2P07 Class 1

Which two structures primarily compose the Central Nervous System (CNS)?

The brain and the spinal cord.

What are the two major divisions of the Peripheral Nervous System (PNS)?

The somatic nervous system and the autonomic nervous system.

Which system regulates voluntary motor control of skeletal muscle?

The somatic nervous system.

What is the primary function of the autonomic nervous system (ANS)?

Regulating the body's internal environment through involuntary control of organ systems.

The autonomic nervous system is further divided into the sympathetic and _____ divisions.

Parasympathetic

Which four lobes make up the forebrain?

The frontal, parietal, temporal, and occipital lobes.

Which structures are the primary components of the hindbrain?

The cerebellum and the pons.

What term describes densely packed cell bodies specifically located within the CNS?

Nuclei

What term describes densely packed cell bodies specifically located within the PNS?

Ganglia

Which part of the neuron serves as the receptive portion for incoming signals?

The dendrites.

What is the primary role of the axon in a neuron?

To carry nerve impulses away from the cell body.

Term: Axon hillock

Definition: The cone-shaped process where the axon leaves the cell body.

Which specific area of the axon has the lowest threshold for stimulation where action potentials begin?

The initial segment.

Which substance acts as a segmented layer of lipid material providing insulation to the axon?

Myelin

In the Peripheral Nervous System, which cell is responsible for forming and maintaining the myelin sheath?

The Schwann cell.

What are the regular interruptions along the length of the myelin sheath called?

Nodes of Ranvier

Which circuit of the heart is responsible for pumping blood through the lungs?

The pulmonary circulation (right heart).

Which circuit of the heart is responsible for pumping blood through the body?

The systemic circulation (left heart).

What are the three layers of the heart wall, from outer to inner?

Epicardium, myocardium, and endocardium.

Which layer of the heart wall is primarily composed of cardiac muscle?

The myocardium.

The endocardium serves as the _____ of the heart.

Inner lining

During which phase of the cardiac cycle do the atrioventricular valves open to allow blood into the ventricles?

Diastole

What is the mechanical result of atrial contraction in the heart?

Additional blood is pushed into the ventricles.

During ventricular contraction, the atrioventricular valves are _____.

Closed

What is the primary 'pacemaker' and first component of the heart's conduction system?

The Sinoatrial (SA) Node.

Which conduction structure is located at the junction between the atria and ventricles?

The Atrioventricular (AV) Node.

Which part of the conduction system runs through the ventricles to stimulate contraction?

Purkinje fibres

On an ECG, what physiological event does the P wave represent?

Depolarization and contraction of the atria.

On an ECG, what physiological event does the QRS complex represent?

Depolarization and contraction of the ventricles.

Which event is typically 'hidden' within the QRS complex on an ECG?

The repolarization of the atria.

What physiological event occurs during the T wave of an ECG?

The repolarization and relaxation of the ventricles.

What is the mathematical definition of Cardiac Output?

Stroke volume x Heart rate.

In the context of cardiac output, what is defined as the volume of blood flowing through a circuit per minute?

Cardiac output

Which three factors directly determine stroke volume?

Preload, afterload, and contractility.

Concept: Preload

Definition: The end-diastolic volume of the heart.

Which two types of nerves provide cardiac nervous innervation?

Sympathetic and parasympathetic nerves.

Heart rate control involves $\beta$-Adrenergic receptors binding with norepinephrine or _____.

Epinephrine

In the fetus, the endocrine system differentiates the reproductive system and the _____.

Central Nervous System (CNS)

List two general functions of the endocrine system regarding physical change.

Stimulation of growth and development, and coordination of reproductive systems.

What are the two general categories of hormones based on their solubility?

Water-soluble and lipid-soluble hormones.

Mechanism: Upregulation

Effect: An increase in the number of receptors on a cell in response to low hormone levels.

Which type of hormone usually requires a 'second messenger' to act upon a cell?

Water-soluble hormones.

What are the three primary layers of the skin?

Epidermis, dermis, and hypodermis.

What is the alternative name for the hypodermis?

Subcutaneous layer

List the four main dermal appendages.

Nails, hair, sebaceous glands, and sweat glands.

What are the two types of sweat glands found in the skin?

Eccrine and apocrine glands.

What provides the blood supply to the upper layers of the dermis?

Papillary capillaries

What are the three basic chemical components of DNA?

The five-carbon monosaccharide deoxyribose, a phosphate molecule, and four nitrogenous bases.

Proteins are composed of one or more polypeptides, which are made of _____.

Amino acids

What are the four nitrogenous bases found in DNA?

Adenine, Thymine, Guanine, and Cytosine.

According to PHAC, what is the first social determinant of health?

Income and social status.

Which social determinant of health refers to the availability of work and the safety of the workplace?

Employment and working conditions.

Social Determinant of Health #3: Education and _____.

Literacy

How do childhood experiences function as a social determinant of health?

They serve as a foundational determinant affecting long-term health outcomes.

Which determinant encompasses the safety and quality of the surroundings where people live?

Physical environments

What social determinant includes the networks and emotional resources available to individuals?

Social supports and coping skills.

Which social determinant of health relates to personal choices such as diet or exercise?

Healthy behaviours

What is the final social determinant of health on the PHAC list?

Access to health services.

Involves the synthesis of messenger RNA (mRNA) from a DNA template

transcription

mRNA directs the synthesis of a polypeptide, interacting with transfer RNA (tRNA)

translation

What are the 2 subcategories of cellular injury? Define each

sublethal injury - alters function without causing destruction

lethal injury - irreversible process that causes cell death

What causes a hypoxic injury?

lack of adequate amount of oxygen within cells, which results from reduced amount of oxygen in the air

Most common cause of hypoxia is?

Reduced blood supply

Humans are regularly exposed to external

compounds that are:

• Toxic

• Mutagenic

• Carcinogenic

These compounds are called…

Xenobiotics

Made up of cerebellum and pons which help with coordination and balance

Hindbrain

What is the junction between atria/ventricles and mediastinum

bundle of his

what runs down the mediastinum

bundle branches

Canadians median age is increasing. What does this indicate

living longer means there is an increased likeliness that Canadians will have one or more chronic conditions

term - premature death of cells

necrosis

term - a normal, programmed process of cell self-destruction that allows the body to rid itself of unneeded, old, or damaged cells

apoptosis

term - blood/oxygen flow to a specific part of the body is reduced or restricted 

ischemia