Blood Pressure and Exercise Physiology

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Questions and Answers

What is the primary function of hemoglobin in red blood cells?

To control osmotic balance in plasma

To regulate blood pressure during exercise

To carry carbon dioxide from tissues to lungs (correct)

To transport nutrients from the intestines

Which type of blood cell is primarily involved in immune response?

Thrombocytes

Plasma cells

Leukocytes (correct)

Erythrocytes

What percentage of blood is made up of plasma?

55% (correct)

30%

60%

45%

Which component of blood is responsible for clotting?

Fibrinogen Signup and view all the answers

Which structure acts as the heart's natural pacemaker?

Sinoatrial node Signup and view all the answers

What is the primary role of albumins in plasma?

Control osmotic balance Signup and view all the answers

What percentage of red blood cells are typically found in blood volume?

45% Signup and view all the answers

During exercise, blood flow is rerouted primarily towards which organs?

Brain and cardiac muscles Signup and view all the answers

What is the lifespan of an average red blood cell?

120 days Signup and view all the answers

The conducting system of the heart includes all of the following EXCEPT:

Bicuspid valve Signup and view all the answers

What is the primary role of the sensory division of the nervous system?

Detects internal and external environmental stimuli Signup and view all the answers

Which of the following accurately describes the autonomic nervous system?

It controls involuntary functions of smooth muscles and glands. Signup and view all the answers

What is the structure containing a collection of neuron cell bodies outside of the CNS called?

Ganglion Signup and view all the answers

In which nervous system division do the action potentials travel from the CNS to skeletal muscles?

Somatic nervous system Signup and view all the answers

Which statement about the enteric nervous system is true?

It regulates functions of the digestive tract. Signup and view all the answers

What characterizes the sympathetic division of the autonomic nervous system?

It prepares the body for fight or flight situations. Signup and view all the answers

Which aspect distinguishes the somatic nervous system from the autonomic nervous system?

The somatic nervous system involves a single neuron system. Signup and view all the answers

Where are the cell bodies of the first neuron located in the autonomic nervous system pathway?

In the CNS Signup and view all the answers

Which division of the nervous system primarily handles voluntary actions?

Somatic nervous system Signup and view all the answers

What is the role of the autonomic ganglion in the autonomic nervous system?

It is where the first neuron's synapse occurs. Signup and view all the answers

What is the primary function of the kidneys?

Urine formation Signup and view all the answers

Where are the kidneys located in the body?

Posterior to the parietal peritoneum Signup and view all the answers

What is the role of the renal artery?

Delivers oxygenated blood to the kidney Signup and view all the answers

Which structure is part of the renal corpuscle in the nephron?

Glomerulus Signup and view all the answers

What differentiates juxtamedullary nephrons from cortical nephrons?

Juxtamedullary nephrons have a renal corpuscle located near the medulla Signup and view all the answers

What is the function of Bowman's capsule?

Filters blood and collects filtrate Signup and view all the answers

Which layer of Bowman's capsule is composed of podocytes?

Visceral layer Signup and view all the answers

How does the afferent arteriole differ from the efferent arteriole in the nephron?

It is larger in diameter than the efferent arteriole Signup and view all the answers

What structure directly follows the renal pelvis in the path of urine flow?

Ureter Signup and view all the answers

Which characteristic is unique to the loop of Henle compared to other parts of the nephron?

It extends into the renal pyramids Signup and view all the answers

What structure connects the spinal cord to the rest of the brain?

Brain stem Signup and view all the answers

Which spinal nerves are responsible for the lower limbs?

Lumbar and sacral nerves Signup and view all the answers

Which meningeal layer is the thickest and most superficial?

Dura mater Signup and view all the answers

Where are the cell bodies of motor neurons located within the spinal cord?

Ventral horn Signup and view all the answers

What is the main function of the medulla oblongata?

Regulation of heart rate and breathing Signup and view all the answers

Which type of response is generally faster, a reflex or a voluntary reaction?

Reflex Signup and view all the answers

What is the function of the cerebrospinal fluid within the meninges?

Acts as a shock absorber and protects the CNS Signup and view all the answers

Which part of the brain is responsible for regulating rapid eye movement during sleep?

Pons Signup and view all the answers

How many pairs of spinal nerves emerge from the spinal cord?

31 Signup and view all the answers

The outer layer of the spinal nerves is called:

Epineurium Signup and view all the answers

What is the cauda equina?

Roots of spinal nerves below the spinal cord Signup and view all the answers

Which structure is primarily responsible for coordinating locomotion?

Cerebellum Signup and view all the answers

Which type of reflex involves the contraction of skeletal muscles?

Knee jerk reflex Signup and view all the answers

What type of neuron carries sensory information into the spinal cord?

