Study "Biology", a flashcard deck on FORKSAI.
عرف اللمف، وما هي وظيفته الرئيسية في الجهاز اللمفاوي؟
اللمف هو السائل النسيجي الذي ينتشر إلى الأوعية اللمفاوية. وظيفته الرئيسية هي أن تقوم العقد اللمفاوية بتصفيته، وهو جزء أساسي من جهاز المناعة لاحتوائه على كميات كبيرة من خلايا الدم البيضاء.
MCQ-STYLE: أي من أنواع العضلات التالية يعتبر لا إرادي ومخطط؟ A) العضلات الهيكلية B) العضلات القلبية C) العضلات الملساء D) جميع ما سبق
B) العضلات القلبية. العضلات القلبية لا إرادية ومخططة، بينما الهيكلية إرادية ومخططة، والملساء لا إرادية وملساء.
APPLICATION/PRACTICAL: شخص يعاني من صعوبة في تحريك ذراعه بعد إصابة في الكتف. بناءً على معلومات الجهاز الهيكلي، ما هو نوع المفصل المتأثر، وما هي الأنسجة التي قد تكون تضررت؟
المفصل المتأثر هو مفصل الكتف، وهو مفصل كروي حقي يسمح بحركة واسعة. الأنسجة التي قد تكون تضررت تشمل الأربطة التي تربط العظام ببعضها، والأوتار التي تربط العضلات بالعظام، والغضاريف التي تغطي أطراف العظام لتقليل الاحتكاك.
Define the term 'الأستيل كولين' and explain its primary function in the nervous system.
الأستيل كولين is a chemical substance produced in nerve cells. Its primary function is to transmit nerve impulses across the synaptic cleft. It breaks down quickly after transmission to ensure signal accuracy and prevent continuous stimulation.
How does the process of nerve impulse transmission occur across the synaptic cleft?
When a nerve impulse reaches the end of the axon, a chemical neurotransmitter like acetylcholine is secreted. This chemical then travels across the synaptic cleft, stimulating the dendrites of the adjacent cell, which generates a new nerve impulse.
Distinguish between the Central Nervous System (الجهاز العصبي المركزي) and the Peripheral Nervous System (الجهاز العصبي الطرفي) based on their components.
The Central Nervous System consists of the brain and spinal cord, acting as the main control center. The Peripheral Nervous System includes all nerves outside the central nervous system, connecting the brain and spinal cord to other parts of the body, comprising 12 pairs of cranial nerves and 31 pairs of spinal nerves.
Which of the following best describes the function of the spinal cord (الحبل الشوكي)? A) Regulates all vital activities and consists of billions of nerve cells. B) Transmits sensory nerve impulses to the brain or spinal cord and forms part of the CNS. C) Includes all nerves outside the CNS and connects the brain and spinal cord to other body parts. D) Produces hormones that regulate bodily functions.
B) Transmits sensory nerve impulses to the brain or spinal cord and forms part of the CNS. The spinal cord is crucial for relaying signals between the brain and the rest of the body, and it is a key component of the central nervous system.
A patient experiences paralysis (فقدان العضلات قدرتها على الحركة) after a severe accident. Based on the provided information, which part of the nervous system is most likely affected, and why is its injury considered as serious as a brain injury?
The patient's paralysis suggests an injury to the spinal cord (الحبل الشوكي). Spinal cord injuries are considered as serious as brain injuries because the spinal cord is vital for transmitting nerve signals controlling all body organs and functions. Damage to its neural pathways can permanently or temporarily impair physical and mental capabilities, leading to conditions like paralysis.
Explain how a single spinal nerve (العصب الشوكيّ) can transmit nerve impulses both to and from the brain simultaneously.
A single spinal nerve is composed of a bundle of both sensory and motor neurons, held together by connective tissue. This dual composition allows it to carry sensory signals from various parts of the body to the brain and, at the same time, transmit motor commands from the brain to the body, facilitating bidirectional communication.
Differentiate between the somatic nervous system (الجهاز الجسمي) and the autonomic nervous system (الجهاز الذاتي) based on the types of actions they regulate.
The somatic nervous system regulates voluntary actions, primarily involving cranial and spinal nerves connected to skeletal muscles. In contrast, the autonomic nervous system regulates involuntary actions such as heart rate, respiration, digestion, and glandular functions.