2025-2026 EXAM TIPS FOR -Kin 1A03 Final Exam:
Homeostasis & Embryology Overview Notes McMaster
University
Anatomy Final Exam Notes
Homeostasis
• Exercise = increased body temperature; increased heart rate
• Elevated outside temperatures also affect the body during exercise
• Sweat - comes from a variety of body fluids including blood. Therefore, the more you sweat, the more
decrease in blood volume throughout the body.
• If your blood volume begins to decrease, your blood pressure decreases as well.
• We need to have a significant amount of blood pressure in order for blood to flow easily throughout
the body
• Heart Rate - # of times your heart beats/minute
• Increase thirst = increase water intake: allows to replenish these water stores
• Your body is using several physiological responses to maintain a constant internal environment
Homeostasis definition: - The existence and maintenance of a relatively constant environment within
the body. (Fairly stable)
- The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its
physiological processes. (maintaining a constant environment)
- Factors: Values of variables fluctuate around the set point (average is around 37.0 degrees Celsius as
body temp.) to establish a normal range of values.
- Set Point: the ideal normal value of a variable
,Role of Organ Systems
- Help control the body's internal environment
- All cells need fuel/oxygen in order to function. (maintain constant cell energy production)
- Fuel examples: FOOD (Carbs, Fat, Protein)
- Respiratory system brings in oxygen and transports it throughout the body
- Waste products are excreted such as CO2 (respiratory), feces (digestive), urine (urinary)
,How do we Maintain Homeostasis?
- Uses feedback systems that monitor our internal environment in order to adjust the body to certain
changes
- Two systems: 1) Negative (Good) and 2) Positive (typically not so good)
- Negative: Able to maintain a balanced internal system
- Positive: Alterations in an internal system
Three Components
1) Receptor - monitors a value of some variable (ex: detect changes in blood pressure)
2) Control Center - establishes the set point (found in nervous system and sends signals to react to
changes)
3) Effector - can change the value of the variable
*Stimulus: deviation from the set point; detected by the receptor
*Response: what is produced by the effector
Negative Feedback
- Any deviation from the set point is made smaller (resisted)
- Examples: regulation of blood pressure, body temp., blood sugar levels
Positive Feedback
- When the value starts to deviate from the set point; this deviation is amplified and therefore
homeostasis is not maintained
- When a deviation occurs, the response is to make the deviation greater
- Usually in normal, healthy individuals, leads away from homeostasis and can result in death
- Example of normal + feedback: childbirth
- Example of harmful + feedback: after hemorrhage, BP drops and the heart's ability to pump blood
decreases
Consequences of Homeostasis Disruption
1) Disease
2) Death
*Every bodily function is to overall, maintain homeostasis within the body!!!*
, Terminology and the Body Plan
Anatomy: Scientific discipline that investigates the body's structure
Physiology: Scientific investigation of the processes or functions of living things
*Function is often dictated by structure*
Structural & Functional Organizations
Chemical Level: interaction of atoms
Cell Level: structural and functional unit of living organisms
Tissue Level: group of similar cells and the materials surrounding them (Four basic types: epithelial,
connective, muscle, and nervous)
Organ Level: two or more tissues functioning together
Organ System Level: group of organs functioning together
Organism Level: any living thing (can be composed of one cell or many cells)
Terminology
- Anatomical Position: Body erect, face forward, feet together, palms face forward
- Other Body Positions: 1) Supine: lying face upward, 2) Prone: lying face downward
- Directional Terms: 1) Superior (Cephalic - towards the head end) vs. Inferior (Caudal - towards the tail
end) toward or away from the head; 2) Medial vs. Lateral relative to the midline; 3) Proximal vs. Distal
used to describe linear structures (in other words referring to limbs); 4) Superficial vs. Deep relative to
the surface of the body (ex: skin is most superficial since it is on the outside of the body, while your
heart is deep since it is towards the inside of the body); 5) Anterior (Ventral - towards the belly) vs.
Posterior (Dorsal - towards the back; ex: dorsal fin of a dolphin). Anterior is forward, while Posterior is
toward the back.