Sensory neurons Signup and view all the answers

Which layer of the meninges sits directly over the brain and cannot be removed?

Pia mater Signup and view all the answers

What is the primary role of cerebrospinal fluid?

To protect the brain and spinal cord from trauma Signup and view all the answers

Which of the following statements about cranial nerves is correct?

Cranial nerves can be classified as single or mixed neurons. Signup and view all the answers

What characterizes the sympathetic nervous system?

It is activated during 'fight or flight' situations. Signup and view all the answers

Where are the cell bodies of the parasympathetic nervous system located?

Between S2 to S4 and cranial nerve nuclei Signup and view all the answers

What is a structural difference between the somatic and autonomic nervous systems?

The autonomic nervous system has two neurons in series. Signup and view all the answers

Which effect does the parasympathetic division have on the digestive tract?

Increased motility and secretion Signup and view all the answers

How does the autonomic nervous system primarily regulate its functions?

Primarily through reflexes Signup and view all the answers

What does the term 'dual innervation' refer to?

Both divisions of the autonomic nervous system affect the same organ. Signup and view all the answers

What type of fluid primarily lines the brain's ventricles?

Cerebrospinal fluid Signup and view all the answers

Which cranial nerve function includes a combination of sensory, somatic, and parasympathetic functions?

Vagus nerve Signup and view all the answers

Which function is typically managed by the sympathetic nervous system?

Increasing heart rate Signup and view all the answers

What is the primary function of ependymal cells in the brain?

Produce cerebrospinal fluid Signup and view all the answers

Which of the following is true regarding the actions of the parasympathetic division?

Stimulates digestive activity Signup and view all the answers

Study Notes

Cardiovascular Response to Exercise

Blood pressure increases during exercise due to redirected blood flow towards the brain and cardiac muscles.
Hormonal control includes epinephrine (adrenaline), which increases heart rate and stroke volume through vasoconstriction in response to stress.

Cardiac Conducting System

Comprises an internal pacemaker and nerve pathways throughout the myocardium.
Action potentials generate rapid changes in membrane potential, serving as electrical signals that stimulate cardiac muscle contractions.
The heart has the ability to generate its own action potentials demonstrating auto-rhythmicity.
Key components include:
- Sinoatrial (SA) node: primary pacemaker located in the atrial wall producing regular action potentials.
- Atrioventricular (AV) node: located at the junction of the atrium and ventricle.
- Atrioventricular bundle and branches: conduct impulses from the AV node to the ventricular walls via Purkinje fibers.

Blood Composition

Blood is a life-sustaining fluid, vital for disease diagnosis and composed of:
- Plasma (55%): Mostly water (91%), proteins (7% including albumins, globulins, and fibrinogen), and other solutes (2%).
- Buffy coat: Contains white blood cells and platelets.
- Formed elements (45%): Red blood cells possess a haematocrit value, indicating the proportion of blood that is cellular.
Average blood volume is 5-6 liters in males and 4-5 liters in females, with blood pH ranging from 7.35 to 7.45.

Blood Cells

Erythrocytes (Red Blood Cells):
- Biconcave shape (7.5µm) without nucleus or organelles, providing a large surface area for oxygen transport.
- Contain hemoglobin, which carries 98.5% oxygen and facilitates carbon dioxide transport.
Leukocytes (White Blood Cells):
- Complete cells that indicate infection when their count is elevated.
- Various types exist, contributing to the immune response.

Renal System Anatomy

Consists of:
- Kidneys: urine formation.
- Ureters: urine passage.
- Urinary bladder: urine storage.
- Urethra: urine expulsion.
Renal capsule surrounds each kidney, supported by adipose tissue and renal fascia.

Kidney Location and Anatomy

Kidneys lie posterior to the parietal peritoneum, with the right kidney slightly lower due to the liver.
Each kidney measures approximately 11cm long and 5cm wide, weighing around 130g.
The hilum serves as the entry and exit point for blood vessels and nerves.

Internal Anatomy of the Kidney

Organized into two key regions:
- Outer cortex and inner medulla.
Urine flows through nephrons, the functional units of the kidney comprising various structures including the renal corpuscle.

Types of Nephrons

Approximately 1.3 million nephrons per kidney:
- Juxtamedullary nephrons (15%): Deep cortical location with long loops of Henle.
- Cortical nephrons (85%): Located near the cortex with shorter loops.

Renal Corpuscle

Includes the glomerulus (capillary network) and Bowman's capsule (filtering chamber).
Blood filtration occurs here, with higher pressure in afferent arterioles compared to efferent arterioles aiding in this process.

Bowman's Capsule and Filtration Membrane

Parietal layer: Simple squamous epithelium transitioning to cuboidal epithelium in the proximal convoluted tubule.
Visceral layer: Composed of podocytes surrounding the glomerular capillaries, essential for filtration.

