo′ral), each enveloping a lung -Medial mediastinum(me″de-ah-sti′num). The mediastinum contains the pericardial cavity (per″ ĭ-kar′de-al), which encloses the heart, and it also surrounds the remaining thoracic organs (esophagus, trachea, and others). 2.)Abdominopelvic cavity (2 parts) (ab-dom′ĭ-no-pel′vic) - separated from the thoracic cavity by the diaphragm, a dome-shaped muscle important in breathing. contains the stomach, intestines, spleen, liver, and other organs. The inferior part, the pelvic cavity, lies in the bony pelvis and contains the urinary bladder, some reproductive organs, and the rectum.
What topic would you be studying if you investigated urine production by the kidneys?
Renal physiology examines kidney function and urine production.
Orientation and Directional Term Superficial (external) VS Deep (internal)
Superficial - toward the body surface Deep - away from the body surface
Orientation and Directional Term Superior VS Inferior
Superior - Toward the head end or upper part of a structure; above. Inferior- Away from the head end or toward the lower part of a structure or the body; below
*anatomical position
The anatomical reference point is a standard body position; the body is erect with feet slightly apart, the palms face forward and the thumbs point away from the body.
.Identify the organ system responsible for secreting hormones that regulate growth, development, and metabolism.
The endocrine system consists of glands that release hormones into the blood. These hormones circulate and activate distant target cells, which coordinate processes such as growth, development, and metabolism.
Membranes in the Ventral Body Cavity
The walls of the ventral body cavity and the outer surfaces of the organs it contains are covered by a thin, double-layered membrane, the serosa (se-ro′sah), or serous membrane. The part of the membrane lining the cavity walls is called the parietal serosa (pah-ri′ĕ-tal; parie = wall). It folds in on itself to form the visceral serosa, covering the organs in the cavity. (Look at ballon example)
Orientation and Directional Term Medial
Toward or at the midline of the body ; on the inner side of (the heart is medial to the arm)
Synovial cavities.
are joint cavities. They are enclosed within fibrous capsules that surround freely movable joints of the body (such as the elbow and knee joints).
right lateral (lumbar) region - organ
ascending colon of large intestine
Orientation and Directional Term Intermediate
between a more medial and a more lateral structure (the collarbone is intermediate between the breastbone and shoulder)
right inguinal (iliac) region - organ
cecum appendix
*Levels of Structural Organization
chemical (atoms combine to form molecules) cellular (cells are made up of molecules) tissue(tissues consist of similar types of cells) organ organ system organismal
Subdivisions of Microscopic Anatomy (2)
cytology (si-tol′o-je) - considers the cells of the body histology (his-tol′o-je) - the study of tissues.
Microscopic anatomy
deals with structures too small to be seen with the naked eye.
left lateral (lumbar) region - organ
descending colon of large intestine
Left hypochondriac region - organ
diaphragm spleen
left inguinal (iliac) region - organ
initial part of sigmoid colon
*11 Organ Systems of the Body (REMIND-CLUMS)
integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive systems.
Right Hypochondriac Region - Organ
liver gallbladder
Dorsal body cavity (2 Subdivisions)
protects the fragile nervous system organs, has 2 subdivisions -Cranial Cavity - in the skull, encases the brain -Vertebral / Spinal Cavity - runs within the bony vertebral column, encloses the delicate spinal cord.
Subdivision of Macroscopic Anatomy (3)
regional anatomy - all the structures (muscles, bones, blood vessels, nerves, etc.) in a particular region of the body, such as the abdomen or leg, are examined at the same time. systemic anatomy - body structure is studied system by system. For example, when studying the cardiovascular system, you would examine the heart and the blood vessels of the entire body. surface anatomy - study of internal structures as they relate to the overlying skin surface. You use surface anatomy when you identify the bulging muscles beneath a bodybuilder's skin
umbilical region - organ
small intestine transverse colon of large intestine
Epigastric region - organ
stomach
Gross, or Macroscopic, anatomy
study of large body structures visible to the naked eye, such as the heart, lungs, and kidneys.
*Physiology
the function of the body, in other words, how the body parts work and carry out their life-sustaining activities.
*Positive Feedback Mechanisms
the initial response enhances the original stimulus so that further responses are even greater. This feedback mechanism is "positive" because the change that results proceeds in the same direction as the initial change, causing the variable to deviate further and further from its original value or range. (Break in blood vessel wall leads to platelets adhering to site and release chemicals to attract more plaelets, to plug the wall)
*Negative Feedback Mechanisms
the output shuts off the original effect of the stimulus or reduces its intensity. These mechanisms cause the variable to change in a direction opposite to that of the initial change, returning it to its "ideal" value. (sweating and shivering to maintain body temp)
*Anatomy
the structure of body parts and their relationships to one another.
Developmental anatomy
traces structural changes that occur throughout the life span.
pubic (hypogastric) region - organ
urinary bladdet