Body Planes
- Sagittal: vertically through the body - separates right and left
- Frontal (Coronal): divides the body into anterior and posterior sections
- Transverse/Cross: divides body into superior and inferior sections
- Oblique: other than at a right angle
Planes Through an Organ
- Longitudinal: cut along the length of an organ
- Cross/transverse: cut at right angle to length of the organ
- Oblique: cut at any but a right angle
Homeostasis & Embryology Overview Notes McMaster
University
Anatomy Final Exam Notes
Homeostasis
• Exercise = increased body temperature; increased heart rate
• Elevated outside temperatures also affect the body during exercise
• Sweat - comes from a variety of body fluids including blood. Therefore, the more you sweat, the more
decrease in blood volume throughout the body.
• If your blood volume begins to decrease, your blood pressure decreases as well.
• We need to have a significant amount of blood pressure in order for blood to flow easily throughout
the body
• Heart Rate - # of times your heart beats/minute
• Increase thirst = increase water intake: allows to replenish these water stores
• Your body is using several physiological responses to maintain a constant internal environment
Homeostasis definition: - The existence and maintenance of a relatively constant environment within
the body. (Fairly stable)
- The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its
physiological processes. (maintaining a constant environment)
- Factors: Values of variables fluctuate around the set point (average is around 37.0 degrees Celsius as
body temp.) to establish a normal range of values.
- Set Point: the ideal normal value of a variable
,Role of Organ Systems
- Help control the body's internal environment
- All cells need fuel/oxygen in order to function. (maintain constant cell energy production)
- Fuel examples: FOOD (Carbs, Fat, Protein)
- Respiratory system brings in oxygen and transports it throughout the body
- Waste products are excreted such as CO2 (respiratory), feces (digestive), urine (urinary)
,How do we Maintain Homeostasis?
- Uses feedback systems that monitor our internal environment in order to adjust the body to certain
changes
- Two systems: 1) Negative (Good) and 2) Positive (typically not so good)
- Negative: Able to maintain a balanced internal system
- Positive: Alterations in an internal system
Three Components
1) Receptor - monitors a value of some variable (ex: detect changes in blood pressure)
2) Control Center - establishes the set point (found in nervous system and sends signals to react to
changes)
3) Effector - can change the value of the variable
*Stimulus: deviation from the set point; detected by the receptor
*Response: what is produced by the effector
Negative Feedback
- Any deviation from the set point is made smaller (resisted)
- Examples: regulation of blood pressure, body temp., blood sugar levels
Positive Feedback
- When the value starts to deviate from the set point; this deviation is amplified and therefore
homeostasis is not maintained
- When a deviation occurs, the response is to make the deviation greater
- Usually in normal, healthy individuals, leads away from homeostasis and can result in death
- Example of normal + feedback: childbirth
- Example of harmful + feedback: after hemorrhage, BP drops and the heart's ability to pump blood
decreases
Consequences of Homeostasis Disruption
1) Disease
2) Death
*Every bodily function is to overall, maintain homeostasis within the body!!!*
, Terminology and the Body Plan
Anatomy: Scientific discipline that investigates the body's structure
Physiology: Scientific investigation of the processes or functions of living things
*Function is often dictated by structure*
Structural & Functional Organizations
Chemical Level: interaction of atoms
Cell Level: structural and functional unit of living organisms
Tissue Level: group of similar cells and the materials surrounding them (Four basic types: epithelial,
connective, muscle, and nervous)
Organ Level: two or more tissues functioning together
Organ System Level: group of organs functioning together
Organism Level: any living thing (can be composed of one cell or many cells)
Terminology
- Anatomical Position: Body erect, face forward, feet together, palms face forward
- Other Body Positions: 1) Supine: lying face upward, 2) Prone: lying face downward
- Directional Terms: 1) Superior (Cephalic - towards the head end) vs. Inferior (Caudal - towards the tail
end) toward or away from the head; 2) Medial vs. Lateral relative to the midline; 3) Proximal vs. Distal
used to describe linear structures (in other words referring to limbs); 4) Superficial vs. Deep relative to
the surface of the body (ex: skin is most superficial since it is on the outside of the body, while your
heart is deep since it is towards the inside of the body); 5) Anterior (Ventral - towards the belly) vs.
Posterior (Dorsal - towards the back; ex: dorsal fin of a dolphin). Anterior is forward, while Posterior is
toward the back.
Body Planes
- Sagittal: vertically through the body - separates right and left
- Frontal (Coronal): divides the body into anterior and posterior sections
- Transverse/Cross: divides body into superior and inferior sections
- Oblique: other than at a right angle
Planes Through an Organ
- Longitudinal: cut along the length of an organ
- Cross/transverse: cut at right angle to length of the organ
- Oblique: cut at any but a right angle