Nervous System Overview

Divided into central (CNS) and peripheral (PNS) systems, which communicate through sensory and motor outputs.
PNS further divides into somatic (voluntary control of skeletal muscles) and autonomic (involuntary control of smooth and cardiac muscles).

Autonomic Nervous System

Sympathetic division: Responsible for "fight or flight" responses; arises from the thoraco-lumbar region.
Prepares the body for action in stressful situations and works in conjunction with the parasympathetic division for homeostasis.

Enteric Nervous System

Nerve plexus within the digestive tract managing sensory information and motor functions related to digestion.

Sensory and Motor Division

Sensory (afferent) division detects stimuli and transmits signals to the CNS.
Motor (efferent) division transmits signals from the CNS to muscles and glands for physiological responses.### Reflexes
Knee jerk, Golgi tendon, Babinski, and pupillary reflexes are examples of reflexes.
Reflexes are quick, involuntary responses to stimuli requiring no brain involvement.
Reactions are voluntary, slower, and involve the brain and spinal cord.
Reaction time can improve with practice, demonstrated through actions like catching a ball.

Spinal Cord Overview

The spinal cord runs from the foramen magnum to the first or second lumbar vertebrae.
Split into cervical, thoracic, lumbar, sacral, and coccygeal regions.
Comprises 31 pairs of spinal nerves; configured as follows:
- Cervical: 8 pairs
- Thoracic: 12 pairs
- Lumbar: 5 pairs
- Sacral: 5 pairs
- Coccygeal: 1 pair
Enlargements in the cervical and lumbar regions correspond to upper and lower limbs.

Anatomy of Meninges

Meninges protect the CNS and encompass the brain and spinal cord.
Dura mater is the tough, outer layer with a subdural space for serous fluid.
Arachnoid mater features a web-like structure with a subarachnoid space containing CSF and blood vessels.
Pia mater is the delicate, innermost layer enveloping the CNS and rich in blood vessels.

Spinal Cord Structure

White matter is organized into dorsal, ventral, anterior, and lateral columns.
Grey matter has posterior, lateral, and anterior horns.
Commissures connect left and right sides of grey matter.
Dorsal roots carry sensory nerves, while ventral roots carry motor nerves.

Neuron Organization

Autonomic motor neuron cell bodies in the lateral horn; somatic in the grey matter horns.
Nerve structure consists of:
- Endoneurium surrounding each axon.
- Perineurium encasing nerve fascicles.
- Epineurium encompassing whole nerves.

Nervous System Anatomy

Sympathetic nerve cell bodies are located between T1 and L2 (thoracolumbar division).
Parasympathetic cell bodies range from S2 to S4 and in cranial nerve nuclei (craniosacral division).
Autonomic system involves two neurons: preganglionic and postganglionic.

Brain and Its Structure

The brain weighs approximately 1.5 kg, consisting of around 100 billion neurons.
Organized into the forebrain, midbrain, and hindbrain.
The brainstem (comprised of midbrain, pons, and medulla oblongata) connects the spinal cord and brain.

Brainstem Functions

Medulla oblongata is crucial for autonomic regulation, controlling heart rate and respiration.
The pons acts as a bridge for signal conduction and regulates REM sleep.
Midbrain facilitates reflex movements in response to sensory stimuli.

Cerebellum Characteristics

Smaller than the cerebrum, with an outer grey matter cortex and inner white matter medulla.
Coordinates locomotor functions with the cerebrum.

Ventricles and CSF

The brain has four interconnected ventricles lined with ependymal cells.
Largest ventricles are the lateral ventricles, connected to the third and fourth ventricles.
Cerebrospinal fluid (CSF) is primarily produced by the choroid plexus, cushioning the brain and spinal cord.

Cranial Nerves

Twelve pairs of cranial nerves emerge from the brain, fulfilling sensory and motor roles.

Autonomic Nervous System

Divided into sympathetic (fight or flight) and parasympathetic (rest and digest) systems.
Sympathetic activation quickens heart rate, while parasympathetic promotes digestion.
Both divisions can act on the same organs but in opposing manners.

Regulation of the Autonomic Nervous System

Functions of the ANS are primarily regulated through reflexes and involve central nervous system centers like the hypothalamus.
The spinal cord governs reflex activities, while the brain stem oversees heart rate, respiration, and other autonomic functions.
Higher brain centers, such as the cerebrum and limbic system, modulate ANS responses based on emotional states or thoughts.

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Description

This quiz covers the effects of exercise on blood pressure, including the rerouting of blood flow and hormonal controls such as epinephrine. Understand how the body responds to stress and injury through the cardiac conducting system and its internal pacemaker. Test your knowledge on these critical physiological concepts.